Steel Gantry Machine 1500x750x200

[toomast]

This story is about Steel Gantry Machine with work-area 1500x750x200 for aluminium and wood.
First I was going for a fixed gantry machine but bigger work-area changed my mind. As long as I have to purchase expensive components the price difference for longer components is not so dramatic - but it gives nice advantage. :smug:

http://www.mycncuk.com/attachment.php?attachmentid=14769&stc=1

Main frame welded steel 80x80x4mm.
Steel gantry consist of 2 pcs 100x100x3mm tubes welded together and some 8mm steel plates.
Z assembly is mostly 25mm aluminium with 2,2kw watercooled spindle.
Ballscrews X,Y=1610; Z=1605.
HIWIN 20mm rails all axes. Epoxy leveled.
Please feel free to comment my design. In case of positive feedback then next step would be to order rails and ballscrews. Measure them and then finalize design and start the build.

I have couple of questions for more experienced guys:

Can I use L (0,375" = 9,525mm) pitch pulleys with a 12,7mm wide belt from steppermotor to ballscrew? I can get those pulley for free. Together with 240L belt. But this belt is too long and pulley centre hole is 10mm, whish I cant use on Nema 23 anyway. So I have to buy half the pulleys and belts. May as well buy proper with belts and pulleys all around?
What ballscrew machining are you using when belt pulley will be attached?
Hole gantry with Z and everything will be close to 80 kg. Can I put my money on 2x Nema 23 3,1Nm together with a decent 70Vdc PSU?
What HIWIN blocks do most of you prefer: HGH or HGW? Sure it depends from design but I think I will go with HGH20CA from BST Automation.


Tanks for reading!

[JoeHarris]

The bed looks quite low on this, you may find the z axis is unduly extended if cutting mainly sheet material. That said I don't know what you plan to cut? Looks like a nice strong frame, you will want some leaving feet on it particularly if going for 6 legs...

[toomast]

Thanks JoeHarris!

I would limit Z axis movement with proximity switches to about 100mm + detachable smaller workarea bed when aluminium cutting. This will keep Z in sweet-spot while cutting but also adds weight. I choose unnecessary weight over adjustable bed? But now when I think about it... I will get both actually! Will have to think this over.

Also I have made some updates to the model.

http://www.mycncuk.com/attachment.php?attachmentid=14829&stc=1

Do you think this long 1610 ballscrew will start whipping on X-axis?

Brg,
Toomas

[Boyan Silyavski]

Hi, good luck with your build!




Can I use L (0,375" = 9,525mm) pitch pulleys with a 12,7mm wide belt from steppermotor to ballscrew? I can get those pulley for free. Together with 240L belt. But this belt is too long and pulley centre hole is 10mm, whish I cant use on Nema 23 anyway. So I have to buy half the pulleys and belts. May as well buy proper with belts and pulleys all around?

No.You can but i wouldn't. The correct belt for this build is 15mm HTD . The correct Nema motor has 8mm shaft. The desired pulley is steel 20t. Belt length maximum 350mm




What ball screw machining are you using when belt pulley will be attached?



Standard. Puley bored to 10mm -/16xx ball screw/




Whole gantry with Z and everything will be close to 80 kg. Can I put my money on 2x Nema 23 3,1Nm together with a decent 70Vdc PSU?


Yes. You are at the limit of it, but given the working area size and my real life experience, you will not need the maximum achievable speeds at all. When we speak of max speeds and similar stuff we refer to heavy industrial application where your machine works full shift trying to produce max result



What HIWIN blocks do most of you prefer: HGH or HGW? Sure it depends from design but I think I will go with HGH20CA from BST Automation.

I buy from him and he has both. They are same price. For the gantry legs the wide blocks. Everywhere else the thin ones.




I would limit Z axis movement with proximity switches to about 100mm + detachable smaller workarea bed when aluminium cutting. This will keep Z in sweet-spot while cutting but also adds weight. I choose unnecessary weight over adjustable bed? But now when I think about it... I will get both actually! Will have to think this over.


No need for this. As you may know i have designed and build this machine. last week i was cutting aluminum fully extended Z, speed 900 mm/min and 1.5mm deep without any problem. 0.8kw spindle only. From the sound of it i could dig at 4mm with the 0.8kw spindle but still my friend does not have cooling which is critical.


Use well the spindle itself for strengthening the Z plate.

However your Z design slightly but critically differs from mine,may be its its weaker, please show better and closer pictures so we could see it in detail/, you could again read when you have time my first build/link in signature/ how exactly i made the Z.




Do you think this long 1610 ballscrew will start whipping on X-axis?

No, don't worry about that. Just design it exactly long. I see you are doing it right. It has been commented many time by more experienced by me members that in real life it will not be a problem. And as i told you before, rarely you will reach similar speeds.


Some comments:

At my second build i was again at the point of making the same mistake as at the first one. Same as what you are doing here. Trying to save on frame bed and machine weight. Now checking prices of T slot track, T slot solid aluminum, T slot aluminum profile, plain aluminum sheet and plastic sheet, i have it quite clear: The bed must be as strong as possible, crossing profiles as near as possible even bed made of welded profiles as the gantry is made, if you will do mainly aluminum.

Why that? Cause all else for serious fixing is darn expensive. Now i am hitting my head these days why i did not weld solid profile 1/2 of the bed for the 2600x1300 i am building for my self now.

So my recommendation here is to make the near to you half of the bed very strong as possible. So later you will not need to pay ridiculous amount of money for aluminum sheets and so.

What i am saying is you weld a strong structure for bed with the chosen profile. Then go to somebody who has shop, like a welder or machine shop. Ask them for their scrap and rests of different profiles. And that cheap stuff you use to weld in between to make it solid. It could be thin walled.

[toomast]

Thanks Silyavski!

I will go with HTD belts then.

Ballscrew standard machining leaves 15mm space for the pulley. Standard pulley is about 26mm. How do you solve this?

I think Silyavskis steel Z axis is coolest one I have seen :) I have studied that design but dont feel certain that I can pull it off. As I have good access to 20-25mm aluminium flatbars I go with the "usual" aluminium Z axis design.
Btw what is the weight of you steel Z axis, Silyavski?

I will beef up the frame and will rethink the bed fixing system.

I need to order rails and screws before EURO is totally useless :(

[njhussey]

Thanks Silyavski!

I will go with HTD belts then.

Ballscrew standard machining leaves 15mm space for the pulley. Standard pulley is about 26mm. How do you solve this?

I think Silyavskis steel Z axis is coolest one I have seen :) I have studied that design but dont feel certain that I can pull it off. As I have good access to 20-25mm aluminium flatbars I go with the "usual" aluminium Z axis design.
Btw what is the weight of you steel Z axis, Silyavski?

I will beef up the frame and will rethink the bed fixing system.

I need to order rails and screws before EURO is totally useless :(
If you ask for the machining (F dimension I think but a few years since I ordered mine) for the pulley to be 30mm then you'll have plenty of room...

http://tapatalk.imageshack.com/v2/15/03/09/50711d5a468f1eed54571dac9632a6f4.jpg

[JAZZCNC]

Do you think this long 1610 ballscrew will start whipping on X-axis?

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

[Boyan Silyavski]

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

:panda: Sorry, totally missed that 1500mm. I was thinking about something else. I will have to whip myself :hysterical:

[JAZZCNC]

:panda: Sorry, totally missed that 1500mm. I was thinking about something else. I will have to whip myself :hysterical:

Argh thought it was strange you saying was fine.. . Lol and Don't Whip your self get a nice fit blonde to do it much more fun..:toot:

[Boyan Silyavski]

I agree Dean. I was deep into reading about HF plasma grounding and just glanced at it and thought 1500 total length of screw -300mm in gantry legs gives 1200, minus more when he betters the design, so he could go away with that, cause anyways most people don't go faster than 10m/min in real life. And it was 1500mm travel , not screw length. I hope he did not order the screws. Anyways i will buy them from him if that mistake happened. its never a bad thing to have some extra ball screws.

[toomast]

No worry's mates! Have not ordered anything yet :) except the whipping blond...

[Sven]

I'd change the plate you have now for the Z-axis for a 80x80 steel tube and connect the dust collection to that.
That works really well.

Do put a brace between the mounting of the spindle and the oposite face, otherwise the mount may flex. Probably not as bad as my 35 mm high kress mount but still....

[toomast]

I'd change the plate you have now for the Z-axis for a 80x80 steel tube and connect the dust collection to that.
That works really well.

Do put a brace between the mounting of the spindle and the oposite face, otherwise the mount may flex. Probably not as bad as my 35 mm high kress mount but still....


I don't quite follow you. Do you have a sample picture how the 80x80 steel tube would work as dust collector?
Dust is the problem that needs solving in my design though. I was aiming for some simple bracket that holds dust extractor tube...some housing with brushes...I need to put it on the drawing.

For spindle mount I will order tha thick cast aluminium version. Nice and rigid I think.

[Sven]

Complete with dust shoe:

I have the tube clamped to the z-axis, so it can be set to a height.
The next one would just be on linear rails.

The height of the clamp is only about 30 mm, that requires cross bracing with the rear of the tube or it will flex at high feeds. (It did with this one)
The cast aluminium one is much higer, probably will not need cross brace but you can always add it later, should you need it.

A section of 100 mm pvc pipe can easily be fitted to the 80x80 if you heat it.

Picture of a few years back:

[Boyan Silyavski]

Sven, we dont see the images??

[Sven]

Oh, sorry guys, I guess you can not see these images they are on another cnc site. I see them in the post but I am loged in to the other site... I'll have to see what I can do about it.

[toomast]

My spindle arrived and its bigger than I imagined :)

http://www.mycncuk.com/attachment.php?attachmentid=14927&stc=1

I hope to find time this weekend to work with CAD so I can order rails and other stuff from Fred next week.
I will delay other electronics purchase as long as mechanical assembly is finished. Also I have ordered 12mm proximity switches.

[toomast]

Hi guys! So what do you think about my bed idea?
I would have the big steel sheet laser cut and holes tapped. Then welded to the square tube frame. Then replaceable aluminium bars on top. I want to have it separated from main frame - for easier transport. That been said... CAD calculates 204 kg for the bed weight :playful:.
Overkill?

http://www.mycncuk.com/attachment.php?attachmentid=14965&stc=1

[njhussey]

If you make the 10mm steel base a bit bigger than the strips you can put sides on it and then a drain in one corner and if you use coolant then you can drain it.....if you're not going to use coolant then ignore this :rolleyes:

[toomast]

If you make the 10mm steel base a bit bigger than the strips you can put sides on it and then a drain in one corner and if you use coolant then you can drain it.....if you're not going to use coolant then ignore this :rolleyes:
Thank you sir! I will do it.

[toomast]

Things are moving slow...but at least they are moving forward.
I wanted to do all steel Z-axis but as I had something thrown together in CAD I changed my mind. Main reason is weight. Steel Z will be at least 7-10kg heavier. As my hole gantry is at the edge of using servos I will go with aluminium Z design.
I'm not quite finished alu design but it will be from 25 mm thick material.
Here is a picture of my alu design (left) and steel design (right side).

http://www.mycncuk.com/attachment.php?attachmentid=15053&stc=1

[Boyan Silyavski]

I did all from steel cause i was doing the machine on the cheap and did not have somebody to machine it for me at that moment. Time wise is better to do all from aluminum. cause steel needs straightening, adjusting, first hand primer, second hand paint,...

[Sven]

I can't follow the reasoning for not using steel, except for silyavski (http://www.mycncuk.com/members/10304-silyavski) reasoning. If the gantry is steel, 7-10 kilo'sfor the z-axis will not make things that much different. Except for stiffness!

If the machine is for wood and this big, acceleration is less of an issue than top speed and for top speed stiffness is paramount. And all is designed to be stiff, except for this z-axis....

Besides, you can get 20 Nm steppers of the shelf....

[toomast]

I can't follow the reasoning for not using steel, except for silyavski (http://www.mycncuk.com/members/10304-silyavski) reasoning. If the gantry is steel, 7-10 kilo'sfor the z-axis will not make things that much different. Except for stiffness!

If the machine is for wood and this big, acceleration is less of an issue than top speed and for top speed stiffness is paramount. And all is designed to be stiff, except for this z-axis....

Besides, you can get 20 Nm steppers of the shelf....

I don't have first hand experience for none of them. But I dont think 25mm aluminium stiffness will be worse than 10mm steel.
Popular belief in this forum is that weight is important and 20 Nm is not always better.
Anyways I have an opportunity to find out...

[toomast]

I know silyavski told you No but he's Wrong it most definatley could whip at that length at higher rapid feeds. 20mm is much better screw to use at this length and won't cost much more in either Money or performance.

What would be the maximum length of 20mm ballscrew in this application? What would be critical length that needs rotating ballnuts?
Im thinking of getting more distance from gantry travel...

[JAZZCNC]

What would be the maximum length of 20mm ballscrew in this application? What would be critical length that needs rotating ballnuts?
Im thinking of getting more distance from gantry travel...

Oh very hard to answer because depends on the end fixing etc but I wouldn't go above 2000mm and at that I would have Both ends with Fixed bearings and slight preload on them. When I build 4x4 size machine I always use Fixed/Fixed end bearings as the slight cost difference is worth the extra support it gives.

[Gary]

To work out the critical speed of a screw there is a calculator on our site.
http://www.zappautomation.co.uk/index.php/ecalculators.html

In the lower part of this page is a link for the calculator.

[JAZZCNC]

To give you an idea I recently built a Slaved axis 4x4 router with 20mm Dia 10mm pitch screws 1700mm length Fixed/Fixed ends with 2 x 3.1Nm steppers running 70Vdc on EM806 digital drives. It safely reached 15mtr/min while testing and probably could have pushed it slightly more but felt no need.
Machine is actually tuned much lower than this at 10mtr/min rapids to keep a very generous safety margin. 10mtr/min is more than enough speed for machine like this.

[toomast]

I am still amazed by the time it takes to get things organized ;)
So anyways here is the gantry. Bit on a heavy side - 84 kg. For sure there will be some more fasteners, dust collector, cable-chain etc adding weight. Plan is to use 2 x 2000mm ballscrews 2010 to drive it. Fixed/fixed ends. 3,1Nm steppers.
Can I make it work?
I dont want to go servos on first build :)
http://www.mycncuk.com/attachment.php?attachmentid=15575&stc=1
Now my frame is looking like a toy :) Will make it 100x100mm tube instead 80x80 and beef it. Also I will ditch the bed design and try making some-kind of hybrid from marine plywood and aluminium surface for smaller parts...
If you guys approve the design I will order screws and rails and stuff from Fred...

http://www.mycncuk.com/attachment.php?attachmentid=15576&stc=1
Thanks for listening!

[JAZZCNC]

Can I make it work?
I dont want to go servos on first build :)


Yes it will work thou with 83Kg + gantry you'll have lower feed rates than I posted lower down. Think the gantry on that machine was 50Kg.

Now regards 100mm over 80mm then being totally honest I think this kind of building to excess is unnecssary and the little you gain isn't worth the cost and trouble. 80mm is more than enough for a frame this size. You'll gain more thru less resonance using 80mm or even 60mm but buy a thicker walled tube than going with 100mm thin walled (big base drum) tube.!!. 100mm thick wall tube is expensive and complete OTT for machine this size.

Other than the OTT build strength of the gantry the only thing I see which I'm not sure about is the flimsy looking ballnut supports on gantry ends and Gantry ballscrew.
Also not sure to how your mounting the motor and fastening to ballscrew across the gantry because pics don't show it very well. But it looks like your planning on connecting ballscrew to rear shaft of stepper and mounting stepper to a plate using normal stepper mounting holes.
OR doing reverse and mounting stepper to plate using rear holes and having the front hang out in space connecting to ballscrew.? . . . .Both bad idea.!!

Can you show better pics of what you have in mind.!

On the Bed idea.! I see you have large distance from bed frame to spindle and no adjustment which will be fine for wood etc but no so good for harder materials. So if you don't need all the bed then think about a 2 tier setup with the alumnium cutting area raised up to bring material closer to cutter.
The raised section could be made removable for when full bed needed and using a torsion box setup for stabilty.!

[toomast]

Here are closer pictures. All laser-cut steel is 8mm and ballnut brackets are welded...
http://www.mycncuk.com/attachment.php?attachmentid=15581&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15582&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15583&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15584&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15585&stc=1

[toomast]

So guys do you think I'm OK with the design?
Next week I want to order screws, rails and other stuff. Unless... :courage:

[njhussey]

I'd brace your ballnut mounts, they just look a little flimsy compared to the rest if it. Looking good!!

[Boyan Silyavski]

Yes, why would you save money from the ball nut housing? They are so cheap and are preferable , cause with coupled with straight plate, there is no need for reinforcing, but as you have done it doesn't look strong.

[JAZZCNC]

Yep just beef up the Ballnut mounts and your set to go.!
One thing I see is that you don't have much room for adjustment or alignment with that threaded bracket setup so give a little thought to how you'll do this for both directions. Ballnut housings tend to be easier to adjust than fastening ballnut direct to plate like that.

Those little white brackets sticking out on the end plates are those for triggering limit switches at each end.? . . . If so have you thought about using a traveling switch and save your self a lot of wiring and messing around with brackets etc. I do all my machines this way and it saves alot of work and easy to setup.

[toomast]

Yep just beef up the Ballnut mounts and your set to go.!
One thing I see is that you don't have much room for adjustment or alignment with that threaded bracket setup so give a little thought to how you'll do this for both directions. Ballnut housings tend to be easier to adjust than fastening ballnut direct to plate like that.

Thanks guys! Improvements implemented.
http://www.mycncuk.com/attachment.php?attachmentid=15602&stc=1



Those little white brackets sticking out on the end plates are those for triggering limit switches at each end.? . . . If so have you thought about using a traveling switch and save your self a lot of wiring and messing around with brackets etc. I do all my machines this way and it saves alot of work and easy to setup.
Yes these are brackets for limit switches. And I have not thought about using only one traveling switch!
Simple and ingenious - for sure I will also implement this!

I will go ahead and order my stuff from BST Automation.

[Boyan Silyavski]

Thats better.

I believe Dean meant 2 switches per axis, one wired home other wired like limit. With the benefit of all limits and all homes wired together respectively with the exclusion of the A home switch /second long axis/ which has to be wired separately, so you could perform gantry squaring

[toomast]

Thats better.

I believe Dean meant 2 switches per axis, one wired home other wired like limit. With the benefit of all limits and all homes wired together respectively with the exclusion of the A home switch /second long axis/ which has to be wired separately, so you could perform gantry squaring
Are you using similar setup on your 1st build?

I will put 2pcs homing switches on both sides of gantry for squaring. And only single limit switch on long axis and make it traveling?

[Boyan Silyavski]

Yep, similar. As i described it above. Though tit did not come to my mind to use only one limit switch at Y,:cat:, anyway, i bought more than i needed.

I would say that the 4 most important things are:
-to drive them at 24VDC
-to mount them so that the head of the sensor is perpendicular to steel plate or whatever and body long wise in the same axis of movement
- shielded wire
- good quality flex wire not very thin, if budget permits same as stepper cable

[eurikain]

What an awesome build ! I'd be interested to make the same one along the way ! Not sure if I did this right but I send you a PM ;) I'd be interested to make drawings from your model :)

[toomast]

What an awesome build ! I'd be interested to make the same one along the way ! Not sure if I did this right but I send you a PM ;) I'd be interested to make drawings from your model :)

Hi Eurikain,
Thanks for kind words! But actually all credit should go to users in this forum. Since all i have done is been reading and copying other build logs. I might as well could use Boyan Silyavski (http://www.mycncuk.com/members/10304-Boyan-Silyavski)
1st build model ;) But I find it helps me better to truly understand my machine if I have at least drawn it from ground up.

Details from Fred arrived yesterday.
Excellent packing, fast shipping and all according to requested dimensions.
http://www.mycncuk.com/attachment.php?attachmentid=15704&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15705&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15706&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15707&stc=1

[eurikain]

Ohhhhh boy that looks sweeeeeeeeet !!! Really nice packaging !

[suesi34e]

Hi Eurikain,
Thanks for kind words! But actually all credit should go to users in this forum. Since all i have done is been reading and copying other build logs. I might as well could use Boyan Silyavski (http://www.mycncuk.com/members/10304-Boyan-Silyavski)
1st build model ;) But I find it helps me better to truly understand my machine if I have at least drawn it from ground up.

Details from Fred arrived yesterday.
Excellent packing, fast shipping and all according to requested dimensions.
http://www.mycncuk.com/attachment.php?attachmentid=15704&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15705&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15706&stc=1

http://www.mycncuk.com/attachment.php?attachmentid=15707&stc=1

Hi toomast,

I look forward to seeing more about your build and some more photos. I was just thinking about a build I hope to start but the talk of a whipping blonde has distracted me!

Best of luck with it

Suesi

[toomast]

Small update which marks the real start of my build :D
http://www.mycncuk.com/attachment.php?attachmentid=15858&stc=1http://www.mycncuk.com/attachment.php?attachmentid=15859&stc=1
Laser-cut parts will be ready tomorrow. Sadly I have one "after work hobby funding project steel staircase" to finish next week so I doubt I can get any progress soon...

[toomast]

Managed to weld up the gantry today :D

http://www.mycncuk.com/attachment.php?attachmentid=15914&stc=1

[toomast]

Managed to weld up the gantry today :D
It seemed quite funny while photographing...tough crowd :D

So I'm all welded up and cleaned for painting. First plan was to weld it all together but ditched that wonderful idea. So now the frame consist of 5 pieces. Connections M10 bolts. Plenty of adjustments.
Next step is paint and then epoxy and assembly.

16397 16398 16399 16400

So now I should think about buying electronics...I have not done any research on this so please recommend! I will go with MACH3, DIY PSU, gantry squaring, home and limit switches. What BOB? Or even motion card? Drivers?

Thanks for listening!

[eurikain]

What a beautiful work ! Seems like you've done this your whole life :)

I am not an expert but everyone seems to fit these kind of machines (steel based, roughly the weights you mentioned) with AM882 drivers (60-80V) (check out AliExpress for those, they are about 68 Euros free shipping with DHL, make sure to buy max 2 at a time or you will have to pay for shipping) with 3.1Nm Nema 23 motors from CNC4YOU (I tried finding them on AliExpress but 8 lead 3.1Nm 4.2A low inductance motors are hard to find elsewhere than on sites like CNC4YOU, Zapp Automation...). PSU I can't tell you yet as I am in the process of making one (helped by JAZZCNC). Ask the gurus and they will help you :D. For the BOB, I use a cheap chinese $10 one. Works good for what I need (5 axis, spindle on/off, spindle speed, limit switches, e-stop). That's even more than I need. Other people here will most likely tell you not to go with that and use a fancy BOB. I don't know much about BOBs so I stick with the basic cheap I've got :)

Looking forward to read other members' recommendations :)

[Lee Roberts]

Agreed, your work on this looks super sweet, should be a nice solid machine frame, nice one Toomast!

.Me

[toomast]

As I have invested a lot of time and money into this project I don't want to create unnecessary problems with cheap components. I know that lot of people use them and are happy but I don't want to waste any hour or even days for troubleshooting - just to find out the fault was the dirt cheap BOB ;)
Any other recommendations for BOB?

[njhussey]

CSMIO all the way if you want a good one...

[toomast]

What you guys think http://www.pmdx.com/PMDX-126 ?
Special offer at the moment together with Mach4.

[Clive S]

What you guys think http://www.pmdx.com/PMDX-126 ?
Special offer at the moment together with Mach4.
These are excellent tried and tested solid boards

[JAZZCNC]

What you guys think http://www.pmdx.com/PMDX-126 ?
Special offer at the moment together with Mach4.

They are without doubt the best BOB on the market. Steve stallings at PMDX is great bloke to deal with and will answer any questions or troubles you have.

Just to make you aware regards Mach4. Mach4 is Plug-in based so any hardware you connect needs to have a plug-in written for it by the Manufacturer.
Even the parallel port is a Plug-in which you purchase separate. This mostly affects motion controllers and there are small handful who have written a plug-in for them and then they are at differant stages of development. This means some are better than others and at the moment None of them are at level of stabilty I consider good enough for users with lower level of experience.

Steve Stallings is quite involved with Mach4 development and his plug-in's for the products he sells that need them are probably one of the best but Mach4 is constantly changing which causes troubles for him and every other manufacturer. To be honest it shouldn't have been released IMO because it's still very buggy and tempramental. Effectively users are being used has beta testers so if you want to just install and go then I'd seriosly suggest you Don't buy Mach4 yet.
It's getting better and the Mk2 update and following updates have really ironed out some of the bugs but it's still too itchy scratchy for me so I'd avoid using it.!! . . . . Lets put it this way I've had it since day one and used it with CSlabs, ESS, Pokeys plug-in's and other than for testing it I won't trust it to run my machine unattended.

PS you don't need a Plug-in to use the PMDX126 it's just a BOB.

[toomast]

... To be honest it shouldn't have been released IMO because it's still very buggy and tempramental. Effectively users are being used has beta testers so if you want to just install and go then I'd seriosly suggest you Don't buy Mach4 yet.
It's getting better and the Mk2 update and following updates have really ironed out some of the bugs but it's still too itchy scratchy for me so I'd avoid using it.!! . . . . Lets put it this way I've had it since day one and used it with CSlabs, ESS, Pokeys plug-in's and other than for testing it I won't trust it to run my machine unattended.

PS you don't need a Plug-in to use the PMDX126 it's just a BOB.

Thanks for heads up! They do market MACH4 as ready goods... I will keep away from it for now.

[toomast]

Hi guys,

Is 156.-EUR reasonable price for:
WEST SYSTEM EPOXY 105 - 5kgHARDENER 206 - 1kg?

[JAZZCNC]

Hi guys,

Is 156.-EUR reasonable price for:
WEST SYSTEM EPOXY 105 - 5kgHARDENER 206 - 1kg?

Yes ok price for 5lt but really you want 209 hardner not 206. you need very slow cure time to allow plenty of time for epoxy to level.
I have used 206 before but you get much better results with 209 and not so rushed.

[Boyan Silyavski]

Dean, good that you spotted that number cause it could have made one pull of his hair, if ordered and mixed the wrong hardener :sorrow:

[toomast]

Thanks guys.
Temperature in my workshop is about 5-10c. Should I still go with 209? My supplier does not have 209 in stock...
Or I just keep my pants on until normal temperature arrive?

[JoeHarris]

Are you in a rush? I'm waiting till summer for my pour!

[eurikain]

I totally understand the rush, can't wait to have it built :) How about you heat up your workshop for two or three days ? You can just rent a propane or electric heater.

[JAZZCNC]

Thanks guys. Temperature in my workshop is about 5-10c. Should I still go with 209? My supplier does not have 209 in stock...

Thats to cold you must get it up around 20c and keep it there for 3 days.

[toomast]

Thats to cold you must get it up around 20c and keep it there for 3 days.
Then I will wait and go with 209.
Feeling quite awful for the slow progress...
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[njhussey]

Then I will wait and go with 209.
Feeling quite awful for the slow progress...

Sent from my LG-D605 using Tapatalk

I'd still go with the 206, if it's not in stock the wait for them to order it with their next stock order won't be a problem.

Your progress isn't as slow as mine, it took me 5 years to build mine....and its still not finished!

[JAZZCNC]

I'd still go with the 206, if it's not in stock the wait for them to order it with their next stock order won't be a problem.

Your progress isn't as slow as mine, it took me 5 years to build mine....and its still not finished!

NO don't do it you will regret it if you go with 206.!!!!!

[njhussey]

NO don't do it you will regret it if you go with 206.!!!!!
Oops....sorry, got my knickers in a twist, thought the 206 was the extra slow setting hardner [emoji17] teach me to not stop and think....listen to Dean, I'm talking boll###s.....

[Boyan Silyavski]

My workshop was 5-10C when i poured the epoxy. It took 4h instead of 1h to harden a bit and not be liquid, then 24h to harden more or less, and a couple of days to harden truly. Dont be in a rush.

[CanonGuy]

Then I will wait and go with 209.
Feeling quite awful for the slow progress...
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Sent from my LG-D605 using Tapatalk


Build is looking very good and stout! What route are you going to take for the machine bed? Didn't see that discussed anywhere.

[JoeHarris]

Read this: http://westsystemcom1.site.mobi/site/ss/cold-temperature-bonding/?smallView=1

[toomast]

Having problems getting hardener 209 in my country.
Do you think I can get away with using 207 (Extra clear fabric applicationand clear coating)? It has slightly longer working and cure time.
If I preheat epoxy, hardener and workshop and super-quickly mix the epoxy and make tha pour? By heating I mean getting it more liquid and better flowing-leveling. But heating also shortens the working time. So the question is to heat or not to heat? How long is the rough time-window for the EPOXY to be able to self-level?

[Clive S]

Having problems getting hardener 209 in my country.
Do you think I can get away with using 207 (Extra clear fabric applicationand clear coating)? It has slightly longer working and cure time.
If I preheat epoxy, hardener and workshop and super-quickly mix the epoxy and make tha pour? By heating I mean getting it more liquid and better flowing-leveling. But heating also shortens the working time. So the question is to heat or not to heat? How long is the rough time-window for the EPOXY to be able to self-level?Have a read through this http://www.westsystem.com/ss/use-guides/
The 209 give you about 8-10 hours for it to level out. It won't level out in one hour.

If you can't do it with epoxy then you will have to use shims instead.

[toomast]

Hello. Im back!
So mechanical assembly is finished and electrical has been started.
What cable type would you guys advise for:
1. VFD
2. Steppers
3. Inductive sensors

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[Boyan Silyavski]

Welcome back then

Post #9 (http://www.mycncuk.com/threads/8672-Where-to-buy-12-multi-core-flexible-shielded-cable-for-encoders?highlight=servo+cable)

[Tom J]

This story is about Steel Gantry Machine with work-area 1500x750x200 for aluminium and wood.
First I was going for a fixed gantry machine but bigger work-area changed my mind. As long as I have to purchase expensive components the price difference for longer components is not so dramatic - but it gives nice advantage. :smug:

http://www.mycncuk.com/attachment.php?attachmentid=14769&stc=1

Main frame welded steel 80x80x4mm.
Steel gantry consist of 2 pcs 100x100x3mm tubes welded together and some 8mm steel plates.
Z assembly is mostly 25mm aluminium with 2,2kw watercooled spindle.
Ballscrews X,Y=1610; Z=1605.
HIWIN 20mm rails all axes. Epoxy leveled.
Please feel free to comment my design. In case of positive feedback then next step would be to order rails and ballscrews. Measure them and then finalize design and start the build.

I have couple of questions for more experienced guys:

Can I use L (0,375" = 9,525mm) pitch pulleys with a 12,7mm wide belt from steppermotor to ballscrew? I can get those pulley for free. Together with 240L belt. But this belt is too long and pulley centre hole is 10mm, whish I cant use on Nema 23 anyway. So I have to buy half the pulleys and belts. May as well buy proper with belts and pulleys all around?
What ballscrew machining are you using when belt pulley will be attached?
Hole gantry with Z and everything will be close to 80 kg. Can I put my money on 2x Nema 23 3,1Nm together with a decent 70Vdc PSU?
What HIWIN blocks do most of you prefer: HGH or HGW? Sure it depends from design but I think I will go with HGH20CA from BST Automation.


Tanks for reading!

Why gantry 100x100 is only 3mm thick? I would make at least 5mm - 1.2m long

[Boyan Silyavski]

Why gantry 100x100 is only 3mm thick? I would make at least 5mm - 1.2m long

Its ok. Its only 1 meter long. In the middle where 2 beams meet is 2x3mm so quite strong there, like an internal brace

[toomast]

Why gantry 100x100 is only 3mm thick? I would make at least 5mm - 1.2m long
Do it.

[toomast]

My router made its first moves on 1st 2017.
There are some issues that need solving:
1. The guy who bored my pulleys obviously did not know what he was doing - terrible runout on some of them.
2. VFD is causing my PC video card some troubles. While spindle is on my screen goes black for 1-2 seconds with an interval of 10 seconds. All cable shields are grounded and no other anomaly occur.
3. Spindle watercooling
4. Final bed design with side-covers
5. Dust extraction
6. Probe
7. 4th axis
...

I put on some temporary bed and made some chips :D

It is the coolest project ever! Thanks guys!

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[njhussey]

Well done, looks great!! Always good to follow a build through to completion...though I do believe a video is needed of it cutting 😁

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[Clive S]

Yes + one on the vid and a good pic of the control box. Well done. Now the leaning really starts:beer:

[Boyan Silyavski]

Great machine! Happy chipping

PS. and change that pulleys. If you dont know who and how, order them bored from Belting online. Their pulleys are perfect and so is the job done. Only once i did no buy from them and i had problems with pulley straightness.

[toomast]

Hi guys! Just needed to share, couse felt a little success moment today.
Not anything too special but...
It has been a deeeeeep learning curve last 3 months. Made some chips and broke some bits [emoji1]
Have tried different materials: wood, ply, pom,acrylic,alu. Its been great - lot of learning [emoji106]
So today I did aluminium. 2d adaptive, 6mm doc, 14300rpm, 785mm/min, 2flute carbide endmill, z fully extended, wd40. Best sound so far for alu! Honestly...it was quiet! I constantly thought that something is wrong and will screw up.
Finishing pass + chamfer. Though chamfer was a little bit disapoitment in radius section.
Did not wanted to make a video. Since few years back I promised myself that I will never going to manually apply wd40 and compressair, or hold a vaccuum hose next to spindle [emoji4].https://uploads.tapatalk-cdn.com/20170415/6f245862a1f84d00598daf5dbadcf917.jpghttps://uploads.tapatalk-cdn.com/20170415/a56e353ec1f01fc232c838b3526a79fe.jpg

[Zeeflyboy]

looks great :)

[Boyan Silyavski]

That is definitely a great success. The cut looks very nice. Chamfer also needs a finishing pass. Same like normal side milling. I am almost sure you did not do that? So no real reason of disappointment. 0.05mm or 0.1mm will do the job next time. Also workpiece needs to be tightened to bed very strong.

[toomast]

That is definitely a great success. The cut looks very nice. Chamfer also needs a finishing pass. Same like normal side milling. I am almost sure you did not do that? So no real reason of disappointment. 0.05mm or 0.1mm will do the job next time. Also workpiece needs to be tightened to bed very strong.

You are correct, I did not do it. Lesson learned again. Thanks Boyan!

[toomast]

Hi guys!
I have an issue with my machine.
Please look at the pictures.
Outside dimension should be nominally 50.00mm and inside 30.00mm.
Same toolpaths with finishing pass.
I use Fusion360 for cam. Mach3 for controller. Probably messed up settings/offsets somewhere?
https://uploads.tapatalk-cdn.com/20180114/85e265e7b438ef7568973969e56519eb.jpg https://uploads.tapatalk-cdn.com/20180114/f279e14371f110a51d6b7584e136302a.jpg https://uploads.tapatalk-cdn.com/20180114/b3924aa046de87c04a8b022cc7fdf15e.jpg

[Neale]

What cutter are you using, and how accurate do you believe it is?

I normally use single-flute cutters, and my experience is that they tend to cut as if they are slightly smaller than their marked size. For example, I get pretty accurate results from my nominal 6mm cutter if I specify it as 5.7mm in my CAM software.

I spent a lot of time chasing this kind of inaccuracy and whatever tests I did, the machine seemed to be pretty good. However, when I cut a simple test square and measured it, the size was always wrong. Now, I do a quick test with every new cutter to work out its "real" diameter. The problem is that you cannot just measure single-flute cutters. Maybe they are just cheap cutters and no-one else seems to have this problem, but this is the only way I can get accurate, consistent, results.

Looking again at your measurements, though, I'm not sure that this is the case here. If, for example, the cutter were cutting 0.3mm undersize, the internal dimension would also be wrong (29.7mm). Similarly, a scaling error would also see errors in the internal dimension. Maybe it's something silly like using an offset in the CAM settings for the external cut? Or did you forget the finishing cut? Sorry if this sounds rude, but sometimes the answer is a small error that you have made and you only find it when you show it in public! That is something that you might find if you examine the gcode.

[toomast]

I use 2 flute 6mm cutter from sorotec.de.
Inside measurement is spot on. Thats the reason I can not blame the cutter diameter? Or am I missing something?
I think this kind of problem has been there from the start. But now I recalibrated all my axis with Mitutoyo digital indicator and all is repetable within .005mm (i dont claim the machine to be that accurate) First axis calibration was with digital caliper which accuracy cant be trusted below 0.02mm. So now I see this strange variation.This part X and Y measurements with caliper dont vary more than 0.02mm.

[Neale]

I've just made an edit that you might not have seen. Yes, it does look like an offset problem in the CAM settings for the exterior cut. Can you go back to your F360 operations and double-check?

[toomast]

For Compensation Type I use In Computer.
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I will try other options today - will try changing tool offsets in Mach3.
Although I have been using my machine for a year now, I am quite clueless about G-code :( If I need something to change I always go back to CAM and repost...
For faster/better workflow I should compensate in Mach3 I guess.
For roughing passes I leave 0,5mm stock which is default by F360.

[Nr1madman]

Im not good at this stuff, but just a thought..
Do you get the same error in the rough cut?

Skickat från min SM-G955F via Tapatalk

[toomast]

I will measure in the evening. I use adaptive cuts for roughing out - little circular cuts with 2,4mm load. But I guess I should be able to measure 0,3mm. Will try.

[Richard]

Very nice build! Is this really your first one??? Can I ask a couple of questions?

Did you use epoxy on the gantry as well or did you get it machined flat?

Did you have any problems getting everything square?

I see you have the z rails on the moving z plate, which is the better method. Is the z plate rigid enough with just the rails bolted to it? I wondered if C channel steel or a box made from ali plate would be better? (the rest of the machine looks super rigid)

(that's 3 questions! Sorry!)

[toomast]

Very nice build! Is this really your first one??? Can I ask a couple of questions?

Did you use epoxy on the gantry as well or did you get it machined flat?

Did you have any problems getting everything square?

I see you have the z rails on the moving z plate, which is the better method. Is the z plate rigid enough with just the rails bolted to it? I wondered if C channel steel or a box made from ali plate would be better? (the rest of the machine looks super rigid)

(that's 3 questions! Sorry!)

1. Yes, its my first CNC machine build.
2. I used epoxy on the gantry too.
3. Squareing is time consuming. Have to use creativity and long machinist squares.
4. I can measure quite a lot of deflection on my Z. For sure you can design it stronger. Steel is more rigid. It all depends on your requirements and budget. It is nice to have a super strong machine, but it all comes with a cost. Also I like to point out that good machinist can produce superb parts with mediocre machine. There is no black and white, only gray :D

[Richard]

There is no black and white, only gray :D

Ha! very true!

Your design is very similar to one I started to draw up, with the deep sides to avoid the bendy gantry sides many people have...

I wanted to as long Z travel as possible, so I used steel channel for the Z plate. The fusion360 sim showed that a flat plate would flex a lot.

Your build is very impressive and it looks really nicely finished.

Do you make any mistakes at all???

Would have done anything differently?

So how did you do the epoxy on the gantry? I can see you have rails on the top and underside of the gantry (good design to keep Z close to the gantry!), so the top epoxy would be easy! The bottom????

[routercnc]

Hi Toomast,

In support of post #84 (but not an answer !) I also use F360 for CAM and Mach3 for control. I had a similar problem, although the other way around.

One of the last parts I cut out (a simple rectangle) was roughed out with 0.1 mm stock to leave, then a finish pass was applied. I forgot to do the finish pass on one of the parts (and had removed it from the machine) but as the dimension was not critical I left it there. One the second part I made sure it did the rough and the finish.

When I measured them both the first part was spot on the dimension (but should have been 0.1 mm larger) and the second part was 0.1 mm underside (but should have been OK). As they were simple cover plate it did not matter but I wondered what had happened.

I've cut lots of part out and not seen that before. Unfortunately my machine is now a pile of bits so I won't find out any time soon. Just thought I'd post my experiences . . . .

[toomast]

Hi routercnc,

Thanks for shareing. Las night I did some experiments. But now I realize I only did contour cuts. I tried all compensation options but results where the same. Inside dimension spot on and outside 0,3mm extra.

Does Mach3 DRO shows coordinates with compensation or without? Since DRO (both work and machine) was spot on but cut was 0,3mm off... Right now I already doubt my axis calibration. Workshop is a bit colder but i dont think shrinking is to blame here.

[needleworks]

If you are using an adaptive toolpath in fusion, are you also following it with a 2d contour ? In fusion when you use 2d adaptive, there will be an option for "radial/axial stock to leave" You can of course set these to 0, but I always follow adaptive toolpaths with a 2d cleanup contour.
Just a thought !

[toomast]

If you are using an adaptive toolpath in fusion, are you also following it with a 2d contour ? In fusion when you use 2d adaptive, there will be an option for "radial/axial stock to leave" You can of course set these to 0, but I always follow adaptive toolpaths with a 2d cleanup contour.
Just a thought !

Yes. In 2d adaptive I leave 0,5mm stock. Which I clean up with 2d contour as a finishing pass.

[Davek0974]

What cutter are you using, and how accurate do you believe it is?

I normally use single-flute cutters, and my experience is that they tend to cut as if they are slightly smaller than their marked size. For example, I get pretty accurate results from my nominal 6mm cutter if I specify it as 5.7mm in my CAM software.

I spent a lot of time chasing this kind of inaccuracy and whatever tests I did, the machine seemed to be pretty good. However, when I cut a simple test square and measured it, the size was always wrong. Now, I do a quick test with every new cutter to work out its "real" diameter. The problem is that you cannot just measure single-flute cutters. Maybe they are just cheap cutters and no-one else seems to have this problem, but this is the only way I can get accurate, consistent, results.

Looking again at your measurements, though, I'm not sure that this is the case here. If, for example, the cutter were cutting 0.3mm undersize, the internal dimension would also be wrong (29.7mm). Similarly, a scaling error would also see errors in the internal dimension. Maybe it's something silly like using an offset in the CAM settings for the external cut? Or did you forget the finishing cut? Sorry if this sounds rude, but sometimes the answer is a small error that you have made and you only find it when you show it in public! That is something that you might find if you examine the gcode.

I think its normal - I do exactly the same with all my cutters, the 2mm SF carbides i use only give true results if cam'med for 1.96mm so a test is needed if dims are critical.

[Nickhofen]

Sorry if someone else mention it and I didn't notice.
Have you try with another program? Design the same object and cut?

[toomast]

Managed to sort out my problem. Almost too embarrassed to tell but.. as it turns out it is not wise to calibrate machine axis with a dial indicator. At least a machine that has not super accurate ballscrews. Also the testpart that showed inside measures correctly and outside wrong, was coincidence I believe. I re-calibrated my axis with a 300mm caliper. Problem solved.

So anyway here is a little cherry on my strawberry cake:
Material: S335
8000rpm, 350mm/min, DOC 3mm, 2-flute TiAIN 6mm endmill.
Some chatter but nothing major... Shitty workholding. Nice blue chips where flying :)

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