This is my first BUILD please help.

[DigiSoft]

Hi. I am researching this field for months and I decided to make one. I ordered almost all parts except the linear rails. I am going to make them.
I have all the parts but I'll post pictures tomorrow because it is late now to take pictures :fat:. Anyway this is the parts info:



4 x Axis Driver 2M542 4.2A & Breakout interface board for Router system for CNC
2 x ballscrew RM1605-1300mm (for dual X axis)

1 x ballscrew RM1605-900mm (for Y axis)

1 x ballscrew RM1605-250mm (for Z axis)

4 x flexible couplers

3 x NEMA23 425 oz-in CNC stepper motor /3.0A (two for X, one for Y)

1 x NEMA23 287 oz-in CNC stepper motor (for Z)

4 set BK12/BF12 ballscrew end support
12 x SBR20UU BLOCKS
3 x Cable drag chain wire carrier 10*20mm 1000mm (40")


I have all of this parts and I hope I am on the right track, I'll be so frustrated if I made some mistake because my budget IS VERY VERYYYYYY TIGHT.
Anyway I would like a little help.

1. What is the best alu plate thickness I should use for the Z construction and the gantry. I was thinking of using 20mm plates. Is that good?
2. How should I place the linear support rails on the Y axis? Should they be mounted on the front of the alu plate or one at the top and one at the bottom? What is better system?

I have some drawings on paper but still nothing on PC and I am not sure if I make because I am not that good in 3D software.
Please help me with this first questions. THANK YOU

PS: Like I said I'll post pictures tomorrow.

[D.C.]

Sketchup is free and really easy to learn, there are some very good tutorials here:

Sketchup for Woodworkers - Home (http://sketchupforwoodworkers.com/)

You can import all the standard things like your ballscrews etc straight into the program so you don't have to worry about trying to draw them.

[DigiSoft]

Sketchup is free and really easy to learn, there are some very good tutorials here:

Sketchup for Woodworkers - Home (http://sketchupforwoodworkers.com/)

You can import all the standard things like your ballscrews etc straight into the program so you don't have to worry about trying to draw them.

Yes I know about the sketchup but where can I find the ready-made parts? I really don't have time to design every part and bolt from ground up.

[D.C.]

From inside sketchup, goto file import and then search for sbr20 and up pops a linear rail, bearings and mounts component.

If you can't find something inside of sketchup try a google search for 'rm1605 ballscrew sketchup' and download the file onto your computer, then you can import it into sketchup from your computer.

To be honest it seems a little odd to buy all the parts first with no idea about how to arrange them into a working machine and then start trying to figure out how to do it with no money for making mistakes and no time to learn how to do things.

If you take a look at the build logs most people seem to take many months to assemble their first machine, it might be best to put a plan together first either properly done technical drawings on paper or a CAD model that way people here will find it much easier to help you.

I'm just starting to put together a plan for my own first build and from most of the information I've garnered it seems that 20mm plate is fine and the top & bottom rails on the gantry is quite popular.

Try reading this thread, it has CAD drawings and photos to help you visualise:
http://www.mycncuk.com/forums/diy-machine-building/4299-z-axis-design-advice.html

[DigiSoft]

From inside sketchup, goto file import and then search for sbr20 and up pops a linear rail, bearings and mounts component.

If you can't find something inside of sketchup try a google search for 'rm1605 ballscrew sketchup' and download the file onto your computer, then you can import it into sketchup from your computer.

To be honest it seems a little odd to buy all the parts first with no idea about how to arrange them into a working machine and then start trying to figure out how to do it with no money for making mistakes and no time to learn how to do things.

If you take a look at the build logs most people seem to take many months to assemble their first machine, it might be best to put a plan together first either properly done technical drawings on paper or a CAD model that way people here will find it much easier to help you.

I'm just starting to put together a plan for my own first build and from most of the information I've garnered it seems that 20mm plate is fine and the top & bottom rails on the gantry is quite popular.

Try reading this thread, it has CAD drawings and photos to help you visualise:
http://www.mycncuk.com/forums/diy-machine-building/4299-z-axis-design-advice.html

I already said that I HAVE the plan in my mind and I have some drawings on the paper but not on a computer. I'll do some sketchup on PC and post it. Anyway, I ordered the parts because I have figured out how the machine will look. I also spend months and months ordering and thinking. It's not like I got up in the morning and ordered some random parts to make myself CNC.
The position of the rails is something that can be changed during the process. It is not something you buy and make mistake.
The rails are the same, but the design is different.

[D.C.]

My apologies, I was trying to help not infuriate.

This post has the rails/screw models in if it helps.

http://www.mycncuk.com/forums/cad-cam-software/4819-google-sketchup-tips-discussion-4.html#post35866

[irving2008]

The bit I don't get is you've ordered some top quality (read expensive) kit and the SBR20UU blocks yet you are going to make the linear rails. Clearly your working envelope is 1200 x 800 x 150 approx and its hard to see how you'll get the accuracy required over those sort of lengths. What exactly are you planning to do there?

[Robin Hewitt]

My apologies, I was trying to help not infuriate.

The toys did leave the pram PDQ, probably best not to ask how he intends to make the rails :disturbed:

[martin54]

Like DC I am new to this & still planing but he offers some good advice from what I have learnt so far. What materials & components you use will depend on what you intend to cut with the machine. What sort of material will you be cutting as the more experienced members will ask you this.
20mm has been used for a few builds but you need 20mm plate not 20mm flat bar. What else will you be using for the gantry construction other than the aluminium plate?
What experience of machining or what tools you have available will make a difference.

[DigiSoft]

OK thanks to everyone for the answers BTW D.C there is no need for apologies, it is OK :).
I am planning to use the CNC for milling some thin aluminum, then wood, plastic, that kind of materials.
I am forced to make the support for the linear rails because those parts are really heavy and the shipping to my country is $$$.
I have the roods from pro-chrome but I need to make the support rails. Now this is really a problem so that's why I am asking for help.
I was thinking of using two L shaped profiles and one aluminum bar in the middle like sandwich and tight that up with nuts and bolts on every 5cm or so. Like this

_|[]|_

I know it is not perfect solution but what do you think about it? Can you give me another idea of making the support rails?

THANK YOU VERY MUCH for the understanding.

[DigiSoft]

Here are some nice pictures to get started.

71637164716571667167716871697170717171727174717571 767177717871797173

Right now I am working in google sketchup and trying to do some design.
Anyway can someone answer me the first question if the rails for Y are better top-bottom or front face.

thanks.

[D.C.]

No problem digisoft, just a misunderstanding. :)

Unless you already have access to a workshop you will probably have to rig something up to grind a 45 degree angle in your supports like this guy has done:

Grinding a 45 degree angle for a linear rail with my CNC - YouTube (http://www.youtube.com/watch?v=Il6N9q7El_8)

One problem with this approach is that you have to use v-groove bearings as wheels and the wheels will need frequent adjustment as the rail wears and your wheels become loose. The v-groove bearings are also really expensive and hard to get hold of.
It might be easier to use a piece of box section or square bar at 45 degrees as the rail like this:

/\
\/

That way you can use skate bearings (just the normal wheel bearings from skateboards) which are really cheap, it wears down slower so it requires less adjustment and it means a lot less work to setup.

[martin54]

OK if I have picked you up correctly you are going to make your own supported rail using the ally profile & chrome bar. First question would be what sort of equipment do you have access to because I would imagine you would really struggle to be able to drill & tap a length or round chromed hardened steel bar with DIY gear unless you already have your own workshop.

[DigiSoft]

OK if I have picked you up correctly you are going to make your own supported rail using the ally profile & chrome bar. First question would be what sort of equipment do you have access to because I would imagine you would really struggle to be able to drill & tap a length or round chromed hardened steel bar with DIY gear unless you already have your own workshop.

YES YES that is what I am trying to do.
D.C. that is not a solution because I already have the ball bearings.

I have workshop and I have big table drill and other tools. I don't have router and I can't melt aluminum :D
Please help :)

THANKS TO ALL!!!!

[DigiSoft]

I calculated the Z part and ONLY the aluminum 20mm plates will weight 11Kg. It is not included, the rails, sliders, stepper etc etc, only the aluminum plates construction. Is that too much? Should I sue thinner plates?

[irving2008]

A typical gantry will weigh in at 20 - 25kg. Without seeing a drawing of how your gantry is designed its impossible to say what the impact of making them thinner will be. Rigidity is key...

[DigiSoft]

A typical gantry will weigh in at 20 - 25kg. Without seeing a drawing of how your gantry is designed its impossible to say what the impact of making them thinner will be. Rigidity is key...

Here is some unfinished design.
Please tell me what do you think.

Thanks.

7200

[Hobgoblin]

Going off advice given to my design, and the veiws i know others share I'd say it seems to have the right things in the right places pretty much.

Critisism: flip the stepper motor and mount it on the back then use a belt and pulley system. This will reduce resonance, as well as other things? (correct me)
Perhaps also mount the ball nut inline with the rails, might help give greater travel in x?

Finally, ignorance is getting the better of me, are you really from chernobyl?

[DigiSoft]

Going off advice given to my design, and the veiws i know others share I'd say it seems to have the right things in the right places pretty much.

Critisism: flip the stepper motor and mount it on the back then use a belt and pulley system. This will reduce resonance, as well as other things? (correct me)
Perhaps also mount the ball nut inline with the rails, might help give greater travel in x?

Finally, ignorance is getting the better of me, are you really from chernobyl?

Hahahahahahhaa no my friend, I am not from there. I just put it like that :D
Thank you for the help.

Can you tell me if the Y distance of the rails (vertical distance between the Y rails) is better to be 150mm or 200mm. Y will be 1140mm long

PS: I am still working on the Y boll-nut. I just put it like that, it is not in place.
PSS: I was also thinking about belt and pulley for the Z but I don't have those parts and it will complicate my design. What do you think? Is there that much difference?
All aluminum parts are 20mm tick.

I changed the design little so the Y distance between the two axis is 150mm
7202

Do you think this is better?

[irving2008]

Its always better to have the y-rails as far apart as you can and as low down to the bed as you can to improve torsional stiffness...

I think you could reduce the thickness to 12 or 15mm without undue effect...

What is the box section between the rails? material and dimensions?

[DigiSoft]

Its always better to have the y-rails as far apart as you can and as low down to the bed as you can to improve torsional stiffness...

I think you could reduce the thickness to 12 or 15mm without undue effect...

What is the box section between the rails? material and dimensions?

This is my newest version. I found that I must put the ballscrew in the sandwich so I can use the maximum length.
The box section of the two pieces that hold the rails is 50mm x 60mm at 4mm thickness?. I am thinking of using stainless still. What do you think. Will they bend?

7203

[D.C.]

I don't think the backplate on the rear of your z-axis adds a great deal to the performance of the machine, if you get rid of it you can bolt a plate to the back of you gantry to improve stiffness. If that still doesn't provide enough stiffness for what you are using the machine for you can always pour concrete into the box section.

Concrete is obviously heavy but weight can be reduced by adding things like vermiculite/perlite/polystyrene beads etc into the mix to displace the sand and and some fibre glass or fine steel fibres to add reinforcement.

[DigiSoft]

hmm so you say the backplate won't do much think?hmmmm
I am thinking to use 5mm for backplate.

[irving2008]

Assuming a typical spindle/z-assembly the 50 x 60 x 4 isnt strong enough for that 1140mm length if its aluminium, the deflection in the middle will be around 0.1 - 0.2mm and torsionally the deflection under cutting loads at the tool tip will be similar, so needs to be steel. You'll still need to join the two box sections with a plate, or a series of plates at the ends and in the middle to transmit torsional forces from one to the other and to maintain the rail seperation accurately else you'll get binding. The other issue is that box section isnt flat enough to mount those rails on unless its ground flat after assembly, you'll not be able to maintain the rail spacing accurately enough to prevent binding. Aluminium extrusion is better but again needs to be bigger, e.g. 100 x 50 for tortional stiffness. 5mm plate is probably too thin, the deflection at full Z extension under cutting load could be ~0.2mm. 15mm plate seems to be the norm, and will limit the deflection to <0.1mm. These calcs are very rough.

[DigiSoft]

Tomorrow I will be cutting the aluminum pieces for the Z gantry.

For now I have two questions.

1. What type of bolts should I use? What is preferred size for bolting 20mm aluminum?
2. There are two screws on the Linear ball sliders. One is on the top in the center and one on the side of it. Why are those used for? I heard for tightening the bearings but why two?

[DigiSoft]

Here is some progress i made so far. Everything is made of steel except the font panel of the Z axis, that is 20mm alu.
Please comment.

10155101561015710158101591016010161

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[kingcreaky]

wow! -- excellent work.

keep the pictures coming

[DigiSoft]

Thank you, I'll make new more quality pictures. These were taken with my phone :)

[EddyCurrent]

Looks good, how did you join the side plates to the ends of the big box section ? I can see there are 6 bolts used somehow.

[DigiSoft]

Looks good, how did you join the side plates to the ends of the big box section ? I can see there are 6 bolts used somehow.

The big box section (140mm x 60mm x 5mm) has welded 12mm steel plates on the both ends. Then the ends are machined to get 90 degree. I used 6 bolts M8 to bolt the sides.

[JAZZCNC]

Here is some progress i made so far. Everything is made of steel except the font panel of the Z axis, that is 20mm alu.
Please comment.

Nice Job and like colour it must be heavy thou with those big lumps of steel what weight is it.?

[DigiSoft]

It is around 100 Kg +-10

Tomorrow I'll make quality pictures and I'll take some pictures of few unmounted new parts.

[JAZZCNC]

It is around 100 Kg +-10

Tomorrow I'll make quality pictures and I'll take some pictures of few unmounted new parts.

So with Spindle and other attachments like X ballscrew mounts and cables etc you'll probably be pushing 120Kg+.?? . . .At this weight your going to have to be careful with motor tuning using slaved stepper motors. The inertia of this thing at higher feeds will try pushing like crazy so if your thinking to use machine for router type wood work then you may need to consider servo's.?

You'll certainly need to keep plenty of torque in reserve with slaved stepper motors otherwise your open to racking. What do you plan to use machine for.?

What pitch screws.?

[DigiSoft]

YES YES I will be using slaved steppers for X axis. 1 stepper at each side. I use 425Oz 3A NEMA 23 stepper motors. I bought 42V 750W / 15A PSU. I would like to be able to work on steel too. Do you think it would be possible?

Today I ordered steel working table. They will be making T slots in it. I have access to CNC shop with big cnc 2000mm x 2000mm working table. My table will be 1500 x 900mm and around 200KG.

The gantry complete like you said will be around 120kg.

I use RM1605 (5mm pitch / 16mm diameter).

I do not need fast machine. I just want to be stable and precise.

[JAZZCNC]

At lower feeds which you'll run for steel and aluminium you'll be probably be ok but they will struggle with higher feeds or heavy cutting conditions.
Personally I'd be looking into small servo's or at least Nema 34 motors and high voltage drives. Even small 400W servos will be fine has they give linear torque so won't restrict machine potential.

The 3Nm motors and low voltage you plan will be very limiting to machine performance has speed increases.! They should handle lower feeds ok but seems a shame to build what sounds like is going to be a very well built and sturdy machine and not be able to exploit it's full potential.!! . . . . That said they will get you started but think you'll probably quickly want to upgrade.

[DigiSoft]

I have made a big progress with my CNC.
The worktable is finished and the construction is welded. It is night so I couldn't make better picture, but in few days I'll post more work progress. Everything is made of steal. Tubes are 80mm x 80mm x 4mm. The worktable is machined from steal.

Overall weight ~ 500KG


11751

[EddyCurrent]

That is one hell of a substantial frame and bed, I can see why it weighs 500Kg, great job :applause:, pity the pigeon's have shit all down it though :highly_amused:

[DigiSoft]

ahahahahahah it is not from pigeon. It rolled over on the concrete while we tried to turn it up side down :D

[DigiSoft]

I made a lot of progress.
Here are some pictures, I hope you like it.

12069120701207112072120731207412075

[EddyCurrent]

Tidy job but the gantry and supported rails seem quite a bit less substantial than the base and bed, that's not to say it won't perform well.
Next you will have to skim the bed to make sure it's flat.

[DigiSoft]

Yes I should have used 30mm rails but it would be to expensive so I used 20mm.

The profile under the rails is 140mm x 60mm x 5mm wall thickness.

Tomorrow I'll make new pictures.

Do you think I'll have problem with 20mm rails?

[EddyCurrent]

Please do not take my comments as critisism because your machine is excellent, it's just that for me there looks to be a mismatch between the gantry and bed frame.
Well I'm no expert on rails but from what I've read and found with my own machine I think you would have done better using the low profile rails such as Hiwin. Lots of people use the rails you have and they seem to work well but somehow they are not in keeping with that substantial base. Hiwin rails however would have been more expensive.
There 's one thing for sure though and that is the frame and bed will have enough stiffness.

As an experiment maybe you could add some test results to this thread ?
http://www.mycncuk.com/forums/gantry-router-type-machine-building/7155-stiffness-measurements-cnc-mk3-2.html

[Jonathan]

'Linear guide (https://www.google.co.uk/search?q=linear+guide&es_sm=93&source=lnms&tbm=isch&sa=X&ei=5FROU9uTMYSQOMrggcgF&ved=0CAgQ_AUoAQ&biw=1366&bih=600)' is probably a better term to use than profile rail, to avoid confusion.
I agree that the machine is currently a bit mismatched - by far the lowest stiffness parts will be the round rails. Still, try it and see and if it does what you need then no matter...

[JAZZCNC]

The biggest problem with the round type rail and esp the cheap chinese type is the bearings quickly become loose and sloppy so lose accuracy and need regular adjustment.
They are no where near as accurate to start with compared to profiled linear rails which just work and last for years without any attention other than lubrication now and again.
They won't take the abuse Profiled linear rails will take and dusty or abrasive conditions will quickly take it's toll on them unless you take precautions to protect with wiper seals etc.

Like Eddy I agree these rails let down what looks like a nice substantial machine and IMO Profiled linear rails make the difference between Average DIY and Professional machine.
Don't look at it so much in terms of they are expensive which they are not in long run because they give a much better and far more reliable machine but more they will return there investment 2 fold later down the line if you ever decide to sell the machine as they will still work just the same and not be wornout plus appeal more to potential buyers who are prepared to pay more for professional looking machine fitted with correct components.

[DigiSoft]

I agree about the 'Linear guide (https://www.google.co.uk/search?q=linear+guide&es_sm=93&source=lnms&tbm=isch&sa=X&ei=5FROU9uTMYSQOMrggcgF&ved=0CAgQ_AUoAQ&biw=1366&bih=600)'. I wanted to use them but I calculated they would cost me 1200 euros. This rails cost me 350 euros. I'll run the machine with this and if there is need for linear guides then I'll make major modifications. :)
Also I wanted to use servos, but that would rise the price even more.

When I finish this machine I'll make small mill with linear guides and servos :) but with smaller axis length because of the price.

[DigiSoft]

Here are some update pictures
Sorry for bad quality I promise next will be HD :D

121511215212153121541215512156

[JAZZCNC]

Excellent work and that machine certainly won't be walking across the floor.:applouse:

On the drawings you show the motors connecting to ballscrews directly.! Can just recommend you think about using timing belts and pulleys.
They greatly help reduce resonance which acts upon the motors and can cause rough running and lower performance. On a Box section steel machine this is esp important for obvious reasons and esp if the tubes are not filled with sand or some other form dampening ~(expanding foam isn't much good.!).
You'll also get the benifit of being able to apply a ratio if you ever feel like more speed or need more torque.

I do this on every machine I build regardless of what material it's made from and on every Axis because the benifits far out weigh the cost and extra time.

[DigiSoft]

Excellent work and that machine certainly won't be walking across the floor.:applouse:

On the drawings you show the motors connecting to ballscrews directly.! Can just recommend you think about using timing belts and pulleys.
They greatly help reduce resonance which acts upon the motors and can cause rough running and lower performance. On a Box section steel machine this is esp important for obvious reasons and esp if the tubes are not filled with sand or some other form dampening ~(expanding foam isn't much good.!).
You'll also get the benifit of being able to apply a ratio if you ever feel like more speed or need more torque.

I do this on every machine I build regardless of what material it's made from and on every Axis because the benifits far out weigh the cost and extra time.

Yes I was thinking that too but can you tell me where can I find 2:1 belt and pulley ?
I don't know how to search them on ebay. Can you help me?

[JAZZCNC]

Very easily found. Often your local bearing stockist will keep them or get them in for you.
Other option is to use someone like these people Timing Pulleys (http://www.beltingonline.com/timing-pulleys-bars-272/)

The belt type you want is HTD 5mm pitch and 15 or 25mm width, personally I use 15mm. Pulley size I use for 2:1 is 18 & 36 or 20/20 for 1:1 ratio. Don't go too small other wise you have less teeth engaged and the belts wear quicker or worse they jump teeth due not enough teeth engaged to handle the torque.
Equally don't go too large else the inertia of the pulleys starts having a negative impact. If you must use larger pulleys then look for aluminium ones.

Pulleys often come with a pilot bore so you'll need to able to bore them or have them bored for you, the compnay in the link I posted will do them for you at a price. Don't go for taper lock as they are heavy plus you won't find them at small sizes anyway but in any case don't for the larger size in them either.

You'll need to calculate the belt size from the centres of each pulley and pitch/no teeth on pulleys, there are lots of calculators on the tinternet.

[EddyCurrent]

Also you will need this, Jonathans belt length calculator

http://www.mycncuk.com/forums/machine-building-faqs-problems-solutions/5848-calculating-timing-belt-lengths.html

That's a lovely looking machine, you've done a great job on it, very professional, I like the monitor arm too. I forgot the gantry was made from steel until I looked at earlier posts just now.

[IanS1]

Very nice looking machine. Tell us more about the machine bed. How much did it cost?

[DigiSoft]

Thank you all for the support, I really appreciate it.


Very nice looking machine. Tell us more about the machine bed. How much did it cost?

The bed is made of 30 mm thick steel plate with dimensions 1500mm x 950mm. I payed 300 euros for it (weight around 370Kg). Then It was flattened on both sides using big Siemens CNC.

Then we made ribs inside the plate and on top we put wider metal ribs bolted with m10 bolts. This metal ribs are 10mm thick. At the end, it was flattened again on the both sides.

On the picture you can see the monster CNC Siemens. We've done a lot of parts for my cnc on it.
It has travel of 1500mm x 1300mm x 950mm

12159

Does anyone knows how can I shim down the sittings for the rails and the bed? I was thinking of epoxy but I am not sure. Can anyone give me an idea?

12160

[DigiSoft]

Today I made holders for the stepper motors. I was thinking of using belt and pulley but it would cost me another 60 euro, so I decided for now I'll go on like this. :)

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https://www.youtube.com/watch?v=XcfZeZEEdbU

[DigiSoft]

Can anyone help me with shimming down this steel plates?

12248

Please I need ideas.
How can I level them all?
If I use epoxy it wont crack under heavy pressure from the bolts?

[Clive S]

Can anyone help me with shimming down this steel plates?

12248

Please I need ideas.
How can I level them all?
If I use epoxy it wont crack under heavy pressure from the bolts?
Epoxy putty under each plate level then when set bolt down. .. Clive

[EddyCurrent]

If it would fit inside the big Siemens CNC you could skim the plates like you did with the bed.
Or if you had a large flat surface you could turn the frame upside down, the plates would lie on the flat surface than put some epoxy putty on them before setting the frame on top, wait until set before inverting and bolting.

[DigiSoft]

Long time no update. Here are few new pictures of my build.

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[DigiSoft]

Here is comparison, Design vs Real
17384

[routercnc]

Nice work digisoft, should work well

Any photos of the 'front' of the machine showing the spindle / Z axis?

[DigiSoft]

Nice work digisoft, should work well

Any photos of the 'front' of the machine showing the spindle / Z axis?


Yep, I'll make new photos today with better camera.

[DigiSoft]

Here are some more pictures from the front.



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