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HipoPapi
19-06-2014, 02:41 PM
Hi everyone, I am new to the forum and in the process of designing a cnc router. By looking at a lot of build posts and designs it seems to me, that the best way to start the design process is to first have the measurements of all the components I intend to use. In my case the starting point is a cutting bit that I will need to use that has the measurements of 250 mm long (outside the chuck) and 22 mm diameter. I would appreciate any help to find a spindle that meets my requirements.

Thanks,
Me.

HipoPapi
21-06-2014, 03:18 PM
Hello there again,

I have done some research and I have concluded that I need a spindle with an ER32 chuck and Maritools in the us sells a special collet that is 7/8 for ER32 that is exactly what I need.

http://www.maritool.com/Collets-ER-Collets-ER32-Collets/c21_56_59/p2582/ER32-COLLET-7/8-Special/product_info.html

If anyone knows a supplier here in the UK that sells those collets please let me know as that would save me a bit on shipping costs and would be great to have a local supplier in case I need replacements. So far I did not managed to find anyone in the Uk.

I have been looking at the air cooled Chinese spindles like this one:

http://www.aliexpress.com/item/Air-Cooled-6kw-Spindle-Motor-for-wood-engraving/572524003.html

If anyone has experience with those please let me know your thoughts.

I have also found this one and I am leaning towards this one as at least has a brand name :)

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=221347062591&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

Also this video is quite convincing as the Chinese ones seem to have more like a 0.1 run out and not what they claim.

https://www.youtube.com/watch?v=CIdmw5KyO14

At least now I know that I should be counting on 15 - 20 kg for the spindle.

My working envelope needs to be at least 1100 x 600 x 260 mm and on the Z a 250 mm end mill needs to be able to be lift it above the material block. For this I might make a system where I can remove the spindle and reposition it higher when I use the long end mill and lower when using shorter ones.

This CNC will be doing one thing and one thing only ...will be carving ice inside a freezer. There won't be any water as it will be kept at -5 at all times.

Ice is a lot softer than wood but harder than polystyrene. To make you understand it easier when I carve by hand I use a makita GD600 400W

http://www.amazon.co.uk/Makita-GDO600-240V-Grinder-Range/dp/B000I6PIQ2

And with this tool and a 100mm x 9mm end mill I can go to full depth and make strokes in the ice. Although I usually do this in two 50mm strokes.

This is what is available on the market, but I don't like it as is not capable to work with the 250 mm long end mill I am planning to use plus I think is way overpriced.

http://www.icesculptingtools.com/ice_pro.htm

So with all this info my next step is to decide what diameter and pitch ball - screws to use and what size stepper motors as when I start making the 3d model would be great to know the sizes.
I see is often recommended to use a belt to drive the ball-screw instead of direct drive, but I dont think that is an option for me as belts and cold don't play well.
My table needs to be steel as although ice is soft is extremely heavy around 150 kg / block.

I think with this size spindle the gentry should be box section steel as well.

I will be doing a lot of 3d work with this cnc and needs to be fest.

I quite like this one but unfortunately is not finished yet:

http://www.mycncuk.com/threads/6457-Sturdy-and-Fast-all-Steel-CNC-my-first-build

I am new to all this and any input and suggestions would be greatly appreciated to get me on my way.

Thanks for taking the time to read.

You can see some of the type of work I do here:

http://vasscsabart.weebly.com/index.html

Csaba

JAZZCNC
21-06-2014, 06:50 PM
Hi Your Ice sculptures are very nice but do you realise how long Large detailed 3D toolpaths can take.? Air cooled spindles have short duty cycles (the time they can run in one go) and Even at -5 I don't think they will run constantly for the length of time you'll need to cut a large detailed Ice sculpture.?

I would be looking at how long your Models will take to cut and if the spindle will run this long without needing a rest period.? @ -5 it may not be overly long but still you'll need to factor it into the Job and possibly how you toolpath the Job.!

gavztheouch
21-06-2014, 07:19 PM
What about water cooled spindle with some strong antifreeze?

GEOFFREY
21-06-2014, 07:24 PM
I suspect that the spindle bearings/lube may not be too happy ay in a -5 environment. G.

HipoPapi
21-06-2014, 07:31 PM
Hi Jazz and Gav

Thanks for your suggestions I will definitely consider them, but to make it more clear I don't intend to use the cnc to finish the job all the way in 3D as I like to apply my personal touches plus since it is just 3 axes I would have to work on them anyway. I would need just a roughing step most of the time with my largest end mill since the material is quite soft and easy to finish by hand. Most important is that the whole thing is nice and square as often times I use a large amount of blocks. I am talking here about 1.5 tons of ice sometime.

HipoPapi
21-06-2014, 08:06 PM
Sorry got logged out earlier.

At one of the places I work at we have a 4.5 kw Perske spindle and it has been running for years now although it was used just for 2d work well time will tel.
But here is an example of something that would already make my happy and in fact it was done this way:

Here is the 3d model that I have made :

12602
12603
This is how it all fit into the blocks:
12604
12605
And basically I have only did two passes on each block like this:
12606
Each of the passes went in 125 mm. The line across is for alignment basically just a scratch so I know how to align it with the next block.

And when the whole thing was assembled it was finished by hand.

Here is a video I have made earlier of how this works. This was for a pitch for a PlayStation game lunch:

https://www.youtube.com/watch?v=pEM4tL9yHDw

So basically as you see it in the video the whole thing has to fit together as a puzzle and that is the most important for me the rest only needs roughing.

The antifreeze idea is interesting I will definitely look into that. Would that allow me to use the spindle a lot longer?


Any idea on what size ball-screws and steppers to use?

I am planing to use Hwin rails on each axes.

Thanks again for the suggestions finally I can fill this thing rolling :)

JAZZCNC
21-06-2014, 09:32 PM
Erm your a talented Man and I would love to meet the Model riding that beast. . Lol

Don't worry about what ballscrews and motors yet because you have much more to do before you'll need to know that.? First you need a machine size/design and then choose material to build it from which will be needed to answer your ballscrew and motor question. When you have setteled on a size and design then you can choose the screws and motors to suit it.
Worst thing you can do is go buying blind before doing the home work. Just like you plan the Ice sculptures and they have a process how they go together in order building a CNC machine is same there's an order to build it in.? Starting with design again like your Sculpture's.!!

HipoPapi
21-06-2014, 09:59 PM
Thank you for your kind words and suggestions Jazz they do make a lot of sense. I guess is time to start drawing and modeling so we have something to talk about :)
Thanks again and have a great evening.

HipoPapi
21-06-2014, 10:12 PM
Also if there is anyone in London who has built or in the process of building a still frame or in fact any kind of cnc and would be willing to show me his project I promise to brig the Guinness :)
I am part of the London 3d printer group, but unable to find any cnc related meetup groups.

Boyan Silyavski
07-07-2014, 01:38 AM
Hi,

some points:

1. Spindle:

-How did you get to the conclusion that you need ER32 collet? You say ice is soft and easy to route. 2.2KW SPINDLE WILL LOWER THE COST OF THE BUILD CONSIDERABLY. Furthermore there are on the market many Carbide bits that have the cutting area much bigger than the shank. these will be perfect for rough 3d jobs with rapid removal

-Water cooled is a must, just run normal antifreeze.

-Bearing grease will not be a problem. -5C is not a big deal. Just run the spindle slower to faster some minutes every time, so it can heat a bit. You will need to do also the following things: make additional bracket and fit a seal on the spindle shaft, best would be if you change the grease with salt water resistant grease/ Mitchel, etc./ , the one they use in fishing. it is a very fast grease, so no worries there. For sure its better than the original one :-)

2. Frame

it should be at least bi component industrial coating marine epoxy painted or you would be sorry very soon. Best would be inox and then epoxy painted. Yeah, inox rusts too

3. Rails must be inox, Hiwin has inox rails and carriages.



I see your biggest problem with "chip and dust removal and damage" , cause your chips would be water. hence water will go all the time where it should not. Ok, electrical connections could be dipped in polyurethane/ via hot melt gun and polyurethane glue bars/ but never the less all steppers have shafts, so those shafts have to have additional seals.

I see it working if you plan use it in a room where is -5C. I see that you looked at the machine i am making. Following a similar design is easy to protect all ball screws.

But if you plan only an enclosure where is -5C, i see it very difficult-aluminum also f***s in moisture , so more or less every metal part left visible-shafts, plates, bolts, ball screw supports, ball screw nuts etc., should be sealed or painted over. Same goes with the cables, their ends and connections must be dipped in polyurethane.

irving2008
07-07-2014, 05:01 AM
Rather than seal spindle shaft, replace lower spindle bearing with a food grade sealed stainless steel one, lasts forever in adverse conditions.

HipoPapi
07-07-2014, 03:52 PM
Hi,

Silyavski thanks for your input although it seems to me that you might have missed my first post or miss read it. As I explained there my starting point in this cnc machine is an end Mill with the measurements of 250 mm long excluding the shaft and 23 mm in diameter. The shaft is 19.5 mm in diameter so I guess that explains where the Er32 collet comes from. Also due to the length of the end mill the 5 hp spindle is definitely needed. I know this from experience working with ice cnc machines before. We have used a perske 5.5 hp air cooled spindle without any special sealing and 5 years on is still going strong with at least 6 hours run time per day.
Although I might look into special sealing I don't find it necessary as explained earlier there is no water involved at all as the machine and material is constantly at - 5 degrees so all the chips are powder snow... And a lot of it.
Also carbide bits don't work on ice in fact only special bits made for ice work. I have tried all sorts of bits before just to see as ice bits are quite expensive but no luck... hence the price. For instance that 250 mm bit costs 350 dollars and by the time I get it to the UK cost just as much in pounds sterling.
I do appreciate your input and time and hopefully you understand better now what I am up against.
Also the machine won't be in a cell, it will be in a very large freezer in fact my ice studio so even while loading and unloading will stay at that temperature.
My difficulty at the moment is the very large z travel as my material is also 250 mm high and with the bit lifted above it the spindle needs to travel to other areas but would need to work on thinner slabs of ice as well with smaller bits.
Anyway I did not have any free time in the past few weeks to think about it but hopefully will be able to upload some drawings by the end of the week to discuss it further.
Thanks again for the comments.

HipoPapi
13-08-2014, 08:04 PM
Hello again,

I have been quite busy lately with work, but I think I finally know which way I am going with this build and some help would be appreciated.

So far I have the structure and now comes the part where I have to decide what size stepper motors to use and what diameter should my lead screws be as I would like to design the mounts for them.

I assume the stepper motor or servo choice defines the control board choice as well.

A couple of questions:

Can the gantry weight be guestimated ? Yes I am quite lazy to find out the weight of each component :) I know that the spindle motor is 15 kg :)

If yes than what size and torque motors would suite my design? ( I would like it to be fast and strong. Strong enough for wood in comparison )

I assume belt drive is not the best choice in a sub zero environment therefore I have the option of direct drive or Chain and sprocket. What would be the best choice?

I would like to use Mach 3 as the controller and would like to upgrade to 4 axes as soon as I am done with the build. Do you have any suggestions on control boards and the electronics involved?


Here are a couple of pictures of the structure to make things a bit clearer:

Light Grey = 100 x 100 x 3 or 4
Dark Grey = 150 x 100 x 3 or 4
Orange = 10 mm steel plate
White = 20 mm aluminum plate
Blue = ice
Purple = removable module to be replaceable with 4th axes module in future
20mm HIWIN rails an all axes


13077 13078



Any suggestions would be greatly appreciated.

Thanks,
Vass

Boyan Silyavski
13-08-2014, 08:35 PM
Hi,
starts to look good.

Some notes:

- what precision you aim for the cut? Ice will cut, but i see it vibrating if you intend to cut aluminum. It can be made much more rigid if you add some vertical profiles on the gantry, no problem if they are 60x60 and offset from the back gantry plain outwards like 5mm as i remember, so the motor will pass and fit inside the gantry.

-My suggestion is if you like, to have a look at my new gantry design (http://www.mycncuk.com/threads/6619-Quite-an-Unusual-one/page6) , there are some cheap improvements over your design especially of the side plates. using profile, can cheapen the build and lessen the time.


-the table looks like a tank, so good enough for me :kiwi-fruit:


-you must calculate at the end the exact weight of the gantry, cause you can accidentally go in servo territory :lemo: and or need to drive all with some reduction, which will affect the speed, which will affect the motor choice and drives, etc...

HipoPapi
13-08-2014, 08:50 PM
Hi Silyavsky,

I have seen your new build log already and looks great and find it a great idea with the air hammer. I have tried to incorporate your gantry design as not having to laser cut would be great, but in my case it doesn't seem to work as it would make the whole machine 200 mm wider which in may case is just wasted space as the ice blocks are always the same size.

I do not intend to cut other materials than ice with this machine as I have tried on time before and all the filters in the freezer got messed up :)

well than I guess I have to work out the weight of the gantry ):

Thanks again.

HipoPapi
13-08-2014, 09:01 PM
One more question.

at the moment I have left 20 mm of extra rail on all axes in each direction behind where the limit switches would be. So basically when the limit switch stops the movement will still have 20 mm rail left. Is that enough?

HipoPapi
13-08-2014, 10:32 PM
Hello again,

Has anyone used this calculator before?

http://www.onealsteel.com/calculators.html

If this is correct although i dont think so as it always gives me round numbers but hopefully is rounding upwards than my gantry without the steppers or servos, and mounts and lead screw, cables and Hiwin reals and blocks is 137 kg therefore I assume with all those added will be around 160 kg.

Where do I go from here? Please

Thanks,
Vass

HipoPapi
14-08-2014, 07:03 PM
Hello,

Although I have no idea of the stepper or servo size I need nor about the lead screw diameter, what I do know is that I can't find sprocket and chain kits to turn the lead screw with chain instead of belt.
Does anyone have any suggestions where to look for them?

Thanks,
Vass

HipoPapi
20-08-2014, 07:03 PM
Hi Guys,

I don't seem to be getting a lot of love here but hopefully you can confirm or suggest something better regarding my findings.

I have emailed around for quotes and had a couple of suggestions.

The one I am inclined to go for at the moment is the following:

On the X and Y I would have 2010 ballscrews,
On the Z 2005 ballscrew,

On the X and Y I would have Nema 34 easy servo closed loop steppers with 8Nm holding torque(3 phase)
On the Z I would have Nema 34 easy servo closed loop steppers with 4Nm holding torque

For drivers I had the following recommended:

http://www.zappautomation.co.uk/electrical-products/easy-servo-closed-loop-stepper-system/easy-servo-stepper-motor-drivers-closed-loop-stepper-system/es-dh2306-easy-servo-drive.html

And the following Motion controller:

http://www.zappautomation.co.uk/electrical-products/cnc-motion-controllers-18/motion-controllers-from-cs-labs/csmio-ip-s-6-axis-cnc-ethernet-motion-controller-step-dir.html

The motors would be installed in direct drive and I was given the following results:

On the X for one stepper the Maximum Thrust would be 3200N (325KG) At 900 RPM (9M/Min). There are two motors on the X so the thrust value should double.

Please let me know what do you think of the above configuration and some suggestions would be welcome.

Also if you have some tips of where to introduce some savings please don't hold it in :)

Thanks,
Vass

JAZZCNC
20-08-2014, 08:15 PM
Hi Vass,

Love and peace are in short supply around here friend. . .Lol

You won't go far wrong with those Electonic components and ballscrew specs.

Now people on here who have not experienced these components are going to say that for the price of those drives/motors you can buy servo's and they would be correct.!! . . . But this Stepper setup is much easier to setup and get/keep running than servos, almost plug n play.
They match servo's for accuracy and if you don't need the speed servo's offer then basicly there's nothing between them. (Same holds true for any stepper correctly setup and tuned)
Only thing is don't be tempted to go for the lower powered drives as you'll want the high power to get the speed from the motors you need.

The CSlabs motion controller is second to none. I use both the IP-M and IP-S in all machines I build and can tell you 100% it's the best by far in it's price range. Also if you do decide to go with servo's then it's more than up to handling high count servo encoders with loads of I/O. Infact it's actually designed more to suit servo's than steppers with features to Home from servo drives Index signal and other servo specific features.

So your spec so far would give you a very very accurate machine more than capable of doing what you require.

Forgive me but I've not trawled back to far thru the thread but now you want to cut Ice but don't know the machine spec.
What size is this machine.?
What material will you be using for the gantry and approx weight.?
What feeds are you looking for to cut with Ice.?

HipoPapi
20-08-2014, 08:55 PM
Hi Jezz and thanks for the reply.

The gentry is made of 100x100x4 mild steel mainly and 20mm aluminum plate.

The estimated weight of the gantry excluding the steppers/HIWIN rails and blocks/ ballscrews and mounts is:

Y + Z = 135 kg (including 5.5 kw ER32 spindle)

Z = 46 kg (including 5.5 kw ER 32 spindle)

In terms of speed I have no idea to be honest . I was told by someone who used to machine ice that I can push it as fast as I can as is really easy to machine. I guess experimentation will tell.

I was thinking of servos as well, but they need gearing and since planetary gears are expensive and belts aren't an option in the freezer I think I am going to stay with the closed loop hybrid servos.

I have seen your video review of the similar system from zapp and was quite impressed.

Please see the attached pictures for sizes.

Light Grey = 100 x 100 x 4
Dark Grey = 150 x 100 x 4
Orange = 10 mm steel plate
White = 20 mm aluminum plate
Blue = ice
Purple = removable module to be replaceable with 4th axes module in future
20mm HIWIN rails an all axes
13146 13147 13148

Thanks for taking the time to comment.
Vass

JAZZCNC
20-08-2014, 09:15 PM
Ok well given the fact you will be running a resonably heavy gantry at higher feeds then I may be inclined to go with servo's due to linear torque.

Other option is to use higher pitch screws 2020 so you can get the same speed at lower motor RPM. Obviously you will lose some resolution but do you need more than 0.01mm.? I think you won't for ice.
20mm will put the motor in a 450 RPM range where torque is strong for the same speed as 10mm pitch. Where with 10mm at 9M/min you will be in the 900rpm range where torque starts to drop away.

Also I think if you contact belt manufactures there will be belts than can handle the cold so you could either use servo's or steppers with higher pitch screws to increase torque with a ratio.

EddyCurrent
20-08-2014, 09:35 PM
Looking at the side view, it strikes me that things would be stronger if the cutter was further back so it was 'inside' the footprint of the two bearing blocks supporting the end frame. At the moment it is cantilevered out in front of them both.

Boyan Silyavski
20-08-2014, 09:36 PM
Hi Guys,

I don't seem to be getting a lot of love here but hopefully you can confirm or suggest something better regarding my findings.



:love_heart::love_heart::love_heart:

What i don't like about your design, now that i have seen the more detailed drawings is that the spindle center is overhanging so much that is in front of the gantry leg front bearing block. Do something about that. Instead of triangles you can offset the gantry a bit back, so the forces equalize.
This is a major design flaw in my opinion.
Read more here http://www.cncroutersource.com/do-it-yourself-CNC-router.html The picture below is from that link and illustrates how basic forces work there.

13150


I would have used servos. I would have definitely used 220v AC drives even for steppers, so seems your choice is right there.

I would definitely flip the Z design, so that the moving plate is the longer part , with the rails there, and that the Bearing blocks are on the fixed plate

EddyCurrent
20-08-2014, 09:41 PM
silyavski, I just beat you to it :wink: but that's the damn diagram I've trying to find again for ages, so thanks for finding it.

HipoPapi
20-08-2014, 09:42 PM
Hi Jazz,

Thanks for the quick reply.
That is a great suggestion as you are absolutely right that I dont need better resolution than 0.01. In fact I dont need better resolution than 0.5. I know it sounds ridiculous when I see what people are aiming for in this forum but realistically everything I do melts.
Ice blocks come in standard sizes of 1000 x 500 x 250 and they are not perfect so essentially here I need precision is the edges to make them match each other to glue them together with water. The cnc would do just the sides the top and bottom will be done on a band saw.

Thanks again I will definitely consider the 2020 screws.

Vass

JAZZCNC
20-08-2014, 09:54 PM
I would definitely flip the Z design, so that the moving plate is the longer part , with the rails there, and that the Bearing blocks are on the fixed plate

As you know Boyan I would normally agree with you on this one but in this case then it really is best this way due to tool length and the fact the spindle never goes much below the bottom of the gantry as Vass is cutting large blocks of ice with long tool so needs the inverse travel.

To be honest I didn't pay much attention to the design and more focused on the component selection but I must agree with Eddy and Boyan that the gantry would beneifit from moving the CG back. It looks to me like your using Solid works so this will show the CG hows does it look.?

HipoPapi
20-08-2014, 10:04 PM
Silyavsky thanks for the hearts :) feeling much better now.

You and Eddy are absolutely right in your assumption. The design has changed since than. Instead of the 50x100 pieces I have used 100x100 ones all round and now the vertical bit is all the way to the back.Originally I have brought it forward to leave access to the HIWIN blocks but with the 100x100 profile it is no longer necessary.
It looks like this at the moment:
13152

I have tried to design it in a way to have the blocks fixed and the rail moving, but the gentry become a lot taller.
The reason for that is the fact that the lowest position of the spindle is different from what you have seen.
You can see it better in the following picture.
13154

Thanks again Silyavsky and Eddy.

JAZZCNC
20-08-2014, 10:13 PM
Ice blocks come in standard sizes of 1000 x 500 x 250 and they are not perfect so essentially here I need precision is the edges to make them match each other to glue them together with water. The cnc would do just the sides the top and bottom will be done on a band saw.

So what you need is a surface planner not a CNC router.? Have you considered building a four sided planer on linear axis.?

This would be very easy to build and wouldn't need expensive spindles, tools, or controller and drives, ballscrews etc.

Because you know the linear movement you can just use programable drives that don't even need a PC. Use planner blocks and blades with normal motors for the cutting heads. For linear movement the simple chain drive could be used as you don't need precision just to move a set distance.

If you wanted to automate the process so each blade moves in sequence then a simple arduino could do this.

Just a thought.??

HipoPapi
20-08-2014, 10:27 PM
Hi Jazz,

That is an interesting thought, but I intend the use the capabilities of the cnc as well actually quite a bit including 3d roughing and as mentioned earlier would like to add a 4th axes later if this works out alright.

Here are a couple of pictures of similar machines that I have used as reference. The one on the picture is a rack and pinion system and has been working for the past 9 years generally for about 6 hours a day. And it has a surprising setup that blew my mind and in a way made me confident in my design. It has only three HIWIN blocks on the y and also just three on the z. On the Y there are 2 on the front and one on the top and on the z two on one side and one on the other :)

I do a lot of logos in ice which would be done with the cnc. At the moment I do them by hand and it was ok until now, but now that I know that I am designing a cnc I cant stop thinking about how easy it would be :)
13155 13156

Thanks again for the great advice.

Cheers,
Vass

JAZZCNC
20-08-2014, 10:44 PM
Ahh ok well you do need CNC then. . Lol

Something I was going to suggest regards the design was moving the top rail onto top of gantry beam and using the bearing plate to support the rear plate due to it's height and I see they have done this on this machine. This would be a good design change and if you notice they have triangle plates supporting the tall back plate which will resonate while cutting. Now surface finish won't be an issue for you but anything that resonates for long enough is going to have a negative affect on components etc so reducing it doesn't hurt.

HipoPapi
20-08-2014, 11:02 PM
I will definitely consider the triangle plates as my z is higher hence I have the two beams. Mine is higher because I dont want the removable front plate to preposition the spindle all the time when I want to work an a thinner sheet of ice.
I have been thinking of placing one of the rails on the top, but It seems to me that it would be a lot harder to get them parallel, but steel I think that is the right way to go and will do a redesign on that.
Just to give you an idea of what they have got away with on the machine pictured earlier the gantry beam is a 150 x 110 aluminum box section, held by 100 x 50 x 3 aluminum box sections (the vertical bits and bottom bits) and the side plates and z axes plates are 13mm aluminum plates. This hopefully gives you a better idea of what forces are needed for Ice.

Thanks again

JAZZCNC
20-08-2014, 11:24 PM
This hopefully gives you a better idea of what forces are needed for Ice

To be honest I would imagine the forces are a bit less than cutting soft woods so your design is well upto the job.
Personally given your relatively light needs then I would use HD Aluminium profile for the gantry beams and make life very easy for your self. The profile makes fitting rails very easy and accurate, if combined with Aluminium plate for the gantry sides that is manipulated in a certain way then it's very accurate and strong.
Steel is great when mass strength is needed but there is alot of work involved in building with it and getting accurecy. The combination of steel for the base for cost saving and strength but with the ease of building an accurate but still strong gantry with profile/plate is the route I would be taking.

Boyan Silyavski
21-09-2014, 06:44 PM
Hi Vass, what servos you are looking at? You said 750w and 400w but what exactly ? The BOB then? Do you have updated drawings yet?

HipoPapi
21-09-2014, 07:50 PM
Hi Silyavski,

those are the servos:

http://www.zappautomation.co.uk/electrical-products/servo-systems/brushless-servo-motors/smh60/smh60s-0040-30aak-3lkn-400w-ac-servo-motor.html

http://www.zappautomation.co.uk/electrical-products/servo-systems/brushless-servo-motors/smh80/smh80s-0075-30aak-3lkn-750w-ac-servo-motor.html

the drivers:

http://www.zappautomation.co.uk/electrical-products/servo-systems/ac-and-dc-brushless-servo-drivers/cd-range-344/cd422-a-000-ac-servo-driver.html

Controller:

http://www.zappautomation.co.uk/electrical-products/servo-systems/ac-and-dc-brushless-servo-drivers/cd-range-344/cd422-a-000-ac-servo-driver.html

Power:

http://www.zappautomation.co.uk/2902993-uno-ps-1ac-24vdc-100w-power-supply.html

Thanks,
Vass

HipoPapi
25-09-2014, 12:51 PM
Hi There,

I have managed to do some work on the servo mounts yesterday and thought I ask for opinions. I have tried to make it simple and easy to build.

The orangebits are 10mm steel.

24 t pulley on the servo and 48 t pulley on the ballscrew. The bigger pulley in the picture is the 72 t pulley if I want to go with 3:1 reduction.

Opinions would be great as I am planning to send the final drowings for laser cut sunday night as the place where I do my laser cutting switches to thick metals on monday and tuesdays.

O and how much extra space is advisable for the paint layer? 1mm maybe?


Thanks,
Vass

Clive S
25-09-2014, 02:03 PM
Just a quick point how about making the slots in the motor mounts longer to enable you to be able to change the pulley size if needed later. ..Clive

HipoPapi
25-09-2014, 02:09 PM
Thanks Clive,
That is a good point as that way I might have to only change the pulley and keep the same belt. Or simply I would have a lot more options in the future.

Thanks,
Vass

HipoPapi
25-09-2014, 02:15 PM
Or I could drill for extra holes in the back plate and have the option to mount it lower if needed.

HipoPapi
25-09-2014, 02:51 PM
An other dummy question, but those are the sort of things I get stuck on :)

Does belt length matter if I only go from 10 t in mesh to 11 t in mesh?

Thanks

Boyan Silyavski
25-09-2014, 02:56 PM
An other dummy question, but those are the sort of things I get stuck on :)

Does belt length matter if I only go from 10 t in mesh to 11 t in mesh?

Thanks

All belt tech data is for 6 teeth in mesh.

Matter how? If you mean is 10 t in mesh enough - yes it is. HTD 5m 15mm belt is right in the middle for what we use it so even 6t in mesh is ok.

HipoPapi
25-09-2014, 03:02 PM
All belt tech data is for 6 teeth in mesh.

Matter how? If you mean is 10 t in mesh enough - yes it is. HTD 5m 15mm belt is right in the middle for what we use it so even 6t in mesh is ok.

Sorry I did not make it clear.
I have got to the Y axes mount and I would have to use a longer belt. Larger center distance. Is that a problem in any way? Like I said I go from 10 t in mash to 11 t in mash.

I am using 25 mm 5 pitch belts.

Thanks

Boyan Silyavski
25-09-2014, 03:12 PM
How many teeth you calculate the belt to be long?

I have asked that same question before and seems there is no problem.

But personally i would try all belts to be as short as possible. Actually on the machine i am building now i had to use 1200mm belt at one place /z/ and i worked on and changed the design until my longest belt is 305 mm. Again, its absolutely personal, but i wouldn't use something longer than 350mm.

HipoPapi
25-09-2014, 03:34 PM
How many teeth you calculate the belt to be long?

I have asked that same question before and seems there is no problem.

But personally i would try all belts to be as short as possible. Actually on the machine i am building now i had to use 1200mm belt at one place /z/ and i worked on and changed the design until my longest belt is 305 mm. Again, its absolutely personal, but i wouldn't use something longer than 350mm.

Thanks Boyan,

On the X as pictured above at the moment is set for 385 long belts. On the Y I will have to use a 665 long one otherwise I would need to move the servo and belt assembly into a place I dont like as I want to be able to keep my eyes on it and most importantly protect it from the snow.

Thanks for the advice now I know the longer belt isn't a big problem :)

Vass

Boyan Silyavski
26-09-2014, 06:07 PM
Thanks Boyan,

On the Y I will have to use a 665 long one otherwise I would need to move the servo and belt assembly into a place I dont like as I want to be able to keep my eyes on it and most importantly protect it from the snow.

Where is that place? Did you fit it into the gantry between the beams or at the back in the middle of one of the gantry sides? cause that is where i would fit it.

HipoPapi
09-10-2014, 07:21 PM
Where is that place? Did you fit it into the gantry between the beams or at the back in the middle of one of the gantry sides? cause that is where i would fit it.

Sorry for the late reply. I had a serious hiccup with my computer but finally is up and running again. Also I have decided to wait with the laser cut until the linear motion components arrive as I would like to double check some of the measurements.

Yes I had to mount it on the side of the gantry as otherwise the Z axes would hit the pulley as my Z axes travels from outer gantry side plate to outer side plate.
At the moment I have all the axes designed so they can be geared 3:1 or 2:1 will decide on that later all I had to see at the moment is that in either case the belts wont be hitting any of the mounting screws.
http://www.mycncuk.com/attachment.php?attachmentid=13572&stc=1http://www.mycncuk.com/attachment.php?attachmentid=13573&stc=1

Boyan Silyavski
09-10-2014, 10:24 PM
Wouldn't it be better if you make the Z not only for that particular case but to be able to mount a normal tool on the spindle and to reach the bed or near it? I mean what if you decide to do something other than ice block?
Say you decide tomorrow to make a mold for the ice blocks, it must work as a normal machine not only with extra long bits, right?

HipoPapi
09-10-2014, 10:55 PM
Wouldn't it be better if you make the Z not only for that particular case but to be able to mount a normal tool on the spindle and to reach the bed or near it? I mean what if you decide to do something other than ice block?
Say you decide tomorrow to make a mold for the ice blocks, it must work as a normal machine not only with extra long bits, right?


I am intending to use a variety of cutters on the spindle not just this long one. I only have this one always in the spindle because this long bit and the ice block are the things that have defined the dimensions of the machine while designing it as my ice block is always the same size ( I mean this is the maximum size of an ice block that I use ) and the long bit is the one that needs to be able to travel on top of the block.
The Z is designed that the spindle can go down to 6 cm from the table. I dont think I will ever use any smaller ice than that and if I do I would still do the routing on the big block and then cut the finished slice of of it on the band saw because otherwise is way to fragile.
Using the machine for anything other than ice is probably out of the question as the machine will be permanently in a freezer and the freezer filters would get messed up. Also particles from other materials could contaminate the ice blocks in the freezer something I defiantly dont want as they have to be food grade.
I am planning to build a second machine primarily for wood if everything goes to plan with this one.

You have asked me earlier about the servos I am intending to use but than said nothing about them.....any thoughts?
http://www.mycncuk.com/attachment.php?attachmentid=13574&stc=1
http://www.mycncuk.com/attachment.php?attachmentid=13575&stc=1

Boyan Silyavski
14-10-2014, 08:07 AM
Now looking at your latest drawing i ask my self the following questions:

Why this design at all? Wouldn't it be better to do it similar to my first build, where the work piece is inside the base structure, the gantry side legs are much shorter and most importantly the linear rails are outside of any dust/snow flakes/ and the ball screw is protected also.


The only possible drawback i could see is evacuation of snow dust. As the work piece is smaller than the table and both sides left and right- half z axis space is present, so you fit below the workpiece a table bed only sized exactlt as the workpiece, that leaves like 15cm holes each side, so you just have to raise the machine via legs so the whole machine have clearance from floor or table such that the snow dust falls there.

What i say is tried and works. Look at my video https://plus.google.com/u/0/photos/recent?pid=6046895850060831154&oid=111571569713128538019 , only the dark brown plastic is the real bed needed. Light brown can be removed. 2 black plastics at both sides via magnets . As you see even working foam does not make the rails and balls screws dirty.

On your design snow falls on your linear guide, ball screw, ball screw bearings and even motor maybe. I know that your inspirational design is so, but why not make better one.

HipoPapi
14-10-2014, 12:37 PM
You are absolutely right in what you are saying Boyan, and at the beginning stages of the design I have thought a lot about raising the sides as it results in a stronger and lighter gantry in fact I have started with the design of the machine you made for your friend.*But protecting the linear motion components was not one of the positive side of that method.I have worked on similar machines earlier and learned a couple of lessons. One ice block can produce as much as 3 wheel barrels of snow which means I have to do some cleaning while the machine is running also one ice block weighs 150 kg so having clear access from all sides is a must. I work mostly by myself and just* to align the block to a line requires quite a bit of hand torque :)* The big block of ice slides smooth and easy after I move it but I also have to stop it and that also requires some force. With raised sides I could also have my hands trapped between the block and sides.*This cac machine is part of larger project I am working on. The ice block gets on to the cnc bed after being plained on a band saw. The carriage that holds the ice block under the band saw is the same hight as the cnc bad and can be rolled in front of the cnc machine so I can slide the block across easier.*I have designed protection for the screws out of acrylic sheet and I hope I will cut it with the machine before going into the*freezer also I have visited zappa automation and seen a couple of samples of the custom made protectors they make and I found those up to the task.*As far as the design goes I think I am going to draw the line and consider it done also the steel frame has already been welded together. The* next step is to to put on the leveling feet do the channels and pour the epoxy for the X. And while waiting for that to dry I order the laser cut pieces and figure out the gearing.*
Dean has done some calculations for me regarding the gearing and he thinks I would be well off with 400 w servos and I am sure his right but when I have all the final details will ask again.

Boyan Silyavski
14-10-2014, 02:38 PM
150kg? That explains it all. You are right there.