Cnc adventure Vol.1

Hi all!
First of all,thanks to this great community for all knowlege they provide,and numerous other guy's across internet such as Robocnc Jeremy Young and numerous others!!
I'm in first stages of designing my cnc,and I dont wanna start numerous threads across forum,so I will ask questions and ideas here.
I will use mainly this machine for guitar building,footprint about 1250x1160,wich will give me approx 1000x830mm of work space.My intention si to use this machine for hardwood and occasionaly brass and alu,but primarly hardwoods.
It will be sort of desktop machine,the table will be made of wood.
I intend to use 1170mm 2010 ballscrews on y,1150mm 1610 on x and 300mm 1605 on z.Hiwin hgh20c all around.All from fred!
My main concerns come with electronics side,to go with steppers,hybrid servos or servos.
I'm gravitating more towards hybrid servo side.I studied Lichuan HS motors,3phase nema23 3nm and 2phase nema34 4.5nm,down side is that they dont make 4.5nm HS in 3 phase.Another downside is drivers,3phase have rated max voltage of 50V,wich mean I would have to use 48Vdc power supply,when I calculate max voltage for nema 34,i get 57Vdc,how much will motor loose speed with 48 instead of 57v?
Another concern is controller,I more and more gravitate to standalone controllers,such as ddcs 1.3,but they dont support dual axis homing.second option is tomatech 4axis TAC-1004M Milling controller.Does anybody have expirence with this stuff?
Here is design half finished still need to position limit and home switches,and fk/ff supports for x axis,and dragchains.
https://i.ibb.co/7kqf7Nm/bezsss.png

https://i.ibb.co/PwhBt30/Bez-naslova.png

https://i.ibb.co/hMsH3bX/3.png

https://i.ibb.co/GC0s0p1/4.png

https://i.ibb.co/dbjhmZD/zac.png

Machine spec.
1250x1160 mm footprint
Steel frame 60x60 and 180x80(100x80 and 80x80 welded together If i dont find 180x80),epoxy leveled.
Steel plates 20mm thick,except z axis backplate wich will be 25mm.Not sure yet if I will cut all alu at home,or will somebody do It for me.prolly the second option because z axis back and frontplates should be milled.
Hybrid servo drives
2 2010 Ballscrew on y,belt driven 1:1 4.5nm
1 1610 ballscrew on x,belt driven 1:1 3nm
1 1605 ballscrew on z,direct drive 3nm
Hiwin Hgh20ca all around
Alu profile for x axis,ITEM24 160x80
2.2kw spindle
standalone cnc controller
When I started thinking about cnc build,I want it to be as slipstream as possibile,no sticking parts,low overhang on z axis etc.
Looking for critiques and opinions!!

Hi welcome to the forum.

Great start and looking good, please do feel free to post your questions and discuss ideas around the forum as that's what its for :friendly_wink:

Sometimes your questions may get better visibility and response being out of your build log, as not everyone follows all of the build logs and prefer to look for questions they can directly help with.

Regardless its your choice how you proceed of course, good luck with the build !

Thank you Lee!
Can anyone explain me if 180mm(180x80x4) tall y axis is a good idea sound and vibration transfer vise?

Do you mean your gantry across beam ?

If so then yes what you have will be ok, if you wanted to go a step further and add a dampening effect, you could fill the extrusion with kiln dried sand as a relatively cheap and easy solution or go for something a little more upmarket and use an epoxy granite mix, the later being commonly used as a material for building machine bases...better vibration damping...better tool life and so on.

Looking good Scustom :)

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Originally Posted by Scustom

Steel plates 20mm thick,except z axis backplate wich will be 25mm.Not sure yet if I will cut all alu at home,or will somebody do It for me.prolly the second option because z axis back and frontplates should be milled.

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Are the plates Steel or Ali? Little confused there!

You could avoid the need to mill the Z axis by making each half in three sections, one large plate and two smaller rectangles for the carriages to sit on (they'll bolt through all three anyway). Or, you can do this on just one side. I made mine exactly like you've shown, but only because I knew I had access to a milling machine, and it would have been a lot easier to just go with the three section method. The majority of my aluminium was pre-cut by Aluminium Warehouse, it was just as cheap as cutting it myself and they did a decent job.

Quote:

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Originally Posted by Scustom

Steel frame 60x60 and 180x80(100x80 and 80x80 welded together If i dont find 180x80),epoxy leveled.

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Honestly, if I was to do mine again, I'd use Ali profile on both X and Y rather than steel welded then epoxy levelled. The epoxy was just a faff, and probably in the end cost more than the Ali would have done. On my Y axis where I used Ali profile, the whole thing bolted together in a couple of evenings, and both rails went on nicely straight away. On the X, after all the grinding, welding, painting, epoxying, repainting, drilling, etc etc, I'm a little bit fed up of the steel method!! Live and learn...

I'd slightly beef up the T shaped Y axis ballnut connection, making it a triangle or something. Possibly its just that viewpoint, but it also looks offcentre to the groove in the profile which could be fun to mount.

I'd also check that the spindle bit ends up between your X axis carriages when viewed from the side, from the feel of your gantry side plates, it might be just outside of that region. Ideally, it would be halfway between them... but thats a great way to lose travel so I didn't bother :)

Hi Andy
Yep,Aluminum plates,not steel,typing error.
Yes,that would be option 2,I would have to make a 15mm spacer to mount everything together.
Option one is preffered,since milling two faces would not cost a fortune,if I go with handcutting alu plates,and It would reduce overhang by 15mm.I’ve put 240mm long gantry sideplates versus 280mm you did.I’ll have to finish z axis (spindle and mount)and run center of mass analysis,so then I’ll see where I am,if is needed to elongate sideplates or not.
Well steel frame didn’t seem that big of a hassle.I’ll check both options!Thanks for that.
If alu is chosen,kiln dryed sand is an option if resonance and vibratins occur as Lee sugested.
Yes its a bit offcentre so when ballnut and mounting bracket are connected nothing is sticking out of that T bracket,but yes I can beef it up a bit.
Andy you used 2010 ballscrew,so do I in this stages,but did you consider 1610 and making it both sides fixed?Did anybody do that?Rotational mass would be significantly lower with 1610.��
Never went in calculating critical speed for 1610 in fixed fixed arrangement,but I will,just to see what would be results in comparison to 2010 ballscrew in fixed/supported arrangement.

Quote:

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Originally Posted by Scustom

Andy you used 2010 ballscrew,so do I in this stages,but did you consider 1610 and making it both sides fixed?Did anybody do that?Rotational mass would be significantly lower with 1610.��
Never went in calculating critical speed for 1610 in fixed fixed arrangement,but I will,just to see what would be results in comparison to 2010 ballscrew in fixed/supported arrangement.

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I considered it, but went with the 2010 fixed supported as you say. From memory, the fixed-fixed didn't make that much difference to the critical speed (I'm too lazy to go re-calculate it now....). It also constrains the ballscrew mounting slightly more, and I didn't know if that would be a pain later on :)

You're correct it makes quite a big difference to the rotational inertia - but don't forget that the motor calculation spreadsheet has a factor of 3 as a safety margin. The implication is that I'm not overly concerned about that extra rotational inertia (because I'm quite confident my motors can cope with it to decent rapid speeds). That extra headroom on the critical speed means I should be able to push my motors further than initially calculated to find my max rapids without having to worry about whipping.

Yep,doesn’t make much sifference,fixed supported gives higher max speed.
Can someone help me with steppers?
I’m planning to use lichuan hybrid servos,3phase nema 23 3nm on z and x and 2 phase nema 24 4.5nm on y.max rated voltage for 3 phase driver is 50vdc wich means 48vdc PS max.Calculating ideal voltage for nema24(since has highest inductance) ideal PS would be around 57vdc,so 48v is 16%less than ideal,what does that mean to max speed and torque output of the motor?
Is it better to go all axes 2phase and use higher voltage drivers and run them at 60vdc?
Can anyone help me,since I’m really strugling with this one..
Thanks