Upgrading my Homemade CNC
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- Опубліковано 27 вер 2024
- In this video I'll show the upgrades I made to the CNC mill i built in my previous video:
• CNC Mill for under $100
I upgraded to a 500W spindle and built an all-aluminum head assembly, widened the bed, increased the rigidity of the X axis with thicker rails,
installed higher torque steppers on X and Z, and dramatically reduced backlash on all axes by using a double-nut arrangement on my leadscrew
carriages.
The machine is still far from perfect, but cutting aluminum is significantly easier now, and with some adjustments / tightening down / tuning, I
think it will be able to reliably hold tolerances that are at least good enough for one-off hobby projects.
Currently the most obvious weakness is flexibility in the Y axis due to using only 8mm rails.
The board firmware is unchanged from the previous video. I'm still using an arduino Uno with GRBL firmware driving A4988 stepper controllers.
Some links to relevant hardware:
500W Spindle kit:
www.amazon.com...
92 oz-in Stepper Motors:
www.amazon.com...
16x500 mm Linear Motion Shafts:
www.amazon.com...
16mm Bore Linear Bearing Blocks:
www.amazon.com...
Linear rail for Z axis:
www.amazon.com...
500mm T8x8 Leadscrew:
www.amazon.com...
150x70x9.5 Heatsink:
www.amazon.com...
Software used for CNC:
Universal Gcode sender
FreeCAD 0.18
STL Files:
www.thingivers...
Feeds/Speeds
RPM: 12,000
Bit: 1/8" 2 Flute End Mill
Horizontal Feed: Between 500 - 1500 mm/min
Vertical Feed: 10 mm/min
Stepdown/Cut Depth = 0.05mm
Finishing Cut Depth = 0.01mm
I found that for the same amount of volumetric removal rate, a higher horizontal speed with a smaller depth of cut gave better results because of
reduced chatter/vibration. For example, 1500 mm/min at 0.05mm depth of cut was much smoother and had less chatter than 750 mm/min at 0.10 mm
depth of cut. Unfortunately this does put all the work on the very tip of the end mill, but because this machine is pretty limited on
power/rigidity, that's the only viable way to cut.
Music Used:
Eric Skiff - Underclocked
Kevin MacLeod - Groove Groove
Heatley Bros. - Luminare
Serge Pavkin - Elevation
There is nothing more satisfying than watching a video from a few years ago on a channel you've never seen and then seeing there's a follow-up video available!
1. Most CNC machines in the shop will use a filter on the air intake of the electronics to keep dirt and chips out. That should be an easy mod. 2. Use an air blower or preferably an air mister with coolant to blow away the chips to get a better finish. 3. Try to have the end mill stick out of the collet as short as possible to keep the tool from flexing... Awesome project!
Could use second hand mask as air filter. But make sure disinfect it.
Yeah eventually I'll probably set up a solenoid for compressed air + relay for a vacuum on a 555 timer to come on every so often for a second or two
@@HyperspacePirate Great job. How do I privately discuss with you?
I can provide high-quality low-cost processing services. If you need mass production of this product, you can contact me, and the cost will save you 40% to 50%.
You are on the right track with the box. I am a control systems engineer.
This is my explanation to everyone.
You need to make the air in the box slightly higher pressure than the outside.
So you need your fan to suck through a fine filter and *PUSH* the clean air into the box or cabinet.
You'll find many electrical devices have the fan on the outlet of the ventilation system. Go look at the PSU on most desk top PCSs. My PS4 does this and its something I like to slap a few Sony guys for.
The problem is when the fan is at the air outlet its sucking air from inside the box/cabinet which reduces the air pressure inside the box/cabinet. It will then suck in dust from any and every place it can be sucked.
If you aren't happy with the side wall surface finishes, you should create a roughing tool path leaving a few thou of excess stock on the walls, and a secondary "finishing" tool-path to clean them up.. you'll want to reduce the travel speed, full depth of cut minus about a thousandths so you don't mar up the floor finish (only applicable to parts with a floor to finish), and skim the edges to remove the excess stock you left in the first operation, as well as cleaning up, and leaving a uniform wall surface finish.
It's common in CNC machining to create multiple operations like this. roughing passes care little about surface finish, it's all about removing material as fast as possible, and a secondary clean-up pass to remove the last bit of stock and leave an acceptable surface finish.
Hope this was helpful :)
also, with aluminum especially, you might want to make sure you are using the right endmill and feed rates.
@@en2oh setting up an mql spray would probably also do wonders.
I was right... I WAS RIGHT!!! The moment I saw you demonstrating the lack of rigidity in your previous video, I knew we were in for a treat when you addressed the problem.
This is GREAT! You now have a tool that I am sure we will see get more refinement and tuning in the future... you have opened up a "Pandora's box" of possibilities, I will wait with bated breath.
Many thanks, Liked and Subscribed.
On the backlash. Their are backlash nuts that are designed to use a spring to push them apart and they are pretty cheap. The benefit is that since your causing more friction the nut will wear out faster and the spring ensures it stays in good contact despite wear.
Your projects are incredible! They are the perfect mix of using minimal tools to maximise result with clever design.
Thanks for the ideas, I am doing a similar project, the dual lead nut idea is genius.
Thank you very much
Very nice build. Using a backlash nut instead of two individual nuts might make for a simpler mounting bracket, but the effect is essentially the same as what you've done here.
Do you have experience with them?
Just stumbled across this video today. Pretty impressive. Goes to show you, when there's a will, there's a way.
Since you already have access to Aluminum and a way to cut it you can replace all the 3D printed gussets with Aluminum for more rigidity. Also, the whole back of the X gantry can be a slab of Aluminum and you can bolt linear rails to. OR, you can build a V2 and forego all TSlot entirely and use Linear Rails bolted to Aluminum slabs. Just ideas; I understand that $$$ doesn't grow on trees.
Dude you are awesome! You've presented us with a step by step DIY CNC all while keeping budget in mind! Thank you and your videos are my favorite :)
@johnnytheprick I can provide high-quality low-cost processing services. If you need mass production of this product, you can contact me, and the cost will save you 40% to 50%.
Which one would you advise then?
Все на высоте! И речь, и 3D печать и фрезеровка! Браво!
*TO ALL THE WAY TO KEEP STUFF OUT OF AN ELECTRICAL BOX OR CABINET IS POSITIVE PRESSURE.*
You need to make the air in the box slightly higher pressure than the outside.
So you need your fan to suck through a fine filter and *PUSH* the clean air into the box or cabinet.
You'll find many electrical devices have the fan on the outlet of the ventilation system. Go look at the PSU on most desk top PCSs. My PS4 does this and its something I like to slap a few Sony guys for.
The problem is when the fan is at the air outlet its sucking air from inside the box/cabinet which reduces the air pressure inside the box/cabinet. It will then suck in dust from any and every place it can be sucked.
Dang thats cool. Definitely consider an air assist, maybe look into one of those amazon electric air dusters, that could work and keep the size down. Maybe replace some of the plastic parts with exact aluminum replacements, to see if there are any immediate improvements in rigidity? Cool vid!
I've watched the first part and it was a great idea cheap cnc for me. I knew, it was too weak a construction to cut metal, so I waited for the project upgrade. In fact, this time, and despite few changes, the machine is cool. I would like to have something similar on this level for myself. I am a layman in these matters, only for some time I started to be interested in CNC machining. I am waiting for more videos and projects showing the possibilities of your machine. Greetings from Poland.
Such an idea for several episodes will surely be quite spectacular and popular. Diesel engine, from the injection pump and injectors to the whole old style engine.
Good work. We shared this video on our homemade tools forum this week 😎
Cool video..Design Engineer+CNC Programmer+Cnc Machining+mechanical/electric/electronics/Mechatronics assembly u can do everything lol..what a talent
Always a good day when you upload man. Super nice upgrade.
Very nice! I think your design choices are quite effective.
The only thing I would recommend is to use a 10mm screw instead of 8mm
I don't think a larger diameter lead screw would add any significant advantage. Perhaps swap from a trapezoidal lead screw to a ball lead screw would be beneficial in reducing friction and back lash, but that was already discussed.
As he's not dealing with a large build volume, with vast spans of unsupported lead screw, there shouldn't be any problems. Due to the addition of linear bearing rod, and linear bearings, the only forces on the lead screw would be compression, and tension (pushing and pulling) along it's length. As he's not dealing with significantly strong materials, or exceptionally high torque motors here, those shouldn't be excessive enough in this situation to warrant a thicker lead screw in my opinion.... however.. if he's willing to spend the $$, by all means, go for it XD
Having run a cheap desktop CNC mill for many years myself, I would highly recommend using a single flute endmill. You get a much better finish, better clean-out, and lower overall load. Plus, if you are machining plastic rather than aluminum, your cut speed can be greatly increased. I did many many parts in type 2 PVC, UHMW, medium and light density polyethylene, and PTFE. Heck, some of your aluminum parts on this CNC can be re-machined in PVC for a more dimensionally accurate part.
Also, you really need to put flexible couplers on the stepper motors. The threaded rod has a run out, even if it's very small. The flexible coupler will keep that run out from transferring into the stepper motor's bearings, thus increasing the stepper's life.
@James M. : Do you have a preferred type of flexible coupler? I see people complaining of failure of the single-piece alloy versions with the helical slot cut in them. Are the three-part versions with a "+" shaped neoprene centre preferable? Thanks.
@John Colvin For small desktop mills, I've run the aluminum helical couplers for hundreds of hours. But, you do need to make sure there is no axial misalignment. They can take a degree or two of radial but will quickly fatigue with axial issues. The ones with the rubber spacer have the same problem. Only thing is they will break other things in the drive before they fail. Your best bet for the best coverage is an Oldham coupler with a single flex plate on one end. An Oldham coupler has two dovetail joints at right angles from each other. That way, they can slide to allow for axial misalignment. The flex plate will compensate for any radial misalignment. You could run a multi-section flex plate, but those are very pricey.
@@jameslmorehead : Thanks for that. I saw a simple arrangement I was thinking I might try: (the one I saw was using a cheap Chinese stepper that has the motor shaft and lead-screw all in one.) The stepper is connected to the ball-screw by a non-flexible coupling... the stepper itself is attached to a flexible plate, effectively working as a flexure. This allows some axial movement, but controls rotational and radial movement. There is no bearing at the driven end... axial forces are controlled by a thrust bearing at the non-driven end.
Admittedly the machine I saw was a laser, so there was only minimal loads, but anything I tackle will only be small. It worked well, and was a tidy installation.
(I must put Gurgle to work checking out the Oldham coupler! 😉 )
@@PiefacePete46 Also keep in mind, on the scale of small to medium desktop CNC equipment, a deep groove ball bearing can carry a surprising amount of axial load.
I'd be weary of the lead screw and stepper motor combos. They have to skimp somewhere. Plus, you don't want the axial load going into the stepper motor. They have a spring inside to take up axial play, and these springs don't have much force to them. You can easily get a hard to trace inaccuracy from this type of issue.
@@jameslmorehead : Thanks, I appreciate it... I would be best to avoid trying unconventional solutions at the start... if it was that good everyone would be doing it! 😜
A good machine has to be heavy. With a heavier machine you get better finish and precision. As said below try to keep everything as short as possible. Rigidity is the most important in a machine. You have to get rid of those chips while you machine, they can even break the tool. Try using a roughing end mill, to cut out most of the material and then finish it, with a finishing cutter.
That two lead screw approach is also what I came up with for a CNC machine design. Its simple, cheap and easy to repair ... but it will increase friction. However if you are milling metal a little extra force required should not matter!
Instead of tightening the nuts together with nothing to constrain the compression, either shims should be used under one of the nuts, or the mounting holes should be slotted to allow it to be rotated. This way the backlash can be minimised without introducing excessive friction (and the resulting wear).
With the update the machine seems to be more solid ! Great job and video to watch. Thanks
You’ve already got it in great detail…. I’ve read a decent amount of the reactions to your initial upload of this DIY build gem. And i did notice that you take the provided info very seriously and put everything to good use. The result of this build speaks for itself, and it turns out beautiful. You could use 1 or 2mm thick rubber mats for the protection against burs and sliced up loosen material from falling into the frame square/rectangular. By using lubricants to extend your tools lifetime, both wd40 and alcohol based solutions as well just water i warn you that these are all way too thin in viscosity and will have little effect on the purpose of the projective. Be aware that most of the different sort aluminum grades are manipulated in molten state by adding silicate and even harder stone-like materials that will destroy your tools and blunt them way faster than you would think. I mean, silicate is just beach sand. Try little more grease-like substances in small amounts while surface cutting and edge smoothening. Just don’t use grease while cutting inside slots because that will cause the phenomenon “re-chipping” and wear out your tool rapidly plus putting lots of heat in your material to the extent of destroying the tool and failing your end product measurement, looks in surface roughness.
I cannot express how grateful I am having you provide me with this back to back build of a CNC-milling machine. Thanks isn’t somehow cutting it 😉
Adding springs to the ball screw nuts can take up backlash as well, sick build!
Won't do you any good for machining metal. Just get a ballscrew. What are you saving $40 for? Beer?
Came looking for this vid after watching the first one. Fascinating vid mate! Amazing job👍🏼
Thank you for sharing, maybe you can use the PWM from Arduino and with a relay you can turn on/off the spindel and contol the speed from G-Code also.
Suggest you use Klipper, open source g-code to stepper driver with inputshaping capability
plus put a magnet and a hall effect sensor for never skipping a step ever again and now you can run your steppers at full power without fear they will miss steps
It is interesting how were made first machine tools when there were no machine tools?
An interesting topic to discuss
first machines were built by hand , then improved version were built with those machines , and with those machines etc.
@@chriskwakernaat2328 I'm curious about how were made first rotary parts like spindles or shafts
@@HaasMill They make cylindrical parts on lathes. Lathes have been around for thousands of years.
Like you said before, it's hard to get good CNC under 100 buck, we must invest more to get better result
Actually ... Earlier I wrote that you should keep the plastic parts.
50 minutes later I return to write a correction to that suggestion. :)
-I recommend that you replace the plastic parts used in the frame, by metal parts (aluminum should be fine). Eg. the triangles making up the corners are of interest.
If you do this, it should make it much more stable / rigid - and reduce chatter even more.
Nice video...Sir please make a video on higher/improved performance CNC machine something like laser cutting.. I mean all the mechanical parts should be easily available in market and there shouldn't be no 3D parts ( not everyone can make 3d parts, so implementations by viewers will be tough without all parts).
Catia V5 serious piece of kit!!!!!!
This is a godsend. I recently tore down a couple 3d printers I don't use anymore and wanted to convert them into a CNC machine exactly like this. I was just to lazy to design anything and am still a beginner with cad software. This is awesome.
Wait so Your home is 3 km wide and has a cloathing cleaning facility? That's amazing. Good job.
expecting that the next upgrade would be increasing its area for working and we love to see that.
BTW this video deserve a subscribe
8:00 they sell 5 foot long (1500mm) version of these with the pillow blocks, leadscrew, screw nut, 2 linear rails, 4 linear blocks, and a stepper coupler for 150$ on amazon
Hey my man, great couple videos I watched. I watched the original build for this one as well.
I'm glad that you upgraded your vertical supports. I thought they looked pretty weak on the original. Not weak, just not rigid. I felt the same way about the corner brackets on the base.
If I can make a suggestion to you, it would be to get rid of all your 3-d printed parts. That's a great idea for a 3-d printer or light duty router, but I'm quite frankly surprised that it works as well as it does for your heavier duty milling. I would absolutely upgrade the 3-d parts to all aluminium to further enhance the rigidity. You may also want to try linear slide rails instead of the round ones, but that's less of an issue.
Keep up the great work my man!!
I wish I had friends like you
Bravo 👏... Really nicely done... on the web now looking for parts to start my own CNC journey.
Awesome, Now a 5 axis version.
: )
I also recently found downloaded Freecad, but not yet experimented with it.
KSP beat drop, nice
a little 1 gallon flood coolant setup would save a lot of babysitting
Very impressive! Great job!
Я тоже пошел твоим путём и собрал ЧПУ на валах, но в итоге собрал совершенно новый на рельсах MGN 15.
Great experiment and vid ! Thanks !
This is great! Thank you for sharing. I am getting ready to build a combat robot and looking for a CNC mill that will be affordable and hackable.
You sir definitely deserve my subscribe, keep up the good work
Hey man.. I saw u took the Fan off the China spindle u got. I've bought one of them as well as a replacement for the Genmitsu GS-775 I bought. I've noticed a lotta chatter from it. I will use it for something else. The generic spindle from China has had good reviews but u never know what ur gonna git from that place. Thanks for the Free CAD bro. I will download it as soon as once I build my CNC..
I don't know alot about cnc but that looks cool. I'm currently building an mpcnc
nice work
Now you can potentially use your upgraded CNC mill to make parts for upgrading your CNC mill
7:40 many setups use a spring between the nut and the frame.
Incredible project, I congratulate you, you have put a lot of effort into it and it turned out spectacular. Hopefully you could post more details or plans about the general measurements of the whole machine, to see if I can make one for myself. Congratulations.
screw slap can be repaid by clipping the spring
need a greater mill to make a home made mill, smart!
Amazing work 👏 appreciate your vids and efforts
hi sybdynoman, have you become a flat earther yet?
@flat-earther sorry not in the slightest, I've been high enough in altitude to be convinced of a spherical earth...but in contrast I'm not convinced I'm living in just the 3rd dimension so there maybe some wiggle room there. What evidence do you have that can shift my understanding 🤔
@@subdynoman okay. I suggest watching the 13 part series in my about tab to learn how the earth isn't a globe.
How's the plastic holding up? Any plans to swap out the 3D printed plastic parts for self machined aluminum or other material?
Impressive, you have inspired me, thanks
Well done!
thx for sharing , great upgrade ;-)
I don't care about the content.. subbed for the channel name alone 😂
You can get ball screws on eBay starting at $20 they may not be perfect but they are decent
Where do you source the aluminum? thanks
Cool milling machine! envy =]
GJ.. man.., thats awsome for 100bucs,,
Nice upgrade!
Btw you can GET Wy cheaper ballscrews, got some for mine but been lazy to convert.
Also another option is to get some nuts with anti-backlash builtin. I have some problem is they are a bigger.
In the world of a.i. data processing I imagine that's a very good warning 🐶👔
I was thinking about making a CNC machine so I can make stamping dies to remanufacture steel trim
There's CNC services available today. You just want the dies. Who wants the headaches?
You can now CNC all the 3d print brackets with aluminium
I recomend to buy cutting milling tool with larder diameter, may be 6 or even 8 mm. Also you should install dust filters on intake. Please use respirators for prevent damage to your lungs from alluminium dust. Also you can install end point switches for usage with more pleasure.
Does FreeCAD allow you to have a Milling Toolpath generated where it will mill a given depth twice - Once without a clearance offset and once with thus creating a wider channel for chips to evacuate into and not be bogging down the Endmill on subsequent passes? If not, I'd strongly encourage you to drop it like ASAP for the free F360 License allowing you to do that for a much more preferrable surface finish when working with underperforming hobbyist machines.
I think that feature is available, yeah. "Adaptive" milling, where the tool creates a helical path along a line, right?
@@HyperspacePirate Nope, I'm talking about what F360 is calling a roughing pass.
I was kinda having the impression that the channels you're cutting are only as wide as your bit and without you flushing the material out before it comes along for the either a springpass or the next depth you most likely regrinding those chips still in the channel.
With a roughing pass you'll first mill with like a 1mm offset followed by the actual pass you intend to make near the part but now at least your unevacuated chips have a place to go and thus not getting in the way of the Endmill while its _actually_ engaging the part.
I'd describe it as a poor man's adaptive clearing - Still won't allow you to go balls deep with the cutter because after all the roughing pass is as wide as the entire cutter but at least you're regrinding your chips because you don't have a way of evacuating it ( I for one have an MDF Spoilboard so Flood Cooling is an absolute NoGo )
@@Duraltia Expand Profile from Path_Profile
Fusion 360 is not free. I encourage you to learn what freedom means.
If I was building a steam turbine from scratch I would have used Teslas design.
Great result for a obviously low budget machine.
bien bien me gusto mucho ahora me toca hacer el mío ye agradezco mucho el video
That's some sexy shit dude! Upgrade again!!!
“I use the mill to make the mill”
Do you think there is any benefit in using the linear guide rails and blocks used in the Z axis for the X and Y axis for improved rigidity? Cheers and thanks for sharing a great video.
The linear rails can be mounted to anything, so they'd definitely be more rigid than the rods if they were on a solid block of aluminum/cast iron etc
First time I'm seeing your work on this project, and I'm impressed!
Are you sharing your design files?
Do you have a Parts list?
STLs for the 3d printed parts are in the description but I didnt make any drawings for the metal stuff it's kind of just measured out by hand
🚥🚥💡💡💡🚥🚥 I have to admit that is very impressive. I saw the first video I thought it was quite good but could see clearly you are suffering from backlash but now you've upgraded it it does seem a hell of a lot better considering you are milling quite thick aluminium billet so that is very impressive.
Only thing I think I would change for this machine would've been to use linear rails in place of bars and the Lead screws both on the X and Y axis. I realise it's more expensive but it pretty much completely eliminates all backlash, of course what you could do with this machine is now mill all of the plastic parts out of aluminium and you would increase rigidity even more
I think you should also look at the cooling system on that motor because after running 8 to 10 hours regularly I think you could be in for early burn out without a fan on top of it, those motor suffer from heat terribly, interesting to see the heatsinks on the steppers as well, most people forget that and they can get seriously hot.
How about adding a chip extraction system and if you're going to be milling nonferrous metals all the time you should think about some form of coolant because that will improve your surface finish quite a lot and will protect the tooling at €25 for a decent cutter that's important to think about.
It will be quite easy to do just purchase a 30 mm deep wall tray and sit the entire machine into it on some mounts and use a very small hydroponic or aquarium 5 or 10 watt pump with a filter and flow valve to recirculate the cooling solution via a small flexible coolant nozzle onto the piece being milled and tool head. (add a plastic cover with coolant its messy stuff)
Chances are there's a pin out on the board to operate the pump automatically via a cheap10 amp relay to stop and start with the job . Just make sure your stepper motors are out of the liquid . I used to do this with my first mill 8 years ago , an old MX3018 MACH 3 cnc.
Dust is a major problem especially with wood and I would perhaps consider not mounting any of the electronics components or PSU onto the machine, it exacerbates EMI and as you saw collects tons of dust, all you need isasmallchip toenterthe housingandbang goes your circuit board.
It's easy to fabricate an umbilical about a metre long keep it while away from the actual machine and try and shield the power lines
It really is a great build for others to follow and develop and its excellent and generous of you to provide the STL files and links for newbies to follow.. Well done and thank you for sharing your project. 🚥🚥💡💡💡🚥🚥
hi sitgesvillaapartmentneilsc, have you become a flat earther yet?
I rebuilt re designed my z 3 times.
Great build! Would it be possible to mount a vacuum cleaner head right next to the mill for it to suck up all debris as it goes?
What about mailing out upgrades for the c n c mill
When I may ask, what kind of Aluminium is used for the turbine?
please, make more videos of you cnc machine
not sure how this design establishes anti-backlash. this design & diagram does not help. Seems like a pair of floating acme nut (on screws) but in video is not torqued to the block. then i assume you feel backlash and readjust screws? I presume you have to readjust the nut screws once a year?
I'm not even trying to fathom how long it took to 3D all those parts.
Nice! As an add on would a blower hose that moves side to side on one side that blows towards a powerful vacuum with a broad intake on the other side help to blow off and collect the debris from what you are working on?
Nice music
Great video! But I'm not sure if it's a good idea to attach the radiators to the motors with double sided tape. I think it's thermal conductivity isn't great ;-)
It's thermal tape
Where do u even find a kit online to build lathes mills etc online? Looking to expand my welding and woodworking shop on a budget
Get used machines.
Nice video, thanks :)
What's the cost of your CNC now that you upgraded from the $100 CNC?
It cost everything.
Great video man. Could you tell me where cai i learn CATIA?
I do a lot of 3d printing and have never found a suitable adhesive. Can you tell me what you used and whether it holds satisfactorily? Thank you
Bob smith industries insta-cure CA glue and accelerator (gap filling)
Quality content
Hola me gusta mucho tu video, estoy preparando la máquina muy parecida a la tuya, he comprado los mismos motores de los ejes x,y,z pero la placa controladora no tiene suficiente fuerza para mover el motor se mueve pero con poca fuerza, podrías echarme una mano con la parte eléctrica? Qué placa controladora tienes puesta o mandar el enlace de compra
Gracias
Congrats! Love this project! Keep going! I have already started designing mine as I feel a little bit limited with the 3D printer I have in my shop. What level of precision is this CNC capable of?
+/- 1mm ;)
really nice, would be nice to have an estimatoin of total cost and time
hi, awesome project.
is it possible to use a belt driven assambly instead of lead screws. or do belt's have to much back lash.
This is great, I may try this myself when I'll have the balls for this XD
However, you didn't explain why you used new motors.
Also, do you think using POM leadscrew nuts can reudce friction ?
I made lead screw nuts out of HDPE. They're OK. Big chunky nuts. No backlash and they're smooth.