Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Quote:
I have no clue on building a toroidal PSU!! lol so would need a touch of help there!
Look at these two vids.
https://www.youtube.com/watch?v=4OoQ...zD30sZjtp_VyqY
Rapidonline https://www.rapidonline.com/ is a quick and simple place to buy the bits.
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Quote:
Originally Posted by
GrahamWhite
Appreciate the info:)
I can understand all you have said and will take it on board and not order the kit :)
so the steppers are fine ,will have to go with the 4Nm 23's as the mounting holes are already drilled.
An 80vdc board
https://www.cnc4you.co.uk/Microstepp...r-60VAC-CWD872
I have no clue on building a toroidal PSU!! lol so would need a touch of help there!
Yes, I had a feeling you were stuck with 23's hence why didn't push 34's which would be the better option.
Regards the Drives and PSU then those you linked can use AC so all you would need is Transformer the drives will do the AC/DC conversion so don't need Caps and Bridge rectifier. However I prefer to use DC supply as I feel it takes some of the stress off the drives and can have little bit more smoothing.
This will work for you either way. Just add Caps and Bridge rectifier if want to go with DC.
https://www.rapidonline.com/vigortro...-x-25v-88-0012
1 Attachment(s)
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
So this is the progress so far
Attachment 24075
The Y axis to X are not finished yet, still have more support for the gantry to be fitted.
The plans called for ACME lead screw on the Z but after hunting for the elusive 1/2"-8 2 start bar across the planet, I gave up and bought a ball screw 16mm 05 lead off of ebay with the mounts and coupler.
I'm hoping they are similar - the acme was a 1/4" lead per turn where as the ball screw is 5mm - not sure how that will affect the Z performance at all?
I will be running the 4Nm 23 motors at 68-70vdc as Jazzcnc suggested so there should be enough extra oomph I hope to compensate for the Z?
Now onto a redesign of my Z to allow for the ball screw mounts
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Quote:
I'm hoping they are similar - the acme was a 1/4" lead per turn where as the ball screw is 5mm - not sure how that will affect the Z performance at all?
The ball screw is far superior than the acme. With the ball screw I would go with nema 23 3.1Nm
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
The difference in screw pitch will mean very little performance difference. The difference in efficiency, however, will be a lot better.
Now your not going to like this next bit but it's in your interest it's said.!
The Z axis is THE most important part of the machine so whether Acme or Ballscrew won't make a jot of difference because of the weak nature of this Z-axis design. Those V bearings are simply not good enough for Z axis and this design will be massive weak link. It would be wise choice if you changed the design and invested in some profiled linear bearings.
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Yes I have to agree with you:( lol
although it's not so much of a problem now that I have to modify it for the ballscrew anyway.
I'll probably do a quick fix for the vee bearings to make sure on clearances and then the first decent mod. i'll redo the Z.
Would supported round rail be an option over the vee bearings?
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I've gone for SBR16 rail- looking at a few z axis they seem to be built with the idea I have in mind
Also got the 84mm long bearings so plenty of stability I hope
All mounted on 19mmx 90mm 6062 ali plate with 6" piece crossways for the spindle mount
This option works with the X axis as I have bearings studs through the front face so hopefully I can make it work
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Quote:
Originally Posted by
GrahamWhite
Would supported round rail be an option over the vee bearings?
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I've gone for SBR16 rail- looking at a few z axis they seem to be built with the idea I have in mind
Also got the 84mm long bearings so plenty of stability I hope
Yep that will be lot better than V bearings. Just make it strong.
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
So I've ordered my spindle -was going to go for air cooled as I didn't want the hassle of water pipes and pump but the breakout board I will be using has a dedicated pump relay built in so no real issues there!
Also they seem very quite and the price was right as well- seems to be a shop that just sells loads of items in bulk so undercuts everyone else selling the same stuff.
https://www.ebay.co.uk/itm/272749081...m=272749081454
That's the spindle,vfd,pump,water pipe,spindle mount and 1-13mm collet set! £238 delivered from Germany so no import fees unlike my pinion drive plates-just cost me £65 import fees this morning!
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
Suggest you don't use the Relay on BOB and save for something else. Instead, use the Relay built into the VFD.
Reason to not use it is to keep potential Noise away from the BOB where it's more vulnerable to interference.
Re: 8x4 Build based on plans by Joescnc Hybrid R&P
I spoke to cnc4you today and they suggested for rack and pinion instead of running nema23's 4Nm with 3:1 reduction I could have just gone with 34's at 8.7Nm and run them direct or fit a larger pinion for slower speed??? would that be the same?