With those long lengths, you'll probably have issues with the screws whipping at higher speeds.
Hi
Im in for a openbuilds 1500x1500 and want lead screws on all axis.
Will a 1/2-10, 5 start ACME do a good job for a allaround machine capible of doing detailed 3D work aswell as some production runs on big projects and V-carving whit this screw?
I dont have the time at the moment to sit down and learn enough to take a good dessision on the subbject myself and need some input.
(Sorry my poor english grammar)
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With those long lengths, you'll probably have issues with the screws whipping at higher speeds.
Gerry
UCCNC 2017 Screenset
[URL]http://www.thecncwoodworker.com/2017.html[/URL]
Mach3 2010 Screenset
[URL]http://www.thecncwoodworker.com/2010.html[/URL]
JointCAM - CNC Dovetails & Box Joints
[URL]http://www.g-forcecnc.com/jointcam.html[/URL]
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Will that result in bad acurrasy of the machine?
Another noob question on ACME is should lead-screws be tensioned or compressed when installed? I have seen both and am a bit confused.
If they where to have anything, it would be tension, they should never be under compression, these 1/2 acme lead screws @1500 long could only be used for a very lightweight machine like a printer would not be much good for anything else, unless
you used a them with a rotating nut you may be able to do light carving work
Mactec54
Get a ballscrew and ditch the lead screw. I have a 1400m 1605 ballscrew with BK12/BF12 fittings was ~$100 delivered from China I feel a lead screw is the wrong choice here given the cheapness of ballscrews,
You want a 1610 or better a 2010 but costs will still be under $150 with fittings.
there's a calculator for screw whip but I've run it at 4000mm/min with no issues so far but I should have used a 1610.
I have 1500mm 1/2-8 2 start acme screws on my machine, and the whipping causes stalling at about 600rpm. My Y axis has a 1000mm screw, and it doesn't whip at all, even at 1000 rpm.
If you can tension them, it should be better.
Gerry
UCCNC 2017 Screenset
[URL]http://www.thecncwoodworker.com/2017.html[/URL]
Mach3 2010 Screenset
[URL]http://www.thecncwoodworker.com/2010.html[/URL]
JointCAM - CNC Dovetails & Box Joints
[URL]http://www.g-forcecnc.com/jointcam.html[/URL]
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
Thanks for the answers so far guys. The main reason i was thinking leadscrew is the simplisity, in my head just buy a slightly to long screew and cut it to length, throw a delrin thread-clamp/thread-cupler in each end with a washer against a thrust bearing and go right? Also as mention earlyer i have been told a 1/2-10, 5 start should be good combination of speed/precission/torque. I se machines like cnc shark as example using lead screw on their extended bed models and i dont think it is a thicker screw than this? This is my first cnc router, probably gonna build a better bigger and more ridgid one in the future when i am more in to cnc routers and calculating screw pitch and other aspects, so verry high productivity/speed is not a absolute nessesary at this point, just get going with a desent and simple/cheap machine that work ok and take it from there.
Just to clear up a couple of things: are leadscrews usualy tensioned and if so are there torque spec charts on this? Same with ballscrews does these need to be tensioned?