Different or maybe related topic…got a strange rubbing noise in axial travels. This happens in both x and y… I’d it normal? I honestly can’t remember my machine sounding like this before.
@Corey_Perez you somehow replied as a reshare not sure what happened there. But yes I’ve gone through and tried tightening up my ACME, but to be honest its really hard to do. When I give it a good thwack it has a nice dull bass note sound, but it definitely moves more than I’d like.
Regarding the speed, this is slow! You can tweak up the acceleration and max speed values quite singificantly from the TinyG defaults. I think Brandon shared some revised configs a while back. Up until today I was running at max velocity of 8000mm/min in XY, with 5000mm3/min max jerk settings. I’ve dialled it back a bit since then, this was limited at 3000mm/min since I was getting some stalling today at 8000. Wondering if my drivers are overheating since I’ve been putting quite a strain on it lately.
As far as the noise is concerned its strange, its evidently rhythmic and has something to do with the rotation, both axes do it. I’m thinking either the bearings are wobbling in their housings, or its the acme nut making the leadscrew vibrate.
Sounds like vibration to me as well. Kind of odd all the issues lately, I beat both of mine all day and night in Al. without sounds like this. Do check the bearing to cap you mentioned. Also check the bolts on the motors are tight.
Recently, yesterday, a guy noted that the flexible couplers could be adding to ACME vibration. Going to clamp style couplers or solid couplers may reduce this. I’m experimenting with this myself right now.
Doesn’t sound like bearing vibration to me, but probably something on the ACME that is making the ACME vibrate (guessing from the low pitch sound). I’d check the ACME nuts or the lock collar at the end of the ACME.
Ran around and checked the motor mounts, couplers and acme lock nuts. All good. Still doing it. I may try backing off the acme backlash nut since I think it may have started happening after I adjusted them a couple of weeks back.
So the vibration is gone? The ACME is whipping. Can you take that out at the coupler?
I didn’t hear a lick of chatter, why… Ben I believe you have officially whipped Al. cutting!
Vibration is still there. Having real trouble tightening the acme using the nut at the end. Any tips?
But yes I am churning through a lot of Al now mostly dry at crazy speeds. Going to need to build an enclosure it’s throwing chips right across the garage.
I like the white shields… :-).
Vibration, @Darren_Lee , and tightening ACMEs.
The vibration is the reason I got away from thrust washers and using TR8x8 brass nuts to crank down. I could get them tight like a guitar string but the vibrations would get so bad it wore the drive out in hours, not years.
I’m happy to make a change and implement and ship to you guys if you come up with something else.
You can flip the end plates over and put them in compression like the OB team designed.
Recently a guy went to clamp style couplers as he believed the set screw type was creating the ACME wobble. I switched one of my machines over to this. My ACMEs still move the same way. It’s not excessive never has been on any of my R7s and I’ve never had it cause an issue in cutting or accuracy. But, again I’m open to suggestions always.
Vibration -
I’m playing a lot with stepper drivers. I can’t say for sure but I think there might be a relation to microstepping and the harmonics of the machine.
Ben are you on 1/16th steps?
@Brandon_Satterfield I am on 8th steps. As you noted these noises don’t seem to be affecting the cuts so I am not too worried but it’s a bit disconcerting. There is clearly binding or rubbing going on somewhere since the noise happens in the same spot on a circle each time.
I will try tightening a little, and maybe see about varying microsteps or maybe alignment again.
If it sounds like running look for bolt scratches on the inside web of the C-beam. Like one of the mini wheel bolts.
Ok so tightening the acme seems to have helped! Rubbing noise completely gone, I’m betting it was rubbing against the acme nut maybe. Didn’t tension it a lot, but its definitely not whipping as much as it was.
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The cut is so pretty and you are getting massive flakes now. Great job Ben!
Getting there man, finally can just chuck something on the bed and get it cut.
This tubular piece was done with a 1/8" 2 flute bit using 1.6mm DOC with adaptive clearing at 1000mm/min with 0.635mm stepover and 24000rpm. Took about half an hour to cut out all those little pockets. Came out beautiful.
Oh and if you’re going to try an adaptive clearing toolpath…be sure to stop using Chillipeppr first! It can’t deal with the massive gcode it creates, this cut above was 6mb. Even with the 3d viewer off and it running on my macbook pro it died repeatedly after about 14k lines. Switched to CNCJS and its flawless.
What are you doing for leveling with CNCJS? Guess it’s not too important with this as you don’t have a perfectly defined depth.
Looks great by the way, can’t wait to see the completed project!
I’ve been skipping the levelling, I probe to the top and have setup my stock height after manually measuring it in a few points. Seems to work well enough, especially as with the HSM toolpaths the maximum DOC is actually a much wider acceptable range. I’m doing 1.6mm passes with a 1/8inch bit - a variance of 0.1 or 0.2mm doesn’t really matter.