Hi,
Trying to set up my lowrider cnc and the drill doesnt cut the part in the same area; when it goes to do the second pass it gets stuck and moves position as the axis jams - I think that its not going in in exactly the same position. See picture. Speed 8mm/s 6mm diameter bit and i’ve put holding tabs on too but it does the same thing without. Any help would be great thanks.
There are all sorts of things that could be. To narrow that down you need to watch to see what is going on. The feeds could be wrong, the belts could be obstructed, the wheels, the CAM, that is a large diameter bit, so depth could be a factor, is it an endmill, what board, drivers, steppers, pulleys, crooked start point, snagged hose, snagged cord.
What you showed was a skipped step, anything could cause that. I suggest running it again in the air and see if it messes up again.
I was using a 6mm end mill with 4 flutes. I’ve tried putting a pen and drawing it and it seems perfectly fine. What I noticed was that when it was plunging into the second layer, it wasn’t perfectly in line. Is there a method on estlcam which allows for a larger area for the bit to plunge into? I’m using a skr1.3 tmc2208 0.9deg nema 17 and a tft touchscreen with endstops.
You can set the plunge angle so it moves while it plunges.
What current do you have the TMCs set to? You should be forcing them into the spreadcycle mode and the holding current should be full current (1.0).
If you try it again, try to get a video. You can post it to google photos or youtube and share it. It will tell us a lot.
I have the current set to 0.9 which I think is correct. How can I change the plunge angle on estlCAM? Also how would I know if it is in spreadcycle mode?
Thanks
Stealthchop.vs spreadcycle is here (You should.comment these out):
Holding current is here (You should set this to 1.0):
Might also try to find some two or one flute endmills. Four is probably too many for the speeds our routers are spinning.
Thanks, just ordered a 2 flute end mill. When I comment out stealthchop my axis don’t move anymore and make a constant noise. Any ideas?
Hmmm. I’ve only used the TMC2130s. I know enabling TMC_DEBUG and sending M122 can sometimes provide clues.
This might be a silly question but how do I do this? Sorry I’m new to this!
It is here:
You have to enable it by removing the leading ‘//’.
Then in repetier host, you send the M122 command and take a look. If you post it here, I’ll take a look too.
Hi,
Thanks for the replys! I have got the machine working thanks to you but the part I’ve shown cut in 16 minutes! What depth of pass and feed rate should I be using to 12mm plywood?
Every machine is different. You have to just adjust it with tests. After about 8-10mm/s, it’s better to go deeper (and have fewer passes) than go any faster.
What settings would anyone reccomend for a 4mm drill bit cutting 12mm plywood?
Have a look through the milling basics page. Jeff just summed it up though get to 8-10mm/s if all is good go deeper, equal steps through your material.
Yes they were the setting which I used for my first cut. If I am using 1mm per pass, what speed can I go up to? Also for the finishing pass how deep should this be? I had it at 1mm pass depth and as a result it was going round 24 times (12mm depth, 12 roughing passes and 12 finshing passes) and took twice as long! Any help would be great.
thanks!
The finishing pass is just a touch, so it should have almost no load. You can do a full depth finishing pass.
1mm is very shallow. That is going to mean the machine is moving very fast to get anywhere near it’s limits and you’ll only be using the first 1mm of the bit. If you did 10mm/s and a 4 mm DOC, it’s about equivalent to 1mm DOC but 1/4 wear on the bit and the stepper drivers are actually stronger and more accurate at 10mm/s than 40mm/s. I would try your test again, but leave the speed at 10mm/s and increase the DOC. Then when you have a comfortable max, add a full depth finishing pass and see how accurate that is.
Ok that makes sense! I tried to cut at 6mm DOP at 8mm/s but the bit snapped! I’ll try 4mm DOP and 10mm/s with a through cut finishing pass and let you know how it goes.
You’re also using a 2mm bit, right? I have only used 3.175mm (1/8") bits.
I’m using 4mm bits with 2 flutes. How far should the bit stick out of the collet?
