Hey guys!
I'm having a little problem.
I have always been cutting pine with a feed rate of 1700 mm/min (~67 ipm).
Had no problems so far, yesterday I tried to cut 2 pieces of wood with a depth of ~20 mm.
Bit was a 3.15 mm (1/8") downcut bit. Depth per pass was 1.5mm (~1/16") at ~16.000 rpm.
Had stuttering and then the machine cut through the middle and screwed the whole project.

Are the feed rates to fast? Thought I could go even faster.
Is my controller overheating? I use an arduino protoneer shield with DRV 8825 and a small fall above it.
Strange thing is that I have been using the same wood/settings for quite a while now and never had any problems.
Is it time to get an xPro controller?

and @Ryan Lock : Would I need any special plate to attach it to the back of my machine? Do you sell them seperately?
Could not find them on your page.

Thanks a lot!

 

Ah. I attached a photo but seems like it didnt upload.
I tried it again with a smaller part. Was the same problem pretty much at the same position.
And it was not the position where the bit plunged in.


Edit:
Just tried it again with 1200 mm / min.
After around 95% it did the same thing, although
it was smoother around the corners

 

Nice. Can I use my 24V power unit with these? As far as I have seen, I can get 4 for around 140 usd. Would I need an additional fan?

Thanks. Checked everything a couple of times. Only happening on long cuts and at the end of the cut :/

1/8" downcut bit, 1/8" shank with 2 flutes. Wood is "spruce"(? not really sure. Thought it was pine).
In general I would like to speed up things a little bit. Would a larger bit be better?

Thanks for all your support!

 

Good to hear. But well, the DRVV8825s cost around 14 usd for 4 pieces, where the DQ5442MAs are 140 usd. At least I think there is quite a difference
Right now I just have a box where the arduino hardly fits in and got an 80 mm fan blowing on top of all the (small) heat sinks at the same time.
Worked really well so far, but seems like it is not working anymore

Could you share some example feed rates / bits / woods you can cut 3000 mm / min with?
I would really love to get to that speed? Do you own an Ooznest machine as well?

 

Thanks. But I just ordered the drivers that Giarc suggested. As I said, have never had any problems with the same settings.
There must be something else wrong. I am using a dust shoe, nothing more. And would you use max RPM? Currently I am running at 16k rpm of 30k rpm that are possible.
Is the machine itself rigid enough to cut at speeds like 3000mm/min?

The drivers should arrive next week. Hope an 20 awg wire will work

 

@Ryan Lock @Giarc Its been a while already.
Unfortunately with the new drivers the problem seems to get worse and worse.
So I got TB6600 drivers instead now. All set to 8 microsteps.
GRBL step settings are
$100=26.667
$101=26.667
$102=188.976
Are these settings correct?
Tried to cut with a V-bit. Seems like its having problems to move to the left side (-x position).
Carriage is moving smooth. Before when the Nema23 motors were on power, I was able to push the cariage with a little more pressure and it "jumped" a couple of cm.
So I adjusted the eccentric spacers to be it a little bit more tight, so that I have to put a little bit more pressore on it to move.

Right now I am switching from the Arduino "soldered" version to an Arduino screw shield.
Here is a picture of what went wrong. Three triangles were cut. The one of the right side you can already see that it
is getting "unstable" when it is moving to the left side. But here it is loosing steps or something and then the second pass it is already
way off the path. The cut was with only 1000mm/min, 1.5mm per path and 20k rpm, so this shouldnt be the problem.
Any ideas? :/

Thanks for your help again!


Edit:
Just did a test cut in the air.
The longer it is running (total cut 10 min), the less it is moving to the left side.
After the "cut" was complete and after "homing" it was 30 cm(!!!) off to the right side,
although the whole cut should be only 20 cm in width. What is going on? :/

 

Sorry for the late reply.
I am using the exact settings Ryan has posted here once.
I just did a complete resoldering of the cables.
Hopefully this week my 2 120x120 mm fans will arrive, so I can make sure its not the heat that is making problems

 

They were quiete loose before, so I tightened them and the problem was still there.
Do you think at all that a double belt would/could help as well?
If yes, I would order 3m in your shop right away

 

Hello all. I have just bought the Bluebee bluetooth module and dongle from Ooznest (thank you Ooznest). It works fine with the dongle. I am trying to pair it with the inbuilt bluetooth in my laptop but struggling. I have created a new thread here, any help would be appreciated:

https://openbuilds.com/threads/bluebee-bluetooth-module-pairing-on-xpro-v3.12382/



On a more related note to previous posts... My workbee has been working fine for the first few major projects. Then it randomly started skipping steps, but using speeds and depths I have consistently had success with previously, so I dont think I am overloading it.

I cannot tell if it is the motors stalling under load, or if it is the belt slipping on the drive pulley. Is there away to diagnose one from the other? I tried tightening the belts and managed to snap one. I have replaced them now, and double belted it while I had it all apart.

I have adjusted all the roller wheel eccentric spacers while I had it all apart and the X gantry slides along the Y quite easily. I have adjusted the current on the drivers, none of the motors are getting hot so I turned the current up to just below maximum (maybe 1/16th below fully clockwise).

Is it possible the belts are too tight? Is there anything else I might be missing?

Thanks in advance.

 

Thanks for the help guys

This whole saga started randomly one day. It just started skipping randomly without me changing anything. I then tried tightening the belts which eventually resulted in the broken belt.

I have now replaced the belt and upgraded to double belts but the problem is still there. To answer your questions, yesI did stick the bottom belt down with that special 0.5mm 3M tape stuff.

I did some more trials this evening and altered the belt tension in different amounts but the same outcome whatever I did. I tried a new end mill in case that was the problem. I was communicating by USB but am now running on Bluetooth so I presume it’s not a comms issue.

I am trying to cut 18mm hardwood ply at 2500mm travel speed, 2.5mm depth, dewalt D26200 router on speed 1, using a 0.25” 4 flute up cut end mill.

The thing that makes me think something is wrong is that I cut loads of this stuff at 4.6mm depth and 3000mm speeds without any issues. I will do some more trials tomorrow but if anyone has any bright ideas I would love to hear them!

 

@Tobin seems like I got the same exact issue as you got. Mine was working fine all the way as well and suddenly starts to skip steps on the y-axis.
Did you check the pulley setscrews? I just did, but the screws are already so "screwed" that I can neither tighten nor loosen them. So I can not confirm right now that they are tight (enough). I saw a picture of someone using a way bigger screw. Guess I will try to find one like that as well. Then I will do the pen-test once again.

Oh, by the way: did you try to switch from bluetooth to usb again? just to make sure?

 

Is this also the right place for support? Because I need some...


I just set up an Ooznest OX CNC that a friend of mind baught from you last year and I encounter some issues.
The first time that I connected a computer with Universal G-Code Sender installed (nightly v2.0) the machine did react to jog commands and moved the axes as commanded. But then, after playing around a little bit (and after some collisions making the steppers skip steps) and also changing the GRBLparameters to the suggested parameters from the manual, the motors don't want to move anymore.

When i give a command, the led's at the motor outputs on the xPro ectually all stop and the designated motor seems to "want" to move and makes a short sound, but it can't even make one step - it just falls back to its original position. Meanwhile the Universal Gcode Sender shows the movement of the axis which actually didn't take place.

What could cause this issue that the motores don't really move?

Another thing that I found is, that if I set in GRBL $1=255, then the xPro will remain in the 'state' as if it was busy with something (motor led's off) and wouln't react to any new commands given. Is that normal?


Thank you very much for your help!

 

Okay, I found the issue: With my board $4 needs to be set to 1 with my board.