Hey guys! Maybe anyone can help me here with this
My Arduino Controller arrived today and I connected it.
The motors itself work fine.
But I got stuttering for the X-Axis and on the Y-Axis both motors do not move the same speed / at the same time.
May this be due to the settings of the eccentric spacers?
I tried to do it like the manual said, but somehow it seems it is not working too well right now.
Everytime I read "There should be a small amount of friction." in the manual I get confused.
Does that mean, that the wheels still should be able to rotate freely, without moving the X-Carriage?
Rotate with friction, so that the X-Carriage does move with the wheel (but the wheel sometimes has a "burnout"?
Or should it be so tight, that everytime I turn the wheel the X-Carriage HAS to move?

I hope you know what I mean

Oh and I killed a screw within the Flexible Coupler :/
Guess there will be some work to done.

Thank you!

 

Nema 23, Power Supply 400 W 24V.
Setup for Y-Axis is the same. Differences are tiny, but it is Not running smooth

 

Yes sure.
I use an normal Arduino and installed the Protoneer CNC Shield.
The Y-Axis is cloned and all motors are set to "Quarter step".
Before it starts stuttering I can hear a little knocking on the left Y-Axis.
If I leave the motor alone for a minute or so, it works better than before (like for one movement).
Here I just created a small video. Hope you can see what I mean:

And thanks Ryan, but I already ordered a new coupler and some more stuff from your shop
Z-Axis has no priority at the moment.

 

Didn't see that there was anything to adjust at all!
I will buy an volt-meter today and give it a shot later or tomorrow.
I will let you know, but thanks a lot already!

 

It might be your acceleleration curve too...

 

Thanks for all the info!
Unfortunately I bought the wrong multimeter, so I was not able to test it.
Ordered another one now. And I just bought the DRV8825 drivers, because they seem to be more powerful.
Will let you know if it worked soon

 

I have a question about wiring. I want to use a CAT5e (or CAT6) cable to connect physical controls and an emergency stop button to xPro. Will this is ok, or do i need a shielded cable?

 

I am interested in building a 1500x1500 ooznest for furniture, mostly 1200 x 2400 plywood.

Size; Could the sheet stick out the end to allow me to cut one end then cut the other end? Is it actually possible to source v-slot longer than 1500? Presumably joining two pieces makes it rather weak. Does the Ooznet mod with a plate on each side of the Y axis (though making x axis better, not allow for more racking on large beds, which would be made particularly bad by joining lengths to make a longer Y axis?

Router; What sort of feed speed would the dewalt router manage, would getting a more powerful spindle be of benefit? Cutting 18mm birch ply with a 1/4inch bit in two or three passes, what speed can the machine handle- is it going to take hours per sheet? Additionally, I have read through the forum for a few hours and I understand its not really advisable to go large on the belt drive because of stretch, though I see some people have doubled up the belts. Presumably could ballscrews be retrofitted to an Ooznest... Could the same motors be used?

About the z axis- Although the machine would be used mostly for 18mm sheet work, I might want to mill smaller deeper 2.5d things, such as 100mm thick foam for a mould? Keeping the plates are they are, could I cut between the beams into an area below the bed if the Z axis extrusions were longer? Say if I were to put the foam between the crossbeams.

Thanks!

 

Hi all, got my ooznest up and running but I'm not sure if the noise is making is normal or not? Seeems to be fairly loud, especially on the y axis. Loosened the belts a bit, but that didn't make much difference. Perhaps a have the eccentric spacers to tight? It is this normal?

 

check for any loose screws ,my normal cbeam did make that sound when the screws on the end plates were loose

 

Hi Ryan
Thanks for the reply, that is helpful.

Do you recommend that on a 1500 machine you are best to do the double belt mod anyway? Can this have negative consequences too? Why wouldn't everyone do that on any machine?

How deep could the machine go into the foam? Would that be the entire z travel of 69mm?

If it were to be modified, what's the maximum it could sensibly achieve by swapping in a longer z axis v-slot and the leadscrew? (If these are the only bits that would need to change) Could it cut right through a 100mm piece for example?

Thanks again.

 

Thanks darathy, will do. But i just listened back to that video and the audio on it is horrendous!

I recorded another video, but first removed the belts and the noise seems to just be the nema motors. again this could be completely normal?? this time recorded with camera not phone

 

Does seem like its the motors but cant really tell. You could also put a rubber sheet or a blanket under the CNC ,vibrations could be coming off the table from all the vibrations the machin is transfering.

 

Just to give you guys a little update.
It was exactly this problem!
I ordered an multimeter and checked the voltage.
It was completely different for every single driver, ranging from 0,5V to 2,2V. Probably the 2,2V just immediately overheated the driver.
I set them now all to around 1V for the A4988. But I already ordered the DRV8825 drivers as well and will set it to 1,2V, which should give the motors around 2,4 ampere each (DRV8825 supports up to 2,5 amps).

Need to exchange the flexible coupler now, which will be a pain.

What would be an easy way to "test" the cnc? Get an easy image and "engrave" it into the air?

//edit:

Oh and I created a video. X and Z seem to work fine. Y Axis still makes weird moves.
Are the belts too tight / loose? What is the correct settings for the steps?



Thank you!

 

Thanks for the settings!
Yes, currently I am still using the A4988's. The DRV8825 will arrive on Monday or Tuesday.
I set the A4988's to 2A. Maximum of the DRV8825 is 2.5A if I'm right, so it should not be way more power.
Somehow sometimes it sounds like something is loose. I already adjusted the eccentrics so that the wheels have a little bit of fraction, so that should usually not be the problem.
But I will try the DRV8825 as soon as they arrive. The new Flexible Coupler arrived yesterday as well. Thanks!
Although it was not exactly the same as the one that came with the Kit. :/
Still seems to fit!

 

@Conehead

Look out for the orientation

 

Thank you for all your comments.
Today the DRV8255 drivers arrived. I set them to 1/8 step and gave it a try with the settings Ryan posted here.
Unfortunately the motors were really slow (maybe half a cm / sec) and they made a real high pitch sound.
And in addition the drivers turned really really hot (which the A4899 did not).
I set the potentiometer to 1,25V which should be 2,5 amps (max of the DRV8255).
Any idea how the xPro Cnc is outputting?
Thanks!