Kerry Veith published a new build:

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Thanks @Mark Carew ! We are really happy with how the build turned out. Everything is almost dialed in, but there's always stuff to change and upgrade, lol.

 

Copy and paste error. Thanks for catching this. Updated.

 

Hi all, Here are some of the projects I've made since we got the machine up and running. People really like the black stain on white pine.

Traveler's Sign

Vectric Xmas Sled Project pre assembly

Friend Family Birthday's

Highschool Sweethearts

Cat Lovers

Baby Shower

Disney Lovers

 

No special prep done. Just a good sanding. I think it's minwax brand from lowes. Ebony. I used a sponge brush to put it on. Let it sit for 30 seconds and wipe it off. The signs have 2-3 coats that way. Thanks for the feedback!

 

Thanks for the positive feedback! Even though the signs are simple. We have overcome a lot of little battles getting all the kinks worked out. It seemed until yesterday every time we tried a different style project the machine would have an issue(mostly on the mks sbase config file). I think we are ready to start digging into the metals soon. Cheers!

 

@Mark Carew I'm having somes issue with my X Axis and I hope you can shed some light/point me in the right direction on finding a solution. A lot of this is still new to me, i'll do my best to make sense talking about the problem below.

The issue: When cutting 3d projects the x axis will hang in one spot, make a horrible grind sound and skip steps throwing the whole project off. The acceleration on the board we are using is set as mm/second/second. The board config default was at 3000, I initially dialed it back to 300. Everything seemed fine, then the issue happened again. I turned it down to 100 mm/s/s and all of my projects have been running great. I came in today to run a successful project a second time and it happened again. I thought it was a fluke since it worked fine the first time around. I ran it again and again and I was able to get it to stop when I turned the acceleration all the way down to 25 mm/s/s. I feel like this is really slow, but I don't know the standards on acceleration. Web searches provide a ton of mixed feedback on the topic. Another observation is that the lead screw is getting scorching hot where there are a lot of back and forth movements on the design.

Some background...
We are using the mks sbase board (I know it's a knockoff smoothie board and we are going to upgrade at some point, but it's what I have to work with for now.)
1/32 Microstepping
Nema 23 Stepper Motors
Not using external stepper drivers at this point (potentially part of the problem)
The X Axis was not moving the correct distances so I adjusted the steps per mm to 795 and it seems spot on now (this is likely unrelated to the issue), Y and Z are set to 800 steps per mm.

So after all that gibberish the questions I am really trying to solve are:
A. Does the acceleration 25/mm/s/s make sense?
B. Should I lubricate the lead screw in any way? (I'm wondering if the friction is causing the motor to overheat/skip steps)
C. Does this kind of thing happen when the stepper motor is going bad?

I have attached my config file for reference if need be.

 

@Darathy thanks for the tips.

@Mark Carew I had thought there needed to be a slight angled pressure between the two nut blocks to act as the backlash prevention and take out any slop that may be in there? I might have made this up in my own mind, lol. What is the best way you have found to set the nut blocks (two in tandum) correctly? I was going to loosen the screws on both nut blocks, turn the lead screw a few times, then tighten them both back up.

Attached is a photo of the feeds/speeds I have set on the 3d toolpath. I'm a fan of being more conservative to achieve better results. But open to suggestions if something seems off.

 

I think I'm getting close to figuring this out. Whenever I loosen both nut blocks, or just one of them the axis moves completely free along the entire axis. As soon as I snug up the second one at all it takes out the slop and it takes a slight more effort to turn(still fairly easy). However, there is a spot right in the middle of axis where it becomes very hard to turn unless i have at least one nut block completely loose. Upon looking closely the screw wobbles pretty bad in that area. I'm guessing if I can get the screw straightened my issues will go away. Any tips on straightening the screw out at all? I'll probably just use a vice and a flat table and work it till i can get it to roll smoothly. It makes sense that motors crap out under the heavy load with high acceleration. Thanks again for all the tips.

 

@Jestah Thanks for your feedback. I wasn't aware that the higher number of microsteps reduced the amount of torque. I feel like that might be something I change in the near future if other adjustments don't fix the issue.

When I first started having this issue, the first thing I did was use an infrared thermometer on the entire control board and the motors and everything was more than cool enough.

I'd love to see the video if you can find it! I will likely be using a vise*, a flat surface, and a lot of patience to try and straighten it out little bits at a time.

My game plan is going to be to try and straighten the screw out and re-test. I will also lubricate the screw. I am wondering if anyone has tried graphite (like the kind used to lubricate locks)? I'm leaning toward that or the silicone spray that @Mark Carew mentioned above. If the combination above doesn't resolve the issue, then I will change the micro-stepping.

I want to thank everyone again for the help! I know helping a newbie can be frustrating at times, so I really really appreciate it.

 

I've always said my vice is drinking beer, I guess we'll see which I use and update the post accordingly.

 

After about 4 hours or so of messing with this....

When I took the lead screw off, it really wasn't that bent or twisted. I tweaked the one area that looked the worst and left the little spots alone (I didn't want to make it worse).

With the two nut blocks: I found that if I tighten one all the way, I can't go past barely snug on the other or it binds. I am really really leaning toward replacing with a single anti-backlash block in the middle. I'm not happy that there is either too much slop or binding, no happy medium to be found. The lead screw just isn't straight or rigid enough for the dual block system. If I had bigger motors I'm sure I could power through it, but I would rather do it right.

I also found that with the 1000mm lead screw, any pre-load adds a ton of wobble to the screw. Event the littlest bit.

I switched to 1/16 stepping. I didn't really notice more torque or less precision so I'll leave it there. Everything seems to be running at the same temperatures.

For now I think I'm good to go. I might try and switch out the nut blocks for a single anti-backlash this weekend or next week. I'm just dreading taking everything all apart, again lol.

Thanks again everyone for your help on getting through this issue. I would've lost my mind without the help. I've learned alot more about the machine than I expected. Cheers!

 

@Jestah That is actually on my to do list before I take everything apart. The other thing I noticed... It appears that the center point of where the blocks are mounted is not direct in line with where the end plate bearings are mounted. When the Z axis is centered it looks like both ends of the screw are higher than the middle of the axis where the blocks are mounted. I need to measure a few more times to verify, but if this is really the case I'm lost on how to adjust.

Side note. I ran the most recent project that I had failing, with the acceleration set a little higher than it was when it failed. It completed successfully. So while I am not perfect yet, I think I am past the worst of the issues.

Thanks!!

 

So far the Nema 23's seem to be doing fine. Dialing in the acceleration and this recent issue with the lead screw binding have been our two biggest battles. Fortunately there is a great support system here on the forums for us. We have done a few very basic test cuts on aluminum with no problem. I haven't dived into anything intense like 3d work etc yet. If you are going to do the same setup, I would consider setting up external stepper drivers for the motors. While it works good without, I kind of wish we would've put them in at the beginning. The mks board only supports 2.0 amps per. I have them all set at 1.9 to be a little safe. The MKS SBase board is a little finicky on the initial setup and there isn't much documentation on it. That all being said, if you have any questions on the way we wired things, the config, or any anything else. Don't hesitate to ask.

 

@jamesdjadams Let me see if I can find the file for it. It was one we took from thingiverse and made it bigger. If I can find it then sure no problem.

I use double sided carpet tape on just about every project (via amazon). I also have mounted oak strips on the front and back sides of the spoiler board. I have small wood strips I go across the projects with to hold them down tight or flat (twisted boards). The other method I have found works good is that I run the hold down strips along side the project to stop it from twisting. Here's a pic of the oak strips I installed.