after fixing my seized arms, loose encoder magnet, and reverting firmware back to 1.17, I was just jogging my machine before my first cuts post fixes, and the machine seemed to have snapped itself.
I can’t find the piece of plastic that ejected, but I think it was from 1 of the 2 router clamps, which upon inspection have both snapped at their fastener hole locations for the clamps.
10 minutes before failure, my machine seemed okay, and was able to calibrate itself smoothly. Then after jogging around the frame to try to zero on some cuts I had previously made, the jogs began to be jittery, and the machine would jump around during movement, like it was encontering increased resistance (I wasn’t cutting FYI). The movements weren’t directly following the directions commanded, for instance if I commanded a diagonal, the machine would sometimes do a zipzag in x and y approximating the diagonal.
It seems like the belts are pulling really tight. My retraction force is 1400, but at any less it won’t retract a few of my belts. Is this value also used when using the “apply tension” command? Sometimes they’ll retract with less force if I first extend and then retract again, but there seems to be little rhyme or reason to this.
Getting to the point where I’m wondering if I’m in sunken-cost-fallacy-land buying replacement parts and trying to debug all these problems
It’s definitely a DIY robotics kit. There is a reason that the product description is “You should buy this if you are excited about the idea of building a robot and being an early adopter. This is still very much a new technology it still requires a fair amount of fiddling to work well.”
I more than anyone want to make Maslow a tool that just works right out of the box every time, no assembly required, and we’re making improvements every week, but I can’t say that we’re there yet.
@RandomDave is there a place I can find the advice for fixes to decrease the retraction force?
@bar It might be useful if there existed a centralized “troubleshooting guide” besides the forum category. Something that is maintained and lists the common failure modes and fixes, so not everybody needs to scour the forums and try to find it there.
I saw you spotted where I wrote about my experiences - but also, it’s pretty much all about friction between the reels and the arm halves, and reducing that. If you search for ‘sanding’ or ‘lubrication’, most of the results will be on that topic and might be helpful - people have achieved it lots of different ways.
So I sanded all my belts per @RandomDave ‘s very helpful post, and now all my belts retract reliably at 800. Reran my calibration with 900 retraction value, and it succeeded.
I still have some issues just jogging around though, the machine makes a clicking noise, and doesn’t follow straight line jogs well, it shifts around laterally while moving in the direction commanded. See video below, any ideas?
can you post a picture of your full system? where are your anchors compared to
the top of the spoilboard? if they are below the spoilboard, that could cause
issues if you haven’t set the spoilboardthickness value
clicking and that movement seems like the belt is very tight still, if the Z
distance from the arms to the anchors is larger than the machine thinks it is,
taht could cause problems
Upper 2 are the same as the default wooden frame, roughly 5mm over my spoilboard. lower 2 are different than default, and have longer bolts than needed. The anchor points sit at the bottom of the bolts, roughly 2-3mm above spoilboard
if they were all the same, you could set spoilboard thickness to adjust this
across everything (postitive thickness if the spoilboard is above the anchors,
negative thickness if the anchors are higher than the spoilboard)
when they are different, you need to tweak the Z offset values (in the fluidnc
settings tab, look at the maslow.yaml settings for the Z distance for each arm)
also set the workpieceThickness value
the other question is if tilting the frame back a bit more would help.
Unless I’m just not seeing them. Where are the linear rod supports and caps?? I played the video several times and I don’t see them. Not sure if that if causing issues or not but it can’t be good.
And as far as the clicking goes I’ve seen and had the belt guards rubbing the belt as well as a motor or encoder board issue. Not sure which it was since I changed them both.
nice spot, a bit of a dumb mistake by me, been taking it apart and putting it back together between tests all day, and for this one I’d forgotten to reinstall. I did notice and rerun, but same problems still existed
And as far as the clicking goes I’ve seen and had the belt guards rubbing the
belt as well as a motor or encoder board issue. Not sure which it was since I
changed them both.
that’s what I’ve seen as well, but I’ve only seen it being a problem when
tension was high.
some people have reduced the noise by lostening the bolts and tweaking the
position of the belt guards a smidge
Have you considered backing up a bit more in the firmware. I’m talking like 1.12 or earlier? Also just a bit of reassurance. It does work. I use mine on the regular but have had to learn these parts and this machine. What everything does and what can affect what. I bet I’ve disassembled this machine a few dozen times at least. The spool thing, really important. For a visual I sanded mine until I could free spin it on either arm half like you were spinning a bicycle tire. Then I used a silicone grease (super lube). Screws cannot be tight. Barely engaged is more the description except the motor screws. Tighten those on down. I run a vertical setup too, about 20 ish degrees. Default frame maybe a little bigger but my center spoil board area folds down into a work table. I saw you post about the broken parts. I’m sure you’ve looked them all over for cracks. Components in this system are very dependent on each other.
I’d also scrap those bottom anchors. Make the default frames just the way he shows it. It has been tested on and tested on. A lot problems get introduced when things get modified before fully understanding how it works.
Original problem being too high friction between the arm and spool, which is now solved (I think)
New problem I think is the motors are just pulling way too tight
@dlang Can you walk me through the various knobs that could be affecting how tight the motors pull?
Belt length for each arm is calculated using the height of the triangle (combination of z-zero, spoilboard and work thicknesses?) and horizontal distance to each anchor (from calibration)
When the machine is “applying tension” is is retracting until it hits a set tension value, or is it retracting until it hits this calculated belt length?
Z-zero is used in order to calculate the above belt length, but the machine has no knowledge of the tool inserted into it
it seems like z-zero should be 2 different values, but IMO there’s only the one in the software
1 value is used to calculate the height offset between each arm and its anchor
1 value is used to set the tool zero so you cut at the right height
When does the machine calculate the belt lengths? I’d like to run some tests to decrease the tension. If I update the z-zero, or spoilboard/work thicknesses, will the machine update its correct belt lengths it should pull on each arm? or do you need to restart the machine each time you update these values
