I would like to retract my previous statement regarding “no problems”
I was in the middle of a few more cuts and the controller decided to take on a mind of its own and ignore the gcode…
it was doing fine and then all of a sudden it decided to do this…
It has been a rough few days with this part… its not the first time this controller has done this either.
Both tinyG V8’s I have do this from time to time… Does anyone else have or have had the same issues?
Things I have tired…
- Setting my controller in mm even though all my machinist tools are imperial.
- making sure the CAM files from fusion 360 are in mm rather than imperial.
- cutting my CAM files into smaller sections. so rather than writing the gcode for the entire part. I will just post sections at a time to reduce the file size.
- making sure to run the "get G1 Representation of G2/G3’s from 3D Viewer Object…
There was still several processes left to be done on this part. Finishing the slots, boring 6 holes, and then cutting the profile.
I have had to scrap this part 3 times now. Has anyone had issues like this or is it just my bad luck?
I really need some answers or a different controller. I hate to let this one go if I don’t have too, but I can’t keep scraping parts and hope one comes out.
Can you be a bit more specific about “decided to take on a mind of its own and ignore the gcode…”
Does it seem like one axis stops working?
I had this happen a few times but it was due to set up errors on my part. What type of machine are you cutting on?
C beam… It tends to happen after I have been running the controller for a while. What setup errots did you make?
@cmcgrath5035 all the axis were working that’s why if you look at the part you can see it was cutting an arc.
What it was supposed to do was stay in the smaller arc and make a few more passes until it broke threw. Then lift the tool move down and cut another one. Like it has been doing.
I didn’t have good work holding (carpet tape only) causing vibration in the aluminum. Not choosing a proper DOC/Feed/speed combination.
I see… my part didn’t move at all. If you look closely you can tell it was a heavy cut but the part stayed put… Infact the cut was so heavy the shavings melted back together partially…
@John_Johnston what kind of spindle are you running and how is it mounted? Just curious if you could send me a picture of your setup in hangouts I would love to see what you are working with
@John_Johnston On closer inspection, after your description, I’ll guess that the tool jammed making a cut, causing both X and Y motors to skip steps mechanically but not logically. When it did recover, it proceeded in a now-bogus coordinate system.
You need to separate control issues from machine issues. On way to gather useful incite is to run you job cutting a very simple material, such as foam or soft wood. AL and HDPE are at the far other end of the “easy to cut” scale.
@cmcgrath5035 I’m not sure how it’s possible to tell the difference.
For me watching it when it happened. The tool never retracted it was if it lost its position and then just decided to cut and arc at the previous depth.
Is it no possible the controller lost its posistion? I’ve have run old bridgeport cnc’s and from time to time they will do this…
For this machine to alter the tool path that much in the way you suggest wouldn’t it have to loose alot of steps?
Also as a result how would that cause the arc to be cut at a different angle? Offset I could see, buy that just seems odd…
Do you have any examples of one of these loosing steps personally so I can have a baseline?
It was cutting very smoothly at very low feed rates the entire time 100mm/per minute…
I’m going to run the job again in wood today and see if I get the same issues…
“Do you have any examples of one of these loosing steps personally so I can have a baseline?”
With 440-20, no personal experiences simply losing position in simple materials… Forum has revealed some issues with inch dimension Gcode, you included.
The most frequent cause of ‘loss of position’ is steps not executed (mechanically) due to inadequate current or mechanical jamming, causing X,Y and Z to loose logical reference. I have had that experience with 440-20 cutting heavy HDPE, bit would occasionally jam/load up with molten plastic.
The area in your picture above where the bit appears to have jammed looks familiar, in a bad way.
Suggestions:
- Run you job completely in air (no cutting).
If that passes, then
- Run job cutting simple material (foam or soft wood)
If 1.) fails, try run job in air with spindle shut off. Spindle noise can also be an issue
well I ran the part again. This time using pine lumber. I ran the part with out any breaks. I wanted to load it up with out over loading it and see if it would do what it did in the metal…
As you suspected it must be due to the fact its loosing steps and that just happened to be what the controller does when that happens…
Now my question is how would I go about resolving this?
Is it because the drivers are not capable of holding the motor in position or is it because the motor just simply doesn’t have the torque to hold its self?
Would getting external drivers be a possible solution?
If so, what ones work best with this controller?
@John_Johnston Do you believe there is one, or a few areas where this repeatedly occurs? if so, extract those to a shorter Gcode sequence and try to re-tune your machine (current, speed) to do a good job on the tough part.
The controller, tinyG, will try to do the job up to it’s max current rating. Whether that will be enough is a matter of machine - motor, linkages, etc.
@cmcgrath5035 understood… I guess I was looking for a better solution as I will be cutting a lot of 6061. I would hate to have to keep scrapping parts…
I did add a heat sink to it last night… I never noticed this drivers getting hot enough to over load, but they must have done since I see one of them with a pin hole in it haha…
Has anyone in here added external drivers perhaps in the future I want to build a machine with nema34’s on it and I need to drive those… I have a lathe I’m looking to convert in the future
I took a quick look back in this thread and am still not sure what type of machine you have.
I suggest you dig thru posts to find someone who is successfully cutting 6061, then emulate them.
There is only so much you can make up for with higher torque in the motor, which is a combination of motor copper and drive current.
External drivers can work well with tinyG, Google is your friend to find examples.
yes I am looking at the Gecko driver right now… The G210X and the G213V look as though they will fit the bill… I found where it has been used successfully with the Tiny G https://www.synthetos.com/topics/about-external-stepper-drivers/
Thanks for you help!
John, it’s easy to wire Tinyg to the G210x with 34s because they take the 3.3v from the step and dir. Other 5v drivers for stepper and servo motors can also be run using a small voltage leveler that is easy to wire.
I’d like to have a TinyG without drivers and with the levers built in to use with big machines that already have 34s and servos on them using various 5V drivers that only need the indexer and Chilipeppr to convert.
Any update on the cause?
I too am running into mystery tool path issues. I have ruled out mechanical and have played with current trim and microstepping. No success. Seems to be worse with speed. My next step is dropping pulley size, 32T down to 20T.
-Tinyg v8, no enclosure with fan
-Win7x64
-Fusion and/or easel CAM
-ChilliPeppr and/or UGS
Are you using G2-G3 code? I found when I converted to all G1 point to points with arcs alot of my issues went away
