Rough cutting
 

MM3 is creating me serious grief. When both x and y are cutting, arcs or a diagonal line, we are getting rough bumpy cuts. But when only 1 axis is cutting its neat and keeps to true shape ie square and correct size. we stripped off the motors and checked the gears and re lock tight the grub screws, adjusted the swing plates and springs, v rollers all secure, rails and gear rack secure. Then we checked wire connections at motor and they are good and so is the connection on the gecko. Anyone have any other suggestions? Rather urgent since we are swamped and i see MM5 is 50% better but thats not good enough for most jobs. MM2 is fine and MM4 is to busy with a job to test right now.

MM4 is also 50% better but not good enough. i find it weird that all of a sudden the 3 machines i built at same time mm3-5 are all giving grief and 2 of them use smooth steppers. i'm wondering if its something to do electronically, of which i know a very little about

last year MM3 started randomly loosing its coordinates during a job so changed and tested everything, then out pure curiosity we changed the transformer and then the issue was fixed. What i found funny about that is the 3x control boxes had the same 3x transformers made by the same company at the same time and the other 2 never gave me grief

Sean,
I' sure your aware of this, but if your using Mach3, I would at least review the CV settings and re-read the paper about it on the Mach3 site. I tried to get a link for you, but the site seems to be down right now. It could be that code is 'stair-stepping' on angles causing a rough finish. Anyway it is just a thought.

My guess is that this did not happen suddenly. You saw the problems on one machine and then discovered similar problems on the other machines.

I do not see that it is an electronic, software, or Mach tuning issue - do not change any of those settings! (The transformer change, if I remember correctly, was to a higher voltage transformer.)

My gut feel says to keep looking at the mechanicals - those machines have worked hard and have had very little maintenance. Are the gears worn out? (the tips of the teeth should not be touching the roots).

Gerald I have the same Issue but I am looking at gearboxes that are giving me issues are yours direct.I do however see movement on my Y-car when it is stationary grubscrews are tight.My next step is to upgrade the v-bearings as I suspect the ones I have to be f...I did sort out the plumbness of the cutter to the table as I had ridges on my cuts.wil post on a new thread what I did.

Ours have OM gearboxes, but that does not mean they are immune to wearing out. Yours are Fulling (Fuller?)? Mechanical wear and tear must catch up with us sometime - we can't really expect these machines to last forever.

On the electrical/electronic/programming side, we can expect just about everything to stay constant and last forever. The only exception I can think of now is the capacitors - they do decay with time, particulary if they are being used to their voltage & temperature limits (which isn't our case).

Off the wall mechanical to check: router or spindle runout / bearing wear.

When both x and y are cutting, arcs or a diagonal line , to me only looks like mach3, computer or power supply issue. maybe v-wheels?

Gerald I tend to look at the v-wheels also.Our machines have a gantry for a 1850 board size and those bearings do take a lot of weight.Yes I do have play in the gearbox shaft.I had the one x-axis motor that was like that and I then swapped it with the z-axis motor which doesn`t work that hard compared to the x and y axis.Now I picked up that the y-axis also has that play.I have 7 motion king motors in a box that I can use direct but I don`t have the time to change them.I also loosened the tention on the springs.My cut is not that bad but if you work for a client and the compare your cut to a multicam machine one does tend to feel a little k.. for myself I can get away with it and sandpaper but it is annoying.


The other thing is how long does the belts last on a belt driven gearbox?what happens when one cut and the one x-axis belt snap.Then you twist the whole works and break a cutter.Alan how is things with your belt driven boxes?

No problems or sign of wear on the belts or teeth, but my machine does not work full out every day for the full day as Sean's do. I dont worry too much about the belt breaking as those belts have little steel strands inside them - it would take a hell of a lot to just break. I dont think our steppers could apply enough force to the belt to make it break - the motor would slip internally long before that becomes a possibility. (I had a belt break once on the Biesse but that machines gantry weighed about as much as my whole MM and the servo that was driving it could pull you up Table Mountain!)