Question milling problem (uccnc)

Good day to everyone!
Could please anyone help to solve the problem? I'm a starter in CNC, I bought Stepcraft2/600 with UCCNC and the problem appeared during milling, the idea was to mill 3 equal pockets, the 1-st pocket ok, while milling 2 pocket the mill just gone aside (coordinates moved). Started from the beginning and the same problem appeared with pocket 3. (8 mm mill, 20 mm walnut)




Thank you,
Maria

You could try a dry-run and see if machine runs smoothly or it gets stuck. If no mechanical problems then maybe try again with other cutting parameters (feed/speed/cutting depth). You could also try a smaller diameter mill (3mm) at first and then move on to larger ones when you have some experience.

Thank you,
dry-run was perfect, 4 mm mill worked good also with this project...before these run and as appeared after (restarted computer 3 hours ago and everything became ok (as for beginner)...I just would like to understand the problem, is it just a software glitch or something else?

Hi,
No suggestions but I had a similar problem today on the X axis, lost steps and ended up about 20mm out - cup of tea and called it a day!

I had a similar experience. I noticed that when i kick on my Shopvac the lights dim a bit. I'm wondering if a bit of a brownout occurred causing the mill to miss a few steps?

to make sure its not hardware related

>>config
>>axis setup
>>X and Y and Z axes in turn
>>change velocity to 5000mm/min
>>make sure accel values are 350 (not 500 - 500 is too high an accel value)
>>hit apply (and then do not hit save)


if the STEPCRAFT is tuned correctly it should run at 5000mm/min raipids okay and sing. it may stall now and then on rapid jog but it should be stable.And stable right to the end of travel.


if this is the case then you have a well tune machine. If not - then you need to tune more.


you should be able to run this toolpath with a pen at the max feed (3000mm/min) without lost steps for a number of times.

Thank you,
The problem came back:( Rory, I'll try to do as you advice, thank you.O could this happened because of wrong post processor(aspire 8.0 Mach 2/3 Arcs (mm)(*.txt)?

Rory, thank you, did like you said, appeared that Y is not going good (stuck), X and Z perfect. Could this be the problem? Working with Y...

Oh, I recognise this...using Aspire 8 too.

But in my case it is a hardware issue: the screw on the servo drive pulley stick out a little (despite the Loctite blue I used??) and damaged the tooth-belt. After that, a lot of things went wrong.

Maybe my belt was set too tight too, but anyway, I'll have to exchange some parts to make it work again.

The belt system on the Y axis is a weakness imo.

Same issue with Y axis only. Im now having to adjust it the last two occasions in the past few days ive used it.
I retune it works fine do some cutting leave it a day or two then find the y axis stalls again. No way mine will do velocity of 5000mm/min.

The funny thing is the Y axis is fine moving to the rear end of the cnc, just moving to the front has the issue.

Btw, at least in my machine the belt didn't go straight, as the pulleys on the lead screws were more in than the pulley of the motor. This meant that the belt did make a small twist when going from the lead screws to the motor and then to the tensioner. This was easy to see by putting metal ruler on the pulley and seeing that pulleys are not on same level. I fixed this on my machine by moving the motor in for 1 mm, by adding extra washers between the motor and the frame of the machine.

Not sure if this will help, but you have problems with the belt, you might want to check this too. I noticed it when I was running the machine without toothbelt cover, and the belt jumped off from the tensioner almost immediately.

I have not yet finished tuning my machine so currently I am running it with slower speed in Y direction.

Tr wrote: Thank you,
The problem came back:( Rory, I'll try to do as you advice, thank you.O could this happened because of wrong post processor(aspire 8.0 Mach 2/3 Arcs (mm)(*.txt)?

unlikely

Tr wrote: Rory, thank you, did like you said, appeared that Y is not going good (stuck), X and Z perfect. Could this be the problem? Working with Y...

yes this more likely the issue

Denus wrote: Oh, I recognise this...using Aspire 8 too.

But in my case it is a hardware issue: the screw on the servo drive pulley stick out a little (despite the Loctite blue I used??) and damaged the tooth-belt. After that, a lot of things went wrong.

Maybe my belt was set too tight too, but anyway, I'll have to exchange some parts to make it work again.

The belt system on the Y axis is a weakness imo.

Have seen examples of applications where 3-4000 labels were made on a stepcraft without any issue with the belt on Y axis. its sensitive to setup but does work well if setup correctly.

jonalm wrote: Same issue with Y axis only. Im now having to adjust it the last two occasions in the past few days ive used it.
I retune it works fine do some cutting leave it a day or two then find the y axis stalls again. No way mine will do velocity of 5000mm/min.

The funny thing is the Y axis is fine moving to the rear end of the cnc, just moving to the front has the issue.

loosen the bolts holding the orange plate #4 in Y axis extrusions #10 x 2. then jog the machine to the front. You will notice the holes are oversized and will allow some "float" of the front plate #5. Jog the machine to the front with the holes loose and you should feel the friction reduce. then when the machine is at the end of travel on the that size tighten the bolts. you an even move the machine with the belt in and out a little as you tighten to feel for the friction.

Thanks a lot, Rory could you please tell is it ok for Stepcraft 2/600 to work about 6 hours per day, and in this case how often do I need to calibrate axes (like you advised) and lubricate guide strip?

6 hours per day = production duty cycle (not advised).

you need to lubricate and clean every day.

full service every 10 hours or so.

Good day to everyone,
Rory, could you please help to find the problem: after setup (as you recommended (velocity 5000 sings)) works well 3-4 hours, but after 3-4 hours Y stick even when velocity 2000, cleaning and lubricating every day...Found out, that after belt put off and put on machine works ok, but putting off the belt is not the way out...

How are you lubricating? Watch that the rollers are not recyling grease down into the spindle / nut interface (#14 and #59)

Rory that could be my issue with Y axis, I'm sure its something to do with lubrication Ive noticed that when the problem occurs if i put a fan heater for 1 min on each side of the y axis screws the problem goes away then the issue comes back again after not using the machine for a few hours... strange

Thank you, Rory,

understood that my lubricating was wrong.

Im now using silicon spray only and seems to have sorted out the Y axis and can now do 5000 velocity.
i think room temperature effects the viscosity of the supplied grease.

Spray better in our opinion... it cleans also as it sprays and it doesn't attract as much dust etc... but needs to be done often. don't over grease the top slide between the ali and the brass as it can get worked down into the ballscrew spindle / nut interface.