Damaged Servo? Belt slippage 3040?

[MC Design]

Im having a odd problem when engraving. I replaced the tube last night
My machine is cutting perfect today, but im having engraving problems.

Did one 50mmx50mm engraving on some wood, came out perfect.
Went to do another and the machine will engrave fine for a few seconds then jump up and down the x axis as if the belt is slipping.

But the belt is tight and theres nothing blocking the machine. I did have a problem when I turned the machine on after the tube install that it went to the edge and tried to keep going, slipping the belt for a second before I stopped it. But if this was the problem why did the first engraving come out perfect.

Any ideas? Im completely lost.

[MC Design]

I turned down engraving speed from 350 to 100. Seems to have solved the issue. I presume that means I do need a belt?

[laser]

Hi, does it seam to jam and then skip irrationally? How old is the machine?
Cheers simon

[MC Design]

Yes it seems irrational but I cant tell if its the belt or not. Have you suffered something similar?

[MC Design]

Now its happening alot, I think it might be the roller bearings on the gantry. I think they are shot and gunked up. Im going to see how much chris sells them for monday and replace them. It wasnt the belt as iv inspected it its perfect.

[robburge@sky.com]

My 3060 does this more and more. I cant figure it out - sometimes perfect but more often not. Belt tension seems OK - not speed dependent.

I've noticed other problems with misaligned layers even when cutting at 4mm/sec, so its not a speed thing. And sometimes, when contouring, it ends up 3mm or so north of where it started.

Very odd and very annoying.

[MC Design]

How olds your machine?
What do you generally cut with it? I do alot of wood engraving, so I think my bearings got gunked up.

[robburge@sky.com]

I think I've solved the slipping problem. I had been trying to clean the Z belt with alcohol. You can pull the belt out a little, twist it and get at the teeth. I now know that iso alcohol will not touch the gunk that builds up from cutting lots of wood - but there is something that does, cleans it like a dream, doesn't cost anything, have you guessed it yet... SOAP and WATER. Get a container of water and stand it on the bed, get yourself a bar of your favourite soap - the macho amongst you will go for a good carbolic but I suspect the ladies will prefer something a little more scented. Get a stiff brush or a toothbrush and liberally scrub the belt, bearings,et all with soap and water, at the same time vigorously moving the head up and down. This will dissolve and liquefy the gunk that has built up on the Z drive cog wheel. Keep this up until the brown slime disappears and clean up and dry up. Re-oil the guideways and the bearings.

There is a down-side to this tale. I had lost confidence so much in the ability of my 3060 to cut consistently that I have ordered another laser from China. My 3060, with a new tube, is now cutting great and its just like the old days. My new laser is in a container somewhere on the high seas - but will probably end up on Chesil Beach!!

Try soap and water to clean the rest of your machine too.

Rob

[PhillyDee]

I have found a few cleaning solutions which work, one is Bug Spray (pink liquid, from asda) for your car, seems to help dissolve the acrylic residue, a quick blast from a pressure washer rinses it nicely, only for use on the actual bed. You can use Acetone, but it is very very harsh, and not a nice solvent due to its ability to strip coatings, dissolve paints and most plastics.

[robburge@sky.com]

Well the cleaning with soap and water works well but the laser is miscutting a lot now. I can not now predict when and why, some days its fine but sometimes (quite often) it misaligns the layers. Its a real battle and quite stressful, and I'm wasting lots of material and time. Its not a speed thing - I'm cutting some files at 6mm/sec., so I'm sure the belt isn't slipping on the teeth. What about the gear wheel itself slipping on the Y motor - does anyone know how the belt wheel is fixed to the motor shaft?

I'm leaning towards a memory corruption problem as sometime I can reload the file and its OK.

Any thoughts and wisdom would be most appreciated.

Plan B looms though - my Chinese import has made it to Felixstowe!

Regards

Rob