Clicking Noise!!

[texasinmi]

OK, so I found the c clip on the back of the gear rod. Gear rod shows no bad wear like some of the posted pics.

Next question, how does one get the old bearings out? Is there a special tool or technique? Obviously, I am new to the world of pulling bearings. All of the bearing pullers I have ever seen are much bigger than these little things.

Thanks in advance,

texasinmi

[bergerud]

You have to lightly tap with a punch through one bearing to the other. Work your way around as you tap.

[Digitalwoodshop]

A ridge between the bearings, tap out through the hole to the far side.

Measure the shaft if you can? Or use a small crecent wrench to check the thickness in a few places, looking for thin at the gear??

AL

[Alan Malmstrom]

Like posted above, the clicking is the servo motor splined shaft turning and the big plastic gear tilted toward the center of the machine under load. The gap opens and the servo motor turns but the gear leaning away clicks letting the Y head get off of home position.

When you open the Y Motor Gear box and remove the big plastic gear you will likely find the shaft worn thin letting the gear tilt toward the center of the machine. The two 685ZZ Bearings have long ago failed and the big gear shaft has been sliding inside the the inner 685ZZ bearing sleeve, metal to metal, grinding down the shaft.

Good News.. The Y Gear and Shaft is a item you can purchase from LHR as seen in that old invoice but at a newer price. Bearing you can find local as they are 5 mm x 11 mm x 5 mm with ZZ or 2 metal shields.

http://www.avidrc.com/product/1/bear...-bearings.html

We recommend replacing the 2 685ZZ Bearings when you change your Cut Motor Brushes at 250 Cut Hours.... They last longer but it is cheaper to replace the bearings early then replace the gear.

Hi AL

I have taken my Y axis apart and found that the bearing nearest the gear is extremely wobbly. So I'm going to order new ones. Do you think that it would be worth the money to get one of these ceramic bearings for $36: http://www.vxb.com/page/bearings/PROD/5mm/Kit8427 Or just go with these for $13: http://www.vxb.com/page/bearings/PROD/5mm/Kit9390

I saw the ones that you gave a link to that cost a dollar but I'm thinking maybe that's too cheap. Would ceramic last forever or would it not be worth the cost in your opinion? Maybe one ceramic for next to the gear and the other one for the outside. Or maybe just get a bunch of the $1 ones.

[bergerud]

Ceramic are for high rpm. The balls might even crack under this low rpm, high load application. No to ceramic. This is not an application that requires expensive precision either. The cheap ones seem to last as well as others. I have not heard of anyone complaining that the cheap ones fail. I have one machine with the cheap ones and the other machine with my larger bearing gear case.

[Digitalwoodshop]

Ceramic are for high rpm. The balls might even crack under this low rpm, high load application. No to ceramic. This is not an application that requires expensive precision either. The cheap ones seem to last as well as others. I have not heard of anyone complaining that the cheap ones fail. I have one machine with the cheap ones and the other machine with my larger bearing gear case.

I agree.... Cheap ones.... and measure the shaft nearest the plastic gear for wear... IF THIN it will let the shaft lean toward the center of the machine and still give you problems with new bearings. LHR sells a shaft gear combo if you need it.

The trick here is to start replacing the Y bearings everytime you replace the Cut Motor Brushes.... We are pretty much down to the only Troubleshooting Posts we see are Y Gearbox Related. As more users adopt the replace at 250 hours the less and less Troubleshooting Posts we will see.

Due to the stress the Y Gearbox gets doing it's job, we need to be pro active and just replace the bearings on a schedule. IF you do alot of Acrylic then I would replace them more often.

We had seen a few posts over the years where eBay bearings were undersize. So beware.

AL

[Alan Malmstrom]

OK

My machine has only 160 hours of carving time on it. But I do a lot of deep carves. Maybe that's why its worn out.

I don't think the shaft is worn out next to the gear. The gear was wobbly but still spun very easily. And it was stuck on to the shaft. It was a bit of work to get it off. I'll check it with my micrometer though. I don't know why they didn't put a bearing on both sides of the gear. Seams like that would be a lot more stable.