Y Stall, Y Jerky Motion, Y not smooth - Fix

[Digitalwoodshop]

Y Stall, Y Jerky Motion, Y not smooth are all signs of dirty Y rails and Y bearings. It can also be wood chips in the belt.

I am posting this for the people searching this problem and adding more info and pictures.

I finished cutting 5 signs the other night and found that the last carving resulted in a error in the cut along the Y Axis. I quit for the night and the next morning though that since I had scrubbed the rails before starting the signs, that I eliminated the rails as the cause. All the Y Bearings were rolling, so I pulled the Y Motor.

I found what I had expected, the shaft of the Y Gear Box had worn letting the big gear wobble. I checked the Cut Motor Hours and it was 721. This is the 3rd machine I have replaced the Y Gear Box on out of my 4. I have replaced each one at about 700 hours using the old Z Gear Box from the Z Bundle upgrade.

So for users getting near 700 hours or even 500 hours, a inspection of the Y Gear Box could be helpful. Removing the gear box and cleaning the shaft and possible even rotating the 2 bearings front to back or even spending the 10 bucks to get replacement bearings.

I couldn't put my finger on the Bearing web site but it was posted a while back. Use Metric Measurements when ordering it.

When you attach the Gear Box to the motor, there is a trick to get the plastic gear meshed with the motor shaft properly. You can actually mount the gear box without the gear even touching the motor shaft. You can also press the gear too hard to the motor shaft leading to a future motor bearing failure. There is a happy medium to getting the proper mesh to spin the gear without binding and being too far away leading to too much slop in the gearing. This is known as backlash, the distance the motor travels when reversing directions before the gear teeth are engaged again. In my old Navy Analog Gun computer days we used a spring to pre load the gear train to minimize backlash.

So getting the gear and motor mesh is easy, just be sure to turn it a few turns after tightening the screws and don't be afraid to re adjust it.

When you mount the Y motor back in the machine in it's U Shaped slot, try to center it in the U shaped area. Once the shaft is worn, the plastic area between the belt and gear will rub on the U area causing the jerking of the Y.

Hope this helps.

AL

In picture 4 you can see the shaft just as it enters the plastic is worn thin.... The bearing must have failed....

[mtylerfl]

Hi AL,

I just want to say Thank You for your excellent post and photo documentation, yet again!

A lot of folks (including me) have been helped time-and-time-again by your thorough descriptions and detailed/captioned closeup photos of practically every nook and cranny of our fine machines! If it wasn't for you, a lot of us would still be scratching our heads in confusion!

Thanks for taking the time to do what you do for all of us.

[c6craig]

For Sure. Thanks again for everything Al!

Craig

[Spanglerg@hotmail.com]

Bearing Information Site:

http://www.jp.nsk.com/app02/BearingG...aring48240.htm

[Digitalwoodshop]

I just looked at the other bearing post and snagged the website for the bearings.


http://www.vxb.com/page/bearings/PROD/5mm/kit768

There is another source on that post too for the same thing.

I believe that putting the Y Bearings on a 500 Cut Motor Change out will help many users let the machine live longer. They are easy to change and I did NOT need a bearing press to remove and replace them playing around with the Gear Box.

Considering the cost of a New Y Motor with Gear Box is about $80.00 throwing in a new set of bearings for less than 10 bucks makes it a good investment.


To buy LOCAL use the following Cross Reference Numbers for the 5 mm x 11 mm x 5 mm with metal shield.

NSK Brand - 685ZZ

KOYO Brand - W685ZZ

NMB Brand - L-1150ZZ

Once the shaft is worn thin replacing the bearings will still let the shaft wobble.

AL

[Jeff_Birt]

Great info as always Al!

[Digitalwoodshop]

Time to add to this old post.....

Another Y Bearing Post... I had 6 CW projects to cut today but only got 2 done. After changing the Cut Motor Brushes this morning I noted that the Y Bearings in the gear box are getting worn..... On the 2nd project cutting 3.5 x 7 FRP on a Carrier Board, I noted with the 2nd sheet I was getting a problem in the Y.... I was watching it Vector Cut, always fun.... And I hear a Click in the Y while it is cutting..... You can see with the stack blanks I made that the problem was getting progressively worst...

I actually stopped it on the last set as the bit was starting off the left side of the board... That would make the first one too narrow... I had the first sheet even cut the markers for the Grommet Holes...

This is a new Fire Product. Each Truck will have one and each day, the seat assignments will be made and a tag hung on grommet and ring. At a Fire this holder will be taken to the Accountability Tag main board.

Looks like I have enough blanks for the order and will go to the store tomorrow and get the bearings. I looked at all the gear boxes and they are all worn... Note that this gear box was formally a Z Gear Box due to the hole on top for the spring screw.

Looks like the wood signs will need to wait.... Even with 4 machines.... I have been stealing gear boxes.... I should have ordered that 10 pack of bearings long ago....

I took the encoder cover off too...... I was working on my deck and a breeze took some of the fine dust before I could get my camera..... Lots of dust in there....

AL

[Capt Bruce]

Hi AL,

I just want to say Thank You for your excellent post and photo documentation, yet again!

Thanks for taking the time to do what you do for all of us.

A hearty SECOND to Michael T's note of Thanks

[CarverJerry]

So Al, you going to order the bearing you and I talked about (that 10 pack) that I found on line? I ordered them myself as a back up.

[Digitalwoodshop]

Ended up ordering the 10 pack from the link above.... vxb.com Came to $31. something with shipping.... I may end up running all around looking for the bearings here.... Not much of a selection.... I have work to do in the shop to keep me busy...

AL