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/BearingGuide/html/bearing48240.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

[Frederick_P]

This post is serendipitous as I am currently experiencing this exact problem. Thanks for the great info! Can you order a replacement for the gear box or gears or do you need to order the whole motor assembly?

[Digitalwoodshop]

I don't know the answer to that question....

I make this series of posts on machine Consumables like this bearing and Cut Motor Brushes so people plan to replace the parts before they get worn like the shaft of my Gear at the top of this post.

Many here will wait until the shaft of the gear is worn thin and replacing the bearings will not be much help... It took me a few gear box changes to see the error in my ways.... Now I am trying to be proactive with replacing the bearings before the shaft wears out.... Same with the cut motor brushes... before a broken bit...

As all of our machines age I would like to see LHR add 2 more parts to the available parts for the machine.....

1 is the Gear or the Gear box.... And 2 The Armature for the cut motor.... Since both are mass produced... Getting components to SAVE US MONEY would be nice.... 2000 hours would be a good time to have a Cut Motor Armature in stock for a repair..... That would cover the Commutator and cut motor bearings.

I bought my brother a Fein Multitool for Christmas... That would be the ideal tool to cut the gap in the commuators....

AL

[TerryT]

I bought my brother a Fein Multitool for Christmas... That would be the ideal tool to cut the gap in the commuators....

AL

An old hotrodders trick (that means when I was young and didn't have any money)... We always used an old hacksaw blade to clean the commutators on the generators. Of course that was when cars HAD generators. The blades usually fit perfectly between them. Our girlfriends always carried an important tool for filing the ignition points (cover switch) also, an emery board. They kept them in the pockets of their poodle skirts!

[Frederick_P]

Al, I ordered the replacement gear from LHR. Part number A2073. Good price... only six bucks each. So I ordered three of them. They may also have your armature. When I phoned, I was transferred to the specialty parts guru who was able to look up the part for me. He may be able to do the same for any part on the machine. I also ordered a new Y-belt (just in case) for $10.51, two Y tensioner assemblies for $1.68 each and while I was at it, just to have on the shelf for that inevitable fateful day, a complete Y motor assembly for $79.50. It would be good to have a list of all the parts that would be likely to wear and need replacement in the future. A savvy sales person at LHR would put together a "Carvewright Refurbishing Kit" containing all these parts. My guess is that there would be a lot of folks that would order it. Oh, and I also ordered a stack of bearings from the third party company.

Like I always say... "It's better to have it and not need it than to need it and not have it!".

[Digitalwoodshop]

The A7023 (A2073 is the correct number) is the Gear Box gear? That is GREAT if it is..... And six Bucks.... Good Deal....

Yes, a refurbishing kit would be good... Even with the Drill Rods for the Rails and Bearings with screws for the rails...

Good Job,

AL

[Smoken D]

AL, ya got the numbers transposed, here it is
Products orderedSKUProductItem priceQuantityTotal
http://f597.mail.yahoo.com/ya/download?mid=1%5f60525%5fAN0MDUwAACI5TM8tPQTYTkyy8 AY&pid=3&fid=DENNIS&inline=1MWM A2073Y Drive Gear/Pulley Combination Assembly $6.00 1$6.00 Subtotal: $6.00 Shipping cost: $12.00 http://f597.mail.yahoo.com/ya/download?mid=1%5f60525%5fAN0MDUwAACI5TM8tPQTYTkyy8 AY&pid=4&fid=DENNIS&inline=1Total: $18.00

[Digitalwoodshop]

Thanks.... The Dis Lexia kicked in and I did not proof it....

Thanks for the info....

I always try to order a few things to help with the shipping... Cut Motor Brushes would have been a good add...

LA (snicker)

[Smoken D]

I was paying attention to this post because the same problem was occurring with my CW. Was getting the famous Y problems popping up on the machine which would stop carving.

The very first thing to do when errors show on the machine is to look up AL's book of troubleshooting, in other words use the search function. With the "Y Stall" showing I checked the rails which were OK. The next carve had the stall so I checked the tension on the Y belt and tighten it a little. This time a 6 hour carve and at 80% completion the "Y Stall". Now I noted that the cutting truck when moved along the belt was VERY hard to move. Unplugged, no power. Also noted that half way across while moving the cutting truck was a jerking motion and would not travel smoothly. Next on AL's book is going to be the Y motor gear box and bearings. I probably ordered them the same day AL did a little over a week ago. Received the gear/bearings this past Saturday and on Monday was able to tear down the machine. Great instructions on the Y motor replacement by LHR. When I opened the gear box and handled the gear. That sucker wobbled what seemed like a quarter of an inch. No broken teeth noted. Taking the gear out and the bearings, the nearest bearing to the gear seemed to be frozen and not spinning. Examining the gear the area nearest the gear was worn down in size. Not the same diameter as the outer portion. Clean up the box, install the new bearings and the new gear, put everything back together. Wow, the cutting truck now glides along the rail. Now, guess what, I only have 337 cut hours on the machine. Dang AL, I planned on changing them at 500 hours, didn't make it, so it can happen. In the photos you can see where the shaft on the gear is worn and not the same diameter as the outer portion.
I did a test carve for 30 minutes and everything went as it should. Thursday I will be able to do that 6 hour carve for the Marine I was making it for.

Thanks ever so much for great instructions AL, I pay attention to em :rolleyes:

[DickB]

My son and I used to race R/C cars and trucks on dirt tracks. Each vehicle had numerous bearings like this, such as on the rear axles and front wheels. To maintain top performance and win, it was essential to clean and lube these bearings regularly, like before each race day. Some would do it between races. I don't recall ever having a bearing fail. Most of the time, the bearings could be cleaned by soaking in solvent for a while, then rotating the bearings by hand. You could feel when dirt was present and when it was not. Sometimes we had to remove the seals to get the bearings clean. I wonder if this wouldn't work as well as replacing the bearings.