y,z gearbox big gear

[55president]

Is there a source for the y,z-gearbox gears? the nylon/plastic one with the idler gear on the top and big meshing gear for the motor and has the
steel shaft going through. I was getting them through cravewright, but now they are just selling the motor assembly. My process really beats these
shafts up, I am just getting 100hrs or so out of a shaft, before it wears.

Any ideas?

FXP

[CarverJerry]

Is it possible to press the shaft out and purchase a piece of drill rod of that same diameter and press it back in? I know drill rod is hard and comes in MM and Inch measurments.

[unitedcases]

Good idea carvejerry.

Sent from my ADR6300 using Tapatalk 2

[bergerud]

A plan I had was to remove the shaft, replace it with a bigger, fixed shaft and put bearings in the gear.

Just what are you doing that takes out the bearings so fast?

[Digitalwoodshop]

I just called Ryan at LHR and did a Stock Check for the Gear with shaft for the Y and Z and they STILL offer it. MWM-A2073 at about $6.00 a pop. So call them...

Sometimes you just need to know the part numbers. You might have gotten a new guy. OR a new policy that is just getting out today.

This is where the "Preventive" part of Preventive Maintenance comes in.... If you are getting only 100 hours on the Gear than you should plan to change the 2 inner bearings sooner. Depends on how you use your machine, it you are doing stuff that really stresses the Y Gearbox then the bearings will wear out quicker... It is like the X Gearbox plastic gears.... I and a few others were thinking in the early years that we should have Rjustice make them for us out of BRASS..... Once I thought that through it was a bad idea... The plastic gears act as a safety valve or fuse for the X Drive Train at a reasonable price. Designed to snap or strip in a JAM saving the more expensive Servo Motor or the Computer with it's Servo Drivers built in... Saving you HUNDREDS of dollars...

It took me a while to come to the realization that I needed to change the Y Gear Box Bearings as Preventive Maintenance as once they fail, and I have had at least 4 fail since 2007, the Shaft GRINDS thin. The $6.00 gear and a new set of bearings brings new life to my spare parts.

The inner Bearings are 685ZZ One of many places to get them. http://www.avidrc.com/product/1/bearings/170/5x11x5-Metal-685ZZ-bearings.html

Good Luck,

AL

2011 prices on the picture, my last order for parts.

[bergerud]

the nylon/plastic one with the idler gear on the top and big meshing gear for the motor and has the
steel shaft going through.

Are you taking about the x gears? We all assumed you were talking about the y gears, but maybe you mean the gears driving the sandpaper belts. There may be some confusion here.

[55president]

I'm talking about the y,z gear and shaft not the x gears -- Al has the right part number, and I must have talked to a new guy as he didn't know.
But that's OK i needed a whole new y gearbox and motor. What I was using was an old z motor turned upside down for clearance. It worked so
that was OK. I've considered getting a heavy duty shaft machined and resuse the plastic gear , but have broken every plastic gear I've tried to take off.
I make linocuts with my machine and it's heavy y axis usage- I figured I've run through 5 shafts already at about 777 hrs on my machine so that's
about 125 hrs a shaft. I have regularly changed bearings in the y and once in the z....
I keep a log of repairs on my machine and the first real problem was stripping the x gears. Next was the y gearbox at about 125 hrs, totally shot
bearings and shaft.
So just trying to keep this all together and cutting.

[Digitalwoodshop]

Interesting.... I just had a thought..... Why not in your case get a HOLLOW Pipe type material that fits over the worn shaft making it thicker in diameter and look into bearings that might work.... A alteration to the back of the gearbox might be needed.... OR our Machinist Ron could come out with a thicker shaft gear and a heavier bearing ALONG with a metal gearbox to match with heavier bearings.

OR here is a wild idea.... Change the 2 inner bearings every 75 to 100 hours as it is the cheapest way to solve this.... So as I understand this, the Y is being used heavy and the 2 bearings are failing then the shaft is worn thin.... So to solve this change the CHEAP bearings sooner...

Too bad there was not some way to remove the stress from the Y Belt to the open ended bearings much like a wheel on your car that is also supported by one end..... Imagine something attached to the open end or the end where the BELT is that gives more support to the END of the shaft.... Weather it is a bearing that attached to the bent end and to a bracket much like a pulley for a close line... Closed or supported on both ends with a removable bracket to change the belt. Something to support the open end.... Just dreaming.... Replacing the bearings sooner would be better.


Good Luck,

AL

Just had another thought looking at picture 6..... A large bearing placed on the SMOOTH part of the big plastic gear between the belt and the gearbox. With a turn buckle type fitting over the big bearing that is threaded into the FRAME in line with the belt, JUST OPPOSITE of the other end of the belt... Taking some of the stress off the gear always being pulled toward the center of the machine.... OR same bearing and a bracket mounted on the center of the machine side in line with the big bearing putting pressure on the bearing away from the center of the machine.... OR just change the bearings sooner........

[55president]

the last bearings I had were not worn. the Shaft was so there had to be slop somewhere,
but I'm not sure it was the bearings. When I changed the bearings last time and shaft at
the same time everythingwas tight. but I think the shaft must be softer then the bearings.

FXP

[bergerud]

I was thinking about your problem and I think I would use blue Loctite on the inside bearing. That way the bearing may wear out and destroy itself but the inner race would stick to and protect the soft shaft. This would also give you a heads up when the bearing wears out. Instead of the shaft slipping and all seeming well as the shaft wears down, the grinding of the bearing parts would alert you that it was gone.

(There are standard needle bearings that would fit but they would have to roll on the soft shaft. If one found a way to have a hard shaft, the needle bearings would be the way to go.)