Author Topic: Fixing drive gear slippage  (Read 2425 times)

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Fixing drive gear slippage
« on: March 01, 2010, 03:25:46 PM »
In the plans you are required to make a sleeve that is pressed into the bore of the drive gear to fit the main shaft . But it will eventually break loose and slip as there is a lot of pressure on it and I found  locktite will not hold, (found out the hard way). To correct the problem I pressed in the sleeve and drilled for a roll pin through the keyway in the gear into the shoulder of the sleeve and pressed in an .093 pin then used a small bit of solder to hold everything in place. I use Brownell Hiforce 44 low temp silver solder. I  faced off on both sides. I also made a spacer to hold the gear in place between the back plate and gear.
You may have better luck with locktite but it would not hold for me.
Thats my story and I\'m sticken to it. :D

  • Guest
Fixing drive gear slippage
« Reply #1 on: March 01, 2010, 05:17:46 PM »
Rolland\'s right.
The roll pin thru the main shaft in the plans is baloney too. The solution is a hardened pin(drill shaft) with the side facing the roller bearing seat faced off flat. Cranking forces and it\'s cylindrical contact will crack the seat as it it hard and brittle(Don\'t ask how I know).
A deeper than spec drive pin/main shaft groove wouldn\'t hurt either.

  • Guest
Fixing drive gear slippage
« Reply #2 on: March 01, 2010, 05:52:26 PM »
I used a piece a 3/32 ? drill that worked out stronger than a roll pin. you just have to be careful on the depth you cut the groove so you don\'t weaken the insert, but yes a slightly deeper groove does not hurt either.
The other mod in that area I did was, since I used a piece of brass for the crankshaft gear support I made the slot for the drive gear a little wider and cut a washer out of drill steel to go inbetween the pin slot and support so it did not eat up the brass. As the gear tends to press against the support when turning.

  • Guest
Fixing drive gear slippage
« Reply #3 on: March 01, 2010, 07:39:42 PM »
Which leads to the inevitable... The drive pin slowly working it\'s way out and locking up against the crank block!

My solution is here, and a pic the next time I open the receiver up.
viewtopic.php?f=5&t=10
 ;) Ha! It\'s been a while, since I had to open it up(I was doing it regularly), because the pin retainer is doing it\'s job now!

  • Guest
Fixing drive gear slippage
« Reply #4 on: March 01, 2010, 07:51:11 PM »
Here is the helical pin retainer on the main shaft, it\'s the white part.

  • Guest
Fixing drive gear slippage
« Reply #5 on: March 02, 2010, 08:56:51 AM »
I\'m not to this point in my build but am coping this post and putting it in the prints to know what to do when I get there.
 Thanks
Bill

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Fixing drive gear slippage
« Reply #6 on: March 02, 2010, 09:44:02 AM »
BTW, Sheet 48-00 page 3 of 3 shows that \'spacer\' between the back plate and the gear.  It\'s listed as .170 thick or adjust as necessary.  Don\'t make it a tight fit as it will gall the back plate.  I leave .010 clearance and grease it as well.  
Dick C. (gatguy)

  • Guest
Fixing drive gear slippage
« Reply #7 on: March 02, 2010, 11:09:30 AM »
Yeah Dave,
That spring on your main shaft really should be a spacer sleeve. It shows in my pic above a post or two.

Offline Dave

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Fixing drive gear slippage
« Reply #8 on: March 04, 2010, 07:59:02 PM »
Then every time the head space is changed, so is the spacer.

  • Guest
Fixing drive gear slippage
« Reply #9 on: March 05, 2010, 10:40:56 AM »
I thought that this pin was to get you in the ball park with all the barrels and then you have to head space each barrel by threading it in till it was correct or deeping the chamber. We are head spacing off the rim of the shell correct?
bill