Chainsaw Repair

Chain - Grinders - Filing - Wood Milling - Tools - Welding - Machinist - Mowers - Tillers => Chain - Bars - Grinders - Filing => Topic started by: Elden on December 02, 2020, 07:41:29 pm

Title: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on December 02, 2020, 07:41:29 pm

   I am attempting to do a chain vise and stop pawl modification, similar to a Silvey 300 or 510, on an Oregon 511A. There is a post on Arboristsite (of which I am a member but heretofore have been unable to post there) that shows the modification I am attempting to accomplish.

https://www.arboristsite.com/community/threads/511a-grinder-improvements-tweaks.197073/post-5581905

   It appears that Grande Dog of Left Coast Supplies is not available to obtain information from.

   The "Faultless" stop pawl assembly is available from Madsens, but the vertical arm (stop mount bracket) on which it mounts is not. Neither is the other vertical arm (tooth length adjustment screw mount), through which the adjustment screw is threaded, available.

   Not having a Silvey or ever seeing one in person, I would like to ask a few questions of Silvey Round Ground chain grinder users.
1.  How far above the top of chain bar does the stop mount bracket extend? (preferably to the center of the stop pawl assembly's pivot bolt)
2.  How long are the stop pawls that are mounted on the above stated (question 1) stop mount bracket?
3.  What is the distance between the point where the grinding wheel would contact the top of the chain bar and a line drawn perpendicularly to the top of the chain bar from the bottom pivot hole of the stop mount bracket?

                          /
  |                     /grinding wheel
  |                   /
_|_________/_____________
 o                chain bar
_|______________________

   I plan to purchase the pawl assembly from Madsens, but want to be sure that they are the correct length for the dimensions of the parts that will have to be fabricated. Hopefully those parts can be fabricated without a lot of trial and error.

Many thanks,
Elden
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Cut4fun . on December 03, 2020, 07:34:19 am
Sorry no help here. I never owned a Silvey round or Oregon.

Just a Stihl USG round and Silvey square.
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Cut4fun . on December 03, 2020, 07:37:11 am
Try contacting Shaun at @srcarr52  because last I knew he was making pawls for the silvey square grinders. He might know. Heck he might have them or can make them too.
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Cut4fun . on December 03, 2020, 07:38:40 am
https://youtu.be/wp4xnqvBF80
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on December 03, 2020, 01:13:14 pm
Cut4fun,

   Thank you for the reply. Will try contacting him.

Elden
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on January 18, 2021, 10:28:17 pm
   I have been making slow but sure progress on the modification. Started with making the arms out of wood as it is easier to tweak than metal. After it is finished I will try to post some pictures and dimensions. Definitely like the way the stop pawls lock the cutters down.
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on January 25, 2021, 09:57:58 pm
Using temporary wooden arms to determine functionality. Works well for 0.325 and 3/8 lp chains but may have to increase the height of the pawls slightly for full size 3/8.
[attachimg=1]
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: 3000 FPS on January 26, 2021, 12:01:56 pm
Is the stock pawl not good enough to give consistent results.   Just curious.
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on January 26, 2021, 03:08:57 pm
   I personally have had trouble getting consistent results with that pawl assembly. It is not due to the pawl itself but to the arm assembly it sits on. It will flex fairly easily. By using a very light touch when seating the cutter against the pawl, results are pretty good. I am sure there are many who have no problem with it.
   I have a couple of Foley 308s on which the pawl assembly is more sturdy, thus I am probably prejudiced. From the preliminary trial with the temporary set-up, I am pleased with the results. Once the permanent metal arms are made, the return spring installed, and the vise tensioner installed, I should get a better idea of its practicality through usage.  At this point, I am thinking the Foleys may get a similar modification.
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on February 26, 2021, 11:27:52 pm
The project is mostly completed. Thus far I am impressed with its performance. It holds the tooth down well and seems to be very solid. The original Oregon set-up had the possibility of a fair amount of flex. Pictures have been quite shrunken and clarity well reduced so forum software will accept them hopefully.....

Prototype following the wooden arms (stop mount bracket and tooth length adjustment screw mount).

[attachimg=1]

Disassembled stop mount bracket, tooth length adjustment screw mount and tooth length adjustment screw; stop pawl assembly

[attachimg=3]

[attachimg=2]

Getting close to final assembly. May eventually shorten the tooth length adjustment screw and fit a knob on it instead of the acorn nut.
 
[attachimg=4]

View of the backside of the vise assembly. The casting is sloped on this side. A wedge was fabricated to make this surface at a right angle to the hole for the stop mount bracket pivot bolt. This hole was not originally in the casting.

[attachimg=5]

Depth gauge check tool in position (backside of vise). Relief slots that were filed into the arms are visible. These were necessary for the tool to fit while the chain is in the vise. I grind depth gauges on a separate Nielson grinder but do the initial depth gauge check (go, no go) here.

[attachimg=6]

Cheater handle for the old man who has lost his strength! Not necessary all the time, but it is amazing how tight it can be sometimes even though it was hand tightened.

[attachimg=7]


Elden
Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Cut4fun . on February 27, 2021, 07:23:48 am
Amazes me what people come up with and make for themselves. Nice job. 

Title: Re: Oregon 511A vise & stop pawl modifications similar to Silvey
Post by: Elden on April 21, 2021, 12:15:47 pm
   I am enjoying using this modification and am impressed the way it works. After doing a couple dozens of chains,  in my opinion, the fabrication time was well spent.

Elden