HELP! Calling rim drive drum guru's I need some detailed information.

[Bill G]

Well folks I am looking for some detailed information on rim drive clutch drums. I am going to try to explain what I am looking for but I am betting I will confuse the heck out of most because I have a tough time explaining the hair-brained ideas in my head. They make "perfect" sense to me but I cannot explain them.

I am trying to compile a list of clutch drum dimensions.
I am looking for the actual dimensions of.....
1. The internal bore of the center with bearing removed.
2. The external diameter of the crankshaft it fits if known
3. The internal bore of the drum with clutch removed.
4. The application for said drum
5. The part number if available.

Here is a common drum for a McCulloch 125
1. The internal bore is minus bearing is 0.682
2, The crankshaft diameter I need to measure
3. The internal bore (clutch area) is 3.109 but it is worn
4. The application is many McCulloch saws such as the 125
5. The Oregon part number is 10624

Now folks let's see if you can dig out some drums and measure them

 

[Bill G]

 

[heimannm]

Crankshaft is 9/16" or 0.562...the models with the threaded clutch (instead of a nut to retain them) are 5/8" or 0.625.

Mark

 

[Bill G]

I appreciate that.
I used the 125 as a general reference.

We need many folks to post some measurements and see what can be found out.

 

[heimannm]

I think you will discover the list is extremely long, and unless it is compiled into a well designed data base the information will be very hard to find when needed.

 

[Wilhelm]

Wouldn't You need specs on drum depth too?

Modern saws feature quite shallow drums.

 

[Bill G]

I think you will discover the list is extremely long, and unless it is compiled into a well designed data base the information will be very hard to find when needed.

Well right now there is nothing and something is better than nothing.
Rome was not built in a day.
Magnus thrives on lists and documenting things so I thought he would jump on the idea but he has not said boo on the Swede site.
The simple fact is every year the availability of parts and tools to keep old saws going is dwindling. We have to compile some information so we can adapt modern parts to older applications.

 

[Bill G]

Wouldn't You need specs on drum depth too?

Modern saws feature quite shallow drums.

Yes, that is very true. Right now my thought process is on the center bore and drum bore but you are very correct the depth is important.