I bought a used manual thumb that was on a Komatsu 200.

I traded 10 cords of firewood to get it welded on.

Can someone really familiar with thumbs take a look at these pics, I think the thumb is too short; I may have to weld on extension fingers...


usera.imagecave.com/whitedwarf4/Thumb/

Something isn't right about that installation...do a google search on "thumbs".

Get the bucket and thumb down in the working position and see what it looks like. You cram the thumb against the bucket when you have a load in it in order to keep the load in the bucket. Take pics. in the working conditions and with a load in bucket and see if it holds the material in it. catskinner

On the excavators I've run, I seem to remember the thumb overlapping the bucket teeth by several inches and actually going between the teeth.

"ol'_Grump" wrote:

On the excavators I've run, I seem to remember the thumb overlapping the bucket teeth by several inches and actually going between the teeth.

Yeah, when I bought it I thought it was "one size" too small.

I figured I could just weld extensions on it if it did not work properly...

I have not tried to use it yet...

I looked on Machinery Trader before I welded it on, and the guy who welded it is a weld shop manager, taking care of over 100 excavators for a company, he said I put it in the right spot, but the thumb is just too short for the bucket...

I was going to buy a new one, just like this: www.excavatorthumb.com/ping-crosby/mt306...xcavator-thumb-8.php

But my Dad found a used one this size: www.excavatorthumb.com/ping-crosby/mt245...xcavator-thumb-1.php

I figure I need to weld on 4" extensions, to get the geometry to look more like this: www.excavatorthumb.com/ping-crosby/mt245...cavator-thumb-16.php

It'll probably work as is. .but there's a chance that being too short it's gonna REALLY pack stuff in the bucket. .that's the problem here where we have a lot of clay.

"ol'_Grump" wrote:

It'll probably work as is. .but there's a chance that being too short it's gonna REALLY pack stuff in the bucket. .that's the problem here where we have a lot of clay.

In all honesty, I only want to use it for tree stumps and logs.

I think it will work ok as is for stumps, but trying to pick up a single log off the ground without getting half a bucket of dirt will be a problem.

If it bothers me enough, It will be a nice winter project welding on extensions...

Oh, and for the guys who remember, when I was looking to buy this machine I thought the boom was cracked.

I ground off the paint, and all I saw was a slight scale line in the plate...

The welder ground into the mark a bit, and told me there was no crack to weld up...

I guess I'm happy it was not cracked after all...

If that's all you want to do is pick up logs and stumps, that short thumb will probably work just fine. .although you may wind up "shortening" a few logs 'til ya get the hang of it. . .lol