TWIDDLING MY THUMB

[escavader]

POST #1 Winter blues are setting in/no snow to ride my sled so,IT IS TIME TO START MY THUMB PROJECT
Been on the internet,and tbn looking at thumb pictures.IAM finalizing my thoughts,of what i want:a fold up thumb,like a pro built one,that can be adapted to hydraulic in the future,if i dont like it mechanical.lightweight[only got a bx-23],but strong.Im thinking about some 1/2 flat stock and cutting it out on the plasma cutter at work.Then welding the edges with wear surface rods for tough ness.Mild steel should be good enough for my hoes strength right.say 1/2 by 4 inch arms with welded cross pins?ANY THOUGHTS?
ALAN

 

[HomeBrew2]

Very anxious to see what you come up with /forums/images/graemlins/smile.gif
I'm in the second season using my thumb ... just harvested another nice crop of rocks. My neighbor just finished making one of my design. And, bird1968 has contemplated manufacturing a foldup version of it.
I just threw mine together out of 3/8" x 1.5" bar (leftover concrete form stakes) and it has proven to be plenty strong. If you anticipate a great deal of side-to-side stressing, you might go to 1/2" x 2" bar but, 1/2" x 4" would be pretty impressive /forums/images/graemlins/wink.gif
Cheers!

 

[escavader]

Let me pic your brain for a minute.I was thinking today,sometimes i "pinch " a rock to move it. If i had my thumb on,could i still do it with it folded in the stored position.If you say yes,then should i couragate both front and back,so i could get a good grip on either side? CAN YOU DO ANY DIGGING WITH YOUR THUMB EXTENDED?Also was thinking of using square u bolts to mount it temporary til im sure i got it where i want it,then ill weld it on yes ...no?
ALAN

 

[radair]

I'm working on a design similar to this one:

 

[escavader]

I like the base mount it looks easier to build than the ones ive seen.Are you gonna weld yours on?
ALAN

 

[escavader]

I dont know what i was thinking of doing the back side,now that i looked at a pic again.HAVING A NUMB SPELL I GUESS /forums/images/graemlins/grin.gif
alan

 

[HomeBrew2]

> ... "pinch " a rock to move it ...
I don't have any experience pinching rocks (betw the stick and boom) so, no help there.

> CAN YOU DO ANY DIGGING WITH YOUR THUMB EXTENDED?
My thumb is fixed but bolted on so it's always extended but, yes, I can dig with it. Though, I may need to move the tractor forward or reverse to get the dig angle right so as not to plow too much with the thumb.

> ... weld it on yes ...no?
Sounds ok to me. I preferred to not weld mine on. But, if it folded up, I'd probably weld it on ... after a season of using it to make sure it was right. Yes, I'd use U bolts to start.

 

[escavader]

RADAIR,
With the one in your pic ,you would have to remove the support bar to fold it up correct?
ALAN

 

[nobull1]

Here is a couple of pic's of mine if they might be of any use in your design

 

[nobull1]

And another. One thing I did was to get a arm that was longer than what shows in the pic's. What I found was the thumb at 90 degrees to the connecting arm was too far back. My thumb now is closer to 45 degrees facing downward towards the bucket and makes picking up rocks a lot easier. If you might want to do that make sure that the thumb is long enough to still hit at the teeth. If the thumb is too short it goes inside the bucket and can crush things a lot easier.