TWIDDLING MY THUMB

[escavader]

Heres a pic of the roughed out arms 20 minutes later. I am gonna clamp them togeather,put them in a vise,and take that 9 inch grinder to them to even things up.Didnt do much else ,except chase down some wicked nice 1 inch bolts[im making my own pins],heavy wall 1 inch pipe[for bushings]got a scrap of 4 inch channel etc.
Question: should a flat plate stock be welded in the end[away from bucket teeth]to aid picking up fines[leaves,roots etc]just a thought.
I think im gonna incorporate in my design,allowal to convert to hydraulics.There for the support arm,im gonna size[length]for a hydraulic piston.I also make the connections easily adaptable.I got to look in NH at the pistons,to check available lengths,and what the ends got[hopefully a 1 inch hole[i could use the same pins]
ALAN

 

[countrybumpkin]

Nice looking thumbs, I'm keeping a eye on this post. I'm going to start mine this week, as soon as I get BH cylinder repaired.

 

[escavader]

Well,didnt get to work on it much this weekend.I grinding with my 9 inch grinder for an hour[no ear plugs,had to stop]...i got a long way to go.I got the two thumb arms clamped togeather,and in a vise,tring to make them exact.I would reccomend if any one can,use a plasma cutter that will cut through thick stock,so you can do both at the same time.The one i used was only rated for 7/8 max,and i didnt quite get them the same.
holy cow,theres alot of planning involved to building one of these,unless your copying one to the tee.Where do the bushings go...in which piece...how wide will this have to be to fit in this...which side do i put this on...how long do the brace arms have to be...position.................
Iam not going to go like a house a fire,i want it to fit my ideas,but ill keep you posted.Im gonna try to do a little each night ,but snowy weather is approaching.I hope you guys show yours as you go,so i can learn from YOUR mistakes /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif instead of mine.
ALAN

 

[IslandTractor]

Why bother trying to get the two jaws to be exactly matched? The rocks you pick up won't care. Sounds like a lot of time grinding just for cosmetic reasons. If the pin holes line up I don't see there would be any impact on function if the teeth were a bit crooked.

 

[jhb]

Kubota makes thumbs for the excavator series, would they fit a BX23 boom? Someting tells me "no", but I like the idea of using the hinge pin for the bucket and thumb, it keeps the hardware/welding to a minimum.

 

[escavader]

You are exactly right ED ,i am way too fussy.Im one of them nut cases who Paints the scratchs on the TRACTOR,at seasons end.I just want my chicken scratch build job,to at least look like i tryed. The rocks will probably chew the teeth off any how.Gonna try to wear surface them though.
try a search of tractor thumbs on the internet and you will find nice ones...around 500 usually for mechanical ones.I think i ought to be able to build my own,under 50 bucks,ought to be just as good i hope.
ALAN

 

[escavader]

The grinding is done,they look awsome I KNOW IM SLOW family fun ,and tractor stuff keeping me out of the garage.I also have had a bit of touble drilling holes,aint finished yet ,broke the belt on my press.Heres a pic of the arms getting drilled,one for the pivot pin,one for the brace,or future hydraulic cylinder
ALAN

 

[escavader]

HELLO ALL,
Icant drill no holes,as you know,because i dont have a belt,so i decided to build the support bar.After carefull consideration,and a mockup on the bench,i got a length figured.I want the thumb to fold ip and replace the pin in the first hole in my"support bar holder" which will be welded to the hoe.Knowing this location ,i was able to swing the thumb arm up to90 degrees,and then i measured to my furthest hole out.I was then able to determine the length of the support bar.The thumb will be able to be out at 45 or so when i move hole positions in the support bar holder.well it might sound confusing ,but you will see what im trying to say when its all said and done.
Here i am flattening a peice of thick pipe to weld on the main support member.
ALAN

 

[escavader]

Welded one end on now the other
ALAN

 

[escavader]

OK now we want to keep it from bending the other way.I also cut some peices to reinforce them pipes.Ahoe has alot of poWer you know,here is my dry fit,i cut them tight enough so i didnt need no clamping
ALAN