Building A Progressive Thumb

[wolf44]

paint pictures

got it painted today!!!!!!!!!:drinkup:drinkup:drinkup

 

[wolf44]

Material Used

: just out of interst did you use mild steel for the link arms, i know Kubota use some kind of cast steel? Also what did you use for your pins, are they hardened or just mild, also have you got hardening equip?


All the parts are either T1 plate or 4140 heat treated. I will be showing the custom pins that I have made for this project soon. The main bucket pivot pin is made from S7 and heated treated to 55 -57 rockwell C all the other pins are 4140 heat treated to 50-52 rockwell C

 

[wolf44]

Kit

Here is a picture of your $5000.00 progressive link kit!!!
Lol lol...

 

[coopers]

That looks really good! Any pics with it back on w/ paint?

 

[wolf44]

Reassembly

Still waiting on heat treat on the pins they will back in the morning. What I was able to get done today is get the hydraulics hooked up and tested. Got the lines made and the big win for today is moving the line on the right side of the boom to the left side to match up with the cylinder ports. Went to the local Kubota shop Mason Tractor yesterday and got new bushings for the bottom of the stick and new seals so I can have a fresh tight new install. Also picked up a little touch up paint to spruce up the under carriage.

 

[Canadian_digger]

Our bobcat mini the Aux hydraulic line crosses on the top part of the boom so it does not obstruct your view. Thumb looks great. You sure do some excellent work.

 

[Canadian_digger]

Its hard to see but you can kinda see it in the picture.

 

[wolf44]

Our bobcat mini the Aux hydraulic line crosses on the top part of the boom so it does not obstruct your view. .

You might be right I did not see that till I posted the picture. I sometime get so involved I can't see the forest for the trees. I will try it as is for a while and if it's in the way I will change it. now that I have a better look at the assembly. Thanks for the help.

 

[wolf44]

Almost

Just a few few items to finish.

 

[Hendrik]

Looks good but the only thing I would suggest is to route a solid hydraulic feed pipe to the bottom of the thumb cylinder, if you get something stuck in the thumb and lift it up, it may damage the hose.

 

[stock]

Looks good but the only thing I would suggest is to route a solid hydraulic feed pipe to the bottom of the thumb cylinder, if you get something stuck in the thumb and lift it up, it may damage the hose.

Definitely agree with Hendrik on the steel pipe for the retract side of the cylinder but I would suggest an additional guard to protect it....or at least the bottom hydraulic fitting anyway..............

 

[wolf44]

It's DONE!

Well it's been a lot of work and about a month in the making but at 5:24 this afternoon I finished the thumb project. I am going to do a recap of what I have spent money wise and the time I have invested in this project for your fun.
Here are the final pictures.
The first picture is the left over parts
Second picture is the tooling needed for the project

 

[wolf44]

one last picture

The last picture

 

[Hendrik]

Looks good, hate to think how much the total cost is, including labour.
Guess quality costs?
Do the sides of the thumb unbolt, so you can just have the center section?

 

[wolf44]

Recap

hydraulic cylinder $92.50 Design time 32 hrs
leader pin thumb $52.00 tooling time 16 hrs
leader pin y link $74.57 welding time 4 hrs
S7 bucket pin mat$28.00 machining time 32 hrs
heat treat $150.00 paint prep time 4 hrs
Touch up paint $24.00 assembly time 23 hrs
Paint and painter $ 258.00
4140 mat 1.25 dia. $25.00 Total time 107 hrs
4140 2.5 dia. $45.00
3/4 x 8 gr8 bolts $ 45.00
hydraulic lines $170.70
Bushing and seals $156.07
T1 laser but shapes $ 355.00

Materials total $-----$ 1475.00

Design time 32 hrs
tooling time 16 hrs
welding time 4 hrs
machining time 32 hrs
paint prep time 4 hrs
assembly time 23 hrs

Total time 107 hrs

It's been fun I am glad it's done. I got what I wanted.
thanks for all your input and watching my progress
:usa

 

[wolf44]

Looks good, hate to think how much the total cost is, including labour.
Guess quality costs?
Do the sides of the thumb unbolt, so you can just have the center section?

see the recap post for the costs
Yes the sides unbolt when I use my 12" bucket

 

[wolf44]

Test Report

I got to put the thumb to the test in the boulder pile tonight. If anybody had any doubts about if the shape of the thumb picking up rocks or any thing else, fear not. This thing has exceeded my wildest hopes. Holly cow can you grab massive rocks, logs and trees any way you want. I am super pleased. Worth all the time I put in this project. The bolt on tines are rock solid. The machine as a hole is much better since I removed a lot of the slop in all the joints. A win in my book. I will modify my 312 for sure now
wolf44

:drinkup:usa

 

[nobull1]

It is nice when a project works as expected the first time around. I find
made from scratch projects usually need a few mods to a complete redesign before working as expected. Good planning and experience were a asset to your job.

 

[strott]

Looks brilliant whilst still being functional- well done.

 

[cps]

So wolf what about the bigger 312 your going to do, any start made yet?