Shrinker Stretcher

[Charst]

Thank you DIYer

Charst

[Mikell17]

That’s awesome. Eckold jaws are expensive but they are probably the best. The function of eckold at a lot less expense. Looks better also. Could be fun to make this into a steampunk looking tool also.

[juan_alberto_13]

Hello charst, incredible team that you designed, please let me know to do it for my workshop and I want to know if it is possible to obtain the information of plans and measurements and where you got the Eckolds, sorry my English is quite bad and I use a translator since I only speak Spanish

Thank you

Juan Alberto

[ianinsa]

i too would be interested in drawings etc. if you would be so kind.
ian214@live.com-thanks in advance

[Jon]

Congratulations Charst - your Shrinker/Stretcher is the Homemade Tool of the Week!

Nice follow-through; it was good to see this build from design through to completion.

Some more good builds from this week:

Hot Wire Cutter by Kovanca Polock
Hydraulic Cylinder Machining Fixture by Frank S
Tool Holder by celsoari
Marking Gauge by Mazay
Track Saw Guide by Didpoolhall
PID Controller by JKeetonKnives
Wood Stove Log Grate by Frank S
Lathe Tailstock by Es Welding
Drill Press XY Table by mariost
Rollers by thehomeengineer
Tube and Pipe Drilling Jig by Kwandotechnic
Router Biscuit Joiner Attachment by shopandmath
Octopus Jig by Christofix
Welding Fixture by Kwandotechnic
Drum Sander Feed Mechanism by RCTURKA
Flat Bar Twister by Kwandotechnic



Charst - we've added your tool entry to our All Homemade Tool of the Week winners post. And, you'll now notice the wrench-on-pedestal award in the awards showcase in your postbit, visible beneath your username:



You'll be receiving a $25 online gift card, in your choice of Amazon, PayPal, or bitcoin. Please PM me your current email address and award choice and I'll get it sent over right away.

Nice work!

[Charst]

Hi again,

I have made a small demo video of my shrinker-stretcher. Just follow the link...

[wizard69]

Wow! Very nice build, certainly deserves tool of the week!

Your design is very interesting, I’d like to ask a question or two.

First; why the cam action? Is it to magnify pressure.

Second; is the cam a hardened piece of steel?


Pretty neAt machine. Maybe in the future I will build something like it. Too many in process builds at the moment to start another one.

[Charst]

Wow! Very nice build, certainly deserves tool of the week!

Your design is very interesting, I’d like to ask a question or two.

First; why the cam action? Is it to magnify pressure.

Second; is the cam a hardened piece of steel?


Pretty neAt machine. Maybe in the future I will build something like it. Too many in process builds at the moment to start another one.

Hi Wizard

Answer 1: The membrane cylinder alone gives 5kN and abt. 70mm of movement. The cam together with the lever ratio on the arms give me abt. 30-35kN and abt. 10mm movement on the tools. So yes, the cam magnifies the forces (Cam ratio is 3,5:1)

Answer 2: The material of the cam is the only weak point so far. It is made of mild steel (S235). The material starts to deform in the area of the highest load on the cam. However it is not that bad. But next time I'll be using C45E or better.

Cheers

Charst

[bimmer1980]

Very nicely done! It's great to see it in action. I found it interesting to see how much the frame deflects when it is putting pressure on the material to stretch or shrink. As heavy duty as the design and built, it generates a lot of force!!

What do you plan to make with it? I see a motorcycle in the background......

[Charst]

Yes 7.800 pounds is quite something... but it's within the permissible yield strength.
I am mainly using it for bodywork on motorcycles or artwork (see pic)

Cheers

Charst