Shrinker Stretcher

Hi Folks

Just wanted to show the result of the last days of work on FREECAD on my Shrinker/Stretcher.
Waterjet cutting is already in progress and abt. 90% of the other parts are in my workshop and waiting to be assembled.
Apart from the 300 mm throat depth, one special feature are the swiss made jaws from ECKOLD with quick release mechanism. The machine is designed for 1.5mm mild steel sheet metal or 2mm aluminum.
Machine uses a pneumatic membrane cylinder from a truck brake system. It will bring 3 tons of pressure on the jaws by putting 5 bar of air pressure on the cylinder.
Will post photos when it is finished (hope this is done sometimes in March 2018).

Greetings from Germany

CharstAttachment 21631

Looks like a nice design!

I'd be interested in a set of the .stp files. I just got solidworks, so should be straight forward to open the files.

I'll be interested in seeing some pictures as you get all your parts together and start assembling it!

Thanks for posting!!

I'd be interested in the step files. If they are available.

mark at kravchenko-audio.com

Hi Charst

Any project photos and finished parts to show to those of us who are interested and jealous yet?

Mi

Any progress updates?

Hi Folks! It's been a while...

Here are some pictures of my finished Shrinker/Stretcher. Works great. I optimized the working speed (cycles per minute) by implementing a quick pressure release valve on the pneumatic membrane cylinder. Depending on the work piece it can be up to 30/min now. I also figured that the forces required for shrinking are way higher than for stretching. With the current setting it easily shrinks 1,0mm mild steel and stretches up to 1,5mm. If I had to do one again, I'd use a larger membrane cylinder and a stronger material for the excenter (see 3D pic) which is 2x 12mm plates made of S235, bolted together.
Just ask if you have any questions...

Charst


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Awesome pictures! I see a quality tool that you have made. Something like this can be very useful for panel work and even bending bar and angle iron. If you were to do it over what metal thickness do you think it would be capable of shrinking or stretching?

Did you ever release the STEP files? I use FreeCAD to!

Great build!
Any video of it in action?
I would also be interested in the step files if you're willing to share.
How much did the jaws from Eckold cost? Looks like it would be great for deep shrinking or stretching work.
Thanks
Kent

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Thanks Charst! We've added your Shrinker Stretcher to our Metalworking category,
as well as to your builder page: Charst's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/homemade-shrinker-stretcher-2"> <img src="/uploads/226903/homemade-shrinker-stretcher-2.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/homemade-shrinker-stretcher-2">Shrinker Stretcher</a> <span> by <a href="https://www.homemadetools.net/builder/Charst">Charst</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/shrinker-stretcher'>shrinker/stretcher</a>, <a href='https://www.homemadetools.net/tag/pneumatic'>pneumatic</a> </div> </div> </div> </div>
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Hi Kent

The Eckolds are used ones. I was really lucky to get them for a very, very low price :cool:
I accidently have deleted the set of STP-Files a couple of months ago and was too lazy to make new ones. I Just have the original .FCStd-Files from FREECad, the DXF-Files for the waterjet cutting and a parts list (German). It's a 10mb Zipfile package that I can send you. Send me a PM with your email adress.

Cheers

Charst

Thank you DIYer

Charst

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.

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

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

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:

https://www.homemadetools.net/forum/...OfTheWeek4.pnghttps://www.homemadetools.net/forum/...eWeekIcon4.png

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! :thumbsup:

Hi again,

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

https://youtu.be/jy5sNmDKLR0

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.

Quote:

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Originally Posted by 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.

---

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

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......

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

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Hi Charst,
It‘s a great tool and project, what you don’t find each day...

Would it be possible to receive some files to rebuilt it?

Thanks a lot....

Best regards
Charmilles

fit bit of gear whats the chances of getting any Drawings/plans of this wonderfull piece of kit

Thanks Charst for that great device! I am interested in step files. Is it any chance to get ones?

Looking for info on the air chamber and the drawings fornthe mechanics of thw machine. I am getting ready to build mine using a brake chamber from a air brake system off a truck but that looks much easier! Thank you so much