TGP for hydraulics

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hobgobbln
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TGP for hydraulics

Post by hobgobbln » Mon Jul 16, 2018 9:21 am

I’ve had an idea floating around in my head since I was a kid that would require miniature hydraulic cyclinders. So I figured I’d give it a shot.

I know how hydraulics work but other than rebuilding a couple snow plow cylinders I have zero experience.

I’m wondering if TGP shafting would be smooth enough to use as the piston. I’ve seen 1/4” 1045 TGP available and that would be small enough for my use. These would only see 100-300 psi of pressure and limited cycles. They’re for positioning and would never be able to hurt anyone if they fail but I’d like them to last if I’m going to go through the trouble of making a dozen or so.

Is chrome plated actually required for hydraulics or would that shafting work?

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GlennW
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Re: TGP for hydraulics

Post by GlennW » Mon Jul 16, 2018 9:49 am

Check out a screen door closer at Ace or Home Depot, etc. as they should have a chrome plated shaft about that diameter.

I just made some hydraulic shafts from 12mm chrome plated shaft, but I don't see anything near 1/4" available.
Glenn

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hobgobbln
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Re: TGP for hydraulics

Post by hobgobbln » Mon Jul 16, 2018 10:02 am

So is it safe to assume that chrome is a must?

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warmstrong1955
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Re: TGP for hydraulics

Post by warmstrong1955 » Mon Jul 16, 2018 10:08 am

If you have a hydraulic rebuilder around, you might give them a call for the real thing, or where to get it. I have never used any smaller than 1/2”. Most cylinder rods are 1045/1050 IHCP. Most is case hardened, some is thru hardened.

That said, chrome is not required, but a good finish is. The smooth finish will make the rod seals last longer. Chrome also prevents rust, and dings. I have built cylinder rods with various different TG&P’s, but it was always a temporary fix due to availability of the CP rod we needed. Things rust quickly in most mines.

Bill
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John Hasler
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Re: TGP for hydraulics

Post by John Hasler » Mon Jul 16, 2018 10:12 am

Consider using air cylinders with oil instead of air.

hobgobbln
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Re: TGP for hydraulics

Post by hobgobbln » Mon Jul 16, 2018 10:39 am

These will be part of an animatronic hand so environment and issues with abuse don’t apply since it’s just for me and will live indoors.

Ok so I guess I could get away without chrome for a while. At least for testing purposes. I supposed if they work in the end I could maybe have some chromed.

Thanks for the help everybody. I’m sure I’ll have more questions before I’m done =]

Griz

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warmstrong1955
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Re: TGP for hydraulics

Post by warmstrong1955 » Mon Jul 16, 2018 10:58 am

You might check online for robot parts & supply companies. Thy might have some small diameter chrome rods. Used to get stuff like that from Small Parts Inc. They were absorbed by the Amazonians....

A friend of mine, years ago, helped his brother design the hydraulics, including the cylinders, on a robot. It was a big dinosaur car-eating thing. Saw some pics and videos of it when they got to testing. One of 'em, it choked on a bad Datsun, and popped a hydraulic hose in it's mouth! :) But that's what testing is for!

Bill
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hobgobbln
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Re: TGP for hydraulics

Post by hobgobbln » Mon Jul 16, 2018 11:57 am

I think it will take me a while to get to fine vehicle dining. :D

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warmstrong1955
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Re: TGP for hydraulics

Post by warmstrong1955 » Mon Jul 16, 2018 12:01 pm

hobgobbln wrote:
Mon Jul 16, 2018 11:57 am
I think it will take me a while to get to fine vehicle dining. :D
LOL!
I hope you post some pics, or better yet, vids, when you get it pokin' at things!

Bill
Today's solutions are tomorrow's problems.

DavidF
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Re: TGP for hydraulics

Post by DavidF » Mon Jul 16, 2018 12:11 pm

would 6mm chromed rod work for you??
https://folgertech.com/collections/line ... ter-cnc-o1

MrWhoopee
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Re: TGP for hydraulics

Post by MrWhoopee » Mon Jul 16, 2018 12:58 pm

The hard-chrome plating on chrome rod is principally for abrasion resistance. A little dust under a rubber seal with the shaft cycling back and forth will eat up the shaft in a surprisingly short time. In your case, this is probably not a major consideration.

Thomson shaft is available in 1/4 in., and will definitely hold up. The question is whether you can machine the features you need.
https://www.thomsonlinear.com/website/c ... oducts.php

hobgobbln
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Re: TGP for hydraulics

Post by hobgobbln » Mon Jul 16, 2018 2:43 pm

As long as that 6mm isn’t hardened it would probably work. I was thinking 1/4” because it looks like I can get a hone for doing the cylinder body, but I didn’t look for metric ones. I’ll have to look around later and see what I can find.

I was originally thinking about bearing shaft but I don’t have any way of machining it for seals, rod ends, etc if it’s hardened. That’s why I was asking about the TPG because it said it COULD be hardened which to me meant it wasn’t.

Thanks for the links.

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