Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.
hobgobbln wrote: ↑Mon Jul 16, 2018 2:43 pm
That’s why I was asking about the TPG because it said it COULD be hardened which to me meant it wasn’t.
Hardening, unless you have the ability to deal with the resulting scale and change in diameter, isn't a good idea. Even with a controlled atmosphere furnace, the heat treat process will demand further finishing. Small parts are best machined oversized, heat treated, then ground to assure proper size and finish. A small cylindrical grinder would help you immensely.
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Neither do 3 in 1's, but I have machined 1" to 3" diameter 1045/1050 IHCP cylinder stems on a Smithy 1340. Step down for the piston, big radii, and threads, and all.
Can't take big deep cuts as a 'real' lathe, but it's very well and easily doable.
And, I would much rather machine 1045 IH, or 4140 Q&T, or most any hardened steel, than ugly old mild steel. Even on my old Smithy. Sharp tooling...set up right....know the machine...and yup....you can do it. Even on a Horror Freight. (Done that too)
Im a bit confused. are you using the shaft for the piston or the rod? sounds like you are planning on using it for the piston ??
is this a push pull cylinder or only a push??
DavidF wrote: ↑Mon Jul 16, 2018 11:52 pm
Im a bit confused. are you using the shaft for the piston or the rod? sounds like you are planning on using it for the piston ??
is this a push pull cylinder or only a push??
I believe it’s called the piston rod. It would be the (generally chromed) shaft that moves when fluid is pumped into the cylinder.
As far as single or double acting goes, I’d like to eventually make a double acting, but just to experiment I’ll start with a simple push with an exterior spring return. These are meant to move the fingers in a mechanical hand so the size needs to be relatively small. That’s also why I’m not sure if I’ll be able to do double acting because the additional port and plumbing for the retract will take up extra space. I did dream up a compact double acting design that works in my head, but I’ll wait to see if it will work. My main concerns are getting a couple single acting made that don’t leak first.
Ok, now I get where you are going. You wouldnt need to hone the cylinder and might not even need to machine the rod. Just make the bore on your cylinder body a lil over sized so the rod does not touch and at the rod end of the cylinder fit it with a reamed bushing the rod would slide on and an O ring for the seal. This could be made from free machining brass and the cylinder body from brass tubing.
Here is a great site for the making of your own hydraulic cylinders http://rctruckandconstruction.com/
and if your up for the challenge try making your own pump....
Nice lookin' little gear pump!
If you have never taken a brand new one apart, first time you do, you will think that it's already destroyed. Typically, when they pressure them up after assembly, the gears will wear into the housing. AS it turns out, talking to the Commercial Shearing guys back when, that's a normal part of the engineering & design.
DavidF wrote: ↑Tue Jul 17, 2018 7:40 am
Here is a great site for the making of your own hydraulic cylinders http://rctruckandconstruction.com/
and if your up for the challenge try making your own pump....
20170527_152617_resized.jpg
Thanks for the link! I’m sure I’ll have a lot of reading to do there.
I wasn’t actually planning on a pump. The plan was to use another cylinder in a sort of closed loop. There’s a bunch of videos of people making robot arms out of cardboard and two plastic syringes plumbed together. That’s the sort of idea I had in mind but with a stepper and leadscrew to move the remote cylinder. It would be a different volume so it could act as a fluid reserve too in case my hand cylinders weeped a little.