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fishfrnzy
12-02-2010, 02:15 AM
Looking to make a small cylinder similar to the one shown to set the feed on a smallish saw (app 7" x 12"). 4" of stroke should be enough. The questions is what to use as seal on the piston and what to use to seal the shaft entance to the cylinder. I have a couples sizes of DOM tub that can be honed ( the one ithat I checked was very round on ID at both ends.) the valve I'll post in separate thread.

http://i875.photobucket.com/albums/ab312/fishfrnzy/cylinder.jpg

macona
12-02-2010, 02:22 AM
I built one around middle school for my dad's Jet 4x6 bandsaw. I made it out of the parts I scavenged from an old shock absorber. Cut it open and used a lot of it. The rod and piston, the cylinder and the end caps. The piston had a check valve in it already so when you lift up the oil flows through the piston. On the down stroke the valve closes and oil passes through a fitting on the bottom of the cylinder, through a valve, and back into the top of the cylinder.

AllThumbz
12-02-2010, 09:00 AM
Here is a source for the piston:

https://www.surpluscenter.com/item.asp?item=4-1486&catname=air

and the Flow control valve:

https://www.surpluscenter.com/item.asp?item=9-4313-A&catname=hydraulic

and here is a thread that outlines the process:


http://hobby-machinist.com/index.php?topic=242.msg817#msg817

drmico60
12-02-2010, 10:37 AM
Looking to make a small cylinder similar to the one shown to set the feed on a smallish saw (app 7" x 12"). 4" of stroke should be enough. The questions is what to use as seal on the piston and what to use to seal the shaft entance to the cylinder. I have a couples sizes of DOM tub that can be honed ( the one ithat I checked was very round on ID at both ends.) the valve I'll post in separate thread.

http://i875.photobucket.com/albums/ab312/fishfrnzy/cylinder.jpg

I've made a small hydraulic cylinder for my bandsaw. You can see it here:
http://mikesworkshop.weebly.com/bandsaw-hydraulic-cylinder.html
The design incorporates a needle valve to control the rate of descent of the saw and a bypass valve so that the sawarm can be lifted easily
Mike

deltaenterprizes
12-02-2010, 11:59 AM
I bought the whole assembly from The Surplus Center for $20 delivered and mounted it to my saw.

murph64
12-02-2010, 02:59 PM
I bought the whole assembly from The Surplus Center for $20 delivered and mounted it to my saw.

Is the oil flow restricted in both directions, or just one? I also picked one up from SC, but what I didn't know was the restriction was for both directions of the cylinder. But with that valve mentioned above, I might actually install this thing :)



Andy

fishfrnzy
12-02-2010, 09:46 PM
Nelson,
Thanks for the reference to SC. I may go that way of it proves too difficult to make but I already have all the material as scrap and the "can it be done factor" must be persued first.

Drmico60,

Very creative. I use a similar flapper arrangement for a 4" ID PVC raft pump.
Maybe I'll go with an oring for the seal on the piston.

Here is what I was thinking for the valve. They may aready be made this way for all I know (I've never dissasembled one), but if not I think it should work.

What does the panel of experts say say? FYI flow shows through adjusting rod but would actually flow along side it. The questions are numbered below.

http://i875.photobucket.com/albums/ab312/fishfrnzy/valve1.jpg