Hydraulic Rams

[Jerf123]

Seen a thread kinda like mine, Didn't know if to ask there or start another. I don't want to be rude and get every thing off topic. If you machine a Hydraulic ram with a cylinder id of .375 and a one piece rod with piston at bottom, piston od of .375. Do you need a seal on the piston? or will air pass by but oil will not ?

And at the crown can you press in a brass bushing with a rod diameter of .125, brass bushing id of .125 also will it seal or have to insert a o ring into the bushing id?

[Lil Giants]

You'll still need seals on both rod & piston to keep the fluid in.

I've never selfmade any cyls myself, but I would assume you would need 005 to 010 clearances between metal parts.

[Jerf123]

Thank you lil giants that's my argument with my dad, we're making a hydraulic valve for my project . I said it needs o rings on the piston, he said no it it is within .0001 it shouldn't but I still say it needs o rings. If I cut a slot in the piston and inset a o ring ,not to the od but a little larger.where the o ring has to be compressed ?

[Lil Giants]

Correct. Although I don't know how much it should be compressed.

I think there is a thread in this constr tech forum where somebody posted schematics of cyls he made... I'm rushed for time or I'd look myself.

[Jerf123]

Ok first i have to thank you sir for answering my threads. And i seen a thread on there you commented on the Wheeled excavator Liebherr A934, He showed a picture of the rams he built and the seals one green and one blue. Now i seen the link to the website and can not translate it any way good enough to read and search easy. My computer and firefox search i google the name oring - uszczelnienia techniczne and hit translate, but it limits the search and icons to click.So do you or other members know of a english place for seals and o ring like that web site

[Lil Giants]

Steamer is building his own telescoping cylinders for his 789C haul trk that is a converted Tamiya Mammoth.

http://www.rctruckandconstruction.com/showthread.php?t=1350&page=10

Post#207 http://www.allsealsinc.com/ukp.html