machine made rams

[Jackpietrzak1]

I know some teams build or machine their own rams for heavyweights & featherwieghts robots I just want to know how long it takes to make & how much they get sell if other teams ask to have them made?

[maddox10]

Low pressure or high pressure? Material? Starting from a tube or billet? Tie rod, threaded end or screw in endcaps? Standard size of full custom?

Also, selling rams is an expensive proposition. According the rules every custom piece needs an independent certification.

9.7 Rating
All pneumatic components used with pressures greater than 50psi (3.4bar) must be rated or tested to at
least the maximum pressure available in that part of the system. You may be required to provide
documentation or certification to support this.
9.7.1 Custom Components
Custom made components, or parts operating above the suppliers maximum working pressure, must be
independently tested and certified at 120% of the maximum system pressure available at that point.

[Jackpietrzak1]

So for all low pressure, high pressure & full pressure pneumatics systems as well hydraulic systems what is the difference in power when use from co2 power (low, high & full pressure) & hydraulic power (low, high & full pressure) if the ram is built or machined from steel, titanium or even aluminium tubing & billet?
is making a home made ram from steel, titanium or aluminium easier to build than machine it from a block of steel, aluminium & titanium?
if there any thing I should know about building or machining home made rams for featherweight robots & heavyweight robots then let me know as I'm doing a booklet on building robots for my friends & one section will be about have more experience, understanding & more knowledge in building robots in the future & not to make them as a starter.

[maddox10]

Making a ram isn't rocket science, rather basic turning, milling, drilling and tapping.

But going to the basics of machining metal , that's a tall order. I suggest looking such up on the net. Lots of tutorials on Youtube.

If there is a thing different between a commercial ram, and a custom ram, it's moving mass. Keep that as low as possible.

[Jackpietrzak1]

what mathamatics would have to use to know how work out the bore, bar & stoke of the home made ram?
for example FESTO DNC-50-40-PPV-A STK 40MM BORE 50MM 10BAR PNEUMATIC CYLINDER B374069' that I found on ebay.

[maddox10]

what mathamatics would have to use to know how work out the bore, bar & stoke of the home made ram?
for example FESTO DNC-50-40-PPV-A STK 40MM BORE 50MM 10BAR PNEUMATIC CYLINDER B374069' that I found on ebay.

Strange question. You design a ram to do what you want.
Bore and stroke are mandated by the force you want to produce, and the space you have.
But basic mathematics. Force is the result of pressure on a surface.
The surface of a normal ram is a circle. Surface of a circle is radium*radius*pi (radius is half the diameter or bore)
Bar is the unit for pressure in kilo per cm². 1 bar means 1 kg of force on 1cm².


For that tiny festo ram you found on Ebay the following numbercrunching will happen.

40mm bore. In cm you get 2cm*2cm*pi=12.56 cm² @ 10 bar that makes 125.6 kg of force over 50mm.