2240Ti

[Jimsiss]

I know how you feel about fit, I’m working as a CNC turner at a precision engineering company where we specialise in scientific equipment. Working into the microns quite often and I enjoy seeing how close I can get the machines to mid limit

 

[ed_t]

Today was a bit of a slow day but thankfully I now have another 2240 to work on (Thanks to Chris in the sales section) and make bits for. Stainless this time I think, it's gonna weigh a tonne though
Once all parts are proved and safe I'll upload all the drawings for anybody else to use freely for any lawful purpose (make em, sell them, whatever ,I don't mind) I'll chuck up the programs in G-Code and Prototrak format as well for anybody that has access to these machines.

The cylinder tube reducer is the next bit so I can use a 32.5mm diameter cylinder but with a reduced diameter at the rear so I can still have the std 7/8th (22.22mm) diameter body tube and striker etc.

Not sure whether to go for a concave radius or a simple taper (where it says R5 on the drawing) The 32.5mm diam section will be for the Pressure Gauge, Burst disk and Fill adaptor (all fitted on spot face flats)

Weekend should be good and hopefully get a lot more done.

View attachment 958567

Hello Squire, new to the forum and rootling around just found this very interesting thread. I've spent my working life in process plant engineering, piping, pressure vessels etc so would suggest if above is pressure bearing something like a 30 degree taper would be best. The wall thickness on hemispherical pressure vessel heads is half the cylinder thickness and the transition is always tapered through the tangent.

You seem fully clued up on materials and something that has me puzzled is why no one seems to be working with super duplex stainless steels. I first used these for a 400bar working pressure CO2 system. 316 TI tube was close to the knuckle so super duplex it was.

Give or take the same density as the 300 series SS but double the proof and yeild strength.

Listening to the cricket I've occupied myself with the following rough and ready calculation:


Super duplex wins out here for fixed volume/OD/pressure. 7076 alloy would shift towards that for lightness but length is going to be higher, ditto higher strength titanium grades. I've not worked with these so don't have a feeling for the allowable stresses in piping or pressure vessel codes.

Not a big fan of aluminium because of work hardening and cracking, though an air receiver isn't really anywhere near a fatigue life limit.
Anyway, carry on with the good work and interesting thread. Looking forward to see the build complete.

 

[SpookyESU]

Hello Squire, new to the forum and rootling around just found this very interesting thread. I've spent my working life in process plant engineering, piping, pressure vessels etc so would suggest if above is pressure bearing something like a 30 degree taper would be best. The wall thickness on hemispherical pressure vessel heads is half the cylinder thickness and the transition is always tapered through the tangent.

You seem fully clued up on materials and something that has me puzzled is why no one seems to be working with super duplex stainless steels. I first used these for a 400bar working pressure CO2 system. 316 TI tube was close to the knuckle so super duplex it was.

Give or take the same density as the 300 series SS but double the proof and yeild strength.

Listening to the cricket I've occupied myself with the following rough and ready calculation:
View attachment 998476

Super duplex wins out here for fixed volume/OD/pressure. 7076 alloy would shift towards that for lightness but length is going to be higher, ditto higher strength titanium grades. I've not worked with these so don't have a feeling for the allowable stresses in piping or pressure vessel codes.

Not a big fan of aluminium because of work hardening and cracking, though an air receiver isn't really anywhere near a fatigue life limit.
Anyway, carry on with the good work and interesting thread. Looking forward to see the build complete.

Thanks
I’ll get more updates done when I get back, working away pays well but it’s crappo for the social life