Need to construct pic related, any ideas?
Don't know what parts to use, how to bring the main pipe down to an adapter for a valve etc.
Also don't know what sort of valve to use to inject the oxygen into the tube.
It's for a hybrid rocket, so needs to be fairly strong. No woods or plastics. Weight is not an issue.
Feel free to ask me anything you need to know.
only way to do it is to weld the shit together.
you need a tube for the end on your right welded to a circular plate, with a hole in the center. Then you need a pipe for the main body. I don't know wtf you have going on on the left.
What kind of valve depends on what you want to do, how you want to actuate it, how you need to control flow. If this thing is going to be moving and not a bench model you will need an electrically actuated valve. Which means you will also need to carry a battery. If you need precise metering of the ox flow, or if you need a wide range of different flow rates you will need a servo controlled valve. Then you will need a PLC of some sort that you can program, in addition to the battery.
need to know more about the dimensions you are working with. You can buy pre threaded pipe components, but based on your drawing it would be hard to neck your big part down to your small part just with reducer bushings.
One way you could do it is build it like a tie bar type hydraulic cylinder.
So you get a plate to make up your end that the oxygen is going in. I would suggest aluminum.
Then drill 4 holes for the tie bars
Then drill a hole in the center you can tap with pipe thread for your oxygen tube
buy a pre threaded pipe nipple for your oxygen tube.
get a section of pipe or tube for the big part
make another plate similar to the one you just made for the ass end of the assembly
get some threaded rod, sandwich the center barrel between the 2 end caps and draw together with nuts
seal the seams off with epoxy or solder. If you were to really do it right you would machine a groove in the cap plates for the barrel to seat into, and seal itself, but I doubt you have those capabilities.
source, I own a machine shop.
I would do it on a cnc mill and cut the groove and do the holes all at the same time
you can also make each end cap out of 2 plates. Then instead of a groove cut a hole the full diameter of you barrel in one of the plates. So the barrel passes through one plate and butts to the second plate. You would have to have nuts on both sides of your end caps then to hold the plates together. Or just have 2 hole patterns. 1 for the tie bars an one to hold the plates together with bolts.
Alright, here's my rough plan then.
Stainless steel, 1.5mm thickness 70x150mm tube
Two end plates with your second construction method (not sure what metal I'll use)
Need to put O-rings in there so it doesn't explode/lose pressure
How should I mount the inlet valve for the oxygen, and the engine bell?
Is it going to get hot though? The o rings will melt if it does. You can get high temp sealant. You could be less precise with your machining if you had something you could glop in there.
If you are using a pipe nipple for your inlet then you will have male pipe thread on either end. One screws into your end cap. The other end screws into your valve body (sub base).
So you need a 2 position, 2 way directional valve, with a sub base, (this is just an aluminum block that is already ported for the valve, and the ports for the fluid or gas to go through. Usually ports in sub bases like this are o-ring boss. So you just need an adapter to go from the male pipe thread nipple that is coming out of your end cap, to the o ring boss port in the sub base. Then you need to plumb the other port in the valve body to your oxygen.
what is the engine bell?
I don't see why you would use anything but aluminum for the oxygen end. If the other end gets real hot then use steel or stainless.
You want to avoid stainless for anything you are going to machine. Its a bitch to cut.