elevation adjustment

[kydavies]

I hate to go fishing but Im looking for ideas on an elevation adjustment system for the cannon/carriage posted below

[biged]

It's complex but I made a couple "standards"...



One on a replica 4.2 inch mortar, and another on a 81mm cart mounted mortar.

There is a 1" inch RH threaded pipe with a 3/4" LH threaded rod inside of it. The 1" pipe has a wheel welded to it. When you spin the wheel it elevates/lowers quickly due to the counter acting threads. Just like in a T&E (traverse and elevation).

My copy:


Made another style a long time ago using a automotive door window crank. But it looked like hell....

[Zeus]

While that's a very nice system, here's somethin for the folks without excellent skills (I don't know yor capabilities KY, so I'm catering to the lowest denominator.)

http://en.wikipedia.org/wiki/Turnbuckle

[kydavies]

Biged, LOVE the mortar, please tell me its functional
thanks Zeus, but i dont think I could bring myself to use a turn buckle... Here's a hint about my capabilities, CWB qualified Welder/Fabricator with home access to welder (steel and aluminium), basic grinder, Oxy fuel torches and half a drill press (needs new chuck but it sorta works). plus Ive got access to a brake press at work
So as far as capabilities go i can pretty much make anything that doesnt require a lathe or a milling machine
Also I think it'll probably get used as a howitzer/mountain gun as oppose to direct fire so il be needing large changes in elevation. maybe some sort of screw mechanism connected to the frame and the shaft on the bushing...?

[matti]

If your using that cannon with air compressor, you could use pneumatic cylinder for tilting.. I have made one that uses cylinder. You can control pneumatic cylinder with 5/3 directional control valve (5/3 DCV,and model that has "all ports closed at middle position"), that way you can "lock" the cylinder at the desired elevation angle.
With 12 or 24V 5/3 control valve and cylinder it would be fast and easy to tilt the cannon, maybe you could make some control box with battery and up/down buttons ?
You can find very cheap pneumatic cylinders and DCVs from Ebay

[kydavies]

Something more along the lines of this (posted below). I prefer the more mechanical approach with ropes and stuff.

[POLAND_SPUD]

If I can suggest something just get a threaded rod, one of these and a nut attached to the barrel. Plenty of torque and precision.


Mount one of these at the base
and another motor + driver (they have enough torque for it don't worry they are geared step motors)

[biged]

Biged, LOVE the mortar, please tell me its functional

Yes. It's here:
http://www.spudfiles.com/pneumatic-cann ... ml#p208016

[dart guy]

Your rope idea is good, but you may want a gear and a bike chain.also you should make it so that it will lock in place. i will probably be back with more ideas

[kydavies]

Just an update here Cannon kicks butt!! still have to get me some bike gears and chain but were putting manderain oranges 250-300 meters. also moddified the breach to reduce dead space and better air flow

[jackssmirkingrevenge]

Looking good, needs some "fire in the hole!" videos though

[kydavies]

its comming. im headed to the dump tomorrow and il see if i cant find some bike gears and chain for a proper elevation adjustment. Unfortunately my 12v compressor went up in flames after repeated 150 psi shots, so im in the market for one of those too