Wanna move up to 1lb

[MrCATO]

I've turned out probably a hundred 8oz black powder motors now and I want to go a little bigger to lift my headings. 

I don't know exactly where to start though. I was thinking whistle due to it's lifting power, or at least I heard it was better than BP in that regard.

I'm thinking I probably won't be able to crank out 1lb motors with my 1 ton arbor press. I like the electric hydraulic presses caleb makes but those are way out of my price range. Would it be possible to DIY a press using one of those vevor hydraulic power packs on ebay, a cylinder from a local tractor store and build my own frame (not welded)? I prefer something not welded so I can brake it down for storage in my off season. I noticed the one ned gorski uses on one of his video looks similar to my arbor press. It has the threaded rod, pvc and hardware for the legs of the frame. As a matter of fact so does his arbor press and that's where I got the idea from for mine.

 

I'll admit I know very little about hydraulic systems but I'm under the impression I'll need a pressure relief valve. What other things besides hoses and a battery?

Can the base be made with steel channel?

Does the top part that the cylinder mounts to need to be as robust as the base?

I'm also looking to add strobe effects later once I get the whistle part down. Should I go with universal tooling or the extreme whistle tooling?

Edited July 29 by MrCATO

[Arthur]

The lessons learned with previous BP rockets can carry forward to bigger BP rockets, but likely NOT to whistle rockets. 

Be very certain that your press design is up to standard before testing it with a rocket and fuel.

[All10Fingers]

You can use some angle iron and some all thread to make a frame around a bottle jack... Look up "rosin press" people diy them all the time to press weed concentrates. That field actually has lots of things that translate over to pyro well. That's how I got my sieves and  puck making stuff. 

[DavidF]

The generally accepted loading pressure for BP rockets is 6500psi, give or take. A 1 ton arbor press won't do it. BUT, IF you want to use hot (milled 75-15-10) BP and carefully screen 2 1/2% of water through it, you can press nozzleless BP rockets at 3400psi on a 1 ton arbor press. Commercial BP is compacted at about that pressure- also using water. To get 3400psi, the arbor press must exert 1500 pounds of force on 1lb tooling. That's 75% of its rated capacity. Most people are unwilling to try this because all the literature talks about higher pressures- because the 'normal' way is to press dry. Try the water once and see what you get. The first time I did, I never looked back. Now I sound like a broken record. But consider this: finding cheaper, easier ways to do things doesn't sell high dollar stuff. 

To make a water-damped nozzleless 1lb BP rocket I spritz the water in, and screen the milled BP a couple of times, mixing by hand in between screenings. Ideally, it's left to temper in a sealed container overnight. I use a steep sloped funnel and 7.5ml increments, a bit more for the first increment. I use a waxed tube. I use the PtoF gauge to set my torque wrench so that a slow pull clicks it at 1500 pounds. This works out to 105 foot pounds on my torque wrench. ABOVE the spindle, I use FeTi or Ti stirred into the increments for a tail, maybe 1/8 to 1/4 teaspoon per increment. I use 3 increments above the spindle tip, and that provides enough delay. 4 would be a bit much, I think. I mostly use 1lb standard BP motors, and they lift 4" ball shells nice and high. Cohete tooling has a shorter spindle than what I use.

If you don't have 1lb BP tooling yet, try the water-damped BP with your 8oz. tooling, at the same loading pressure (3400psi). That will be 1044 pounds of force on the comp area. The only thing is that the damp powder doesn't want to go down the funnel as easily as granulated powder. The extra futzing is a trade-off for not having to granulate the powder, IMO. That's why I suggested a steep funnel. It's easier to get the powder down on a 1lb tube, and easier still on a 3lb tube.

Another way to get more lift on a nozzleless BP rocket is to use a hybrid propellant, like 25% whistle stirred into 75% BP (dry). When I did that, I used wax-granulated BP and wax-granulated whistle, and just hand-mixed them. In that case, the wax was in the BP, so I didn't wax the tube, since that was not an option yet. DJ, the originator of nozzleless BP rockets, ended up using wax in his, so I just followed along.

Just a few of one pyro's thoughts on it that might encourage a bit more experimentation with what's in hand before going bigger. 

[OnlyFuse]

A popular Youtuber converted an existing off the shelf manual hydraulic shelf press, in the same kind of manner you're thinking of, it may give you some food for thought.

 

[MrCATO]

5 hours ago, OnlyFuse said:

A popular Youtuber converted an existing off the shelf manual hydraulic shelf press, in the same kind of manner you're thinking of, it may give you some food for thought.

 

Looks like an option. The small footprint of that press seems very desirable. Wouldn't be able to weld though. I wonder if cylinders typically come with a way to mount them. I found these at the tractor store, I don't know much about them.

[OnlyFuse]

Hydraulic cylinders with flanged mounting plates do exist.  

Offerings from larger companies like Enerpac, to no name brand Chinese or Indian manufacturers. 

It would be important to select something with suitable stroke, to ensure it will work for your needs. For example, to short of a stroke you may not be able to press the entire tube, without adjusting the height of the ram or the work piece.

Bore diameter is also important to calculate the pressure, but most will be advertised to a certain tonnage. 

A dual action cylinder would be best suited, so the hydraulic fluid can extend the ram, but also retract it. 

Not to discourage you, but you may find that once you add up all the parts, the cost might not be to dissimilar to Woody's offerings. 

Edited July 31 by OnlyFuse

[ThrownBiscuit]

It might be a good idea to modify a bottle jack press or just use the bottle jack press with one of Woody's pressure to force gauges.

Strongway 12-Ton Hydraulic Shop Press | Northern Tool

This press is held together with bolts and breaks down relatively easily.

If you are going with whistle, I would also recommend a piece of plexiglass to use as a bit of a blast shield while you press. Just something to resist shrapnel if things go wrong.

Fab Glass and Mirror Plexiglass 30 in. x 24 in. Clear Rectangular Acrylic Sheet 1/4 in. thick Flat Edge Rust : Scratch Resistant Coffee Table C-ACR6M30X24RC - The Home Depot

 

 

[Mumbles]

Ideally you'd want polycarbonate, not acrylic for a blast shield.  It's more resistant to cracking or shattering.