Your press

[cplmac]

I just got my press today and I'm pretty fired up! Just wanted to share and see what other presses are being used. Here is a pic of my new tool:

http://images.kodakgallery.com/photos2352/3/38/20/59/16/0/16592038311_0_ALB.jpg

This press is a Troy ME8820 20-Ton. Air Hydraulic Shop Press.

[itwasntme]

Damn! Thats one nice press. I don't have a press and dont intend on making one, no metal working skills Hmm, maybe I can read up on metal working and get some equipment for the holidays.

What pressures does that do?

[Mumbles]

You don't need metal working skills. A simple bottle jack and wood can do it.

 

I dunno if you can see this picture, but something like this can be just as strong as a metal press.

 

http://www.passfire.com/archives/issue2_12/comet5.jpg

[ewest]

I have a 12 ton press I bought at Harbor Freight. You just bolt it all together. The only thing I added was a blast shield. I bought 5 sheets of Lexan from Home depot and using a little creativity just bolted them to the frame. I wore out a 3/8" drill bit drilling through the steel but it wasn't so bad.

[Lord Sidious]

ewest: Is that the P2F gauge from wolter pyro tools? I’m thinking of grabbing one when I build a press, and wanted to know how they are.

[cplmac]

Damn! Thats one nice press. I don't have a press and dont intend on making one, no metal working skills Hmm, maybe I can read up on metal working and get some equipment for the holidays.

What pressures does that do?

It is rated for 20 tons, but having seen it assembled and in action today I'm pretty sure it could do more. I don't think I will ever use anywhere near that much pressure though. I made my first 2lb. long winded screamer today. Very happy, complete success. I see a long future with this rocket stuff.

[ActionTekJackson]

You don't need metal working skills. A simple bottle jack and wood can do it.

 

I dunno if you can see this picture, but something like this can be just as strong as a metal press.

 

http://www.passfire.com/archives/issue2_12/comet5.jpg

Sweet!!! I had no idea... and here I was saving money to buy a metal one when I have all the materials I really need out in the scrap pile, wOOt!!

[Frozentech]

I have a 12 ton press I bought at Harbor Freight. You just bolt it all together. The only thing I added was a blast shield. I bought 5 sheets of Lexan from Home depot and using a little creativity just bolted them to the frame. I wore out a 3/8" drill bit drilling through the steel but it wasn't so bad.

Dang man ! You stole my press *and* my P2F gauge. I have the exact same Harbor Freight model, but only 2 sheets of lexan ( a bud gave me a piece of 1/2" thick I might replace that with ).

[psymon]

I use a two ton Arbor press. No blash shield. I only slowly press 34c 5s 61kno3 BP rockets with this. BP is pretty safe to press in my opinion its never gone wrong and I have pressed hundreds of rockets with this. Bought it off eBay for £31 - thats including postage! They retail at around £150.

[ewest]

LOL, yeah that's Wolter's P2F gauge. It works great, takes all the guess work out of Force>PSI and vice-versa.

 

Frozentech all I can say is great minds think alike huh? I'd like 1 piece of Lexan but Home Depot only sold them in thin sheets so I just stacked them. Overall it's a little thicker than 1/2". I figure thicker is better on the blast shield because when pressing rockets they happen to be right at crotch level........don't need that exploding now do I?

[brainfever]

I use a 15 ton hydraulic jack in a home-welded frame, sprayed red to protect against rust.

 

I have yet to fing a piece of suitable material to use as a blast screen, but I doubt I will actually use one ever ... it's only really required for the more sensitive compositions like whistles afaik.

 

 

A pressure meter however IS something I am gonna get myself sooner rather then later.

[ActionTekJackson]

Alright, I just finished my press frame (for the most part) I was cheap and made it out of 2x6 wood, but it's hella strong, I'll post pics soonish. However, I have a piece of 1/4" thick plexi glass, will this work as a blast sheild? The biggest rockets I can make with the frame is a little bigger than 1lb, but I'll mainly be making 1lb'ers, BP, Whistle, and strobe composition rockets. I'm only gonna be using a 4ton bottle jack. The other option is to buy a 1/2" thick sheet of Lexan, can I get away with the 1/4" safely though?

[cplmac]

I've been really kicking around the idea of getting that guage from Wolter ewest, have you had any problems balancing the tooling on it? Also, I took a good look at the picture of your press, everything below the ram is exactly the same as mine, even the black base blocks. Nice set up.

[Frozentech]

Alright, I just finished my press frame (for the most part) I was cheap and made it out of 2x6 wood, but it's hella strong, I'll post pics soonish. However, I have a piece of 1/4" thick plexi glass, will this work as a blast sheild? The biggest rockets I can make with the frame is a little bigger than 1lb, but I'll mainly be making 1lb'ers, BP, Whistle, and strobe composition rockets. I'm only gonna be using a 4ton bottle jack. The other option is to buy a 1/2" thick sheet of Lexan, can I get away with the 1/4" safely though?

The short answer is no. No, do not use plexiglass or acrylic, use Lexan or another brandname of polycarbonate (Tuffak is one). Using plexiglass as a blast shield is similar to using PVC for a mortar tube. 1/4" lexan would be minimal in my opinion, but you can double up sheets for extra strength.

 

A good read on this topic is the blast shield experiment done by Tom Calderwood, a VP of the WPA....

 

WPA Blast Shield Experiement

[Frozentech]

I've been really kicking around the idea of getting that guage from Wolter ewest, have you had any problems balancing the tooling on it? Also, I took a good look at the picture of your press, everything below the ram is exactly the same as mine, even the black base blocks. Nice set up.

I've had no problem balancing tooling on my Wolter gauge. The working surface of it is the exact same size as both my 1# rocket spindle base, and my BP pressing die.

[ewest]

Frozentech's right, plexiglass isn't any good, it'll shatter like a PVC mortar would. Lexan is much better, or plywood, but you can't see thru plywood. mine is 3/8"-1/2" thick. You can also stack sheets to get that thickness (I did), you don't actually need a solid 1/2" thick piece. There's another thread on the forum already about blast shields if you do a search, that might help more.

 

For the gauge on the press, I haven't had a problem balancing the tool on it, that part works really well. But I have had a problem with the upper part cocking the rammer of the tool off to the side. I had Rich Wolter make me some collar sleeves that connect to the upper part of the press rammer that touches the tooling rammer so it wouldn't slide off. I can take pic's of them if anyone is interested. That fixes the problem somewhat, except the the entire press actually cocks out of square when it's under pressure. I thought about welding in some angles to stiffen the whole thing but I like being able to take it apart for traveling.

 

My next revision to the press is going to be some polyethylene (white cutting board) shims between the horizontal bar of the press that slide down the legs. Hopefully this will take up some of the play in that part and it won't go out of square so bad.

[ActionTekJackson]

Alright, I just finished my press frame (for the most part) I was cheap and made it out of 2x6 wood, but it's hella strong, I'll post pics soonish. However, I have a piece of 1/4" thick plexi glass, will this work as a blast sheild? The biggest rockets I can make with the frame is a little bigger than 1lb, but I'll mainly be making 1lb'ers, BP, Whistle, and strobe composition rockets. I'm only gonna be using a 4ton bottle jack. The other option is to buy a 1/2" thick sheet of Lexan, can I get away with the 1/4" safely though?

The short answer is no. No, do not use plexiglass or acrylic, use Lexan or another brandname of polycarbonate (Tuffak is one). Using plexiglass as a blast shield is similar to using PVC for a mortar tube. 1/4" lexan would be minimal in my opinion, but you can double up sheets for extra strength.

 

A good read on this topic is the blast shield experiment done by Tom Calderwood, a VP of the WPA....

 

WPA Blast Shield Experiement

Ahh... Thanks, thats what I wanted to know. I will read up on that link and do some searches just so I can understand the differences between Lexan and Plexiglass. Thanks to ewest as well, much appreciated.

[h&k machineguns]

I have the 12 ton harbor freight press also that I bought almost a year ago spacificly for rockets,and just picked up for free from a local friend 4 sheets of 1/8th Lexan. They were already cut 18"X23".They were a little small for the width I needed but I went out and bought 1X3" oak that I'm going to have on each side of the stacked Lean,making a sandwich. I got 5/16" all thread with a bunch of washers and nuts.

I ordered the Wolter pressure gage also. I figured I needed this gage,cause my rockets are Sooo inconsistant. I think I'm either pressing to hard or not hard enough.

[ewest]

BTW, I noticed recently that Harbor Freight sells a 20 Ton Air/Hydraulic Bottle Jack for $70. It looks like you could just replace the 12 Ton Bottle Jack with this one and easily convert your press to a pneumatic press. It'd certainly make pressing rockets much faster; I'm so tired of pumping that handle on the hydraulic one.

 

In his video's Steve LaDuke uses a pneumatic press and he can press rockets pretty quick, I've always been jealous of that.

[FrankRizzo]

Actually, Steve uses a hydraulic press. In that video, the little unit that you see him pushing the lever on is a hydraulic pump...sometimes called a "power pack" or Porta-Power that supplies the high pressure fluid to the red cylinder on top of the press frame.

 

I've got the large rocket press from Hobby Fireworks that has one of those air/hydraulic jacks that you're talking about. It's great for pressing BP rockets, but you wouldn't want to use it in the air powered mode for pressing whistle, strobe, or any other sensitive fuel. Basically the air pumps the jack in small increments that kind of "hammer" the piston up.

[cplmac]

The valve on my press allows you to operate the press very slowly if you want, I use it to press whistle. If you use the valve at full speed it does have that hammering kind of effect, but the increments are so small I don't think it matters to much.

[ewest]

Ah, thanks guys for the tip on the hammering effect, I didn't know that. I'm glad I commented on the air/hydraulic jack here before I ran out and bought one.

 

The hydraulic pump seems to be the way to go. If anyone hasn't seen Steve's videos where he uses this type of press set-up. It takes him literally 1 second to press an increment, much faster than sitting there jacking on a hand jack.

[cplmac]

It's a lot faster than the air over hydraulic too. I saw a guy at the rocket tent at the PGI this year who had a cool setup. Looked like basically the hydraulics off a snow plow. The 12volt hydraulic pump and a double action cylinder. Very smooth, and much faster than the air over hydro. If you can get that setup I would recommend it over the air system I have. I just needed the sturdy frame my press came with, I have not ruled out modifying it with the plow hydraulic system. There was another guy there with a really cool foot valve set up, so he could just sit at the table and operate the press with his foot up/down and keep his hands free to very rapidly remove the tooling, load a new increment, press and repeat.

[hst45]

It's clearly overkill from a PSI point of view, but I beleive a log splitter could be modified to make a very fast press.

 

1) You would need to fabricate a "shoe" to clamp to the wedge-shaped head of the ram.

 

2) You would need to either be VERY careful not to over-press (crush) your motor unless you either

 

a) reduced the pressure from the pump or

 

" installed a regulator between the valve and the ram.

 

An in-line pressure gauge would be almost essential. This is of course insanely expensive unless you already have a log spliter, but I bet you could use a rig like this to complete a motor in less than a minute.

[cplmac]

Sounds a little risky to me. Not because of the speed, a good valve can fix that, but pressing horizontally might present some problems. You could find that your comp collects on one side of the motor, or spills out on the first increment. But I see no reason why you couldn't stand the thing up vertical. Good idea.