Your force gauges - do you leave then in the press during the whole process, when using a torque wrench?

[mabuse00]

How do you handle this in practice:

assuming you work with an arbor press and torque wrench:

 

Do you leave the gauge in the press and torture it with every increment or do you just use it to calibrate your torque wrench?

In fact the second way seems obvious - but maybe I overlook something here?

 

(Im just in the process to decide wether I need to add the necessary working height to my press for both the tool and the gauge's cylinder or if only one at a time is sufficient... Doing a little brainstorming you know...)

 

 

Edit:

OK, the rammers have different areas - but do you really take the effort with an arbor press, where you can barely overpress...?

Edited July 27, 2020 by mabuse00

[dagabu]

If this is about PTF gauges, there is no wear on the unit, just the O rings and gauge tube itself. Properly oiled and never dropped, they should last a million cycles. Torque wrenches are much more prone to failure. Most have to be annually re-calibrated.

[justvisiting]

I only use the pressure to force gauge to calibrate my torque wrench. I couldn't imagine using a force gauge to press rockets. The subject of adjusting force to actual rammer area has come up many times. Even the best rocket makers don't bother about it, as far as I've seen. Mabuse00, your questions have inspired me to do some experimenting. I'm not ready to write up my test results yet, but I would suggest that you leave yourself lots of throat area to press larger rockets with your arbor press

[mabuse00]

 

Torque wrenches are much more prone to failure. Most have to be annually re-calibrated.

So do manometers. But I agree their wear (when not mistreated) is much lower, they keep their tolerances quite well.

 

In fact for my needs I would not care if a wrench is out of it's tolerance, as long if the values are repeatable.

The manometer is the standard.

 

 

I would suggest that you leave yourself lots of throat area to press larger rockets with your arbor press

The throat is limited to 60mm between the feet. And no, I do not intend to saw the feet of.

But this is OK (for the tools, not for typical gauge). The working height is more serious, but I'll fix that.

 

After that I expect to be 3lb capable

[FrankRizzo]

This is how I modded mine without cutting the front off. You are limited a bit in regards to having tooling fit in the throat, but I haven't found many issues. Many of the cheaper click-type torque wrenches only give a "click" when tightening. Since it's on the right-side of the press, you're using the wrench in the opposite direction to how it would normally function. If you remove the screws holding the top bit together, the whole mechanism can be installed in reverse to allow clicking in the opposite direction. The ratcheting-direction lever might get in the way a bit, but it works.

 

 

Edited August 3, 2020 by FrankRizzo

[justvisiting]

When I modified mine, I removed the spline from the press and ground the right side to a hex shape, and mounted a 1 1/8" socket to it. The 1/2" drive of the torque wrench snaps into the socket hole, and keeps the pull arm closer to the press. I think I got the idea from Ned. I put a wheel on the left side. It's quite handy. I didn't know some torque wrenches only click in the one direction.

[FrankRizzo]

When I modified mine, I removed the spline from the press and ground the right side to a hex shape, and mounted a 1 1/8" socket to it. The 1/2" drive of the torque wrench snaps into the socket hole, and keeps the pull arm closer to the press. I think I got the idea from Ned. I put a wheel on the left side. It's quite handy. I didn't know some torque wrenches only click in the one direction.

 

@Just - Grinding it down to fit a socket would be the ideal way. I left the factory hole in case I wanted to use the original bar, but I can't see myself ever using it. Having the force from the wrench being applied way out where it is on mine creates some weird torques with the frame of the press. Your way is best.

 

Regarding torque wrenches, this was a cheapie from Harbor Freight. It's got a 2ft long handle and tops out at 250 ft.-lb.

[mabuse00]

Do your presses have some kind of bearings or sleeves in them?

Mine just has the bolt with the splines directly running in the cast metal frame...

Even has a little play, I had to put lots of grease in there to make it less obvious

 

@Frank:

Thats about what I have in mind - two metal plates and bolts. Only mine will rest on a wooden contruction.

May I ask what diameter your threaded rods are, and how much they flex under load?

Edited August 3, 2020 by mabuse00

[kaotch]

@mabuse

Get yourself a cheap (Chinese) hydraulic press 10 - 15 Tons it safes you a LOT of work and frustration .Those 1 ton arbor presses are okay for small devices needing lesser pressure opposed to 15mm rockets and also get a good tube support.

[BetICouldMake1]

I'd be leery of using wood. You're looking at something that needs to support 2000lbs of force. I don't see wood holding up without significant deflection. That's a good way to destroy your tooling, or have something come popping out of the press at you. A suitable steel or aluminum plate isn't that expensive.

[Mumbles]

I love arbor presses for shell inserts and smaller rockets. I don't think I've ever seen FrankRizzo's mod before but I really like it. It looks simple and doable with minimal tools

Personally, I like Danny Creagan's the best. If you're applying a force or a load to something, I think it makes the most sense to have the force focused between the supports. It makes sense that you'd want the force on the extension legs focused in a vertical direction than coming in from an angle.

 

I don't know if I agree that a full on hydraulic press is best for smaller things Kaotch. For a 15mm rocket, you're applying about 5% of the total force available from a 10 ton press. This feels very easy to over do if you don't have a good gauge and good control.

[Carbon796]

Do your presses have some kind of bearings or sleeves in them?

Mine just has the bolt with the splines directly running in the cast metal frame...

Even has a little play, I had to put lots of grease in there to make it less obvious

 

@Frank:

Thats about what I have in mind - two metal plates and bolts. Only mine will rest on a wooden contruction.

May I ask what diameter your threaded rods are, and how much they flex under load?

I don't think they have bushings for the pinion. But, they're such a loose sloppy fit, you'd think they should. Just typical cheap china made crap. I bought one probably five years ago or so. It seems like such a cheap piece of junk, I just can't bring myself to build it into something useful. One of these days I will get it set up in the mill, and un-chinaize it.

[mabuse00]

@kaotch:

 

Get yourself a cheap (Chinese) hydraulic press 10 - 15 Tons it safes you a LOT of work and frustration

I considered that, but when Ned and others showed how 2lb rockets can be done with them I decided otherwise. I dont have the link right now, but a few years ago a guy showed a 1lb long spindle whistle motor pressed at 2000psi...

And my press is rated "3tons" - though the quality of the cast leaves me in doubt. Even if I only manage to get 15KN, using the "new methods" that spread through the scene lately I have good faith in producing useful stuff.

I dont like these hydraulik presses, the workflow sucks, and I wonder how long the pumps last... I hate oil puddles.

If the arbor press fails to fit my needs I'll consider it again.

 

@BetICouldMake1:

This is a misunderstanding. The wood wont have to take the force, I'll use bolts, similar like Frank showed.

[BetICouldMake1]

Maybe I misunderstood your post but it sounded like you were planning to use a wooden base. It's not just the uprights that need to take the force but the base plate as well.

 

A 3 ton arbor press will be plenty of force unless you get into larger rocket or big star plates.

[kaotch]

@mabuse,

Mine was cheap Chinese and is working like a charm for the past 10 years. The gauge on top sucks but a ptof gauge under your spindle plate makes pressing rockets

and other devices very comfortable. The press is easy to handle and to store.

@mumbles

Yes it is overkill but it was the cheapest hydraulic press at that time. The ptof gauge is very helpful not to overpress my 15mm ID rockets and once getting the feeling you get very consistent rockets every time.

[FrankRizzo]

Do your presses have some kind of bearings or sleeves in them?

Mine just has the bolt with the splines directly running in the cast metal frame...

Even has a little play, I had to put lots of grease in there to make it less obvious

 

@Frank:

Thats about what I have in mind - two metal plates and bolts. Only mine will rest on a wooden contruction.

May I ask what diameter your threaded rods are, and how much they flex under load?

 

@Mabuse - I *think* it's 5/8", but I'll double-check next time I'm out in the shop. As for play in the rack-pinion, I have a piece of 1/8" thick aluminum bar placed in the recess between the ram and the front plate with the adjustment screws. Aluminum is not really the best material since it's prone to galling; brass would be ideal but I didn't have any handy so I just greased up the aluminum well. There's (4) different screws that you can use to adjust the play.

Edited August 13, 2020 by FrankRizzo