Converting ProTools M105 to hydro....full hydro (or) air-over-hydro???

[Greg72]

What's the difference?

Obviously, the full hydro is self-contained and uses some sort of motor to generate line pressure.....I'm assuming that the air-over-hydro uses the air pressure from a seperate compressor to achieve the same result???

Is one considered "superior" to the other in terms of speed, accuracy, repeatability of bends, better "feel" and control, etc???

I have a very nice upright compressor (60Gal, 4-cylinder) that's got plenty of SCFMs for almost anything.... would an air-driven system be simpler (pronounced: cheaper) to build???

 

[rdn2blazer]

What's the difference?

Obviously, the full hydro is self-contained and uses some sort of motor to generate line pressure.....I'm assuming that the air-over-hydro uses the air pressure from a seperate compressor to achieve the same result???

Is one considered "superior" to the other in terms of speed, accuracy, repeatability of bends, better "feel" and control, etc???

I have a very nice upright compressor (60Gal, 4-cylinder) that's got plenty of SCFMs for almost anything.... would an air-driven system be simpler (pronounced: cheaper) to build???

I have read quite a bit on doing this as I would like to do this too to my bender someday. I have read that full hydro is the way to go. air-over works fine and is deffenatly better then manual but it does take alot of SCFM'S and your compressor has to be up to snuff to bend tube. full hydro is faster. its constant feed with no loss of pressure, as your compressor looses pressure before it kicks on it slows down. and it will run alot bending tube.

as far as price not sure of the cost differences. I know after all the research I have done I am going full hydro no question and regardless of the cost differences as its probably not a great deal different. the gains outway the cost IMHO. theres allways someone who will probably disagree but whatever. with a hydro you dont NEED a compressor, can even be portable. not that your going to go out on the trail and bend tube for someone

 

[mikey_d05]

Alright, here's my story...

No experience bending manually. I don't have a place to anchor the bender solidly to the floor.

I bought a cheap HF air/hydro pump and ran my compressor to it. It'd be plenty fast if the compressor could keep up, but unfortunately the pump will drain it to the point that it's only able to keep up at about 40PSI. 30 gallon, single piston, oilless. Not a great compressor, but meets my needs otherwise and it was cheap. If the compressor could keep up, I'd definitely stick with the setup. Flip the pump into bypass and force the ram back with air pressure.

Repeatability is very good, but that's mostly due to the fact that if you have over 10 degrees of bending to do, it's going so damn slow that you could get it to 1/10 of a degree if you really wanted to. If you compressor can keep up, I'd run this setup, I don't have the room/wiring/budget to get a compressor that'll keep up.

My new setup...a friend and I split an electric/hydraulic pump from e-bay. It's currently governed at 1000 PSI so we'll see if we need to play with that at all. The specs look like it'll bend with plenty of speed. I plan on running a T and ball valve off the pressure line. To bend, flip the switch. To retract, put the air line on the other side of the ram, open the ball valve, and it forces the fluid back into the reservoir, circumventing the pump.

Cost for the original setup, $100something for the pump, $40 for the hose and swivel, $100 for the ram, and $50 for the tabs and such. $10 or so for air adapters and such. Total was a little below $300 all said and done.

Cost for the new one, keep the hose, low pressure hose for the return, pump was like $250, Misc. electrical junk should be less than $50. Fittings and selector valve should come in under $100. Total should be less than $450 when you include the electrical junk and such.

The cheapest kit I can find is like $840+shipping.

 

[mikey_d05]

Also, one other thought, if you wanted to get really fancy, you could run an orbital valve (like hydro steering) and then your speed would be totally controlled by how much/fast you turned that. Just affix the second port to the other side of the ram and you could dial it back with hydro pressure as well.

 

[Greg72]

Well.....

The full-hydro route isn't THAT expensive as a DIY project. I just downloaded a few different threads from people who have done it and did some quick price checking at NorthernTool.com

The big dollar items are:

2000psi hydraulic pump - $429
24" Stroke Ram - $160
4-Way Control Valve - $80

Lots of other smaller stuff like hoses, and adapters....but the whole thing looks achievable for maybe $750 - $800???

With the 24" ram, it's possible to do 90*+ bends in a single shot. The Pro-Tools "hydro conversion kits" only offer a 14" ram, which means you can only do about 40* before re-pinning the die...... not as sexy.

 

[mikey_d05]

If you're planning on mounting the ram in the conventional manner, doing a 90 degree bend in one shot probably isn't a great idea. The farther you push the arm around the bender, the more it's side loading the ram and trying to destroy the seals. I use a 15" or 16" (can't remember) stroke and re-pin every 30 degrees. Not as much of a pain as one would think.