JHCC

Converting an inverted hydraulic press into a light-duty forging press

Recommended Posts

Decreasing the speed of the pump will increase the GPM????????

Patent it NOW!

Share this post


Link to post
Share on other sites
10 minutes ago, JHCC said:

Where I get confused is that this doesn't seem to work with the formula mentioned earlier:

It varies by pump, we always worked with what the paperwork said.

10 minutes ago, JHCC said:

With my 1.5 hp motor running 1,725 rpm, such a reduction would put the rpm at the pump at 1,150 and the effective horsepower at 2.25

No, HP is the product of torque x rpm. Gearing to a lower RPM will increase torque NOT HP. Lower rpm means lower gpm, higher torque means higher psi.  The Presscious will push harder but move slower.

You'll also lose some power due to entropy for every: shaft,  pully and belt but it shouldn't be significant in this small a machine. 

Frosty The Lucky.

Share this post


Link to post
Share on other sites
2 hours ago, Frosty said:

Gearing to a lower RPM will increase torque NOT HP. Lower rpm means lower gpm, higher torque means higher psi.  The Presscious will push harder but move slower.

So presumably the converse would be true, that gearing to a higher rpm will increase the gpm and reduce the torque (and therefore the psi)?  In other words, suppose I keep the same pump and the same motor but increase the rpm input to the motor by 1/3 (from 1,725 to 2,300). If my calculations are correct, that would increase the gpm to just under 1, drop the tonnage to around 16, and increase the ram speed from .23 ips to .3. Does that sound about right?

I suppose that if I were to get a 3 hp motor and gear the speed up by a factor of two, that would keep the pressure the same (since we're doubling the torque and then halving it again) but double the gpm and therefore the ram speed?

Whether or not any of this is beneficial is, of course, another story....

Share this post


Link to post
Share on other sites

Without doing arithmetic it sounds about right. 

Find yourself a 3 HP 3,450 rpm. motor and forget about jack shafts. Then the only thing you need to match is shaft size. PROVIDED the pump is rated for 3,450 rpm operation.

Here's the thing though and why I was squawking about deciding these things based only on HP. in another conversation but it holds just as true now. HP is determined by Torque x RPM. So, if you have two 1HP motors, one 1,725 rpm. the other 3,450. The slower motor will develop higher torque. Pushing identical pumps and cylinders the the slower would press harder, the faster would press lighter but faster. 

Make sense?

So, were I you I'd look around for a 3 HP. 3,450 motor, with matching shaft dia. It'd press just as hard but twice as fast. B)

This is where a few extra $ and KISS live in beautiful harmony. Saving on: pullies, shafts, pillow blocks and belts plus fabrication and misc. parts will go a long way toward defraying the cost of a motor at the surplus yard.  Let us NOT forget the needless scalp irritation you must be feeling with all the hair tearing. :ph34r:

Frosty The Lucky.

Share this post


Link to post
Share on other sites

The existing pump IS rated for 3,450 rpm. There’s a 3hp motor at the surplus place that’s 1725 rpm, but — crucially — single phase. However, my budget can’t cover it right now, let alone the cost of getting 230v out to the garage. 

The thing that appeals to me about regearing the existing pump and motor is that it would give me some idea of the comparative benefit (if any) of lower pressure and higher speed without having to spend a ton of money and still being able to change it back if I don’t like it. 

Share this post


Link to post
Share on other sites

Single phase is a biggy, but 230v is hard to get around or 1.5 HP is about it for motors. You might just have to live with Presscious as she is for now, I know I'm saving my allowance to finally get the shop hooked up to real power.  I know, the wanting almost hurts. 

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Well, I do have another set of narrower drawing dies in the planning stage; we'll see if that helps.

Share this post


Link to post
Share on other sites

Well, that pump sold before I could get to the surplus place for Sale Saturday tomorrow. Ah, well. 

Share this post


Link to post
Share on other sites

Picked up this interesting collection of hydraulic parts at the surplus place. Don't know what the pump volume is, but the motor has about the same RPM as the current setup. Trying to sort out what I've got and if it could be of any use; if not, I'll see about reselling the parts.

So far it looks like:

  • 2 hp Leeson motor, 230v, 3 phase
  • pump, unknown make and model
  • Fluid Controls Inc relief valve/manifold (?), model 1A32-F8T-30S
  • Greer Hydraulics accumulator, model 0018-810070 30A-1/8A
  • A whole bunch of bits of pipes and connectors and hose (oh, my!).

20190128123105706_L.JPG

Got things taken apart and discovered an interesting connection between the motor and the pump:

5FE6F110-D85A-4A8C-B51C-2FD3F6B3952D.jpeg

Not sure if this is something that can be adapted to fit the coaxial drive that currently connects the existing motor and pump.

85FEBD1D-C6A8-4226-BC28-D56359B607CD.jpeg

Share this post


Link to post
Share on other sites

There's a serial number on the underside of the pump that says "705089", which might be a Parker model, but I can't find a good reference to confirm that.

Share this post


Link to post
Share on other sites
3 hours ago, JHCC said:

discovered an interesting connection between the motor and the pump

Further research informs me that this is called a "tang drive" and is for pumps that bolt directly onto their drive motor. Not sure if anyone makes an adapter that would allow me to connect it to the existing motor, but I'm still looking. If I can't determine the GPM of this pump, it may all be moot anyway.

Share this post


Link to post
Share on other sites

Ended up putting the motor and pump on FB marketplace and CL, since it didn't look like getting an adapter would be worthwhile -- even if possible -- at least not without also getting a more powerful motor. I think I'm going see if any of the metal pipes can replace any of my existing rubber hoses.

Probably not worth it to try to install the accumulator, is it?

Share this post


Link to post
Share on other sites

An accumulator hmmmm. . . 

I didn't do much with accumulators but one might do what you want. Using the hyd psi returning the ram to pressurize the accumulator it might, MIGHT, provide enough extra cfm to speed up the ram on the work stroke. 

I don't know where an accumulator needs to be in the circuit I just didn't mess with the couple on the drills and they never needed work. The accumulator on the rod clamp kept pressure to the clamp when the valve wasn't held. This prevented hydraulic bleed from dropping a drill string down the hole while we were moving rod. 

I don't recall what other accumulator was connected to but there was another one down in the netherworld in the frame. 

I wonder if I have anybody in my phone numbers anymore. . . 

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Looking at the picture of your current motor to pump connection, I would try to straighten your pump mounting plate if you can. That's a love joy connection, typically the rubber cushion doesn't last very long if they are not lined up.

I was wonder how your setup would work with the slow speed. Seeing that you aren't overly impressed makes me second guess trying to use my 2 hp motor for a press. It almost seems like you need at least a 3 hp motor to et decent speed and power, but a 5 hp is better. It seems like the route Peppie went is the best, 5hp motor with a 2 stage pump. I have not looked, but I wonder if you could fine a 2 stage pump with low enough flow rates to work with your 1 1/2 hp motor?

Share this post


Link to post
Share on other sites

I can get a new 3HP 115v 1PH 3450 rpm compressor-duty motor for about $150-$190 off eBay. As Frosty notes above, that would give me the same power, but twice the speed. It's just a matter of saving up a few ducats.

Part of the problem is getting something that will work with my existing wiring in the garage. I could get a 3 HP farm-duty 1PH 1725 rpm motor used right now from the surplus place, but it's a 230/460v, and I don't have anywhere to plug it in.

Share this post


Link to post
Share on other sites

If you come up with a 2 stage pump you'll have speed till it encounters resistance then full pressure, it's definitely a big plus.

John, bear in mind the more horsepower the greater the draw on your existing wiring, I don't believe a standard household breaker will carry that much load. However, the only power I have in my shop without firing up the welder generator is on a 100' 10 ga. extension cord and a 20 amp breaker. I can run my 1.5 hp. power hammer and drill press without tripping it IF I don't have all the lights or something else on. 

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Frosty brings up a good point about draw from a 3 hp motor. Someone smarter then me can correct me, but I believe the full load drawn from a true 3 hp motor on 115v is over 20 amps. If I remember right a true 3 hp motor on 110-120v should have a 30 amps breaker? I know I used to have a "3 hp" air compressor and I had to be careful where I plugged it in. I could not use and extension cord, and it would pop breakers pretty easy plugged directly into a 20a outlet.

It may work for you, but I would look at circuit length, wire type, and breaker size before you get too carried away with buying a motor. There is a reason "most" motors 2 hp and under are 110-120v and "most" 3 hp and over are 220-240v.

Share this post


Link to post
Share on other sites

The breaker for the garage is 20 amps, and I've popped it a few times running the MIG welder full-out (especially when the lights were on). 

It occurs to me that the garage is right next to the laundry room. I wonder if I could run an extension cord (or a long power cord) to the dryer's power supply? The outlet is labelled "30A - 250V", and it's on a 60 amp breaker. There's another similar outlet in the basement (for a laundry setup that no-one has ever used), and I suppose I could run a similar cord thither. Or I could use that circuit to run a 230V outlet to the garage. Hmmm....

The breaker box says that our service is 120/240V, for what it's worth.

Share this post


Link to post
Share on other sites

I find it odd you have a 30a outlet on a 60a breaker. It’s not a good thing to have an outlet with an over  rated breaker, although your dryer won’t use more then 30a.

i love to spend other people’s money, but have you thought about using your spare 60a breaker from the basement and putting a sub panel in the garage?

You could also just use that breaker to run a new outlet to the garage, which would solve your 220v issue. 

Share this post


Link to post
Share on other sites

I think running a new 220v (or 230 or whatever) outlet is probably the simplest option. I could also use it to run a heftier welder, should such a thing ever come my way....

Share this post


Link to post
Share on other sites
On 7/11/2019 at 7:51 PM, JHCC said:

There’s a 3hp motor at the surplus place that’s 1725 rpm, but — crucially — single phase.

Checked it out when I was there today picking up a little horizontal bandsaw. The price has been reduced, but it makes a very nasty noise when you rotate the shaft. I think it may just be a dented fan cover, but I'm going to keep an eye on it, see how low the price goes, then maybe grab it on a sale day (if no-one else does first). If it's something that is an easy fix, using it with a jackshaft to increase the pump speed to 1.5 gpm may be an affordable solution.

Share this post


Link to post
Share on other sites

And missed out. Oh, well. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.