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

[JHCC]

An interesting opportunity presents itself. I may have a line on a secondhand pump that's rated for 16.2 gpm at 1725 rpm. If I use pulleys and a belt to get the output of the current 3 hp, 3250 rpm motor down to ~860 rpm, that would increase the power input to about 12 hp and decrease the volume output to about 8 gpm. That would give me about 2.5 inches/second of ram speed and a little under 16 tons of force, which isn't bad at all.

The problem is that the documentation I've been able to find from the original manufacturer talks about the pump running at a much lower pressure than I would be operating at: 200 psi instead of the ~2500 that I would expect to generate with this setup. Would this be as much of a problem as I think it would be? Or would I be able to get away with it somehow?

(Worth noting that the pump does appear to have a relief valve.)

[JHCC]

Just got off the phone with an engineer from the pump's manufacturer, who tells me that this is basically not possible, but I might be able to make it work by reducing the diameter of the gears by a couple thousandths of a inch and switching the relief valve to the suction side. He's still not sure if that would work (there's still a risk of the bearings self-destructing and the innards of the pump cold-welding), but we had a great chat anyway. 

[jlpservicesinc]

JHCC post photos of the pump. sometimes they underrate the pumps. if it is a dual gear rotor pump and the housing is castiron it would do wonderful things. Up to much higher pressures. 

[JHCC]

Here’s a shot of the pump, a BSM (Brown & Sharpe) model 3S:

[jlpservicesinc]

I understand. It's a machinery pump.  i'd take it apart and see how its made. If the housing is solid which it looks like and there is plenty of space for sealing around the gears and casing. I'd probably try it. 

It's either time or money.  It all depends on what is more easily spent. 

[JHCC]

Unfortunately, I currently don’t have much of either. 

[jlpservicesinc]

I feel you.  New shop due in a few weeks. Winter approaching like gang busters. No help and spent 8hrs out doing a welding repair on a 4X4 Tractor that the front end came apart on and someone did a crap job of fixing it originally.  Had to cut out all the old welds and put in new and now in the engineering phase to fix the reason why it happened to begin with. 

Life is grand.  

[JHCC]

Sale Saturday at the industrial surplus place, and I got that pump as well as a 5hp/230v/1ph motor. The pump is jammed, so I’ll have to take it apart anyway. We shall see. 

In the mean time, I need to figure out how to connect the motor to the existing pump. The shaft is somewhat corroded, so an external fitting would be tricky. Might be able to screw something on the end of the shaft.

Since the pump is a tang drive, I might cut a slot in the end of the shaft to match, as I did with this adapter that’s part of the current setup.

(Funny story: the warehouse has lost the pump and written it out of their database. When I found it and went to buy it, they rang it up as “miscellaneous scrap” and charged me two bucks!)

[Frosty]

Before you take it apart pour some hydraulic oil in the pump and let it sit for a day, the seals may just be dried to the shafts.

The shaft on the motor is, "SOMEWHAT" corroded? The threads don't look so good either. Doable though, hydraulics aren't shock loading devices so you can get away with improvising things.

Not the oil fittings though, NEVER Micky Mouse hyd fittings! Hyd oil under pressure can slice like a scalpel to and into bone and it's not a good thing in your bloodstream. 

Frosty The Lucky.

[JHCC]

This is why I’m thinking a slot for the tang drive might be my best option.  

Leaving aside pump questions, my other main concern is how to wire up the motor. The simplest option at the moment looks like running a long cord to the outlet for the dryer in the laundry room (as I discussed in this comment), but would I be able to run this kind of motor off this kind of plug?

(As a reminder, the outlet is labelled "30A - 250V", and it's on a 60 amp breaker. The breaker box says that our service is 120/240V. The label on the motor says it pulls 8.8 amps.)

Also, I’m thinking I‘ll need to replace the cord and power switch on The Pressciouss, unless I can confirm they’re rated for the higher voltage. I suppose one of those switches with a big red OFF panic button would be good.  Chances are that I’ll need a longer cord anyway, as I doubt the existing cord will reach the laundry room, even if it is adjacent to the garage. 

[JHCC]

Took the cover plate off the motor’s connections to see what’s there. Seems pretty straightforward. 

I’m wondering if I could connect this extra dryer cord I have knocking around to the motor, to make sure it works before I invest time and effort in figuring out how to connect it to the pump? Would I be correct that the grooved wire in the middle is the ground?

[Frosty]

I'm no sparky, this is where I ask an electrician or have one wire things. 

Frosty The Lucky.

[JHCC]

That’s why I’m hoping Steve Sells shows up. 

Here are the labels on the motor:

[Steve Sells]

middle wire is ground, the two outer wires are power lines, 230v min draw it is ok for a little more up to the 250v cord set rating, IF YOU WANT A  LONGER RUN,  you will most likely need a heaver gauge wire to compensate for voltage drop

[JHCC]

Okay, so good for testing the motor, then. 

Thank you. 

[JHCC]

Update: THE MOTOR WORKS!

Hooked it up with the old dryer cord, plugged it in, and listened to the sweet hum of 3450 rpm. 

 Now to figure out how to get power to it in the shop....

[jlpservicesinc]

where is your breaker panel?  do you have a sub panel in the garage? 

[JHCC]

In the basement at the opposite end of the house, and no. 

[jlpservicesinc]

It's only 8.8amps.  you could make a 240v extension cord.  I use one of for my lift on a 20amp breaker.    

that beefy 30amp or 50amp cord is not needed.    

[jlpservicesinc]

I have done all my own wiring up to code specs for MA.  But unless you have an interest and willing to learn about electricity sometimes it's just better to hire the right person for the job. 

If money is tight this can be a problem unless you know someone. 

 I installed a 100amp sub panel in the garage and oversized the lines for each main feed so there are only small losses to the electrical flow over the distance from the main breaker panel to the shop installing a 100amp breaker.   150ft of 0 sized wire X 3.  The ground can be a little smaller.  I have a 40hp rotary phase converter  and a high draw welder of 60amps at max. 

I have a 240v 20amp outlet that has the 240V outlet for the special plug.  yes it is a special plug. I don't remember the NEMA number but there are charts online.  For code the proper plug has to be used.  

you can then buy some romex of the proper size i'd guess 10 or 14 (again there are charts online for a given distance) and put on the proper plugs with cord stain reliefs and a receptacle box. 

Do you have a 240V air conditioner receptacle? 

[JHCC]

Money is tight at the moment, so I think my best bet right now is the extension-cord-to-the-laundry-room option. At a rough estimate, a 35' cord will get me from the dryer outlet, around the perimeter of the room, through the wall, and across to The Pressciouss. There's another dryer receptacle in the basement that I think I can cannibalize (making sure to turn off and tape down the breaker, as well as to isolate and insulate the bare ends of the wires left behind), and if the cord is long enough, I could also use the old dryer cord mentioned above between it and the switch on the machine. That should save me a couple of bucks, anyway. 

This means I'll need to purchase:

•  35 feet or so of cable (12 gauge?)
• a NEMA 10-30 plug to connect the cord to the outlet in the laundry room
• a new switch, like this one:

At some point, I'd like to upgrade to either a subpanel or a 240v/60amp outlet (probably run through the breaker for the downstairs dryer) that's beefy enough to run a tombstone welder, but that's a challenge for another day.

It occurs to me that I haven't checked how long and beefy the existing cable is, and whether I might be able to use that for the extension cord. I know it's pretty long, so I'll measure it and see if it has any gauge markings when I get home.

[Steve Sells]

The size for ground wires have rules too,  based on conductor size and amp loads not wild guesses, but as long as  your not smaller than recommended size you are fine,  but if you dont know what is recommended.....  .   Sure people get by with a lot of things but at IFI we prefer to stay with facts, not guesses to save 50 cents, posting guesswork is not being responsible

Motors dont like extension cords.  At start up, the full load current can draw 140% of the running amp load, which is 39.2 amps for 5 Hp Some amateur electrician telling someone to not worry about using the correct size for ground wires or extension cords really honks me off, I had just finished telling him he may need larger to compensate for voltage drop and then JLP s comes along and tells him not to bother listening to my 35 years experience? How is that helping anyone?

[Fowllife]

That amp load seems oddly small to me for a 5 hp motor. If I remember right most 220-240v 5 hp motors are 20-28 FLA?

Also, NM cable (Romex) is not the right type of wire to use for extension cords.....I would highly recommend adding that sub panel now. It's really not that hard to do, and isn't that expensive.

[Steve Sells]

NEC states 28 amps for 5Hp 240V up to 6.4KVa but what do I know.  A 30 amp is the smallest acceptable standard breaker size, 40a is better for the FLA

I should add that making a cord from Romex is asking for trouble  but either you listen or you dont if someone wants to use small romex after what I posted its their fire to worry about.  NEC clearly states Romex is ONLY for permanent installation, and while Code allows for local jurisdictions to add to the rules, they can not ignore existing national code and use less protections

8.8 amp is closer to a 1 Hp so there is a problem there as well since the nameplate does not show Hp and 1HP wont do as much for a press pump

[JHCC]

I’m starting to think that my simplest solution would be to install a 240v outlet in the garage, running from the 60 amp breaker that supplies the (currently not-in-use) dryer outlet in the basement. If I do that with, say, a NEMA 6-50 receptacle, I could also run a welder from that same outlet, right? There’s nothing that says I have to use the NEMA 10-30 cord I used to test the motor. 

21 hours ago, Steve Sells said:

8.8 amp is closer to a 1 Hp so there is a problem there as well since the nameplate does not show Hp and 1HP wont do as much for a press pump

I gather that this motor was originally off a spa pump. The label (in the first photo above) seems to be about the pump itself, and indicates that it requires a motor with a brake horsepower of 5.0. That's where I got the 5 hp number. Was that incorrect?