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


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Take a long screw driver and place the end of it against the pump and the handle part against your ear and use it as a stethoscope, then the front bearing of the motor then the rear bearing of the motor. 

this will help to isolate where the noise is coming from. 

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2 hours ago, jlpservicesinc said:

Take a long screw driver and [...] use it as a stethoscope [...] to isolate where the noise is coming from. 

Tried this, but the motor shut itself off after running for about 8-10 seconds. Pushed the reset button and tried again; same result. I think we have an electrical problem. 

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That sounds like a mechanical obstruction rather than electrical to me but that's a guess.  Send it back.  Ask them to test run before sending you another one maybe? Not likely but they might. I'd be mighty tempted to send them a copy of this video and demand they get a replacement in the mail NOW. You're returning it of course but you are losing production and they are liable. 

This Sucks John.

Frosty The Lucky.

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I've been exchanging messages with the seller in Singapore, and they are suggesting that I get it repaired locally and they will foot the bill. Now to see if anyone around here is actually open.

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Around here there's quite a few electric motor shops, with all the farms it makes sense but even they are dwindling as places like tractor supply sell farm duty motors relatively cheap vs having to drop it off and wait for the repair. Personally I'd do the "shake test" - shake it and listen for something loose, the "spin test" - turn the shaft by hand and feel for it to grab at a certain point, and lastly the "oh, what the heck test" - unplug it, disconnect the capacitor(s), grab a beer, a sheet of paper for making notes, pop out the 4 long screws that probably hold it all together and carefully disassemble it on a clean work bench. It could be something relatively simple that needs to be addressed. It might not be, but you'll probably learn some things in the process and it sounds like you're going to take it to a professional anyway, you might find out you don't have to but worst case is that the professionals will be able to put it all back in working order if you can't. :)

-J

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Good advice, but since the repairs are going to be paid for by the seller, I don't want to give them any excuse to say that I've voided the warranty by messing around with it myself. As things stand now, I've found a local place and will be taking it over there later.

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You may also want to talk to them about if they sell motors.  The repair place I used to go to in Columbus OH used to sell repaired motors that the owner never returned for for the cost of the repairs.

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  • 3 weeks later...

Just got a message from the repair place that the motor has a bad capacitor, so my guess was right. Apparently it's an unusual size, so to repair the motor is going to cost almost as much as what the motor cost in the first place. We'll see what the seller has to say.

In other news, I'm thinking about putting in a two-stage pump. As things stand now, I'm getting about 17 tons at about 3/4"/second, but Northern Tool has a couple of interesting reasonably priced possibilities:

  1. The first would give me about 3.5 tons at 4"/second in the first stage and about 14 tons at about 1"/second in the second stage and would cost about $210.
  2. The second would give me about 4.5 tons at 3"/second in the first stage and about 18.5 tons at about 3/4"/second in the second stage and would cost about $140.

All of these numbers are based on 85% efficiency and are not theoretical maxima.

So, any thoughts? Recommendations? Warnings?

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That really sucks. A capacitor that works is some oddball only available in outer trundlunkia says any other repair parts are same brand. I'd be thinking return for refund and buy a higher quality motor. 

I'd be on option 2. and try to sort the other stuff out while smooshing and selling things with my press.

Frosty The Lucky.

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Well, let's see what the seller says. I should also contact the repair place to see if they have any secondhand 5hp/1ph motors for cheap.

Just for comparison, here's a spreadsheet comparing the original setup, the current setup, and these two options:

HP
Torque
RPM
Displacement in cubic inches/revolution -- 1st stage, LOW pressure
Displacement in cubic inches/revolution -- 2nd stage, HIGH pressure
Piston diameter
Piston area
FIRST STAGE -- LOW PRESSURE SECOND STAGE -- HIGH PRESSURE
GPM PSI Tonnage Ram speed in inches/sec (100% efficient) Ram speed in inches/sec (85% efficient) GPM PSI Tonnage Ram speed in inches/sec (100% efficient) Ram speed in inches/sec (85% efficient)
1.50 4.75 1750 0.097 0.097 4.00 12.57 0.72 3547 22.28 0.22 0.19 0.72 3547 22.28 0.22 0.19
5.00 7.61 3450 0.210 0.210 4.00 12.57 3.14 2730 17.16 0.96 0.82 3.14 2730 17.16 0.96 0.82
5.00 7.61 3450 0.794 0.194 4.00 12.57 11.86 722 4.54 3.63 3.09 2.90 2956 18.57 0.89 0.75
5.00 7.61 3450 1.024 0.254 4.00 12.57 15.29 560 3.52 4.69 3.98 3.79 2257 14.18 1.16 0.99
                                 
                                 
    Cells highlighted in yellow contain calculated values.                  
    Cells with no highlighting contain variables that may be changed.                  
    Cells highlighted in cyan contain values for the original setup.                  
    Cells highlighted in green contain values for the current setup.                  
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Uhhhh, the chart is giving me a headache, I'll have to pass. Definitely ask the repair place about refurbished motors. Last time I took one in to repair I discovered a refurbished one exceeding the power of the deader cost less than repairs. 

What I discovered over the last search were folks trying to get rid of hot tubs at yard sales, etc. were more than happy to give it to you if you'd haul it off. I now have 2 ea. 3hp, x 3450 rpm motors and one 5hp. x 3450 rpm. I'd use the hot tub speed control but it's buried in a huge circuit board so I'm going with step pullies. I might play around with a infinite variable torque converter though but I'm still looking for a splined shaft to suit.

On that note you don't need variable speed. 

Frosty The Lucky.

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  • 2 weeks later...

Update: the repair place came back with an estimate that is more than the motor cost in the first place. The seller isn't happy, but they're honoring their promise to pay for the repair. The new capacitor has been ordered, and I await news of its completion.

Still thinking about a new pump. I'm strongly leaning towards option #2 above, and the Chancellor of the Exchequer has given tentative approval. Also, the numbers look even better than originally calculated; I found some further documentation that clarifies the gpm of the two stages. It seems that the first stage is 16 gpm, switching to 3.5 gpm at 650 psi. That would give me 4.08 tons at 4.17 inches/second in the first stage, and then 18.57 tons at 0.91 inches/second in the second stage (again, speed numbers calculated on 85% efficiency). That's both stronger and faster than the current setup.

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Update: the repair place has finished their work, and I am awaiting instructions from the seller about how to move forward with payment.

In other news, I've been thinking more about the pump situation. For starters, I realized that the numbers in my last comment were based on gpm at 3600 rpm, while my motor is 3450. That means that the first stage would be 14.76 gpm, producing 4.08 tons at 3.84 inches/second, and the second stage would be 2.9 gpm, producing 18.57 tons at 0.85 inches/second (assuming 85% efficiency). I like the tonnage and speed of the second stage, but I wonder if the speed on the first is perhaps faster than I need. There's a slightly less expensive version from the same manufacturer with 10.94 gpm in the first stage, which would give me the same 4.08 tons, but at 2.85 inches/second; the second stage numbers remain the same (2.9 gpm, 18.57 tons, 0.85 inches/second). 

There's another advantage to this option, which is that both inlet and outlet are 1/2" NPT threaded, which matches my existing plumbing. The previous option has a tube inlet and would require some fiddling. Not a huge deal, but notable.

Any thoughts?

PS: since the motor runs CCW (as you're facing the shaft), I would need to get a pump that runs CW, yes?

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Yeah, the 1st. stage seems pretty fast to me too but not crazy fast. I like the speed of the 2nd. stage, it's formidable and makes good squeezing. 

I believe you're correct regarding rotation direction.

Frosty The Lucky.

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Yes, those second stage numbers are a hair slower and a hair heavier than the current setup, so I think they're good for the high pressure side. I'm hoping that the greater speed in the low pressure side will move more metal faster, especially in thicker sections. It seems to me that that puts me in the ballpark of one of Ric Furrer's recommendations elsewhere in the forum:

On 2/5/2015 at 6:17 PM, Ric Furrer said:

you can run a 5" cylinder with that power pack and be quite happy with rather fast 24 tons at 2500PSI and about 1.8"/second at the pump at low pressure high flow and that will drop to about 1/4 flow (0.45" second) at full pressure.

And also favorably comparable with the 16 ton press from Coal Iron (1.5 inches/second for the standard and 4.0 inches/second in the upgraded version).

 

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I'm thinking a fast 4 tons would be good for setting welds, the less time in contact with the dies the better. Of course another 18.57 tons once it's in contact can't hurt. Long as it's not contacting you that is.

I like it but I don't have any experience with a forge press.

Frosty The Lucky.

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