# New (Used) Enerpac Press (Help!- needs work)



## rwm (Apr 6, 2020)

I picked this up today real cheap from a very nice veteran from good old Wilks-Barre PA:




The thing is kind of massive! I am hoping this will make a great shop press but it has some immediate issues.
Most importantly, these threads are stripped and loose:




I have some ideas on repair that I will get into. Any one out there have any experience with Enerpac?

Robert


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## mattthemuppet2 (Apr 6, 2020)

I rebuilt a cylinder and a handpump for one a few years back. The hand pump looks like yours but the cylinder is completely different.


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## extropic (Apr 6, 2020)

Which threads are stripped? The Cylinder to the C-Frame? If so which side is bad?


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## rwm (Apr 6, 2020)

extropic said:


> Which threads are stripped? The Cylinder to the C-Frame? If so which side is bad?



The cylinder to the C frame threads are stripped. It is hard to tell which ones are worse. Her are some pics:







According to Enerpacs site the thread should be 2-1/4 x 14 UN (V shaped non tapered) . If I measure the OD of the cylinder threads I get 2.180. If I measure the tops of the threads in the C frame I get a similar measurement of 2.185. I interpret that to mean that they are both damaged with the C frame being worse. Comments please?
I think this is gonna make an awesome shop press if we can get it to work! Let's collaborate!
Robert

Edit: I should add that there was a set screw entering the C frame collar from the front and engaging that dimple that you see in the cylinder threads. At some point it must have moved, hence the plow marks through the threads!  I have thought of several ways to "repair" this already but I want to hear everyone's ideas and hopefully take the best path.
Robert


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## rwm (Apr 6, 2020)

The specs for the thread are:


Major diameter:2.2483 / 2.2379Pitch diameter:2.2019 / 2.1961Minor diameter:2.1632 / 2.1452Over wires:2.2637 / 2.2580

Actually, looking at the specs, the cylinder threads are knocked down by about 70 thou (diameter)off the major diameter. The C frame threads are knocked down by about 20 thou off the minor diameter. So I assume the cylinder threads are worse? That might be good since I can replace the cylinder more cheaply. Am I reading that right?
Robert


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## mattthemuppet2 (Apr 6, 2020)

will both of those things fit in your lathe and mill? The way I'd fix it is to bore out the threads in the C frame and press in a top hat bushing (wide flange underneath) that's threaded to fit the cylinder. Pick up and chase the cylinder threads on the lathe, using the threaded top hat bushing as a gauge. Could also do it the other way round, doesn't reall matter.

Weird that the cylinder was pushed up like that, going by the set screw gouge. I would have thought that there would be more than enough thread engagement for that thread depth.


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## rwm (Apr 6, 2020)

Thanks Matt. The C frame weights 100 lbs or more. I suppose it could be milled with a boring head on a Bridgeport. I have a Sherline so that's out! But I like the way you think. That is a good plan. I am wondering if I replaced the cylinder if there would be enough thread engagement? I am thinking yes?
I can get one on evilbay:



If most of the thread wear is on the cylinder then this would work.
Robert


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## mattthemuppet2 (Apr 6, 2020)

I don't think that kayak will help you one bit though 

I think the sherline would be ideal - remove the Z ways and headstock from the base, mount to fixture attached to C-frame, bore out hole. Simple  Is your lathe big enough to mount the cylinder and chase the threads?

The threads on the C-frame look ok to me, so a new cylinder would work. I'd imagine the thread dimensions are standard for a certain cylinder diameter.


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## Cadillac (Apr 6, 2020)

What if you put long studs in the holes on top of the frame that went to the top of the cylinder then put a thick plate fastened to the studs. So that it would sandwich the cylinder compressing to the frame. Using large enough studs and thick plate should be enough. That is a 12ton cylinder I believe.


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## extropic (Apr 6, 2020)

Does that cylinder say "Enerpac" anywhere on it? I have quite a few and they are all impressed or LASER marked with the brand, P/N and PSI.
I just put a caliper on the threads of a new Enerpac RC106 and read 2.250 on the major diameter (painted).

An off-brand cylinder may be at the root of the problem.

I suggest that you source a replacement cylinder w/ good threads right off the bat. The ram on yours shows shows substantial corrosion anyway.

I'm guessing that part of the problem is related to the PO wanting to orient the cylinder port/gauge toward the front/operator, therefore the setscrew plus the cylinder wasn't bottomed tight in it's mount as it should have been.


when you put it all back together, please mount the cylinder bottomed tight in it's threads. Let the cylinder port fall where it may and orient the gauge via plumbing as required.


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## rwm (Apr 6, 2020)

You know that could actually work with the mill, although I would not trust the tram!
Yes I could turn the cylinder but I think a new cylinder is in order.
I had one other idea. I could use the original cylinder (or a new one) and add support at the top of the cylinder:



Notice the ears on the C frame with 1/2" holes. These are crying for all thread extended up to a plate over the cylinder.

Robert


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## JimDawson (Apr 6, 2020)

Looks like that set screw was just pushed through the threads.  That took a lot of force.  0.005 clearance is pretty sloppy thread ''engagement'' 


If that were in my shop I would bore the threads out of the C frame, well oversize, then thread mill new threads, maybe 2 1/2-14 would be good.  Then rethread the cylinder deeper to get the thread form back, size doesn't matter.  Then build a threaded insert for the C frame that fits both the cylinder and the C frame.

As an alternate, bore the threads out of the C frame, and make an insert as above.  But weld it in place.

I really think the only choice is to somehow get new threads in the C frame.  And the best way to do that is with an insert.

I do see something odd, it looks like a crack running around the edge of the threaded bore in the C frame.  Not sure what that is about, and odd place for a crack.  Maybe that is a threaded insert in there.  Might clean it up to see what is really there, it could be an adapter for a different size cylinder or something?

EDIT:  The colors don't look right for Enerpac, I wonder what you have there.  All of my HF stuff is orange.  But they don't sell a C frame.

Some good advice above also.

What is the OD of that cylinder above the threads?  About 2.200 maybe?


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## extropic (Apr 6, 2020)

I didn't see the "crack" until Jim mentioned it. I sure would like to know what that is about. Maybe the threads in the C-frame are in an "insert" from the OEM. Maybe that's a 20 ton frame with an adapter for a 10 ton cylinder.

What's the nomenclature on the C-frame (can't read it in the pic).


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## rwm (Apr 6, 2020)

Thanks Jim- I think your idea is sound. I do not have the capacity to bore out the C frame but I could get it done. I do not see a crack around the C frame bore. (in real life.) I think it is intact and not sleeved. 

I have another plan I want some feedback on:
What if I machined off the threads on the cylinder to create an unthreaded boss. Then make a thick "washer" that fits into the recess in the top of the C frame with the ID of the washer matching the new OD of the cylinder. I could then use threaded rod and a plate to clamp the cylinder in place. The tensile strength of (2) 1/2" threaded rods should be adequate? Not the most elegant solution but I can't see it failing.
Robert


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## matthewsx (Apr 6, 2020)

You may want to have that thing magnafluxed or use some other crack detection method before putting too much into it. I'd hate to see what happens when one of those things lets go in a hurry....

John


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## rwm (Apr 6, 2020)

Scraped some paint:




Appears to be solid. That recess is cryin for a sleeve or adapter. Keep in mind it's hydraulic. It the pneumatic stuff that you don't want to see fail!
R


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## matthewsx (Apr 6, 2020)

BTW, I have an Enerpac thing here I got as scrap. It's just the fabricated frame with no cylinders, heavy bugger.


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## rwm (Apr 6, 2020)

Is it the same as my C frame? Can you measure the ID of the threads?
Robert


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## JimDawson (Apr 6, 2020)

rwm said:


> Thanks Jim- I think your idea is sound. I do not have the capacity to bore out the C frame but I could get it done. I do not see a crack around the C frame bore. (in real life.) I think it is intact and not sleeved.
> 
> I have another plan I want some feedback on:
> What if I machined off the threads on the cylinder to create an unthreaded boss. Then make a thick "washer" that fits into the recess in the top of the C frame with the ID of the washer matching the new OD of the cylinder. I could then use threaded rod and a plate to clamp the cylinder in place. The tensile strength of (2) 1/2" threaded rods should be adequate? Not the most elegant solution but I can't see it failing.
> Robert



Strange, in the picture it looks like a crack.

That might work, but I would use high tensile threaded rod.  https://www.mcmaster.com/threaded-rods/threaded-rods-and-studs/high-strength-steel-threaded-rods-8/  But you might pull the ears off without a bottom backup plate, maybe about 3/4 or so thick.

What is the OD of the cylinder above the threads?


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## rwm (Apr 6, 2020)

Agree on the 150K psi rod. I was wondering about the ears breaking... 3/4" plate  would cut down on my vertical travel.  Maybe 3/8 cause that's what I have!
About the color- I assumed that this was so old it was before Enerpac went yellow. Seems to be original paint and the C frame has the same features as the current model.
Robert


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## matthewsx (Apr 6, 2020)

rwm said:


> Is it the same as my C frame? Can you measure the ID of the threads?
> Robert



Not a C frame at all, more like a welded rectangle.


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## matthewsx (Apr 6, 2020)

I'd go with the simplest solution first, replace the cylinder with one that has good threads. If that works for you then go no further, if it doesn't then hopefully the failure mode is the threads on your C frame stripping out with no bad consequences. Replacing those threads should be fine if needed but I would hesitate to re-engineer this kind of tool without a clear understanding of the forces involved. In any case I would probably bead blast that C frame and give it a through inspection if nothing else it will make the paint job look great but like I said I'd hate to find a flaw in it by accident.

JMHO,

John


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## rwm (Apr 6, 2020)

My fear is that even if I buy a new cylinder ($150), I won't trust the C frame threads and I will need to use threaded rod and a plate as a failsafe...so maybe just start with the failsafe?
Next issue:
What am I going to get into if I disconnect the hydraulic line from the cylinder? Do I have to worry about bleeding out air when I reconnect? I have limited experience with hydraulics.
Jim- cylinder is about 2.20" diameter.



Robert


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## matthewsx (Apr 7, 2020)

rwm said:


> My fear is that even if I buy a new cylinder ($150), I won't trust the C frame threads and I will need to use threaded rod and a plate as a failsafe...so maybe just start with the failsafe?
> Next issue:
> What am I going to get into if I disconnect the hydraulic line from the cylinder? Do I have to worry about bleeding out air when I reconnect? I have limited experience with hydraulics.
> Jim- cylinder is about 2.20" diameter.
> ...



I'm not going to pretend to engineer this for you. My dad built rockets that went to the moon, me.... Not so much.

That's why I suggested checking it for cracks, it might be overkill but given the consequences maybe not. If it makes you feel better to make a homebrew fail-safe go right ahead, your requirement is cast right into the C-frame, 10 tons.

What I can tell you is yes, when you disconnect the hose you will have to bleed the hydraulic system before it will work properly. Air is compressible, hydraulic fluid is not. You can break the laws of man and get away with it but the laws of physics, well that's another story.

Probably this thing will be fine but nobody can tell you that no matter how many pictures you post on the internet. My take is it's worth checking it out right before you trust it with 20,000 lbs of force. Your local automotive machine shop should have the right equipment to check for cracks BTW.

That's all I have.


John


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## JimDawson (Apr 7, 2020)

rwm said:


> What am I going to get into if I disconnect the hydraulic line from the cylinder? Do I have to worry about bleeding out air when I reconnect? I have limited experience with hydraulics.



Not really, it's pretty easy to bleed the air out on reassembly.  And it will self bleed the last little bit due to the design of the system.



> Jim- cylinder is about 2.20" diameter.



That's what I suspected, 56mm (2.205'') diameter.  No way to thread that for a 2 1/4 -14.  That is the wrong cylinder, it's metric.  The threads in the frame are most likely OK.  Just get an Enerpac cylinder.


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## rwm (Apr 7, 2020)

I was wondering about the cylinder diameter and the threads! If you start with 2.220 there is no way to cut a tall enough thread to reach the correct major diameter. I thought maybe the threads were rolled for strength and got a little taller. So maybe this is not an Enerpac cylinder and is metric?
I will buy the cylinder off Ebay. Hopefully I will get a feel for the thread engagement when I screw it in then decide on a backup reinforcement.
In the mean time I guess I can try to strip and repaint this C frame. Good shelter in place project.
Robert

Jim- You are brilliant. It looks like this is a metric cylinder with a pitch of 2.0. That explains a lot!




Robert


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## rwm (Apr 7, 2020)

FYI the pump has an Enerpac label. It is a P39. Must be a pretty old setup. 
I already dropped the cylinder and broke the glycerine filled gauge so I will be replacing that also. 
Robert


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## rwm (Apr 7, 2020)

Such a mess; always.




This is one kind of stripper I don't like 

Robert


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## rwm (Apr 7, 2020)

Yellow underneath. That paint didn't want to come off but will make a good primer. Even though I stripped it I think I may try to derust it. The table surface is pretty bad.
Robert


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## matthewsx (Apr 7, 2020)

rwm said:


> View attachment 320036
> 
> 
> Yellow underneath. That paint didn't want to come off but will make a good primer. Even though I stripped it I think I may try to derust it. The table surface is pretty bad.
> Robert



If you have a local auto engine rebuilding shop give them a call and ask about hot tanking it. It's usually pretty cheap and if you want it checked for cracks they can do that too.


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## extropic (Apr 7, 2020)

Grainger's list price on that C-frame is $1832.

Your's is looking very good already.


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## gr8legs (Apr 7, 2020)

I'm getting to the party late but I wonder if all the proposed work on this press will actually give you anything but a clean sow's ear.

According to the information it needs at least a new cylinder and gauge. $$$

When you're done you will have a small shop press with an extremely limited work envelope. For about the same money you could acquire a brand new 10-ton H-Press from Freight Harbor with plenty of room for most any pressing project.

Just my $.02

Stu


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## Cadillac (Apr 7, 2020)

As for bleeding the system your lines if their correct should have a checkball on both sides and screw together. When you connect the balls are forced open and when disconnected they shut. You would loose maybe a drop of oil from disconnecting. Yes the system would bleed itself. Press hydro lines have a rating of 10k psi not like a typical hydro line that is rated at 3500. That's why they are double the price.
 Those threads are definitely rolled over opposite the force of cylinder. I have a enerpac 12t H press with the same cylinder. I went and measured my threads on the cylinder and the OD of threads measured 2.230 with a 14 tpi count. Just for reference. Not 2.0mm like you show.


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## rwm (Apr 7, 2020)

I definitely thought about the harbor freight option. I wanted something with a smaller footprint. I only paid 90 bucks for the press. They are listed on eBay for a thousand. Even with a new cylinder at $150 I am okay with it. Assuming I can thread in the new cylinder I think this is going to be a nice setup. If not I might have a sow's ear! (Clean)
And the gauge...well that's my fault and now a sunk cost. Hey, it's cheaper than that last end mill!
Robert


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## rwm (Apr 7, 2020)

And there is nothing stopping me from putting the metric cylinder back on eBay clearly advertised as metric!
R


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## rwm (Apr 7, 2020)

matthewsx said:


> If you have a local auto engine rebuilding shop give them a call and ask about hot tanking it. It's usually pretty cheap and if you want it checked for cracks they can do that too.


That is a good idea. I will look into it for the next mess!
Robert


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## rwm (Apr 8, 2020)

I have never derusted anything this large.




Robert


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## epanzella (Apr 8, 2020)

If it me (you know, the hack) I would thread the cylinder just above the area that goes into the C-frame. Then I would take (at least) a 3/4" plate and bore/thread it to screw onto the cylinder. Drill 2 holes to match the ears on the C-frame  and bolt it together. Turn some thick washers to go under the ears to spread the load to the frame.


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## rwm (Apr 8, 2020)

I could have definitely figured out a way to sleeve or adapt the metric cylinder. If I had any 2.25" stock available I would have. I think I am going to try to chase the threads on it an put it on eBay. Failing that, I will have a cylinder for the next project!
Robert


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## rwm (Apr 8, 2020)

Out of the derusting bath. That took off most on the remaining paint but did not do a great job on the rust. I hit it with a light coat of primer to prevent the clean areas from immediately rusting.




I really wish I could surface grind that table! I know it is totally unnecessary but it would look great. I may have to resort to sandpaper!
Robert


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## extropic (Apr 8, 2020)

rwm said:


> <snip>
> 
> I really wish I could surface grind that table! I know it is totally unnecessary but it would look great. I may have to resort to sandpaper!
> Robert



If flat filing won't satisfy your cosmetics, maybe use the two holes in the platen to attach a surface ground plate.   

PS: Before you repaint, please fill that ill-advised tapped hole (setscrew) as part of your refurbishment. I promise not to tell anyone.


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## rwm (Apr 8, 2020)

I did not do that! The hole may actually be factory to keep the cylinder from rotating. I will research!
I am going to try grinding the table with a flat stone by hand. Experimental.
R


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## rwm (Apr 15, 2020)

I was able to scrape the threads and the cylinder now screws in all the way!



You can see I got the table shined up a little. If someone wants to surface grind that for me.....

Robert


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## rwm (Apr 15, 2020)

Ok- Hydraulic questions: How should I put together the 3/8 NPT connections? Teflon tape? Another sealant? Dry? 
How do I bleed the system? There is a plug on the top of the cylinder. It that a bleed valve?
The Enerpac gauge adapter is somewhat expensive but I really want to use the gauge so I think I will spring for it. (eBay not new) I thought about making one but I do not have the 3/8 NPT tap and I have never cut a 3/8 NPT male thread. I assume that would have to be done between  centers with tailstock offset?
Robert


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## JimDawson (Apr 15, 2020)

Teflon tape will be fine.  You don't really have to bleed the system, just make a couple of full strokes of the cylinder with the pump higher than the top of the cylinder. Due to the design, it will self bleed.

A tailstock offset would be one way to do it.


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## Cadillac (Apr 15, 2020)

rwm said:


> Ok- Hydraulic questions: How should I put together the 3/8 NPT connections? Teflon tape? Another sealant? Dry?
> How do I bleed the system? There is a plug on the top of the cylinder. It that a bleed valve?
> The Enerpac gauge adapter is somewhat expensive but I really want to use the gauge so I think I will spring for it. (eBay not new) I thought about making one but I do not have the 3/8 NPT tap and I have never cut a 3/8 NPT male thread. I assume that would have to be done between  centers with tailstock offset?
> Robert



I can't see why you can't just thread the gauge to that port on top of the cylinder. Hydraulic fitting are different because of pressures involved wall thickness on fittings are thicker. I would not use black pipe or any kind of fittings used for plumbing. The only way I'd make one is if it was speced off a hydraulic fitting and I'd probably make it even thicker for my own comfort. Teflon is fine for sealing the threads or a paste.


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## extropic (Apr 15, 2020)

I use Teflon tape on the NPT threads.

I think the "plug" in the bottom of the cylinder body is actually the anchor for the return spring (inside the cylinder). Don't mess with it.

To bleed the system, use the pump to fully extend the cylinder. With the pump and hose above the cylinder, release the needle valve to allow the cylinder to retract. Any trapped air will be flushed back through the hose/pump and vented from the reservoir.

Don't consider yourself limited to using an Enerpac gauge adapter. You can get 10,000 PSI rated fittings at (almost?) any hydraulics supplier (to put a gauge wherever you want it).


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## whitmore (Apr 16, 2020)

rwm said:


> The Enerpac gauge adapter is somewhat expensive but I really want to use the gauge so I think I will spring for it.


The usual scheme attaches the gauge adapter to the pump, not the cylinder, so the gauge
might not point the right way... and I think the 'pipe thread' fittings are NPTF,  which
should work fine 'dry'.   It's NOT exactly NPT.


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## rwm (Apr 16, 2020)

The cheapest non- enerpac tee fitting I could find on eBay was $32. There are some cheaper fitting rated at 4000 PSI. In fact I am having trouble finding fittings rated high enough. Most manufacturers conform to  SAE 140424  which is not adequate.
All the press systems I have seen have the gauge on the cylinder. I assume that is so you can watch the work and the gauge at the same time. Thanks for the tip on the cylinder plug. I unscrewed it partially but then screwed it back in when I realized the size would not work. I hope I didn't mess up the spring? Interesting about NPTF, thanks
Robert


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## rwm (Apr 22, 2020)

I got some work done on this while the site was down:




So I cranked it up to 5000 psi (5 tons) and I could visibly see the cast iron flex! I measured a deflection of about .060" inside the C arm. Not having much experience with hydraulics, I have some trepidation about taking this to 10K PSI. Should I be worried? I was going to cover the thing with some heavy moving blankets and max it out to test it. All the components are rated to 10K PSI and are not the standard hydraulic parts. 
Robert


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## mattthemuppet2 (Apr 22, 2020)

no idea, cast iron is pretty ductile though. Just don't do this in the Arctic 

I may have to look into getting one of those pressure gauges for my 10t Enerpac press, looks like it would be pretty handy to have.


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## rwm (Apr 22, 2020)

The gauge was only $25 on Amazon. The gauge adapter Tee was more! Keep your eye out on eBay for one rated to 10K PSI that is cheap.
Robert


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## rwm (Apr 22, 2020)

I made some accessories also. The 1" x 8 TPI thread screws into the piston.




Robert


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## Cadillac (Apr 22, 2020)

The frame will flex its cast. A press like that is not designed to be maxing it out all the time. More for assy. work and such. Really shouldn’t need more than 5t for most jobs with the exception of a stubborn rusted something trying to get apart. Just remember that pressure is just waiting for a weak spot presses are kind of dangerous with All the built up energy it has. Be careful!


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## matthewsx (Apr 22, 2020)

Probably not an issue but unless you need to certify it why bother trying to max it out. 5 tons is a lot and if you get there often look into something rated higher, I wouldn't want to run a press at much more than 50% anyway for safety reasons. 

But, I'm not an engineer....

However, when I was a kid I was walking across a bridge with my engineer father and noticed it flexing when a truck drove over it. I was worried and said so. His answer "if it doesn't bend it will break". I guess that's why bridges (and tools) are made from iron and steel

Be safe out there.

Cheers,

John


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## rwm (Apr 22, 2020)

I really appreciate all the knowledgeable people who read this thread and the comments! Very helpful.
Robert


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## rwm (Aug 27, 2020)

Just some followup:

I have found this press very useful on several projects now and I really like it. I have come no where close to near needing 10 tons!
I used it to press the socket into this wrench.



The socket has serrations and it ain't gonna move! I have about 6 thou interference.
I have also realized it will work great if I need to use a die punch.

Robert


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## extropic (Aug 27, 2020)

I've been away from this thread since mid April. Didn't get notifications for some reason.
Anyway, caught up today. Your press is looking great. Those end effectors you made look excellent. Eventually you'll end up with a drawer full of different bits to do-what-needs-doing.

I was surprised at the .060" deflection that you reported. I just wouldn't have guessed that much. I'm not suggesting a risk of breakage, however it makes it pretty clear that some sort of spherical joint should be in the load path if a "straight / perpendicular" push is critical. If I ever get one of those C-frames, I think I'll contact Enerpac technical support and ask what the expected deflection is at 10 tons.

Overall, I think you've added a great piece to your shop.


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## john.k (Aug 27, 2020)

If you want to eliminate deflection,use the two holes in the"ears" for tierods down to a sub plate.....it doesnt take much to completely eliminate the deflection.......I would also suggest the C frame is forged high tensile steel,heat treated,which is why it costs.......I expect the HF cheapie is very likely a cast ductile iron ,which while strong ,to a point ,is no comparison to the Enerpac one....PS I have a 100 ton Rogers puller for dozer sprockets ,and it bends 1 1/2" thick mild steel adaptors ,yet the 1"UNC Cat brand bolts hold ,and unthread with fingers after a pull.


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## extropic (Aug 28, 2020)

@john.k 

I think you're correct on all counts. I wonder if the ears on the top line up with the forward mounting slots in base.


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## rwm (Aug 28, 2020)

Thanks guys!
The thing sure looks cast, but you could be right about forging. The ears do not line up with the base holes but I could easily support the frame with threaded rod if I ever really needed to max it out. 
I like the small footprint this takes up in the shop. 
Robert


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