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mrriggs
04-21-2013, 04:29 AM
This is the 20 ton press I built a few months ago. It was inspired by posts I had read here about using an inverted bottle jack as a ram.

Because of the four picture limit, it's going to take several posts to fit it all in. So please bear with me.

I suppose you could say I cheated a bit from the get-go. Rather than build the frame, I used a 55 ton press frame that was given to me [minus the hydraulics].

http://www.gofastforless.com/junk/BigPress02.jpg

For the ram, I bought a $35 20-ton bottle jack.

http://www.gofastforless.com/junk/BigPress03.jpg

First step was to drain the oil and pull it apart. I don't have a big enough monkey wrench for the top nut so I held the nut in a bench vice and unscrewed it from the bottom with a pin spanner (which was made years ago to hold a Husky flywheel).

http://www.gofastforless.com/junk/BigPress04.jpg

My strap wrench wasn't strong enough to remove the cylinder from the base so I had to just work around it. Here, I am drilling the base to accept a pressure gauge.

http://www.gofastforless.com/junk/BigPress05.jpg

mrriggs
04-21-2013, 04:38 AM
First an 1/8" hole that went clear under the cylinder, then open the end with an 11/32" drill. Finish off with an 1/8" pipe tap (not shown).

http://www.gofastforless.com/junk/BigPress06.jpg

An intersecting hole was drilled through the bottom of the cylinder. That was not a fun task with the cylinder still in place.

http://www.gofastforless.com/junk/BigPress07.jpg

The reason to open it up in the first place was to add a "straw" to the feed hole so that it won't suck air when inverted. I grabbed a chunk of brake line, beveled the end on a bench grinder, dabbed on bit of LocTite then tapped it into the hole.

http://www.gofastforless.com/junk/BigPress08.jpg

Cleaned it up, put it back together, and filled it with oil. Notice the pipe plug since I don't have a gauge for it yet.

http://www.gofastforless.com/junk/BigPress09.jpg

mrriggs
04-21-2013, 05:05 AM
This press features a sliding head so mounting the ram was fairly simple. There is a one inch plate that sits in a track below the top beam. I removed the plate, drilled some holes in the base of the ram, set it on the plate, marked the hole locations with a transfer punch, then drilled them out on the drill press. The holes were tapped to accept some cap screws. I also drilled and tapped a hole for a shoulder bolt which will be the anchor for the lever pivot.

http://www.gofastforless.com/junk/BigPress10.jpg

The head was cut off the shoulder bolt and a cross hole was drilled. Mounting the pivot in front of the pump reverses the motion so that I am pulling the handle rather than pushing. Also notice where I drilled out the "pimple" that originally kept the bar from sliding through the back of the lever, and added a roll pin to the new back to serve the same purpose.

http://www.gofastforless.com/junk/BigPress11.jpg

The screw tip of the ram is peened internally so that it can not be completely unscrewed. I had read where some people would grind the ram where the nut is swaged, in order to disassemble it. I found it much easier to simply unscrew the tip as far as it would go, cut it off, grind a slot in it, then screw it into the ram with a flat blade screwdriver. The ram is deep so the remnant won't interfere with anything screwed into the end.

http://www.gofastforless.com/junk/BigPress12.jpg

http://www.gofastforless.com/junk/BigPress13.jpg

mrriggs
04-21-2013, 05:22 AM
The idea is to make a new tip for the ram that can be easily removed and faced in the lathe any time it starts to get beveled or mushroomed. I can even make custom tips for particular jobs to rely less on scary spacers.

I grabbed a steel bar from the scrap bin and faced / chamfered one end.

http://www.gofastforless.com/junk/BigPress14.jpg

The other end was center drilled and turned down for the threads.

http://www.gofastforless.com/junk/BigPress15.jpg

I ground a HSS tool to match the profile of the original threads and got the bar all mounted up in the Atlas. It wasn't until I went to setup the change gear for the 6mm pitch that I realized that I didn't have enough gear bushings. I was nearly ready to throw up my hands and say, "Well, there is nothing I can do until I order that part." Then I noticed that the third bushing simply held an idler gear. There was no need for the special keyed bushing. I dug through my junk box and found the appropriate hardware, then turned an aluminum bushing out of a gate stub. The new hardware would only allow the idler gear to mount in the "back position" so I had to flip the entire gear arrangement front to back, including the "stud gear". It all went together and worked like a charm.

http://www.gofastforless.com/junk/BigPress16.jpg

Chasing the thread was pretty straight forward. It's a metric thread so the half nuts stayed engaged the whole time and the motor was reversed to return the tool for the next cut. The depth was limited to 0.003" per pass. Seriously, even at 0.004" things got pretty scary since it's like threading with a parting tool.

http://www.gofastforless.com/junk/BigPress17.jpg

mrriggs
04-21-2013, 05:27 AM
The original screw was really loose so I intentionally made this one larger to try and get a better fit. The first attempt did not fit.

http://www.gofastforless.com/junk/BigPress18.jpg

I put it back in the Atlas, picked up the thread, then peeled off a bit more. Success!

http://www.gofastforless.com/junk/BigPress19.jpg

mrriggs
04-21-2013, 05:35 AM
I wanted a permanent handle on the release valve rather than use the end of the jack handle.

http://www.gofastforless.com/junk/BigPress20.jpg

I dug around hoping to find an old spigot handle or something. What I found was an old gate stub that was the right size.

http://www.gofastforless.com/junk/BigPress21.jpg

Just cut it off, drill two holes in it, tap the pin out of the bleed screw, stick the screw in the handle, then tap the pin back in.

http://www.gofastforless.com/junk/BigPress22.jpg

Quick, effective, and free.

http://www.gofastforless.com/junk/BigPress23.jpg

mrriggs
04-21-2013, 06:02 AM
I extended the ram, set the whole thing on a bathroom scale and measured how much force was required to retract the ram. It came out to 120 pounds which led me on a futile search to find spring that pull 120 pounds and stretch six inches.

I eventually switched gears, stepped back and asked the real question. "Why does it take 120 pounds to retract this ram?" The answer of course is that this is a "bargain" priced item and therefor not built correctly. More specifically, the o-ring groove in the nut was not made deep enough so there was excessive friction on the ram.

The solution was to setup the nut in the four jaw, indicating off of the bore...

http://www.gofastforless.com/junk/BigPress24.jpg

Then turn the groove deeper.

http://www.gofastforless.com/junk/BigPress25.jpg

I wasn't sure how deep to make the groove so I just took a little off at a time. After each cut, put the o-ring in and slide the ram through it. I stopped cutting when it felt right.

With it all reassembled, it took less than 20 pounds to retract the ram. I had no trouble finding springs that could handle that.

I also had a happy accident when it was disassembled the last time. I managed to knock over the container of hydraulic oil and make a mess of everything on my work bench. That wasn't the happy part. The happy part was the night and day difference in the pumping action from the replacement hydraulic oil. All I had to substitute it was 15 weight fork oil which was a bit thicker than the original oil. With the original oil it felt like half of the lever travel was used to seat the check valve, probably why some guys recommend mounting little springs under the ball. With the thicker oil, the ram starts moving as soon as you pull the lever, there is no more "slop".

mrriggs
04-21-2013, 06:18 AM
The last piece I had to make was a spring bracket for the ram. This was again made from pure scrapbinium. I drilled and bored a hole in it, then made a small counter bore so it would fit snug around the OD of the ram.

http://www.gofastforless.com/junk/BigPress26.jpg

Final assembly.

http://www.gofastforless.com/junk/BigPress28.jpg

http://www.gofastforless.com/junk/BigPress27.jpg

Ram extended.

http://www.gofastforless.com/junk/BigPress29.jpg

That's about it. With one lucky score, $50 out of pocket, and roughly 20 hours of labor, I have a handy addition to the shop.

Tony Ennis
04-21-2013, 08:09 AM
Very nice work. Now, crush something for us.

flylo
04-21-2013, 08:11 AM
Nice build! HF has the air.hydraulic if your arm gets tiredfot $89. I ordered one for mine last night. 20 Ton Air Hydraulic Bottle Jack Item #:95553

Looks great!

Robo
04-21-2013, 10:41 AM
Nice....if the frame is rated at 55 ton how come you didn't get a cylinder to match? Just curious :)

Wish I could luck into "finding" something like that. Been wanting a shop press for years.

mrriggs
04-21-2013, 11:33 AM
Nice....if the frame is rated at 55 ton how come you didn't get a cylinder to match? Just curious :)

There are a few reasons. I think the 55-ton rating was a bit optimistic. It may technically be able to hold that much, but I had used this press before it was decommissioned and it didn't seem quite rigid enough to really push it that far. The highest I ever took it was 30 tons and there was quite a bit of spring back when the part popped loose.

The most obvious reason is price. A 20 ton bottle jack is much cheaper than a 50 ton. Plus, the bigger it is, the more times you have to pump the handle to get it to move a given distance.

For the majority of the work I do, 20 ton is more than enough. If I ever have a steady need for more than that, it would be simple to add a second ram because of the sliding track mount. For one-off jobs I could just go to the place I got the frame from and use their press. They replaced this one with a 75 ton press.


Wish I could luck into "finding" something like that. Been wanting a shop press for years.

I have been using a cheap Chinese "12 ton" press for over ten years. For most of that time I have had my eye out for a "real" press and was finally lucky enough to be in the right place at the right time. Don't get me wrong though, that cheapy press has served me well. It's paid for itself a hundred times over. If you don't already have one then get one. You will be surprised how much use you will get out of it.

A.K. Boomer
04-21-2013, 11:40 AM
Nice - was wondering how you got that cylinder to work upside down,,,

my little 12 ton HF just butt's the top of the drive of the bottle jack up against an A-frame whilst the lower part of the jack fits on top of a drive plate with a guided center shaft...

Mike Nash
04-21-2013, 11:48 AM
That release knob really keeps catching my eye! Kinda mushroomy.

I am "needing" a press about now for about 5-6 bearings in my tranny rebuild, but I looked at the Harbor Freight offerings previously and was underwhelmed. I really like that inverted jack you did as opposed to the moving support like the HF uses.

vpt
04-21-2013, 12:08 PM
Nice job!

bborr01
04-21-2013, 12:21 PM
mrriggs,

That was an excellent write up. My press looks just like yours as far as size and it has the same sticker except mine reads max 60,000. My press also uses a 20 ton bottle jack. I have a 30 ton but I think the 20 ton is about what I am comfortable with. I might use your idea of adding a pressure gage. Do you have a conversion chart that converts psi into tons on the ram?

Brian

Glug
04-21-2013, 12:36 PM
Nice build and excellent write-up!

I've always wondered what the deal is with cheap presses. Now I have much better idea of their limitations.

One improvement might be moving the jackhandle off to the side, or down below, so it isn't so centered and in your face. I imagine a hydraulic hose would allow that. Another idea would be a foot pedal, leaving both hands free to, uh, be pressed :P

A.K. Boomer
04-21-2013, 12:52 PM
I really like that inverted jack you did as opposed to the moving support like the HF uses.

Personally (even though my HF is not half the press) I really like having gravity on my side when pumping the jack handle,,, you can apply more pressure - it's more controlled - and with light things the jacks not trying to take off or wobble... just my 2 cents...


Just went back to look AND read - looks like he's got that covered and reversed the mechanism also - thought he was just moving the handle position,,, now I like it even more...

Scottike
04-21-2013, 01:27 PM
Do you have a conversion chart that converts psi into tons on the ram?

By reading pressure directly from the ram cylinder, no conversion is needed except to convert 2000 psi = 1 ton.
On some presses I think the pressure reading is taken from the pump which is different from the applied
cylinder pressure, hence a conversion chart would be needed.
Then again, I could be wrong. It certainly wouldn't be the first time, and I'm sure it won't be the last.

mrriggs
04-21-2013, 01:39 PM
The force applied to the work is the pressure times the area of the piston. My piston has an area of approximately 3 square inches so the force would be the pressure times three. Ten thousand PSI would apply a force of 30,000 pounds or 15 tons. To actually hit 20 tons it would take a little over 13,000 PSI. I have my doubts as to whether this thing could actually do that.

Pherdie
04-21-2013, 02:15 PM
A very nicely done project and certainly one that appeals to many of us here.

Thanks for taking the additional time to document and share with us, much appreciated!

Scottike
04-21-2013, 02:27 PM
I stand corrected - I knew it wouldn't be the last time I would be wrong. :o
So a piston area of 2 sq." would directly read tons - sort of.
10,000 psi x 2sq." = 20,000 lbs or 10 ton.

kNucKlbustr
04-23-2013, 01:18 AM
Curious as what you will use for gauge fittings, that will withstand 10k-20k psi.

Jaakko Fagerlund
04-23-2013, 03:58 AM
Curious as what you will use for gauge fittings, that will withstand 10k-20k psi.
Just about any steel with a little wall thickness can withstand it, heck I've even made them from aluminum. Just requires a small calculation to determine the needed wall thickness, when the inside diameter, pressure and material tensile strength is known.

kNucKlbustr
04-23-2013, 10:01 AM
Im at the point you are. 20T, no gauge.
Near the max of the pump for my projects. Blew the seal in the 1st pump.
Using a dial indicator to determine.

Purchased a surplus 4" 20000psi gauge for $15.
Noticed hi-pressure elbows or Ts sold are under-rated.
Only setup I could think of is using a pipe-tapped 1" thick steel block w/ 1/8" holes.
Pipe threaded steel rod to join pump to block. Need to buy a pipe die.
And tap gauge to top of block.
My setup is upright so the block rests on the steel beam.
Fabbed a steel blast shield in frt of the block asy, just in case I screw up.

mrriggs
04-23-2013, 10:38 AM
Curious as what you will use for gauge fittings, that will withstand 10k-20k psi.

A 45° grease gun elbow would be perfect for my setup but I haven't found anyone who sells them in small quantities. To be honest, I haven't looked all that hard.

Jaakko Fagerlund
04-23-2013, 03:50 PM
For example: 1378 bar pressure (20k psi), basic steel (S355) with 355 N/mm˛ tensile strength and outside pressure of 1 bar (atmosphere) and round part with a 10 mm hole in the middle requires about 7 mm wall thickness to withstand the pressure.

If you are purchasing properly made components, then they usually have 4:1 safety factor. For example, 6x1 mm hydraulic tube is said to withstand about 390 bar, but the bursting pressure is about 1500 bar.

mrriggs
05-09-2013, 01:18 PM
Just a quick follow-up. I finally got around to putting a pressure gauge on the ram. As previously mentioned, finding a gauge is easy, it's the fittings that are hard to find. The fittings I used are only rated to 5,000 PSI, but factoring in the 4:1 safety factor they should hold up to 10,000 PSI. Since it uses a [very] low volume hand pump, I'm not too worried about what would happen if a fitting did fail. I worry more about parts or tooling flying out of there which is why I always wear protective gear when operating the press.

http://www.gofastforless.com/junk/BigPress30.jpg

There is a 90° elbow coming out of the ram, then a 45° elbow, a quarter inch adapter, and finally, the 15,000 PSI gauge.

http://www.gofastforless.com/junk/BigPress31.jpg

I did a test run up to 12,000 PSI and was actually more surprised that the ram held that pressure than I am about the fittings holding the pressure. That works out to 18 tons and I physically couldn't pump it any further without a cheater bar (which I will never do). So all said and done, I put together an 18-ton press for about $100 (not counting the tooling).

mrriggs
11-11-2013, 10:44 AM
I made one more revision to the press. Bottle jacks are made with a sealed reservoir so that the oil will not spill when moving it around. The sealed reservoir was causing issues with the pump feed because it pulls a vacuum as the ram is extended. Since this ram is permanently mounted, I can vent the reservoir and spilling will not be an issue.

I pulled the ram from the press frame and removed the reservoir. Then I drilled a hole in it and soldered in a tube.

http://www.gofastforless.com/junk/BigPress32.jpg

Put it all back together, filled it up with oil, and put the ram back in the press. I found a small filter in the junk box that slides on over the tube to keep bugs out of it.

http://www.gofastforless.com/junk/BigPress33.jpg

Having the reservoir vented to atmosphere made a huge difference in the pump action. Plus, now I can squirt oil into it without having to remove the ram.

Paul Alciatore
11-11-2013, 02:16 PM
Nice build.

Now you can crush your beer cans when they are empty.

pauldolb
08-08-2016, 09:47 AM
[QUOTE=mrriggs;845741]This press features a sliding head so mounting the ram was fairly simple. There is a one inch plate that sits in a track below the top beam. I removed the plate, drilled some holes in the base of the ram, set it on the plate, marked the hole locations with a transfer punch, then drilled them out on the drill press. The holes were tapped to accept some cap screws. I also drilled and tapped a hole for a shoulder bolt which will be the anchor for the lever pivot.

thanks mr riggs for the great info...i'm new to the forum and found your article because i'm preparing to invert a bottle jack on a similiar press frame ,the 30 ton version of yours..... i'm using a 20 ton jack in a 30 ton frame ..can you please explain or picture how the 1" sliding plate removes from the channel track it sits in ....is the plate just small enough to allow for removal by tilting?..or how ??????................the track looks to be made from3/4" steel angle that is welded to make up the channel....correct? if possible pictures of the track and plate mounted to the press frame would be a great help ..thank you paul

brian Rupnow
08-08-2016, 04:19 PM
I have seen a few of these presses where they didn't invert the bottle jack, so no modification to the bottle jack were necessary. It still used the "add on" return springs to lift the press head when the bottlejack pressure relief valve was turned. Why would you go to all the problems of modifying the jack to use it upside down?

J Tiers
08-08-2016, 04:27 PM
I presume so as to have a solid mounting for it.

Easier to pump, less side force on the moving part from pumping, potentially less wiggling of the parts if doing something like using a keyway broach.

pauldolb
08-08-2016, 09:24 PM
the tubular vertical guides on mine are no longer plumb with the press frame ..when the jack is inverted it becomes a ram with straight down force and nothing to bend or move sideways

darryl
08-08-2016, 11:51 PM
Nice mod. When I built my press I inverted the jack as well. On mine the threaded stub was captive also, and my solution was the same as yours. Turns out the threads matched some threaded rod I had so I'm able to make specialty tooling for it. This one is a baby at 6T, but useful as all getout in my shop.

To deal with the upside down jack I used the fill hole as a port and piped it to a tank which sits above the jack. Normally you leave some air space in the jack since you fill it to the point where the oil level is at the fill hole height. In this case all the air had to be purged, so once my connecting pipe and tank were connected I laid the jack on its side and twirled a feeder tube into the jack from inside the tank. Once that was in place I injected oil through the tube until all the air was displaced and clear fluid only came out from around the feeder tube. This was a bit messy as the jack and the tank are on their sides at this point. But uprighting the tank and with the jack upside down, all that's left is to put some amount of fluid in the tank so it doesn't go dry when the jack is fully extended.

To extract any remaining captive air I loosened and removed the valve (lost the ball once, found it again) and lost more fluid with the remaining air that bubbled out. Now it's purged and working fine, no sponginess. It's been fine ever since, and my gooped-on fittings have never leaked. The tank has a cover but it's not air-tight, and it shouldn't be as you need some pumping room.

I like the upside down jack idea. It works well and in my case the jack is fixed in position centered in the frame. Where you have a piece of bar to hold the springs, I have a full width assembly that doubles to hold the extendable part well centered in the frame. In my mind, if you can eliminate any side motion on the piston, you also minimize things going wrong when the pressure is on.

The only mod I did the the jack itself was to move the pump handle off the jack and put it on the frame of the press. A connecting rod then goes from the pump rod upwards to a point on the handle. The handle has its own return spring. I got rid of as much play in this area as I could, and it makes it very positive in use.

Dave C
08-09-2016, 12:48 PM
Great job on the press and the write up. I built one a few years ago, but was not lucky enough to get a ready made frame. Had to go at it from scratch, and wish I had known then how to turn the jack upside down. I'll have to start another thread to show off my bed elevating mechanism.

pauldolb
08-09-2016, 07:31 PM
Great job on the press and the write up. I built one a few years ago, but was not lucky enough to get a ready made frame. Had to go at it from scratch, and wish I had known then how to turn the jack upside down. I'll have to start another thread to show off my bed elevating mechanism.

please show your bed hoist ....and please tell me how to find it when you post it ..(i'm new ) ..i'm still hoping the original poster of this article explains the removal of the jack mounting plate ..or is able to post pictures..thanks paul

R W
08-11-2016, 04:30 AM
I have seen a few of these presses where they didn't invert the bottle jack, so no modification to the bottle jack were necessary. It still used the "add on" return springs to lift the press head when the bottlejack pressure relief valve was turned. Why would you go to all the problems of modifying the jack to use it upside down?

Built one along these lines over 20 years ago , designed it for at least a 20 ton jack. The main advantage of this set up that the jack can be utilized elsewhere and any suitable jack can be used in the press, frequently a smaller jack is suitable for lighter work.

greystone
08-11-2016, 11:42 AM
Great stuff.
Congrats. Thanks for write up.

Dave C
08-11-2016, 11:43 PM
please show your bed hoist ....and please tell me how to find it when you post it ..(i'm new ) ..i'm still hoping the original poster of this article explains the removal of the jack mounting plate ..or is able to post pictures..thanks paul

look for my PM

Dragons_fire
01-24-2017, 03:20 PM
Sorry to resurrect an old thread, but I have been thinking about this for a while now, and would like opinions on flipping an air/hydraulic bottle jack. Anyone have any idea if it would be the same process or would it not be possible? this is the one im looking at, and the sale price is pretty tempting.

http://www.princessauto.com/en/detail/20-ton-pneumatic-hydraulic-bottle-jack/A-p8003606e

Thanks

darryl
01-24-2017, 04:25 PM
A jack can be flipped, not sure about this one though. When I built my press I flipped the jack. What's required is to have the fluid supply above the pump, so my mod adds a fluid tank that sits higher than the jack when it's all installed. It uses the fill port to plumb it in.

The air over system is interesting- it might be fine upside down if it doesn't have any gravity assisted valving or anything like that. I'm just guessing though. Would be an interesting adaptation, and one which relieves you of a lot of hand cranking I'd presume.