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madman
10-17-2011, 09:29 PM
Well...I got a 30 ton homemade press from a fellow and after dragging it home figured it would be Perfect?for doing my Motorcycle Crankshafts for my Drag Bike. Well..I am amazed how much the steel frame will bend contort and twist when I get that 50 ton Cylinder going full force,, NOW im asking for some help as I need to build a press frame that can easilly withstand 50 tons of pressure, I ve alrready made up 3 inch thick plates to support the crank Bits,,, What size should the support Pins (Im gonna use 2 on each beam this time maybe ??one inch dia>??? and what size side and top beams shouls I be scavenging? My press was made from what I call 9 inch jumior beams (the type home builders seem to throw into the Yards and let lay around ,,that kind, anyhow I need some tips guys , I cant see doing precision type crank work with this abortion I currently Have in my new shop.. I am even thinking of a 4 post type press since all I wiash to do with it is Crankshafts (multi piece GS suazuki types )Thanx Guys Mike

Ries
10-17-2011, 10:26 PM
sounds seriously underbuilt to me.
a commercial 50 ton is gonna have at a minimum a 3"x 12" channel for the vertical, that would be a .280 wall, and weigh about 20 pounds a foot.
None of my books list 9" junior beams- only 8" and 10", but an 8" junior beam is only 6.5 pounds per foot with a .135 flange thickness- so its probably about 1/3 the amount of metal it should be.
Pins for a 50 ton should be at least 1 1/2", 2" is better.
Cross frame at top, to hold cylinder, and across to hold the work, should be at least another 12" channel on each side. Bigger is better.

50 tons is nothing to mess with.
Unless you get a real engineer to do the calcs, I would suggest severe overbuilding is far better than underbuilding.

wierdscience
10-17-2011, 10:27 PM
Well here is a bright,shiney new Dake 50 ton press we got in for a customer,lot prettier than our old rag in the shop.

http://img.photobucket.com/albums/0903/wierdscience/DSCF0005-1.jpg

They used 7" channel with a 3/8"web for the top,bed and side rails.The pins are 7/8",but 1"-4140ht would be better.The pins on our old Dake have been bent several times,dunno why:rolleyes:

It's a great press,but if I had to build it one thing I would change is eliminating the channel for the uprights.In it's place I would use four pieces of 3/4x4" flat.Easier to drill than the channel,allows for a bigger pin and leaves the sides open for shaft straightening.Kinda like this OTC press-

http://www.google.com/products/catalog?ds=pr&pq=otc+50+ton+shop+press&hl=en&sugexp=kjrmc&cp=4&gs_id=3&xhr=t&q=OTC+SHOP+PRESS&qe=T1RDIFNIT1AgUFJFU1M&qesig=h7zKKbdD0LnE_bpMtgxUeA&pkc=AFgZ2tkC0U9bgiPxlmZ0UVP8-nSqcy9QjgQv6BMBXzJdoVGCla1VcQTaFl-azfBrfoFj4MuXN_M-DRyl-Bd-CPAic4p3g-7cPQ&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&biw=1152&bih=651&wrapid=tljp131890481802600&um=1&ie=UTF-8&tbm=shop&cid=3006970066831187666&sa=X&ei=_uOcTuiYNKfk0QH8mZSdCQ&sqi=2&ved=0CG0Q8wIwAA#

Don Young
10-17-2011, 10:53 PM
It seems to me that two pins would be just as good as four. If you intend for the table to be adjustable it would need some pretty precise hole locations to share the load between four pins. If only two pins are in contact, there is little point in having the other two.

Ries
10-17-2011, 10:57 PM
I built this press based on the then commercially available enerpac-
its a whole lot herkier than that DAKE.
Its a 30 ton model, and I sure wouldnt go smaller than this for 50 ton.
Enerpac no longer makes this model, their current ones are made from flat bar, not channel.

http://img.photobucket.com/albums/v132/rniemi/press.jpg

wierdscience
10-17-2011, 11:29 PM
I built this press based on the then commercially available enerpac-
its a whole lot herkier than that DAKE.
Its a 30 ton model, and I sure wouldnt go smaller than this for 50 ton.
Enerpac no longer makes this model, their current ones are made from flat bar, not channel.



It's morbidly obese:D No the old Dake in the shop is built lighter than that new one and it's a 1929 model.Been up past 55tons several times no problems at all.The only way I would go bigger than an 8" channel would be if I wanted a wider opening between columns.

J Tiers
10-17-2011, 11:33 PM
50 tons = 100k pounds

At 15,000 psi, that is about 7 square inches of tension part, split between the two sides..... I'd probably go with 1.3 x just because of off-center (normally the cylinder is right in middle though), so that's about 9 square inches of uprights cross-section.

the Dake in Weird's pic has around 6+ sq in of tension area, when you take out for the pin holes. Close to my 7.

1" pins x 2 would be about 3.14 sq in, for a shear of 32k per sq in, which is too high, so figure 4 x 1" pins, (or larger diameter pins, but those could take too much of a bite out of the channel). If the tolerances are not too loose, it will seat in and share with 50 tons load, it's 12.5 k lb per pin end.......;)

The beam has no answer yet, because we don't know how wide you want the opening.

pturner
10-18-2011, 02:31 AM
Mine is 50T also, with a movable cylinder. I had to use 1-1/8 4440 for the pins to get a reasonable safety margin. Also check bearing strength, I had to add 1/2 " flat bar to the 12"x20# channel bed to get enough bearing area. Flat bar for the uprights is nice, but drill holes through the whole bar and you cut into your strength a lot, meaning you need bigger bar.

boaterri
10-18-2011, 06:19 PM
You might want to visit this website for some ideas. His press looks like it would do everything you want.

http://www.davepropst.com/Article/Art6/Article6.htm

Rick

Ohio Mike
10-18-2011, 07:39 PM
My guess is that Dake specifically uses the small pins to provide a weak point so that you bend or break the pins before you twist the frame into a pretzel. Easier to buy or make new pins that straighten out the H frame.

I keep kicking around the idea of making a press, so I'm curious to see what everyones ideas are.

Also flat bar is nice too from a fabrication stand point as you can clamp or tack weld them all together and then drill all the holes in one shot so they all line up perfectly.

shawnspeed
10-18-2011, 08:55 PM
Do you really need 50 T to press those cranks???I press 2 cycle and single 4 strokes cranks with a 20 tonner and it does a fine job....Or is this a matter of bigger is better??? Shawn

wierdscience
10-18-2011, 09:44 PM
Do you really need 50 T to press those cranks???I press 2 cycle and single 4 strokes cranks with a 20 tonner and it does a fine job....Or is this a matter of bigger is better??? Shawn

Presses are funny,people buy or build them with the idea in mind"I'll only be pressing such and such no need for xxton press".

Then about two days later they run into something that the new press won't budge,or they quickly find other uses for the press.

50tons sounds like a lot,but from day to day experience over the past 20 years I have found a whole bunch of stuff it wouldn't push.

jkilroy
10-18-2011, 09:51 PM
Lots of nice presses shown here and I didn't see a single shield in the form of chain curtain or rubber guards. The shop I started at did lots of heavy equipment work and there were several large presses about for pressing bearings and gears, all sorts of stuff. Every one of them had some form of protection from flying objects should something shatter. You shatter an axle shaft at 100 tons and the individual parts are like bullets.

J Tiers
10-18-2011, 11:55 PM
Lots of nice presses shown here and I didn't see a single shield in the form of chain curtain or rubber guards. The shop I started at did lots of heavy equipment work and there were several large presses about for pressing bearings and gears, all sorts of stuff. Every one of them had some form of protection from flying objects should something shatter. You shatter an axle shaft at 100 tons and the individual parts are like bullets.

And if you buy SOME types of press, and the asian maniacs supply a CAST IRON block with it....... I saw one "painted orange", with a cast iron block/platen/whatever you call it supplied. I know, because it had a chip out of it.....

I broke a CI platen on an arbor press once and pieces flew... I don't want to see it at 30 tons.

bborr01
10-19-2011, 12:26 AM
Lots of nice presses shown here and I didn't see a single shield in the form of chain curtain or rubber guards. The shop I started at did lots of heavy equipment work and there were several large presses about for pressing bearings and gears, all sorts of stuff. Every one of them had some form of protection from flying objects should something shatter. You shatter an axle shaft at 100 tons and the individual parts are like bullets.

I ran some 300 ton presses in a die room and they all had one inch lexan all around. Even with that, if I had something that didn't budge after about 100 tons, I would stand beside it with the steel frame between the part and me.

The one inch lexan had cracks in it.:eek:

I am pretty sure that a 30.06 has nothing on the things that can fly out of even a 30 ton press.

Brian

wierdscience
10-19-2011, 12:41 AM
Yep,I had a friend who was killed when a bearing he was pressing shattered and a piece of it went through his Heart.His wife found him on the floor bled out in his garage.

Plastic sheilds,sheetmetal rings even a leather shop apron or glove is better than nothing.

Andrew_D
10-19-2011, 01:00 AM
Also flat bar is nice too from a fabrication stand point as you can clamp or tack weld them all together and then drill all the holes in one shot so they all line up perfectly.

That's what I was going to do...4 uprights, original thinking was minimum 1" x 5" uprights, tack them together, stick it on the radial drill ( :D )for the holes (1.25-1.5"). Was going to have the table sitting on 4 pins total (2 per side), for some extra strength...

Now I just gotta find some material...all I really have so far is the power pack and a couple of big hydraulic cylinders...sigh...

Andrew

Willy
10-19-2011, 08:31 AM
.............. You shatter an axle shaft at 100 tons and the individual parts are like bullets.

Boy does that bring back memories!
Late 60's, I was working in a shop at a bench assembling a cylinder head.
Buddy about 30 feet across the floor shattered a large bearing race. All at once it's raining oil all over my bench, I look up at the shelf in front and above me, where there are about 2 doz. metal quart cans of oil.
A chunk about 3/4" went completely through 3 full cans of oil and was lodged into the fourth!

Boy, you should have seen the size of everybody's eyes!
For about thirty seconds you could hear a pin drop as we all looked to make sure that everyone was still standing. Lucky we all went home with a valuable lesson that day without any bloodshed.

A.K. Boomer
10-19-2011, 09:19 AM
I built this press based on the then commercially available enerpac-
its a whole lot herkier than that DAKE.
Its a 30 ton model, and I sure wouldnt go smaller than this for 50 ton.
Enerpac no longer makes this model, their current ones are made from flat bar, not channel.

http://img.photobucket.com/albums/v132/rniemi/press.jpg



Damn that is a monster --- I was going to say that the length of the horizontal beams have everything to due with the rating but yours are offset and that increases the rating even further although it decreases the ratings on the adjusting pins off to the loaded side more due to them not divying up the load evenly, still - nice practical design for odd parts and such but limits the parts with even overall radius and that gives me an Idea,,, maybe a pinned sliding cylinder for both dead center operations and offset parts...

edit; just went an looked at the pic and it looks like yours is adjustable??? very nice if so.

Scottike
10-19-2011, 10:46 AM
This is my old "buck a ton", 40 ton press, $40.
Construction is of 1" steel, the top and carrage beams are 1" x 9", the pins are 1" dia.

http://i1085.photobucket.com/albums/j422/Scottike/40TonPress.jpg

torker
10-19-2011, 07:11 PM
Guys! Please be real careful with these "shop built" presses. I recently had a similar press explode on me. We "think" it's rated at 60 ton...
It can bend the two pieces of 10" channel on the bottom like spagetti.
I was just squashing some pipe ends on it...an easy task...when all of a sudden there was complete failure of all the welds on one side of the top crossmember...a 4"X12" I beam...
It had been mig welded by someone years ago...welds LOOKED great!
But...no penetration and I almost got whacked because of it.
It shook so hard when it came apart...the force blew the electrical box all to hell. Even blew a magnetic switch to pieces.
I spent two days beefing the press up with big gussets on the top and heavy side plates and strongbacks on the working crossmember.
Dang thing still flexs more than I
'd like but it's much safer now...specialy since I found the hydraulic release valve and turned it way down.
Take care!!!
Russ

Ries
10-19-2011, 07:13 PM
Damn that is a monster --- I was going to say that the length of the horizontal beams have everything to due with the rating but yours are offset and that increases the rating even further although it decreases the ratings on the adjusting pins off to the loaded side more due to them not divying up the load evenly, still - nice practical design for odd parts and such but limits the parts with even overall radius and that gives me an Idea,,, maybe a pinned sliding cylinder for both dead center operations and offset parts...

edit; just went an looked at the pic and it looks like yours is adjustable??? very nice if so.


Yes, the entire cylinder assembly can be moved left or right.
And the winch on the left is for winching up or down the lower set of cross bars.
Daylight, left to right, is about 36".

This design is lifted from the old Enerpac press design almost exactly- I figured with their liability insurance, they would overdesign, and I like that.

You can find the current, 4 flat bar post enerpac designs online as well, with basic dimensions shown in their catalogs.

John Stevenson
10-19-2011, 07:33 PM
Years ago I was asked to press the crank pins out on one of those 50cc works Honda twins, CR93's I think they were.

My press only went up to 15 tons and wouldn't move it so took it to work and put it on the 40 tonner, still no joy.

Took it round to ZF Gears and used their 90 ton press but by the time it had got up to 85 tons on the gauge and everything was creaking and groaning I bottled out and gave it him back.

I cringe at seeing some presses and what they are rated at, spindly uprights and pins that would do better service as tooth picks.

This is my broaching press.

http://www.stevenson-engineers.co.uk/files/broaching_press.jpg

The overload valve is set at 10 tons and even at a lowly 10 tons it bends the 3/4" thick steel bed plate. Pins are 1 1/4" or 30mm diameter.

dfw5914
10-19-2011, 07:39 PM
...It had been mig welded by someone years ago...welds LOOKED great!...

Good 'ol "pretty" MIG welds, this guy may have used the same welding service:

http://www.bangshift.com/blog/Instant-Classic-Carnage-Video-If-At-First-You-Hit-the-Wall-Don-t-Try-Again.html

wierdscience
10-19-2011, 08:32 PM
I've seen weekend racers lay Mig welds on top of OEM epoxy paint.

I've seen weekend racers want to build link suspension with 1/2"Heims.

I've seen weekend racers spend $4000 on paint and $199 on they're welder.

Not all weekenders are like that,but some are damn scary:eek:

jep24601
10-21-2011, 12:17 PM
From A HD shop manual:

"An arbor press of aproximately 10 ton capacity is needed to assemble and disassemble crankpin in flywheels."

Paul Alciatore
10-21-2011, 03:19 PM
Thanks for the education on presses. I never thought of a possible explosion hazard, but it makes sense at those pressures.