DIY machine jack

Hi,

I have a lathe and a milling machine in my home shop. I want to install levelling feet under the machines, so I need to lift the machines at each corner. The machines are rather heavy. The lathe is 3700 pounds and the mill is 4200 pounds. I have looked for machine jacks that would be able to lift these, but they are around 600$ here in Turkey. I don't want to spend this much for a tool that I will maybe use just one time, so I decided to build something that I can use to lift the machines, one corner at a time.

I want build a hook from 3cm x 3cm mild steel rod and then I want to push this hook up using a regular hydraulic car jack. So the hook will look something like: I will also use suitably thick I beam to make a 4 legged frame that has a rail where the hook can go up and down and a spot where the car jack will be placed.

Machine The edge hook | ===== | || ^ | || _| || | =====

My biggest concern is how to weld these pieces together. I have a 250A 3 phase stick welder. What kind and thickness of rod must I use for the

3cm x 3cm rod and for the I-beams (1cm thickness maybe). Any recommendation for making a solid weld to carry the above load much appreciated...

Timur

Reply to
Timur Aydin
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Can you get a hydraulic engine hoist / crane there at a reasonable price? They run about $200 US. Lifting the machine ends from a higher point will help with stability, and those hoists are good for other shop uses like lifting heavy rotary tables onto the mill.

Reply to
Pete C.

Timur, 3700 lbs is not that heavy, you should be able to find or make a big pry bar to do what you want. You can also look up "johnson bar" in google.

i
Reply to
Ignoramus543

Hi, I already have a large pry bar, but I really can't push it down to lift one edge of the milling machine. Maybe I can hang a load to the end of the pry bar to give me an advantage...

Timur

Reply to
Timur Aydin

Thanks for the response. I have seen economical engine hoists, but they are rated for around 800 Kg. That might strain the hoist, especially when lifting the lathe at the headstock end, no?

Timur

Reply to
Timur Aydin

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Sounds like a "Toe Jack".

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Include 'feet' on both sides of the lifting surface so that the jack doesn't tip forward.

--Winston

Reply to
Winston

I've seen setup similar to this for jacking safes and appliances, though I wasn't able to find a picture just now in a search. A regular bottlejack, which is welded on a plate which sticks out the side opposite the pump, maybe 3 inches or so. This plate is maybe 6" wide, and has a 3" notch in that edge, so basically forms a pair of feet that stick out 3" to one side of the jack. Maybe 1/4" thick. A piece of heavy bar (about 1/2" x 2-1/2"?) forms the upright, with a foot that is also 1/4" thick, and fits between the feet on the baseplate. The top has a section that extends back over the top of the jack, and has a cup that the top of the ram sits in. I want to say that the one I saw had this section reinforced to the upright by a couple of angled webs. It also had a small chunk of rubber on the top as a nonslip foot, so that once you had something lifted past the height of the jack, you could reposition it and keep lifting.

If you are at all competent with your welder, I would not worry terribly much about the strength of your welds--Most welding rod is good for 60,000 to 70,000 lbs per square inch.

Just remember when using the jack to push safety blocks (wood or brick) under the machine before you reach under to attach the new feet, in case the jack breaks, or more likely, slowly leaks down without your noticing.

Reply to
Glenn Lyford

There we go, that's what I was trying to describe. --Glenn Lyford

Reply to
Glenn Lyford

I used it's little brother, the Model# TRJ7102:

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... to lift a bunch of >250 lb concrete slabs into the air, serially. The jack was very patient and held the load up stable and safe.

Disposed of 20 yards of concrete that way. Twas easy, even for a weak old man.

--Winston

Reply to
Winston

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That one is perfect for my machines. The price is also very nice. But unfortunately if I ordered this, it would most certainly end up in customs and that will be the end of it.

But looking at its construction, it really looks simple to do. If I weld the pieces using a 1cm thick mild steel plate on the sides and a 2cm thick plate for the toe and the top section, do you think it would safely lift my machine? Do I need to do heat treatment after the welding? (I hope not, never done it before).

I am also looking into larger capacity engine hoists. That would help me a lot when changing the lathe chuck and lifting the rotary table to the mill.

Timur

Reply to
Timur Aydin

Winston wrote: > Include 'feet' on both sides of the lifting surface so that the jack

BTW: Here is the link to the jack that was 600$. When you say "include feet", are you talking about this?:

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Timur

Reply to
Timur Aydin

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That's an engineering question which I cannot answer.

The steel for the 'shelf' on the TRJ7102 is about 5.84 mm thick and it is not heat treated. The base, welded to the bottom of the hydaulic jack, is about 14.35 mm thick. The toe is about 12 mm thick and is tapered. It isn't heat treated either. The shelf assembly is fixed to to the top of the hydraulic cylinder with one socket head cap screw.

Welded to the side of the bottle is a length of 48 mm wide male 'U' - channel which engages a slot in the shelf. A shoe on the bottom of the shelf bears on the face of the 'U' channel to translate side force through to the base. So the piston sees relatively little bending force. Nifty!

I applied a little grease to the shoe, where it contacts the channel.

In lifting larger slabs out of the ground, I've pushed the jack into 'safety limit' bypass a few times (> 4000 lb load). I see no bending or other damage to any part of the jack, outside of the expected scratches and dings.

Home Shop Machinist Magazine (IIRC) had a short article about using a small crane for that.

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mounted to the far right corner of the lathe table and swung out of the way when not in use. Very cool.

--Winston

Reply to
Winston

I wasn't talking about the shims the user is placing between the 'shelf' and the base of the mill. Rather, the 'forks' that extend from the base of the jack on both sides of the lifting toe. Without them, no lifting will occur. The jack would simply tilt over.

--Winston

Reply to
Winston

The hoists I'm familiar with here have about four boom extension settings with capacities that range from 1,000# (~450kg) at the longest extension to 4,000# (!1,800kg) at the shortest extension. The hoists are powered by 8T long extension hydraulic jacks.

Reply to
Pete C.

The one's I've seen for $200 are manual and more like 1000# at the shortest setting...but maybe I've been looking in the wrong place.

Reply to
Larry Fishel

Actually, I guess they were rated for 1500# or so, I just remember thinking I wouldn't trust them with over 1000#.

Reply to
Larry Fishel

Winston, thank you for the detailed description of the jack features. Very much appreciated :) Now to the CAD program to draw this up ...

Reply to
Timur Aydin

You are welcome, Timur.

Have a look at page 1370 of mcmaster.com if you would, please. (Part number 8799T31.)

Or just click here:

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There is a clear illustration of the 'n' - shaped 'fork' features that surround the 'toe' when the jack is lowered.

  • Note the subtle 'reverse taper' present on the bottom side of the 'toe'.

  • This is the Lexus version, with a spring to collapse the plunger. The tool I have does not have a spring; one must force the shelf down after each use. (Hint Hint.)

--Winston

Reply to
Winston

Remember (you probably already have) that you won't be lifting the entire weight of the machine, although in the case of the lathe, the headstock end will be substantial.

Not having seen your machines I can't really speak authoritatively but I have never had problems with moving normal size shop machinery by hand. A long (2 M +) lever usually allows you to raise the machine a centimeter, which allows you to put a block under it, then the other side, and back and forth until you get the machine as high as you need it to be.

Cheers,

John B. (johnbslocomatgmaildotcom)

Reply to
John

For years I used a crowbar. But since moving here, I started using my hydrologic 'jaws of life' - like a birds beak - small V shape and turns into a wide area where the point of the V is. So stick in a slot and pump oil - it expands and lifts.

On another machine I used lifting poles that push upwards from the ground.

Making a 'The hook' - is a crowbar - but likely won't handle the weight. A hardened bar can. Or a hydrologic unit.

Some machines are provided with lifting eyes or screw homes for them.

Mart> Hi,

Reply to
Martin H. Eastburn

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