Gantry crane (lift?)

A friend gave me a rusty old girder trolley years ago. 10 hundredweight, adjustable between 2.5" and 4". I tried to sell it, but no interest. So it sat in the workshop for ages.

Then a factory neighbour got rid of a rusty old girder (H beam? I beam?). 3m long, 125mm x 240mm. So it sat outside for several months.

Then the table/vice pivot on the big bandsaw died. It needs carefully lifting off the base, to try and free/repair/re-fabricate the pivot locking clamp.

A plan formed.

1) Re-furb' the trolley. One roller was nearly seized.
Press shaft+bearing out, scrape 60 year old grease, clean and re-pack. Paint the plates while I'm there:
Attachment 398442

2) Adapt the thing for a wider girder. Neighbour kindly gave me some 16mm cap screws, so just machine up some spacers:
Attachment 398443 Attachment 398444
I will work out the middle one later. Maybe a spacer, and two locators, for keeping a sling or chain block's hook in the middle.

3) Create a frame pillar. Grab some rusty 100mm box, cut some 45° steady bracing:
Attachment 398445 Attachment 398446
(Oops, won't get all the way thru 100mm that way. Had to put the vice on the other side)
Then lay the bits on the ground, tack with the MIG:
Attachment 398447
and then use some old welding rods to fill the other side:
Attachment 398448
(with a variety of success :rolleyes: )

4) Chain the pillar to a heavy object, then MIG an angled bracket onto the girder for easy assembly:
Attachment 398449 Attachment 398450
Drill a few large holes to bolt it together. None of my neighbours were there that day, so no mag-base drill, and no 16mm drill.
5/8" reduced shank with a hand drill (ouch, hurt my wrist a few times when it jammed), then Dremel out to 16mm for some bolts.
Nylon/Carbide disc in the angle grinder, to remove the flakey rust, and some RP7 (WD40 wasn't in reach) to help preserve.

5) Next day, weld a little hook onto the end, and a quick lift, hooking onto my Mezzanine:
Attachment 398451 Attachment 398452 Attachment 398453



The neighbours complain about the incomplete welding, and needing proper fixing onto the Mezz' beam. I g-clamped it for now.

Lift should be straight vertical, so I am not worried about the welds.

Should be useable for now. In the future, I might make retractable wheels for the base, and a plate with rollers so it can hook into the Mezz' girder and roll like a proper girder crane?

Nice work, amazing what can be made from "donations".
To roller mount the beam to the mezzanine, that would be a great idea, makes it FAR more usable. Can't quite tell if the stuff on top of the mezzanine beam is on top, or on another beam behind it. If the stuff is on top of the beam, you could undersling the beam, it'll just mean you loose out on about 500mm of lift.
For the chain block carrier, you could use a bit of 12mm plate with 3 holes, 2 for the shafts with spacers on the side and another for the hook.
To make it a bit safer, you could make a "T" on the end of the new beam with rollers, so that it'll remain reasonably square to the mezzanine.
Kryn

Hi Kryn. Yes, a lift that moves in 2 axes is much more useful.

At the moment, it could rotate a little, pivoting the bottom of the H beam on the top of the Mezz's beam.
That was mainly so it would move out of the way, but it could maybe also go back a few metres while loaded
I thought about greasing between the beams, or installing a HDPE gasket (e.g. a cutting board)


There is flooring and handrails on top of the Mezz', so a proper moving girder would need to roll on the bottom of the Mezz H beam. Complicated by the things holding the floor up (perlins?) which are close to the bottom.

I think the lost lifting height might be a deal breaker, so for now will just try it as is.

Hi Nigel, a thought is to fabricate something similar to an "A", where the top of the "A" carries the beam and the bottom has a couple of rollers sitting on the mezz beam, you can gain extra height this way also.
On the opposite side of the bottom rollers at the base of the "A", is another set of horizontal rollers that will roll against a beam of some description, say 100X50X3 laying on its flat side, to prevent the A frame from coming off. The 100X50 could be attached to the mezz beam, by bolting the roller support beam flat bars every metre or so, to the underside of the mezz beam so the bolts don't interfere with the rollers. This will also allow easy removal should the need to move arise.
If unsure of what my thoughts are please let me know and will try to do a sketch for you??
Regards,
Kryn

Hacked up some spacers on the trolley:
Attachment 398481

then put it up there with a rusty old chain block, and started lifting the saw's head off:
Attachment 398482 Attachment 398483





I sort of get the idea for rolling the whole beam, but the back roller is the vague one.
e.g. if I am using standard girder trolley wheels:
Attachment 398484
the difficulty is the space between the wheel mounting bolt and the purlins.
I was trying to avoid finding bearings and making rollers for the back.

Hi Nigel,

This is how I would do it !

Attachment 398488

Just sit the bearing/s on a pin ! A suitable bolt from underneath and a split pin and washer to retain the bearing.

or maybe like this:
Attachment 398493

Quote:

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Originally Posted by BaronJ

Hi Nigel,

This is how I would do it !
Attachment 398488

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All the girder trolley's wheels I have seen are closed on the small side and only bolted from the large side. Adapting one to bolt from the small side means pushing the bearing off the shaft, machining a hole through the wheel, making a new shaft that captures the wheel from both sides, etc.

Quote:

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Originally Posted by jhovel

or maybe like this:
Attachment 398493

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Hadn't thought of welding a strip.

4.5m of weld, at height, is possible, but messy – especially with my welding skills :U

Quote:

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Originally Posted by nigelpearson

All the girder trolley's wheels I have seen are closed on the small side and only bolted from the large side. Adapting one to bolt from the small side means pushing the bearing off the shaft, machining a hole through the wheel, making a new shaft that captures the wheel from both sides, etc.

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Hi Nigel,

Have I misunderstood ! I thought that you were contemplating making new wheels for attachment to the mezzanine girder. So are you going to modify some existing wheels ?

Quote:

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Originally Posted by BaronJ

Hi Nigel,

Have I misunderstood ! I thought that you were contemplating making new wheels for attachment to the mezzanine girder. So are you going to modify some existing wheels ?

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Being basically lazy, I was trying to avoid finding bearings and making rollers/wheels.


If I was making them, would probably do this:
Attachment 398510
(because I can't afford large "axial deep groove" ball bearings :no:)


but that would still need strong bearings in the grooved wheel.
Basically, that wheel is being loaded the wrong way.
Maybe it needs a linear bearing cage/loop???

Hi Nigel, I may be wrong, but, in your pic Attachment 398484, the roller under the floor purlins, I feel, should be the other way up. The reasoning is that the weight being on the outside away from the purlins, would/should lift it up on the inside, as in a cantilevering effect.
Kryn

Quote:

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Originally Posted by KBs PensNmore

Hi Nigel, I may be wrong, but, in your pic Attachment 398484, the roller under the floor purlins, I feel, should be the other way up. The reasoning is that the weight being on the outside away from the purlins, would/should lift it up on the inside, as in a cantilevering effect.
Kryn

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You may be right. My thinking was that it is a "safety net."

• If the whole thing cantilevers, the inside wheels crash into the purlins or their attaching plates, or the plate wedges against the inside of the beam.
• If the outside wheel bends or starts slipping off its roller, the inside one (under the purlins) gets forced harder into the edge/corner of the beam.

The safest one would be horizontal grooved wheels on both sides, plus an outside wheel within the beam?



...If we ignore the possibility of the thing falling out of level, there are simpler options just using large old ball bearings:
Attachment 398515


Of course, I have used it and repaired the bandsaw now, so the motivation to do any gantry modifications is waning :U

Quote:

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Originally Posted by nigelpearson

Hadn't thought of welding a strip.

4.5m of weld, at height, is possible, but messy – especially with my welding skills :U

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You could always bolt on an angle iron if your don't trust your welding skills.... Although you welded the rest of the gantry. Seems to me this isn't anywhere near as critical as the gantry foot.... it only guides the wheels after all. The forces are in the flange, not the strip.