Gantry Crane – A60 Crucible Handling Equipment

It's for my A60 crucible and shank. When I built the A60 shank/cart shown in the earlier post, it was intended to be used on that pouring cart so I wasn’t too concerned about weight. The shank itself weighs 55 lbs. The empty crucible alone weighs 33lbs. So with 35 lbs+ of metal, than means 123 lbs and with an A60 full of aluminum ~150lbs. I don't have any plans for bronze or iron in that size but in theory, if I ever did, I suppose it could be 3x that, but not sure I'd have the stones for a solo pour on my driveway of either of those. Let's see how the aluminum goes .

Best,
Kelly

 

Been busy with other things the last couple days but had something unusual occur with the patterns dipped in refractory coating. After the dip and overnight air dry, the external surfaces were all that uniform light blue-grey color, but the interior surfaces were still darker and not dry, which is normal. So I set them outside in the sun and light breeze to get some air circulation. When I went back to look at them after a couple hours, the interior surfaces had dried out but some of the areas that had wax fillet darkened and looked wet, but were not wet. I’ve never seen this before. It appears to be just filleted portions of the patterns most directly exposed to sunlight? Not sure it means anything other than maybe the UV activated something in the wax layer or caused a reaction between the wax and coating……but very strange. If I have good weather hope to pour them this weekend. Hopefully the molten metal won't know the difference!




Best,
Kelly

 

I was thinking I'd pour the most simple part first, that being the single beam support, and see how it goes. It would only take me 30-40 minutes to replicate that pattern. The other thing is I'm not quite sure what I could do about it other than remake the patterns. -Such is the life of a lost foam caster.....

Best,
Kelly

 

That's a possibility. The melt point of the wax is ~168F. It was 60F outside and though the concrete was luke warm to the touch, surprising that the wax could become heated enough to leach into the coating. Rain in the forecast for tomorrow......Arghhhh!

Best,
Kelly

 

Had a good weather window so I had a casting session this morning. They casted up without incident. I'll gate the other set of patterns and get them ready to become metal. Onward!



Best,
Kelly

 

8 lbs, degated as shown

Best,
K

 

No kidding, really cool. Look how many cores you didn't have to make!

Jeff

 

I got the castings machined. Sort of a dodgy set up but I had this ¾” steel plate and figured what the heck. In addition to being clamped in the vice there was an angle plate behind the extended portion. I took .020” a side cuts and it worked fine.



The other pieces were just relegated to the vice.



I’ll probably eventually buy an aluminum I-Beam, but for now since I only need to support <200lbs, I’ll use a couple 2” square tubes because I have plenty of that. So I fabricated a couple weldments to use that tube for the beam.

The weldment on the left mounts on the casting on top of the gantry post and the beam can slide through it to vary the length of the beam. The double hinged weldment on the right mounts to the furnace cart. There are just a couple of stub tubes in there to simulate the beam.



I’ve cut the tube to length for the legs and the posts but still need to make the tie rod for the caster mounts and the trolley components for the hoist.

-Getting there.

Best,
Kelly

 

He's a grey beard but a good ole boy. At his (our) age and size he doesn't do well in heat and humidity so I air conditioned the shop just for him.

Indeed. I'm resisting that for the moment because I figure they're easily added and I want a test drive, but you're right......a few stitches would definitely improve its load carrying capability as a beam. After some simple beam loading calcs, I added the second tube just in case they become permanent, but it would have been easier to just weld the mounting features onto the beam, at least on one end, but when I make the other side of the gantry, I'll need to duplicate the slide through pocket, which I figure there is some benefit in being able to shorten or lengthen the beam.

When I originally envisioned the project, it was also going to have some short legs so it could be stored straddling a molding bench for lifting.......still a possibility in the future.

Best,
Kelly

 

Turnbuckles for the tensioning rods arrived today. McMaster wanted $8 a piece for tube ends so I decided to just machined a couple sets from 1” bar stock for them.



I got the turnbuckles from McMaster and wasn’t very happy with them. The zinc plating fouled the threads to the point you couldn’t thread a nut on them. . I chased the RH threads with a die and though I have a LH tap, I don’t have a 3/8”-16 LH die. So I wire wheeled the piss out the LH threads and got them passable, barely. Anyway, welded the tube ends onto some 1” tube and the tie/tensioning rods were done, so I did a test fit.



Everything looks pretty good but one thing I can see is I’ll have to be careful how I handle the aluminum tubing or galling will be a potential future problem. The tubing has been laying on a concrete floor and has some scuffs, which will polish out easily enough but it doesn’t take much of a burr in a 3” socket with two similarly soft materials to create galling. I’m probably going to have to polish and coat the surfaces and mill in flats for the set screws, or it’s likely to become a permanent assembly.

Best,
Kelly

 

Yes, both sides.

In the previous pictures I hadn't drilled the (1/2") through holes for the pins that lock/position the vertical column but I have now. It actually requires a fairly precise set up if you don't want to match tubes to each yoke. Not sure how I'll turn out in that regard. I haven't drilled any holes in the 3" tubes yet. I'll eventually drill spaced holes for height adjustment as you suggest but will wait until I build the rest of the free standing gantry to do so. For now I need one hole that suites the furnace mount.

Best,
Kelly