Homemade crucible tongs

Damn.. Those look like mine. Did you add a stop to keep from squeezing too tight? Here's a shot of my adjustable stops. When the tension is high, this keeps me from squeezing the handles too tight. If you don't have the room on yours, you can tack on some adjustable bolts between the handles to limit the amount of squeeze.

 

Looks virtually identical to mine too!

But mine will have bent 99 degree handles when I finish it...

I think Jason is right about the stops. Otherwise you may crush a full crucible which would make for an interesting dance.

 

KK, Welcome to the forum. It would be good to see how your crucible lines up in the tongs. They look to be sturdily built. What metals will you be pouring?

 

I based the build ruffly off these off the ones:
https://www.ebay.com/p/10-Heavy-Dut...asting-Tool/689498391?iid=382005869682&chn=ps

They are made for #10 / 12kg crucible. I hope to pour a set of artworks I have been asked to make for a chapel.

No stop yet. I haven't seen the kind along the base like yours Jason, I think I could fit a stop down there: where there is a will there is a way.

If I find the time I will make a shank tomorrow and I am dreaming on 'seasoning' one of the pair of my crucibles tomorrow.

 

Here's my shank. Been working good so far.
If ya check out any of the videos on my YT channel, you'll see them in action.
I wouldn't try to pour a 20, but a #10 of bronze is doable

 

Yes, a cross tab could be welded on at right angles to the left pivoting arm just to the left of the bolt. A bolt drilled and tapped into the new tab could impinge the right pivoting arm near the bolt---one way it could be done among others.

Sounds like you will be pouring bronze or maybe Al for an art work.

 

Just finished welding up my tongs for my #16 bilge crucible. Maybe a tad overdone but better than fleeing from molten bronze.

Notice the 2 bolts that stop it from crushing the crucible.

 

Looks good.
I agree, much better to be extra strong than not quite strong enough.
It does not look over-built to me, but rather about right.
The brace on the handle side could be shorter and at a 45 degree angle, but no big deal.

 

I'm thinking of making a gantry with an electric hoist so I can raise and lower and pour the crucible on my own.

What do you think of this hoist? Seems cheap & has a high lift capacity.
1320Lbs Mini Electric Wire Hoist
https://www.ebay.com/itm/1320Lbs-Mi...813842?hash=item33e553e992:g:eNoAAOSwLAhbg15n

 

I use a chain fall hoist hand operated that works very well to lift my 200 to 300 pound molds. The fact that it operates by hand allows for varying the rate of lifting from a dead stop to moderately fast. For me, that is important. If I were to use an electric hoist it would have to be not just on or off, but allow smoothly variable lifting rate from zero to fully on. Just on or off is clumsy (herky jerky of you will) in my experience. That would be just as true for lifting a crucible as it is for molds. The other consideration is the heat given off by a hot furnace. The electric winch could not dwell very long above the furnace without the danger of overheating unless your ceiling is very high and thus you could keep the hoist in cooler air.

My chain lift rolls laterally on a barn door box rail and hanger setup.
https://www.zoro.com/national-hardware-plain-box-rail-600-lb-144-in-3fvt8/i/G2964656/
It is a pretty slick and cheap arrangement. The only improvement I would like to make would be to have one on a jib crane.

For lifting my A20 crucible solo I use a walking beam arrangement. I do like not standing over the furnace and over the crucible to transfer it for both comfort and safety reasons. There have been several solutions documented to avoid that scenario.

Denis

 

Good point. Didn't think of jerking or speed of lifting.

Does a manual hoist lock in place if I let the chain go or will I need to tie it somewhere when I go to pour?

Also, how quickly do they raise when pulled? Is there a value in the specs I should look out for?

As for lifting capacity for a manual one, I assume the more lift capacity the slower the thing raises? So I should probably shoot for one in the low hundreds of pounds if I want to raise it quickly?

 

If you look at cheap chain hoists you'll find they all lock when you quit pulling the hand chain. They generally will operate more quickly than the electric ones. I would not go smaller than a 1/2 ton for $39. https://www.amazon.com/Ironton-Manual-Chain-Hoist-Capacity/dp/B00T7UHNB8/ref=sr_1_6?ie=UTF8&qid=1536363049&sr=8-6&keywords=1%2F2+ton+chain+hoist And don't look at the lever operated ones, they are slower and can slip when you are changing directions.

The downside of a chain hoist is if you locate it over the furnace you are reaching over the crucible to operate it. I think the winch arrangement mounted on a jib with a pulley over the crucible is superior so the only thing over the heat is the hook and cable. A cheap electric winch will do the job and they are relatively fast. If you put another pulley on your jib post to route the cable back down you can even use a manual winch. https://www.amazon.com/Reese-Towpow...?ie=UTF8&qid=1536363554&sr=8-7&keywords=winch

You could also use an electric hoist horizontally but chain hoists don't work well horizontally.

 

I do agree that a chain hoist is not ideal for the application of hoisting a crucible. I think it is too slow. And the location is not ideal as noted in post above. That is why I went with the pivoting beam arrangement. A jib crane with a hand operated boat winch could work OK and be fairly fast but is also limited to a single radius that the hook will trace over the floor. (Same objection can be made to the pivoting beam except I put a pivoting dog leg in the support which allows some flexibility as to where the lift point is located.) And to lower the boat winch one hand to hold the safety ratchet is required and the other hand cranks the crank (or if the safety ratchet is the over center type, if your hand slips on the handle the whole works can run away with you.) If you are also trying to position the hook over a selected point on the floor you may have a "handfull." It is difficult for me to visualize how a winch or chain fall can be used to pour your crucible.

At the risk of proferring my own solution I would suggest, if you have not already, you might consider a pivoting beam similar to what I use. See post 7 for a video of the "working model." The video in post 1 was an early prototype.
\http://forums.thehomefoundry.org/index.php?threads/hoist-and-releasing-tong-build.199/

I have used this arrangement for something on the order of fifty or 60 pours now and it has worked flawlessly, is fairly quick, safe, and secure. It does allow me to safely work alone.

Denis

 

Hmmmm. I very much like the look of that. I'm going to have to think long and hard about it.

An added benefit is you are the hell away from the molten liquid if it falls to the ground which is a growing concern the larger the crucible is.

What is the top pivot? Is it a bearing up there as well?

I'd probably have to weld up another pair of tongs since mine probably won't work like yours do.

How does the inside of that lifting tong setup look? Is the V shaped piece of metal hollow inside? So 2 pieces of V shaped metal spaced out a little and welded together to create an open box inside with 2 slots in the top?

 

Zap, I gotta ask man.. Are you ready, I mean really ready for such a big lift? You 2 scared the piss outta me with that last pour.
I know your help was useless and a better system will make it much easier. We just can't have you getting hurt.

 

I know right? But a question in turn. Is anyone ever really ready to pour metal?

That last pour was also hairy for me! I think trying to balance it on that log was not a good idea. I thought it would make it easier to solo pour it, but it was easier to have my uncle help with the other side of the tool.

Ideally I can eliminate the need for help and keep myself as far away from the metal as possible. I like melterskelter's build. I think it might be worth making one.

One thing I don't know is the bearings you used. A needle thrust bearing. I looked them up, they seem to be used by inserting one inside a tube and having another tube come up inside it. Are they welded in? Or somehow pressed in? Did you have to lathe the inside of the tubes to the right size or did you just buy standard pipe? What size pipes did you use and what size bearing? Am I over thinking this?

 

The bearings are not pressed in. I did have to use a lathe to turn the tube to make it adequate in size for the bearing but the tolerances can be pretty loose thus not requiring an expert machinist. Like 0 to +.002 or 3 and all is good. Similarly a lathe was used to face the thrust bearing surface so it was nice and square. The top pivot for the beam is a simple pin and plug arrangement with no anti-friction bearing needed. But for the bottom of the dogleg roller and thrust bearing may not be required but they sure make movement smoother and thus make use of the dogleg easier with less likelihood of slopping a full crucible.

As far as overthinking is concerned, I do not regret the time put into making the hoist considering its convenience and safety.

Denis

 

I'm kind of surprised they don't make that kind of bearing setup for sale. I've seen that used a few times now in various DIY hobby projects since I understood what I was looking at from your posts but haven't seen them for sale.

 

There are bearings available that will function to supply the needed rigidity to the loads involved in joint used in the hoist. Wheel spindle bearings like those used in the front wheel of a car or riding lawn mower would do the trick. Those are just two examples of thousands of similar applications. I machined my combo as I had a lathe in my shop and it was easy to make a compact joint that fit my needs. And no shopping around looking for stuff on Craigslist or at repair shops looking for a piece of equipment that might have the needed bit in it. But, I suspect you might be able to find a usable piece. Then, of course you will still need to adapt it to your purpose. But it might be possible to do that with some pretty basic tools at hand.

Denis