Trying out a design I found on the interwebs... Plans attached but be aware this is work in progress and untested as yet.
Just one observation. It appears that this will only hold the crucible by the top edge? Crucibles get malleable at high temps and this may not be secure. I would consider longer arms that reach towards the bottom of the crucible, especially for a heavy load. Robert
Rule of Thumb The "cleats" if you can call them that, horizontal jaws, are suppose to be positioned in the bottom 1/3rd section of a crucible. Yep, just looked it up and it is considered a cleat.
Before I go ASSUMING anything, What size crucible do you plan on using the tongs for? What type of metal do you plan on melting? 2mm thin material is pretty thin (5/64") and will turn cherry red Real Quick once stuck into a blazing hot furnace at 1200+* to remove a crucible. I agree with Robert about the jaw section as well. Reconfigure/make the lower section that's going to be clamping the crucible. Figure the tallest crucible the tongs can safely handle, fabricate some arms with tab stops at the top and reassemble. I would seriously use 1/4" thick material (at a minimum) for the extension arms & jaw section of your tongs. Honestly, I don't think I'ld be using such a thin metal for this particular application. Don't want to see anybody getting burned up. You did a nice job on the tongs.
Hi Robert, the drawing is not complete i.e. does not show the crucible jaws fully. No tabs at the top provide restraint for the crucible during pouring. When a crucible is closed on, the crucible weight and the top lugs shown provide support during a pour. The crucible is not squeezed at any time, but the grip/jaw is sized to be a very close fit, so 100% support. Hi OCD, Salamander A10. I can go to 1/8" or 1/4" material no problem on the gripper/jaw part, totally customizable, point well taken.
I'll be interested to see how you like them Negative3. Weren't those billed as lift and pour? It looks fine for lifting but where do you grab it with the second hand to pour? In the video, you never actually get to see the pivot and pour with the device, only picking and replacing from the furnace. Stainless is certainly better at retaining strength at temperature and reducing heat transfer and aluminum is one thing but that handle looks pretty close to the top of a melt and how big of a glove will that accommodate? I like whiz-bang mechanisms ergo my lift off furnace but when it came to handling the crucible I went the opposite direction with a dead simple open ring shank. With the lift off furnace you can snatch, pour, and replace with them....sturdy steel and no moving pieces. Now my larger A-60 lifting mechanism has moving jaws but probably wouldn't have had them if I was onto building the open ring shanks before I built it. Best, Kelly
At a thickness of only 2mils, those tongs are going turn cherry red pretty quickly. Some documented info on the subject. https://www.nickelinstitute.org/~/m...ssSteelsinIndustrialHeatExchangers_9005_.ashx
I must be suffering from deja vu! He isn't finished guys... This is what it will be when finished. Brian Olltrig isnt releasing the plans. But our Hero here Negative is hooking us up. Kelly, watch the video again. You'll see the tilt O' whirl design. 6minute mark...
Yes, the video shows the empty mechanism with no crucible being hooked and teetered about but that is not quite the same as manipulating an A10 full of molten metal and hitting the bulls eye.....just sayin. Best, Kelly
The Angle of the dangle, in direct proportion to the heat of the meat, causes the size of the rise, and the mass of the ass, to remain constant... Work in progress
Yeah I think 2mm is way too thin. You have me curious. What thickness metal does the hive mind think is safe for a larger crucible? I'm going to make lifting tongs for my Clay Graphite Crucible - #16B which holds 51 lbs of bronze. I am a bit hesitant to trust 1/4" thick metal for the jaws. But i will probably use a 1" diameter black pipe for the arms. What are your thoughts?
