Furnace Cart and Lift Build

Discussion in 'Furnaces and their construction' started by Al2O3, Mar 10, 2018.

  1. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Had lot’s of great family and shop time this holiday weekend.

    I added the brackets on the furnace body to mount the lifting pulleys and mounted all the guide wheels. I also rattle canned some primer onto places I don’t plan on disassembling again.

    38 Pulley Brackets.jpg

    …..and good grief…..I made four more pulleys LOL!. These are the lifting pulleys for the cables. You know the drill……foamies, mud, tree and sprue them, cast them.

    39 Lift Pulleys.jpg

    I also made provisions for hand brakes to lock the furnace body and lid in position. They just bind the lifting pulleys like the caliper on a disc brake to prevent motion. The 8-Lobe aluminum palm grips at McMaster were $10 a piece. I needed four of them so I just decided to just make some. I made this guide template in about 30 minutes then about five minutes a piece to machine the foam patterns.

    40 Palm Grip Jig.JPG 41 Palm Grip.jpg

    I’ve only went to my pocket for the 5” swivel casters ($50), bronze bushings for the pulleys ($50, there was a boat load of them), and another $50 in miscellaneous hardware; most of which were the shoulder bolts for the ballast carriage axles.

    I added some accessory mounting pads to the cross member. I know I’ll eventually need them to mount the electrical controller, actuator, and other add-on accessories. Experience has taught me that I’ll use them.

    42 Mounting Pads.JPG

    I made the cables using these swagable studs. They’re decking hardware and aren’t really meant for lifting but at <40lbs I figure they’ll be just fine. I didn’t have a swager for them, so I used a center punch to peen the cables in place. The threaded end gives some adjustability, so you can anchor them or mount clevises which were nice for the ballast carriages because they dis/re-connect easily.

    43 Cable Swage.JPG

    I used an electric scale to weigh the furnace body and lid with the ballast carriages hanging on the pulleys. The furnace body has a net weight is 155lb and the lid is net 46lb. Since the doubling block only requires ½ the weight, I need 77.5lb of ballast (38.75lb/side) for the furnace body and 23lb (12.5lb/side) for the lid lift. I don’t have enough dumbells for that so I’m thinking I’ll make a steel mold and cast lead ballast weights from all those wheel weights I melted down. The lid seems to slide nicely. I need ~80lbs of ballast to test the furnace body.

    44.jpg 45.jpg

    Last edited: Apr 1, 2018
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  2. oldironfarmer

    oldironfarmer Silver Banner Member

  3. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Ya-know, thinking about casting the lead ballasts, I'm giving some serious thought to lost foam instead of making a mold. It would actually be nice to be able to make several different sizes. I was just going to use an open face mold at different pouring depth's with premeasured shot size but that's a lot of work just for 4-6 ballasts and then I'll probably never use the mold again. I could easily include some other useful details in lost foam.

    Although the melting point of lead is only 621F, the boiling point is 3180F. As usual I suspect vapor pressure increases with temp but that is a big spread between melt and boil. I would only do this outdoors in open air and definitely stay upwind. We're talking a chunk of foam say 7" x 6" x 1". I'd have to get the lead hot enough to effectively vaporize the foam, and would expect a very long solidification time buried in sand, but I think it would work.

    Afterward, I do think it would be time to dispose of my lost foam sand as it would most certainly be contaminated which is about the only thing I could think of to make it nastier than it already is after 50+ uses with aluminum. The lead itself isn't as worrisome as some of the likely oxides and salts that would be present which I don't want to be around at all because they are readily and easily absorbed by skin. Disposing of 50lbs of sand wouldn't brake my heart nor wallet. This is a one shot deal not something I'm planning to repeat and I've already reclaimed 200lbs of lead from wheel weights

    What do you guys think? I'm thinking 1000F-1200F pour temp.

  4. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Houston, WE HAVE LIFT-OFF!!!;)

    46 Lift Off.JPG

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  5. oldironfarmer

    oldironfarmer Silver Banner Member

    Your assembly is coming together nicely.

    I'm thinking extremely hot lead may not be worth the potential cost. How about making an aluminum mold via lost foam then recycle the aluminum when you're done. Leaded aluminum should be safe.

    You can drill through an offcenter hole with an end mill.

    Some place you said "good enough for who it's for". HA! If it's good enough for you it's over the top for me.
  6. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Thanks OIF. I had a boss early in my career that use to say "If we knew at the onset what it was really going to take to complete a project we wouldn't start most of them". :rolleyes:

    Could definitely do that and was pondering it a bit. The pour temp of the lead may have to be controlled pretty close. If you're making lead sinkers and the aluminum mold is massive compared to the molten lead I think it's fine. In this instance it will be the other way around with ~20lbs-40lbs of lead, and at 800-900F the aluminum wont have much strength.

    For kicks, as I was thinking about lost foam and all the 1" thick polystyrene board I have in plenty. It so happens that the outside dimensions of the ballast carriage plaques are pretty much right on the button of the target weight at 1" thick lead. I have the lead now in ingot and it was free......that could be karma calling me! When your only tool is a hammer, everything looks like a nail ;).

    ....and perfection is the enemy of good enough! -Had to get one more cliché in there.

  7. ESC

    ESC Copper Banner Member

    Kelly, I commented over on AA. A form the shape of the mounting plate from steel, and then filled with the lead, is in keeping with the character of your build.
  8. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I had some 6” steel channel scrap at work and decided to use it to make an open face mold to cast the lead ballasts. I cut two pieces to 7 ¼” long, spliced it to the 6 ½” width, then welded a couple caps from the leftover pieces on the ends drafted at 2 degrees. …..it’s basically just an ingot tray the size of the ballast carriage plaques. I’ll need to drill the mounting holes in each one of the lead ballasts but I can just use pour/shot size for different weight ballasts. I need a couple ballasts around 10lbs and six of them near 20lbs. 20 lbs happens to be about the limit of my current steel crucible and will be a little easier to throw around than a single 40lb slug.

    47 Ballast Mold.jpg

    It was raining all day today and supposed to do the same tomorrow so not not sure when I’ll get to cast the lead ballasts. I rigged up some dumb bells for now.
    ESC, as always I think your suggestions were spot on and certainly would have made better looking parts but figured this was good enough for ballasts, I could cast whatever weight I needed, and I could spend the time savings on other functional features of the build.

    I made a couple simple wooden bucks, worked my way around the circular sheet, and beat some shape into a cap for the furnace lid.

    49 Lid Cap.jpg

    I also made a quicky mold out of polystyrene and with the assistance of a little vibration, cast the vent hole reducer for the lid. The material is insulating castable refractory. This adapts the opening size in the lid vent to all the cooking utensils and plugs from my other rig.

    50 Vent Insert.jpg

    Hey J, this is for you.

    I borrowed the actuator from my other rig and made a couple of mounting brackets. It installs and removes with just an electrical plug and two hitch pins.

    51 Actuator.JPG

    I have this small lead acid battery and remote linear actuator controller. They have manual control and limit switch inputs too. I couldn’t buy the relays and piece parts to do the job for that so I got the remote for free. I still need to add some limit switches.

    52 Battery.JPG

    Here’s the new furnace lift sitting next to my smaller rig. The footprint of the larger furnace is actually a little smaller than the smaller furnace but the latter is a little more accessible.

    52.1 Large and Small Rig.JPG

    I’m eventually going to build a new controller with some additional features for my smaller furnace and use the existing controller on this new rig. Here’s a cut and paste of where I’m heading with that.

    53 Mock e-Insert.jpg

    The 8kw resistive electric insert can either be used stationary on the furnace base or travel with furnace body adding a couple additional ballasts. With the e-Insert installed, it can used as a bake/burn out oven, heat treating, or holding or melting furnace.

    54 e-Insert.jpg

    The e-Insert can be quickly removed so the furnace can be used with a fuel fired burner. Plans are for a Natural Gas burner to be installed in the Tuyere in stationary base section. When used as fuel fired furnace, the furnace body can be manually lifted or the actuator powered with a small battery so it doesn’t need to be tethered to an electrical source.

    I have some other details to attend to but this is pretty much done….to the extent any of my projects are ever really done. Felt like I made good progress in just a calendar a month’s free time. I may have to make the new controller for my other rig, so I can get the e-Insert operational on this unit. It’ll be nice to have another furnace where I can do long cycle programmed burn outs, heat treats, etc while at the same time not interrupting my melting and casting program with the other furnace.


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  9. J.Vibert

    J.Vibert Silver

    Just watched you vid on YT before you snuck in the above post kelly.

    Love the remote control. A little saddened by the lack of limit switches though. Guess you've set the bar too high...lol

    Good to see it up and running. The lift that is. ;)
  10. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    They're coming pal....details!

  11. Jason

    Jason Silver Banner Member

    Slicker than owl poop on a door knob. I want one!
    Remind me again, what's the 2nd tuyere used for?
  12. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    The one on the furnace body was just provisional for electrical power in the event I made it a resistive electric furnace similar to my smaller unit. I elected not to do that opting for the separate resistive electric insert.

  13. Jason

    Jason Silver Banner Member

  14. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Finally got some decent weather so I was able to use the ballast mold and cast up the lead ballasts. There are six in the 18-20lb range and two at ~8 lbs. The lighter ones are for the lid. I use two per side of the heavier ones for the furnace body and then add another on each side to lift the added resistive electric insert.

    55 Casting Ballasts.jpg

    Here they are mounted on the ballast carriages.

    56 Ballasts On Carriages.JPG

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