Ruby Casting (verneuli flame fusion)

Discussion in 'General foundry chat' started by Zapins, Apr 21, 2021.

  1. Zapins

    Zapins Gold

    I've been prowling the scrap yard for the right sized scrap container for a while now. Put out an ad on facebook for slip roller help and called a few mechanical places this week but no luck.

    Let me measure tomorrow for the larger one. I might get away with 12 inches. That would be a super huge help I'm happy to pay for shipping and metal cost and time. I'll try one more place tomorrow since its kind of near work before taking you up.

    Do you think a stepper motor would run with just a driver? Or does it require the speed controller as well to work?
     
    Last edited: Jul 19, 2021
    Melterskelter likes this.
  2. DavidF

    DavidF Administrator Staff Member Banner Member

    Can't be that difficult to build a slip roll...
     
  3. Zapins

    Zapins Gold

    That was my original plan but after I tried cutting the post for my ruby caster on my lathe I saw that it wobbled the bed a lot. It didn't leave a good finish on the post. I doubt I could get a proper roller part made in the 3 or 4 foot length that I'd want.

    The other parts don't seem too hard to make though.
     
  4. Melterskelter

    Melterskelter Gold Banner Member

    Ya, I built mine. It was not a trivial project. There are two types single pinch and pyramid. Pyramids are better and that is what I built. All three rolls are geared together. Allows better control. I'll send plans to anyone that is interested. But, set aside two weeks of fairly regular shop time to get it done plus some time to source gears, TGP bars, bronze bearing materials for round and sliding bearings and some patience to lay it all out accurately and machine it nicely. Then you will have a really nice working tool and not a tool that sort of works. The Eastwoods etc are generally cheap single pinch designs.

    Slip Roll.JPG Slip Roll2.JPG

    Denis
     
  5. Zapins

    Zapins Gold

    What a beut. I'd love the plans. Might be something I can do eventually. Or maybe if I buy some ground bar stock from mcmaster. Sometimes their prices are wonky and cheap for large pieces of steel. Never know might get lucky...

    Gears like that show up regularly at the local scrap yard. I have a few saved as well but never really had a need for them before.

    Are the rollers hardened or regular steel? How do you figure how how thick they need to be to roll a certain gauge?
     
  6. Melterskelter

    Melterskelter Gold Banner Member

    I got my roller material from McMaster. It is TGP 4140 Prehard. Rc 30 or so. The gears I purchased from Boston Gear.
    I’ll get a copy of the plans/write-up that I followed to you. I may need to send it as paper as the online link may be broken. It has pics and drawings and is about ten pages long. It will cover the background info better than I can. Were I to do it again I might scale up to 18” cap.

    The diameter of the arc is controlled by the relative positions of the rolls.

    Added: I found a live link. I’d suggest printing it before this link breaks.

    https://www.nickbaines.me.uk/BendingRolls.pdf

    Denis
     
    Last edited: Jul 20, 2021
  7. Zapins

    Zapins Gold

    I'm looking into infrared flame sensor modules. This one looks interesting. I'm thinking I can simply hook this directly to the power supply of the hydrogen generators so it acts as a relay to automatically shut off the power. Or I can hook it up to a bigger solid state relay if the power draw is too high on the generators.

    What do you think?

    Item Type:Fire Detector Sensor
    Size:50 x 26mm / 1.97 x 1.02in
    Thickness:19mm / 0.75in
    Power Supply Voltage:12VDC(Input)
    Current:>150mA
    Load:250VAC 10A or 30VDC 10A
    https://www.amazon.com/Detector-Sen...s=flame+sensor+infrared&qid=1626833647&sr=8-4
    Screenshot_20210720-222055_Chrome.jpg
     
  8. amber foundry

    amber foundry Copper

    It looks spot on for the money, worth a punt. Very interesting post by the way.
     
  9. Zapins

    Zapins Gold

    Thanks. Ill give it a try at some point.

    As for now I managed to get tubes rolled locally. They also welded them up for me which was nice. Although I may need to cut one in half again.... Will see.

    I'll work on attaching them and building the furnace chamber later. I'm thinking the inner bore can be about 4 inches in dia. Which should give me about 3.5 inches for insulation. 1 inch of refractory and 0.75 inches of fiber blanket behind it. I also have the fused silica window arriving tomorrow.

    20210722_204449.jpg
     
  10. Zapins

    Zapins Gold

    Made the mold for the furnace body.

    I may cast the refractory today. I only have 3000f refractory so hopefully thats enough.

    Turns out I needed 14 inches for the top chamber not 13. Oh well. At least I found a pipe that will work. So I have the metal I need.

    20210724_201108.jpg 20210724_201051.jpg 20210724_201038.jpg
     
  11. Zapins

    Zapins Gold

    I tapped the refractory in the mold. Will wait a day or two then demold. I coated the inside with wd40 to help release it.

    Also started working on the pressure sand container. Cut myself a nice circle and fitted it to the top of the burner tube.

    20210724_233953.jpg 20210724_234012.jpg
     
  12. Zapins

    Zapins Gold

    I'm looking over options for hydrogen generators. This one states it can produce 8-10 L per min at 12-14 v with 140 amps. Now I don't see electronic components in the generator so I'm wondering - what if I power it off my tig or stick welder instead? I don't think the voltage matters very much correct? If I went to 24 volts or 60 volts the amperage just needs to be changed to match so it doesn't overheat and melt the plastic bits I think. Does that make sense or am I missing something?

    Ideally I need 15 L/min output so I can either ramp up the power and hope it doesn't melt, swap out the plastic parts for something that won't melt or just buy a second generator to make up the difference.

    Also doesn't seem too hard to make these things, just looks like stainless steel sheets arranged in a specific way inside a container.

    Here's the generator I'm looking at: https://www.ebay.com/itm/164980131321?hash=item26699505f9:g:Q7wAAOSwnjtgGOSJ
     
  13. I see a lot of complete torch units, this one claims to be 100 litres per hour:

    https://www.aliexpress.com/item/196...xp_id=3b4dfd9a-f537-4159-9878-8e290e2e0eca-14


    Whats isn't apparent is if it produces two gas streams or not as I suspect you need to vary the ratios compare to the 2:1 mix from water electrolysis.

    Also the voltage can't vary too much or go too high as the current required goes up exponentially to maintain the higher voltage. Ideally you'd have a variable dc supply, even something simple like a variable transformer->12V stepdown transformer->bridge rectifier->fuel cell. That would let you use the variable transformer to set the right current level with the twist of a dial.
     
    Last edited: Jul 30, 2021
  14. Robert

    Robert Silver

    This is quite a project! Watching!
    Robert
     
  15. Melterskelter

    Melterskelter Gold Banner Member

    I take it the generator needs to function reliably for many hours or days with no interruption or aviation in output?

    Denis
     
  16. Zapins

    Zapins Gold

    Yes thats what I'm hoping for. Nice steady flow. Needs 15 liters per minute (not hour) which is quite a good flow rate.

    I'm still a bit hazy on how to power these things. Will I need to build my own power supply with rectifier to run them or is there an easier way?
     
  17. Unless you can get some kind of pre-built unit like an beefy lab power supply, anodizing or electroplating rectifier unit, small phone exchange battery charger and so on, then getting hold of a variac (variable transformer) to vary the input AC to a transformer and then rectify it, is a good way to make a variable DC supply. Variacs show up in things like old X-ray units and old CNC machine used to have 3 gang units in case the mains sagged or needed changing so to suit.

    On second thought... you can wire several car 12 bulbs or even a headlight or two in series with your DC welder to limit the current to the right value. Electroplaters did this all the time with banks of bulbs on knife switches.

    Your cell is going to have a target current flow you want for the right amount of gas flow other wise there's too much or too little gas delivered.
     
    Last edited: Jul 31, 2021
  18. Zapins

    Zapins Gold

    Sounds like building the power supply is the way to go?

    What about running it off my tomb stone welder or my syncrowave 250?
     
  19. The tombstone could be used but the TIG welder is going to superimpose a high frequency high voltage AC to stabilize the welding arc so not good for the electrolysis cell and not good for the welder.

    So you'd have the variac controlling the AC input to the tombstone and the welding leads hooked up to a bridge rectifier attached to a fat heatsink to keep it cool.
     
    Last edited: Jul 31, 2021
  20. Zapins

    Zapins Gold

    Hmm. I'll have to figure out how to use a rectifier then. My tig also has a stick welder output on it. May be able to control it with the panel too. But id rather lose the dinky tomb stone welder if I mess up than my tig so thats an option.

    Seems I can also make my own hydrogen generator with 316 stainless for plates. Im guessing I need about 90 plates for 15 l/min. But it may just be easier to buy a premade one than cut a million bits of stainless.

    I popped out the furnace mold. Looks good. A few small breaks which I patched with 3000f mortar. I'll let it dry then bake it in the kiln for a couple hours to cure it.

    I also made a mistake and made the bottom have the fire retention ring instead of the top. Sigh. Ill have to figure out a way to prevent flames escaping from the top.

    20210731_214159.jpg 20210731_214211.jpg 20210731_214228.jpg
     

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