Author Topic: Resurrection of a CFEI 100 KVA Induction Furnace  (Read 83265 times)

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #650 on: January 24, 2021, 05:34:54 PM »
When the working diaphragm is pulled back fuel is forced through the outlet valve to the injector pump.As it returns the inlet valve opens and fuel is admitted to that space from the tank .. I don’t think anything maintains pressure other than by part 10 moving.

It started fine and ran for a few minutes quite happily but we’ll have to see how it works under load tomorrow !
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #651 on: January 24, 2021, 06:30:55 PM »
My guess, only a guess, is that the air space and the diaphragm damps the pressure pulses from the main diaphragm. And perhaps cushion the main pumping diaphragm as well from extremes of motion. In any case if missing, I wouldn't expect it to show up as an immediate problem. And if the cork and rubber gasket serve as a new damping diaphragm (if I'm correct at all), then function is fully restored, as long as it lasts.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #652 on: January 24, 2021, 06:45:36 PM »
It's called a pulsator diaphragm. Though I can't find something exactly like yours, here are two similar images that label it:
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #653 on: January 24, 2021, 06:57:42 PM »
And from the mists of time -- 1945 to be exact, a pretty interesting document find:

http://www.easy39th.com/files/TM_9-1828A_Fuel_Pumps_1945.pdf
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #654 on: January 25, 2021, 04:11:48 AM »
Wow Steve that's quite a document - and yes I've been through it fully ! Who'd imagine there would have been so many minor variants. Many have the pulsator diaphragm, several don't and some have an 'air dome' presumably for the same function.

What I find odd about the rubbery one that I removed is that the illustration definitely shows it as flat, whereas mine is exactly curved to sit fully against the cover with no air (or fuel) behind it, and it is fixed at the periphery by the cover and the centre by the retaining screw thus greatly reducing any potential movement.

No  weeping over night and I've found the massive pistons that I thought I had so I'll do a melt today and load up the engine  and see what happens. But first I need to work out how to cut up the pistons - at 5.25" they won't quite go in the crucible  :bang:

Weighing in at 3 Kg's each it must have been a big engine that they came from !

« Last Edit: January 25, 2021, 10:35:06 AM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #655 on: January 25, 2021, 05:15:57 AM »
The other day I managed to break my coarse bandsaw blade for my upright Startrite 18V10 bandsaw, and although  it has a blade welder, this particular blade stock  doesn't butt weld very well, so . . .

. . . it had to be the horizontal band saw which gives worse holding issues with a piston shaped object - however two cuts and one piston was reduced to manageable pieces for the pot.

I deliberately hit it with rather more energy than really needed as I wanted to load up the engine to make sure that the lift pump was pumping at a goodly rate. 50 kW and the alloy was jumping out of the pot, but the engine note never missed a beat.

So one piston reduced to ingot and the lift pump is performing apparently OK, however I strongly suspect that with the tank sited where it is at least 12" above the injector pump it would probably run without a lift pump at all!
Andrew Mawson
East Sussex

Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #656 on: January 25, 2021, 05:36:30 AM »
Hi Andrew,

I imagine that here are no gas bubble problems with your induction furnace! I was thinking, is it worth ingotting? By the way , you probably know, Al car wheels are a really useful alloy, tyre shops are sometimes a good source!

Cheers, Matthew

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #657 on: January 25, 2021, 07:24:36 AM »
Not sure about gas bubbles yet Matthew as I've not machined any of it, but it's on the to do list - in fact I'll try and do it this afternoon.

Yes alloy wheels generally machine nicely when cast, but with tight lock down at the moment I cannot drive around  to make suitable contacts. It's tempting just to buy an expensive pallet load of LM4 or LM5 - no point in small quantities as the transport gets too pricey.

(Awaiting my invite for the vaccination as I'm in the second tier age-wise - hopefully this week)
Andrew Mawson
East Sussex

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #658 on: January 25, 2021, 08:38:49 AM »
OK Matthew, I've machined both the 'Diecasting Alloy Ingot' and the 'Piston Alloy Ingot'

No signs of porosity / gas bubbles in either and they machined beautifully, despite being a rough and ready hand feeding bit of machining using an end mill out of my 'waiting to be sharpened' box !

Quite pleasing really  :thumbup:

(no saying if there are defects further in, but this is a good indication )
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #659 on: January 25, 2021, 10:21:19 AM »
What I find odd about the rubbery one that I removed is that the illustration definitely shows it as flat, whereas mine is exactly curved to sit fully against the cover with no air (or fuel) behind it, and it it fixed at the periphery by the cover and the centre by the retaining screw thus greatly reducing any potential movement.

HI Andrew. My experience recently rebuilding a couple of outboard motor fuel pumps is that plain rubber diaphragms do often retain stretch over time even though they may start out flat. I also think that some of the modern fuel additives (not just ethanol in petrol but also additives in diesel) can soften the rubber and accelerate that kind of aging.

In normal usage, even though the pulsator is pinned down in center, the thinness of the rubber does allow elastic flexing into the space surrounding.

I think you're right that the height of the fuel tank relative to the engine intake probably provides fuel pressure by itself. I think the function of the pulsator diaphragm is not to provide fuel pressure (that's the function of the pump diaphragm) but to smooth the fuel pulses, and reduce the peak loads on the pump diaphragm and fuel line components. I don't think problems if any will show up in the short term.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #660 on: January 25, 2021, 11:43:37 AM »
Amazing what a new ribbon does for a till roll printer !

This is the analysis of the 'Piston Alloy'
Andrew Mawson
East Sussex

Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #661 on: January 25, 2021, 01:58:54 PM »
Hi Andrew,
I thought that bubbles would be unlikely as your atmosphere doesn't have anything like the hydrogen content that a gas fired foundry has. I've made a de-gasser, (based on "olfoundry man's" one using Argon)  that I've started a video on, I just need for the weather to get better so that I can get outside and do some more casting!

Nice to see the results of the Pistonium analysis.

Good news about the vaccination, my ex-mother in-law who is 96 can't get one in Seaford.

Cheers, Matthew

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #662 on: January 26, 2021, 04:42:14 AM »
Matthew I used to de-gas aluminium alloys with a simple Argon probe. A length of 15 mm stainless steel  plumbing pipe, flattened to seal it at the 'hot' end, with a few 1 mm holes drilled in. Probe connected via flexible pipe to Argon regulator which I set to just bubble up through the melt.

In fact this is why for many years I used straight Argon for mig welding - I was too tight to rent two cylinders! I now have returned the Argon cylinder and have Argoshield which is much nicer for welding but I doubt that it would de-gas aluminium !
Andrew Mawson
East Sussex

Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #663 on: January 26, 2021, 07:04:19 AM »
Andrew,

I only have Argon, as I've don't use my Mig, most of my life I only had a stick welder! The Mig is up for sale, it a very good 400amp welder, withe a sattelite on 10meters of cable!

Olfoundry man's de-gasser does exactly that, it has two disks (mine are cast iron) bolted together with radial lines scratched into one of them, , the argon is fed from the centre between the two discs the scratches are a few 1/100 of a mm which gives very fine bubbles which apparently pick up the hydrogen more easily. When I get to my air bearing project, I'm going to try using one of the off cuts of graphite to try bubbleing the Ag through.

Frankly, I don't think you'll need it with the induction furnace.


Offline hermetic

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #664 on: January 26, 2021, 03:09:30 PM »
I have seen it said that using a lid on the crucible can reduce the contamination  in oil and gas furnaces, you chaps ever use one?
Phil
Man who says it cannot be done should not disturb man doing it! https://www.youtube.com/user/philhermetic/videos?

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #665 on: January 26, 2021, 07:18:25 PM »
I have yet to launch a capsule into space built with homemade castings.

Therefore extreme concerns over weight don't apply, and my aluminum castings are multiple magnitudes of degree heavier than absolutely necessary for their intended purpose. It's frankly a pain to cast too thin a piece, and mass and solidity benefits most machine parts I've ever made   as well as looking more substantial and aesthetic.

Occasional tiny pinholes requiring a magnifying glass to see in an aluminum casting are not therefore viewed as a problem. Now, I'm all in favor of others taking steps to perfect their casting, don't get me wrong. But I cast (as most other home shop sandcrabs do) with scrap, which is not devoid of corrosion, oil, dirt, or included steel clips (pistons, my favorite source of aluminum always has steel cast right into it). So the concept of avoiding contamination is doomed from the start. Luckily, it doesn't matter -- the contaminant either burns away into carbon dioxide or powdery dross (which actually protects the melt from oxidation), is fished out (clips) or skimmed off (dirt, oxides etc.) before the pour.

I did once put a crucible cap on an iron melt. Didn't seem to make any difference.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #666 on: January 26, 2021, 08:03:47 PM »
re. caps....I should add, though, I think a cap would make sense on a brass melt to reduce zinc fuming and oxidation.

And I always felt, when melting aluminum in a charcoal furnace, that charcoal pieces which landed on top of the melt protected it from oxidation. Likewise coke on top of ironman's (luckygen1001 on YT) steel-to-cast-iron conversion melt video did likely reduce oxidation.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #667 on: January 27, 2021, 02:32:31 AM »
No I’ve not used crucible covers in this context. (Yes in the lab on small porcelain crucibles): But  I do use a ‘cover flux’ - I say I do, it’s really’ ‘ I did’ as I doubt that I still have any left, there may be a tub in the cupboards of the foundry benches, memo to self to look !
Andrew Mawson
East Sussex

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #668 on: January 27, 2021, 05:42:40 AM »
As I thought - the cover flux is long gone, but I did manage to unearth some treasures in my search for it:

A wooden 'snap flask' that I made using sash window catches

Several Sand Sieves in different meshes

Another Plate Pattern for brackets

And my Vacuum Pump used for de-gassing lost wax plaster moulds

Along the way I found a cupboard full of all sorts of dangerous chemicals and card board boxes so covered in mould I hate to think what is inside - the cupboard has been against a damp wall for years - must work out a disposal strategy  :bugeye:

Andrew Mawson
East Sussex

Offline vtsteam

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #669 on: January 27, 2021, 02:00:25 PM »
All very nice!  :thumbup:
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #670 on: January 30, 2021, 06:18:31 AM »
Yesterday I took delivery of five 8.5 kg ingots of pure aluminium from a re-cycler -  the analyser agrees that it's LM0 99 % aluminium, and today I've taken delivery of four Range Rover wheels weighing 80 kg so I'm all right for feed stock for a while once I've worked out how to cut the wheels up.

But what IS the alloy in Range Rover wheels ? The analyser says LM25 or 9% silicon with just a trace (0.37%) of magnesium which is fine - it machines OK but can be tough on tooling - but by adding the pure aluminium and a bit of copper I can get a really useful range of alloys and properties.

Andrew Mawson
East Sussex

Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #671 on: January 30, 2021, 06:57:35 AM »
Hi Andrew,

Very interesting to see the analysis of the Wheels! Cutting the wheels is a real problem. The last ones I did were quite small, so I was able to cut them using the Warco mechanical hacksaw, bolted down in place of the vice and for some bits a chop saw fitted with an Al blade. I have one of those RangeRover wheels waiting, they are big! A good method, which is not always very doable, is to heat them in a pit-fire until they are "hot short" you can then tear of bits with tongs. I haven't tried using a press, that way, they might end up a shape that is easy to saw! A bugger to clap down!

Cheers Matthew

Offline awemawson

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #672 on: January 30, 2021, 08:27:29 AM »
I'm going to see if my Hypertherm 900 plasma cutter will do anything for me. It's specified to sever 7/8" mild steel and do proper cutting on 16 mm aluminium. I've only ever used it on mild steel, but I bought it from a ship yard in Wales many year ago where they used in on aluminium plate on a daily basis.

If I can cut the spokes off then slice the rim into sectors it may be the quickest way.

Alternatives are heat up in kiln until 'hot short' (energy intensive), Squash in 60 ton press (might get interesting as bits fly about). Squash in log splitter on tractor (same issues as the press) or wait for better weather and have a bonfire (metal contamination)

Andrew Mawson
East Sussex

Offline NormanV

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #673 on: January 30, 2021, 08:42:26 AM »
I have placed alloy wheels on top of a good wood bonfire and as they melt the metal runs out the bottom. I have no idea what it doe to the composition of the alloy but it does reduce the unmanageable wheels down to usable pieces that will fit into a crucible and can be remelted down, skimmed to get rid of the dross, and then cast into nice clean ingots. It's a bit of a faff but at the time my fuel was free.

Offline mattinker

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Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Reply #674 on: January 30, 2021, 08:55:05 AM »
Plasma cutter should work nicely, I haven't used mine much for Al seems to cut more ragged! Needles to say mask up and if possible cut out of doors! Vaporised Al is really nasty stuff!

Hot short  and log splitter would be really good!!