Tungsten Alloy

[duncan webster 1Participant @duncanwebster1]

Having modelled my loco wheels in Alibre I've worked out that I need some really heavy stuff for balance weights. What I think I want is Tungsten/nickel/copper alloy, which has a trade name of Densalloy. Anyone got any idea where I might get small quantities, I've tried Ebay. Finished size is thick tube, 2.8" OD, 1" ID, 3/16" slices, 2 off.

In the end I'll probably just accept the out of balance, but it's an interesting exercise to work out how good I could get it.

[duncan webster 1Participant @duncanwebster1]

[pgk pgkParticipant @pgkpgk17461]

I'm not sure i understand but guess you'd be slicing those two pieces in half for 4 balance weights? If so cannot you thicken up the size and use lead? Or a quick trip to some forgotten recent war zone for a chunk of depleted uranium (just a tad toxic)?

pgk

[Niels AbildgaardParticipant @nielsabildgaard33719]

In good old days where EDM meant sink sparking the elektrodes were sometimes made of wolfram-kupfer that is easy to machine.Density about 17 I think.

[Neil WyattModerator @neilwyatt]

I suggest you read Duncan Webster's article in the latest ME.

He would probably suggest copying the 9F and fitting balance weights to the axle.

Neil

[JasonBModerator @jasonb]

have a look back at Andrews posts about his Tungsten balls

Other option is to drill out the opposite side pop in a granule of polystyrene and then filler over the top.

[not done it yetParticipant @notdoneityet]

TIG electrodes?

[duncan webster 1Participant @duncanwebster1]

I can't make them thicker, they would clash with the frame.
I've seen the post Jason linked, that went into why I'm not even thinking about DU even tho' I worked in the nuclear industry most of my career.

I'm looking at drilling lightening holes, but I really need both holes and more weights. See my article in ME some time ago. The manual calc of balance available in the existing design was wrong, too low, I've now got manual calc agreeing with Alibre fairly well.

I might try lead, but I think the tungsten alloy is more of an engineering material (not as soft), as well as being heavier. What I need is a supplier.

Edited By duncan webster on 27/11/2018 19:32:11

[Neil WyattModerator @neilwyatt]

Drill out the crankpins and halve their weight.

Can you lighten any other parts?

Neil

[Pete RimmerParticipant @peterimmer30576]

How about grinding down some spent carbide milling/turning tips? They are quite heavy for the size.

[SillyOldDufferModerator @sillyoldduffer]

How about 'Tungsten Fishing Weights'? ebay sells weight stuff ranging from tungsten loaded putty up to 97% solid Tungsten in various shapes up to 50g. No idea how to machine it though!

[Trevor Crossman 1Participant @trevorcrossman1]

Duncan, it might be worth you trying businesses that deal with aviation scrap/used parts. The flight control surfaces use very dense material for the balance weights, sometimes on light aircraft this is lead but more highly stressed aircraft use other heavy metals such as tungsten rich materials, many years ago when I repaired British military aircraft, we would often make up special rivet bucking blocks from discarded balance weights. Aviation tool suppliers stock Tungsten rich riveting bars in a variety of sizes, shapes and weights.

Trevor.

[Anthony KnightsParticipant @anthonyknights16741]

Googled "UK tungsten suppliers" and got 18 pages of hits.

[Jeff DaymanParticipant @jeffdayman43397]

I'm surprised no one has mentioned depleted uranium as a candidate heavy metal for balance weights…..

Unfortunately there's no DU Mart's still open in the UK as far as I know….. maybe still one in Skipton……

Anyone fancy a quick trip to Iraq to literally "pick some up"?

(I'll get me coat and hat now)

[JasonBModerator @jasonb]

Jeff you mist this in one of Duncan's posts

"I've seen the post Jason linked, that went into why I'm not even thinking about DU even tho' I worked in the nuclear industry most of my career."

[pgk pgkParticipant @pgkpgk17461]

I note tungsten powder is available on ebay and other sources… just wondering if mixing it with epoxy into a mould would work?

pgk

[duncan webster 1Participant @duncanwebster1]

I'd been googling Densalloy, tried UK tungsten suppliers and rang one up. Minimum order charge £280. I now have a lead in Manchester and one in Wales which I will follow up tomorrow.

I suspect that tungsten power/epoxy mix would be no heavier than lead, and would be even less of an engineering material.

I've looked at tungsten fishing weights, totally the wrong shape. I'll probably finish up with more conventional metals, brass or monel are heavier than steel (and I've got both)

[Michael GilliganParticipant @michaelgilligan61133]

**LINK**

https://www.ebay.co.uk/itm/AIRCRAFT-TOOLS-HEAVY-TUNGSTEN-BUCKING-BAR-721-GRAMS-1LB-91-2-ounce/273557225151

… You could probably sell the offcuts and swarf.

MichaelG.

.

Alternatively: https://www.lasaero.com/products/article/A00IMGATV

Edit: Yes, I realise that none of these is actually to your dimensional spec.

"Finished size is thick tube, 2.8" OD, 1" ID, 3/16" slices, 2 off."

Edited By Michael Gilligan on 29/11/2018 00:30:12

[duncan webster 1Participant @duncanwebster1]

Thanks Michael, at that price which I'm sure is typical, I'll stick to monel which I've had for 40 years. Originally part of an electrolysis cell I think, bought for peanuts in club auction.

[duncan webster 1Participant @duncanwebster1]

So this is what it looks like with extra weights and lightening holes. A lot better than original design for balance, and I'm bored with it now, as I'm sure everyone else is! Is it possible to insert png images? having to go via Paint to convert to jpg is a pain. And does anyone know why when I press return on this site the cursor goes back to the start of the document, not to the next line? I have to press shift/return

[Niels AbildgaardParticipant @nielsabildgaard33719]

Seek (tungsten pine car) on the USA Ebay

[Michael GilliganParticipant @michaelgilligan61133]

Posted by duncan webster on 29/11/2018 11:51:49:

Thanks Michael, at that price which I'm sure is typical, I'll stick to monel which I've had for 40 years. Originally part of an electrolysis cell I think, bought for peanuts in club auction.

.

This may put that price into perspective, Duncan **LINK**

https://www.ebay.co.uk/itm/LOT-13-GRAMS-TUNGSTEN-90-HEAVY-ALLOY-METAL-PIECES-AS-IS-BIN-Y7-H-03/253973717776

… Your use of Monel metal is probably wise.

MichaelG.

[Phil H1Participant @philh196021]

Would opening out the back of the wheel more reduce the size of the counter weight and lighten the opposite side at the same time?

Would that help?

Phil H

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 29/11/2018 19:41:11:

… Your use of Monel metal is probably wise.

.

… I've just looked at the density of Monel; and have changed my mind.

MichaelG.

[Benjamin DayParticipant @benjaminday94198]

A while ago I came across a material that was rods of titanium cast into copper (I think!) The guy was machining it and etching it to make unusual jewlery pieces, anyway would this kind of method work at all? A number of smaller rods brazed together, then cast into aluminium or copper, which could be turned?
Ben.

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