Tungsten Alloy

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.

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

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.

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

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.

TIG electrodes?

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

Drill out the crankpins and halve their weight.

Can you lighten any other parts?

Neil

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

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!

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.

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

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)

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."

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

pgk

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)

**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

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.

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

Seek (tungsten pine car) on the USA Ebay