Adding poured lead to aluminum flywheel - have you done it?

[VicHobbyGuy]

I'm building some easy air-powered engine models. For flywheels, I have aluminum but no bra$$ or steel that's big enough to add to the flywheel rim.

If you have poured lead 'plugs' into a flywheel, I'd like to have any 'tips and tricks' you discovered. I'm thinking about 6 or 12 plugs in holes that are coaxial with the axle of the flywheel.

I have poured lead before - I solo poured the 4200# keel for my sailboat years ago - so I'm aware of hazards and safety precautions.

I'm wondering about how to prepare the holes in the flywheel - countersunk?. Also, how to seal the underside for pouring so the lead doesn't flow too far. Shrinkage- do the lead plugs shrink enough to be loose? Can peening tighten them up? etc etc....

Thanks.

 

[GreenTwin]

Here is one approach to use lead in a flywheel rim.
I am not associated with this individual.

I am not a fan of adding lead to a flywheel, but I do understand why some would want to do that.
I would recommend adding mass in a manner that would not weaken the flywheel rim.

For a low rpm engine, you would not need a very strong flywheel rim, unless you accidentally over-speeded it.

As you mention, you have to be careful handling lead, but it can be cast with the proper precautions.

My approach to making a high mass flywheel: Cast it in gray iron, but I am aware that most don't have that option.

An overall steel band would retain any lead and prevent it from separating from a rim.
I would guess an overall steel band may have enough mass so that the lead could be omitted, but it would depend on the engine.

I would not modify a gas engine flywheel, due to the risk of the rim failing.




Edit:

I read your post again.
There are some lead materials that expand when they cool, such as linotype metal.
For lead that shrinks, you could pour extra, and then machine it off.

If I were going to add lead to a low speed flywheel, I would probably drill a series of blind holes, and maybe try to make a dike around the rim, and over-pour it, then machine off the excess.

Another trick I have seen in the babbitt bearing business is to use a torch, and fill with a stick of babbitt.
That way you could build up the fill a bit over the top of the hole, filling one hole at a time, and then machine it off flush.

Some plumber's flux may help the lead stick to the steel or iron, or maybe not?

.

 

[chucketn]

The late Bogstandard made a few flywheels from aluminum with lead, steel, or brass inserts in the rim. I'm not sure if he poured led or hammered it in. He used locktite on the steel and brass round stock.

 

[Vietti]

One idea is to thread the holes so the lead has something to grip.

 

[VicHobbyGuy]

Thanks for those ideas - definitely "food for thought". I hadn't considered using blind holes or threading the holes. I have enough aluminum to do a few experiments, so I will post results if and when I get something worthwhile.

 

[JohnBDownunder]

I have also needed to increase the mass of an aluminum flywheel and simply drilled 8 X 10mm diameter holes through the rim. From memory I poured the molten lead to overfill the holes. Set the wheel flush on block of scrap wood to try and prevent the lead running through.
Once cooled I peaned any that seemed a bit loose then mounted the leaded wheel on an arbor and turned the excess off both sides.
Small model wobbler running on air with no problems.
John B

 

[stragenmitsuko]

The late Bogstandard ....

Appologies for the OT .
Chuck do you know what happend to John .
We used to have contact by email . I know he was very sick , and then suddenly his emails stopped .
So I suspected he passed away last year .
Tried contacting his relatives but never got a reply .


Pat

 

[stanstocker]

I'm building some easy air-powered engine models. For flywheels, I have aluminum but no bra$$ or steel that's big enough to add to the flywheel rim.

If you have poured lead 'plugs' into a flywheel, I'd like to have any 'tips and tricks' you discovered. I'm thinking about 6 or 12 plugs in holes that are coaxial with the axle of the flywheel.

I have poured lead before - I solo poured the 4200# keel for my sailboat years ago - so I'm aware of hazards and safety precautions.

I'm wondering about how to prepare the holes in the flywheel - countersunk?. Also, how to seal the underside for pouring so the lead doesn't flow too far. Shrinkage- do the lead plugs shrink enough to be loose? Can peening tighten them up? etc etc....

Thanks.

Perhaps lead shot mixed with epoxy would avoid shrinkage or loosening in use issues. It might be easier to use larger shot so each hole gets only one or two balls to avoid imbalance. A mix of birdshot and epoxy would probably also work well enough, although I think lead birdshot may not be available any longer, seems the hunting world went over to steel shot near water years ago. Not being a hunter maybe I'm wrong on this. The shot I've purchased for making pendulums and loading clock weights has been about 1/8 inch in diameter. I didn't care about the specifics, just asked for a bag of the smallest lead shot the store had in stock.

Mixed with JB weld and sanded once cured could provide a little visual interest or allow a nice paint job. Just use reasonable care if the sanding is hitting lead rather than just epoxy.

Cheers,
Stan

 

[VicHobbyGuy]

Appologies for the OT .
Chuck do you know what happend to John .
We used to have contact by email . I know he was very sick , and then suddenly his emails stopped .
So I suspected he passed away last year .
Tried contacting his relatives but never got a reply .


Pat

Pat: Sad news about John Moore aka Bogstandard aka Blogwitch

 

[VicHobbyGuy]

I have also needed to increase the mass of an aluminum flywheel and simply drilled 8 X 10mm diameter holes through the rim. From memory I poured the molten lead to overfill the holes. Set the wheel flush on block of scrap wood to try and prevent the lead running through.
Once cooled I peaned any that seemed a bit loose then mounted the leaded wheel on an arbor and turned the excess off both sides.
Small model wobbler running on air with no problems.
John B

Thanks. I need to get my 'mini-melter' organized, and then I plan to try just that.

 

[creast]

Hi.
Sorry, only just noticed this link was already referred to.

I followed Myfordboy method for my Kerzel Hit n Miss engine which had cast aluminium wheel with a stainless rim after lead filling. It works well.
There are different ways you can do this but worth watching this route

 

[Bentwings]

I'm building some easy air-powered engine models. For flywheels, I have aluminum but no bra$$ or steel that's big enough to add to the flywheel rim.

If you have poured lead 'plugs' into a flywheel, I'd like to have any 'tips and tricks' you discovered. I'm thinking about 6 or 12 plugs in holes that are coaxial with the axle of the flywheel.

I have poured lead before - I solo poured the 4200# keel for my sailboat years ago - so I'm aware of hazards and safety precautions.

I'm wondering about how to prepare the holes in the flywheel - countersunk?. Also, how to seal the underside for pouring so the lead doesn't flow too far. Shrinkage- do the lead plugs shrink enough to be loose? Can peening tighten them up? etc etc....

Thanks.

I think rather than go to the work of pouring lead I just get a box of tape weights aluminum wheel weights . They have a sticky tape on the back that stays in clean surfaces very well

 

[Rocket Man]

Call your local tool & die supply company order several pre cut metal pieces the diameter and thickness you need, have them mailed it to you UPS. I order steel from Tennessee Die Supply in Nashville TN. have it cut to size and mailed to me. At my age time is worth more than money package will arrive at my door in about 3 days. Call and ask for a price that part is FREE. They sell, steel, cast iron, brass, aluminum.

 

[Steamchick]

From my Industrial experience in the 1970s, I learned to solder onto aluminium cable sheaths (3in to 12in diameter!) on large HV cables and telecom cables (1012 pairs - before fibre optics!).
The process.
Clean back the cloth and bitumen or PVC over-sheath, using a stainless steel wire brush,
Abrade the aluminium (Machined threads free from ANT greasy contamination are OK).
Heat with a blow-lamp, rubbing the surface (close to the flame, but not in the flame) with a Zinc based alloy stick for "aluminium repairs", Using the wire brush occasionally if the zinc doesn't flow and "wet" the aluminium.
Allow to cool.
Clean-up the zinc surface, so it is relatively "pretty" - no lumps, gaps or sharp bits sticking-up.
Conduct a "Lead-wipe" with Plumbers' lead solder, hard to get nowadays?
Tin the brass fittings, or lead wipe the next aluminium piece to be joined, assemble parts. Fill the gap with plumbers' lead solder for a very durable and water-tight, corrosion free joint.
Finally wrap everything in Bitumen coated linen tape, heat until all fused into a water-tight coating that seals everything for the next 40 years.
Bury in the ground and forget.

The Zinc repair rods used to be available in Halfords, as "alloy repair sticks, Could be used for many jobs e.g. of making small aluminium boxes from sheet, but now hard to find and I use "aluminium alloy" repair rods as my zinc ones have all been used-up. But the zinc surface takes lead solder so any part (e,g, a threaded hole) could be "tinned" with the zinc, then filled with lead that will take to the zinc. But you do need to abrade the surface of the aluminium while the zinc alloy is molten so the zinc can take the oxide away from the aluminium and then wet the clean metal. Use STAINLESS steel wire brushes and scraping tools, as the zinc will stick to steel as in Galvanising, but not the Chrome alloys.
As zinc is close to the density of steel, you may be able to adequately load mass to you flywheel with just zinc alloy?
BE CAREFUL not to overheat zinc alloys, as the Zinc can burn (blue flames) and give of highly poisonous fumes. - ALWAYS melt the zinc alloy from hot aluminium, NOT from the blow-torch flame. Molten Lead also gives off fumes that can be absorbed through the lungs to give permanent brain damage (Alzeimer's) so please be very careful to avoid fumes, as well as hot, molten products.
A safer dense material is Gold, if you have a few spare bars ...
Or you could drill and tap the aluminium and add stainless steel studding? Pretty, clean and easy machining?
K2