Attaching lead for balance

[David P Williams]

What is the best way to fix lead balance weight? I have been using left over lead flashing sheet, cut to the correct weight then folded several times to the right size, hammered flat and drilled and bolted to the firewall or i/c engine mount.

What usually happens is that the vibration just opens the bolt holes and it all comes loose.

What's the best way to do this please?

[Robert Parker]

Hi David,

I do exactly as you, when I need to add a lot of weight or for smaller amounts I use self adhesive strips from model shops or if you talk nicely to your local garage they may give you some of their wheel balancing weights.

Yes, they do work loose I use a large washer between the lead and the screw / bolt

 

Regards

Robert

Edited By Robert Parker on 14/02/2017 11:55:13

[Piers Bowlan]

Loctite, cyano, or a stiff nut (nyloc)?

[David P Williams]

Sorry Piers, maybe I didn't explain well enough. The bolts are done up tight with nylocs but the vibration causes the lead to move and open out the holes in the lead that the bolts pass through.

[kc]

Epoxy as well as using bolts & washers. Of course you could always use a chunk of steel of the same weight instead.

[iqon]

epoxy lead in place and use the bolt you are using

[Manish Chandrayan]

Lead is soft and hence compresses easily, vibration does not help either. Therefore the lead that is just bolted down will loosen up.
Once I have arrived at the correct weight I melt and pour that in a balsa mould. Once cooled the lead is epoxied and then wrapped up with cotton thread or glass threads pulled out from glass cloth. Thread too coated with epoxy. Once dry it stays put. For smaller amounts double sided tape, thread and thread soaked in cyano

[john stones 1 - Moderator]

Fit some lagging foam under the lead, it'll stop it jiggling about

[Jon H]

On my Hurricane i hammered captive nuts into the lead and then thread locked the bolts. So far so good.

I would also make sure everything is balanced as excessive vibration could be a major factor. 

Edited By Jon Harper - Laser Engines on 14/02/2017 15:44:05

[David P Williams]

Thanks chaps, I'll try some sort of additional securing, like epoxy. If I can stop it moving it should be OK I guess.

Jon - I've tried different carefully balanced props and spinners and it still shakes like a very shaky thing (it's a Saito 180)

[Denis Watkins]

Lead is soft David, as you know, but is the heaviest metal for our needs. If it becomes critical, as in a scale model, or where there is limited stowage, then cast your lead to fit closely the area it is going into. There are many methods, well documented of making removable plugs in sand.

I usually hammer out soft earth in the garden to represent the shape in the earth, for pouring into, then dig out the cooled lead, and wash it off

Next, try turning the prop, 90° at a time, then retightening in that new position, and look for a reduction there

Also, some props are sold as "balanced" and they certainly are not in balance

Edited By Denis Watkins on 14/02/2017 16:02:23

[Mowerman]

Beware of casting lead in sand or soil, If the sand or soil is wet, the heat could cause the water to boil violently and spit the molten lead out. Molten lead will cause nasty burns when doing just this.

[Bob Cotsford]

If I'm bolting on lead I usually use penny washers plus 1" rubber tap washers under the bolt heads. It allows the lead to move a little without the bolt head chewing it's way through. If there's any way to glue it in I bury it in epoxy or Gorilla Glue.

[ken anderson.]

David...try some silicone...much as you like should do the trick..and is easy to remove to get the lead out/off.

ken Anderson...ne....1 out/off dept.

[Don Fry]

You can get lead shot by the kilo, divers use it for buoyancy control, E Bay applies. Also gunsmiths can supply, they use it to get the balance of a rifle.

[Sam Longley]

Use tungsten split shot from a fishing tackle shop You probably want the SSG size.

You can also use larger tungsten or lead  fishing weights varying in size from a fraction of an ounce to several ounces.

Some weights such as the egg shaped ones ( once called arseley bombs) have swivels attached & you could bolt through the swivel eye. However, one solution would be to drill a hole through the weight slightly smaller than alength of studding & then thread the studding into the weight so it cuts its own thread. You could use a servo control rod.

What you can do is epoxy a length of studding longitudinally into the air frame & then by winding the weight along the studding you can adjust the CofG . This studding can project just below the engine with one end in the fire wall & the weight would be under the engine. You could move it back & forward a bit to suit if you were that fussy. You could then lock it off with a couple of nuts each end. having a thread cut into its length it would be less susceptible to vibration as lead sheet

Edited By Sam Longley on 14/02/2017 18:08:59

[john stones 1 - Moderator]

It's not lead either, been a long while since that was the case.

[paul mcleod 2]

hi dave I get a piece of copper tube. up end it on a piece of steel and warm the tube with a blow lamp .melt the lead into it. weight what you want . then cut to size.in it drill two holes for screws or bolts

paul McLeod

[David P Williams]

Thanks again chaps, some good suggestions there. I like the lead shot idea especially as I was going to buy some to put in ziplock bags to make weight bags for holding down wing skins etc. Seems easy enough to get hold of in 1 kilo increments without hacking shotgun cartridges.

[Former Member]

[This posting has been removed]

[Denis Watkins]

Guys, sleep on this,

I for one value all your knowledge and elequence, and your value to this site cannot be overstated.

We need guys like you, writing daily

Sleep on this

We can unravel it tommorrow

[Jon H]

Posted by David P Williams on 14/02/2017 15:48:16:

Thanks chaps, I'll try some sort of additional securing, like epoxy. If I can stop it moving it should be OK I guess.

Jon - I've tried different carefully balanced props and spinners and it still shakes like a very shaky thing (it's a Saito 180)

the saito 180 is not the smoothest engine ever made it has to be said :\

[Biggles' Elder Brother - Moderator]

A line of debate has been removed from this thread. This forum does not recommend that people attempt to remove shot from live anmmunition.

BEB

[Braddock, VC]

I used to use lead and latterly stick on weights.

My procedure was to pop the model onto my c of g machine (great planes I think) then add 1p and 2p coins where needed until she balanced always, it must be said, after shifting batteries around so they provided max benefit. Then weigh out the lead or stickons and attach them.

At some stage one of the 1ps dropped when I saw the price tag, £4.99 for about 200 grammes of stick ons, a 1p coin is approx 3 grammes, a 2p coin approx 7 grammes. £4.99 worth of shrapnel is approx 1.5 Kg. I wonder if you can guess what I use now.

A small, closeable plastic case (HK send one with turnigy bits in) fastened to either the fire wall or engine bearers with the correct amount of change in with a large dose of gorilla glue in on top after washing the coins and case in meths.

Stick ons are very convenient, especially when the covering is new (I'm dyed in the wool I/C) it has to be said and is worthwhile for small amounts at the tail end but for ballast in excess of 250 grammes, I fall back to plan b.

Incidentally, the coins contain significant amounts of nickel and are magnetic so if you have a flyaway they always go north.... .

[Rich too]

A couple of long HD zip ties, bound to the lead with that reinforced tape, wrapped around the lead a few times.