Weighting rolling stock & Removing BluTack

[Derek Clark]

Just building a couple of Dundas freelance goods brake vans and thinking I should weight them before putting the roofs on.
How much weight, please?

Also, I used Blutack to support the sides while I glued them together. How do you clear away the little bits in the planking grooves?

[Graeme Dunbar]

The 'theory' behind weighting rolling stock is that it should be weighted similarly - not the same but proportionately. The NMRA have a formula intended for USA stock based on rolling stock length I think, but USA stock is almost universally bogie stock. I think the UK equivalent often used is so-much-per-axle, but the only figures I've seen are for OO. Unless weighting all your stock to some standard, a starting point would be making it the same as RTR stock or what you have at present.  I don't know if there is anything to be gained by making a brake van slightly heavier.

The first thing I'd try for removing BluTack is the same as removing it from old posters and so on. Take a lump and stretch and knead it to make is soft and then dab and roll (with appropriate pressure) to lift the residue.

[Hobby]

Enough to make the wagon stable, not too much so the loco can't haul a train!

"Just enough" is the phrase, but like their locos, too many modellers over-weigh their stock, sticking to a set weight and sticking to it regardless of if it's needed!

I would agree with Graeme, use your RTR stock as a staring point and try to make them similar. Of as much, if not more, importance to the weight is the free running. Make sure any kits/scratchbuilt stock runs freely as possible.

[Graeme Dunbar]

Just found the NMRA web page:

https://www.nmra.org/beginner/weight

I reckon about 21/32 of an oz following their formula. You can't argue with the winner of a Golden Spike award!  ;D ;D ;D

More realistically though, - what Bair said.

[Derek Clark]

Thank you both.
I hadn't thought of checking against rtr stock of which I only have two Peco coaches weighing in at 13 grams each. I have a Peco open on its way and I will check that against my kit built open.

That was my method for removing blue tack but the magnifying glass shows a residue film. I'll try meths.

[Derek Clark]

Just found the NMRA web page:

https://www.nmra.org/beginner/weight

I reckon about 21/32 of an oz following their formula. You can't argue with the winner of a Golden Spike award!  ;D ;D ;D

More realistically though, - what Bair said.

That's about 18g and I have 13g. I'll roster a fat guard.

[MickT]

To add to what has already been said: as well as having the suitable weighting (not too much though!), and comparing with equivalent RTR is absolutely sound advice, free running, which has been mentioned, is also very important.

A good simple test for any stock (including RTR!) is to place the vehicle on a level piece of track and give it a gentle puff of wind (blow on it in other words) from about 6 inches and horizontally. If the vehicle doesn't move, then there is a problem and this will often be the axles not seated properly in the axle boxes - particularly prevalent in Peco vehicles with the nylon type one piece moulded wheels and axles which have not had the pin-point ends seated in the "dents" in the chassis properly. The pass mark for the blow test is that the vehicle will move for at least approx 12 inches and will gently come to a halt under its own momentum rather than suddenly stalling and stopping suddenly after it has started to slow down naturally.

Fleischmann 4, 6 wheel and bogie stock is particularly good and consistently will run the full length of a yard of track with only a gentle puff of air. Old and rusty "pre-loved" Ibertren and 1960's vintage Arnold on diecast chassis with the axle held in place with a metal S shaped bracket pushing down on the axle shaft are not quite as good free runners!

Mick

[Derek Clark]

Thank you Mick.
I tried the puff test and the unweighted open from my newbies pack ran sweetly but the weighted Dundas van didn't.
Close examination revealed a pair of wheels that didn't spin very well. A 150mm rule levered against the axle box seems to have sorted it  :)