OO9 loco weight

[Gypsy]

I've got an eBay sepcial 3D printed 60hp Baguley-drewry loco to go on a Kato 109 chassis to play around with but was wondering how much extra weight I need to get into it before I go too far down the painting process!

 

Any suggestions how much it should ideally weigh?!

 

Many thanks,

 

Gyp

[Nearholmer]

The basic rule with 009 locos is that, even if you fill them solid with depleted uranium, they are still too light.

 

In short, fill every crevice, but make sure it balances properly on the driven wheels.

[Gypsy]

 

So if I chuck a load of liquid gravity under the bonnet that will help - though its then likley to be nose heavy...?!

[Moxy]

Whilst I agree with Nearholmer in principle, I wouldn't add too much weight to the Kato108/109/110.  The older 103 & 104 needed more weight, but with the new versions it has been known to cause the motor to come loose from its clips if you add too much weight.  I would start off just with the print on its own and see how it runs, and then gradually add weight until it runs smoothly.

[The Johnster]

Get in as much as you can, and use black hole matter/unobtainium if you can get it.  The more you can get over the driving wheels the better, but leave some room for ventilation around the motor.  If there's limited space above the motor, which there usualy is because that's where you want the weight and life's like that, then by all means stuff ballast in fore and aft of the motor, but try to keep things in balance over the driving wheels.  Your aim is to get as much direct downward force as you can at a point between the driving wheels if it's an 0-4-0 or at the central axle if it's an 0-6-0.  If you are using liquid lead, be careful what you seal it with, as some glues react badly with some plastics, and can swell and split the 3D print plastic body.  Some prints can be a bit brittle, the material being chosen for the ability to incorporate fine detail rather than 'plasticity'.

 

2 hours ago, Moxy said:

I would start off just with the print on its own and see how it runs, and then gradually add weight until it runs smoothly.

 

Nowt wrong with this approach, but I would continue to add weight even after the point at which it runs smoothly, and not stop until the motor comes out of it's clips, then remove as little as possible to restore matters. 

 

A small 009 locomotive with a 3D printed body needs all the help it can get to pick up current from the rails and to gain as much momentum as it can to ensure smooth running.  Goes without saying that railhead, wheel, and pickup hygiene is vital, and that pickups are adjusted to reliably bear on the back surface of the wheels while exerting as little braking pressure on them, so I won't say that.  There, look, I didnt say that.  Aren't you glad I didn't say that!

[zarniwhoop]

In general for 009 it depends very much on the chassis. For this case Moxy has given sensible advice. In the general case (kits, sometimes whitemetal but lacking balance on whatever chassis can be found) people have been known to wear out the chassis by adding too much weight. I don't have links, but I think I've read of gears on old N-gauge steam chassis cracking when too much weight was added.