Sprung self contained buffers for 4mm scale

[robmanchester]

Hello,

 

I usually provide sprung buffers on 4mm rolling stock that is using 3-link or screw couplings by drilling out the existing holes in the buffer body and using MJT/Gibson/Wizard sprung buffer heads. I haven't figured out yet how to proceed on vehicles provided with self-contained buffers such as GWR or BR vans. Any ideas on how to proceed with them ? ...are there any heads avilable ? I would rather not replace the whole buffer assembly on cost grounds as I have quite a few wagons to do.

 

Thanks

Rob

 

[Dunsignalling]

Hello,

 

I usually provide sprung buffers on 4mm rolling stock that is using 3-link or screw couplings by drilling out the existing holes in the buffer body and using MJT/Gibson/Wizard sprung buffer heads. I haven't figured out yet how to proceed on vehicles provided with self-contained buffers such as GWR or BR vans. Any ideas on how to proceed with them ? ...are there any heads avilable ? I would rather not replace the whole buffer assembly on cost grounds as I have quite a few wagons to do.

 

Thanks

Rob

Hi Rob,

 

I take it that the need for thick shanks is the issue?

 

If so, Dart Castings/MJT list some heads with 2.5mm diameter shanks, which should allow you to follow your customary practice, unless they are too big, of course. 

 

John

Edited August 11, 2018 by Dunsignalling

[robmanchester]

Hi Rob,

 

I take it that the need for thick shanks is the issue?

 

If so, Dart Castings/MJT list some heads with 2.5mm diameter shanks, which should allow you to follow your customary practice, unless they are too big, of course. 

 

John

Hi John,

Thanks for the reply. Yes, the shank diameter is the critical bit in converting kit buffers to sprung operation. Somehow I hadn't noticed the MJT ones. A slight issue may be the fact that a kit self contained buffer ( ie Parkside PC88 Banana Van ) comes with the buffer body moulded as part of the end and the diameter of the body is only 3mm which calls for accurate drilling that isn't helped by the kit moulding having the centre hole not always concentric with the buffer body. Alternate ends are included in the kit for spindle buffers which is fine but some variety would be nice. The BR standard van kits that parkside do also come with two sets of ends allowing either type of buffers to be modelled.

 

£9.00 for 20 buffer heads and springs gives £1.80 per wagon for the conversion which is fine. I use MJT inside bearing compensated units ( 2 per wagon with one not rocking to make is easy to add the wheels after painting without straining the axleguards to fit the wheels ) and Bill Bedford etched brake gear.

 

Off topic I just got two of the 'new' Oxford Rail Toad brake vans and am most impressed with the quality. Maybe the glazing on the non-veranda end could do with replacing but the mouldings are first class.

 

Thanks again for the info.

 

Rob

[Bucoops]

As well as MJT, Alan Gibson Workshop also do buffer heads. Although they don't specify the diameter.

Edited August 11, 2018 by Bucoops

[Penrhos1920]

When ABS GWR self contained buffers were still available I used to drill them out 2.3mm in stages, the last stage by hand and very carefully. I then used buffer heads from Wizard and sleeved them with 2.1/2.2mm plastic tube.

[Guy Rixon]

A while back, I measured a GWR self-contained buffer on a wagon stored at Bewdley. The 2.5mm ram sold by MJT is the correct size, but it's nearly impossible to make a true-scale housing for this ram. On the full-size buffer, the outer edge of the guide is only about half an inch thick, or around 0.15mm in 4mm scale.

 

When I came to make up 3D prints of these buffers (which can be obtained by following the link in my signature),  I chose to keep the outer diameter of the guide to scale and to shrink the ram slightly. This means that the turned, 2.5mm rams won't do, so I included collars to go over the more-normal 1mm rams. If I'd expended the guides to suit the 2.5mm rams, then the bases of the buffers would have become too large to fit on scale headstocks.