my latest project Scammell pionner

[septon]

hi pete heres some pics of the wheels

[septon]

got the main structure of the cab built i have use some cloth to make the canvas on the rear window covers as this is the battery box

[grompix]

Fantastic Paul!

Cheers
Chris 

[Mad Fox]

Excellent work.

[BigPanzer]

Hi Septon,

From one Pioneer builder to another, nice one! These things look simple, but they are not, are they?

Mine is also the extended cab version, but fitted with a post war conversion from tank transporter to HRV. Working chassis winch, crane, lights & sound

Problems I had - getting the front axle beam geometry right so it does not bump steer, modelling the rear walking beams containing the drive chains.

Current problem - making a pair of mudguards. How the hell do I make a pair of motorbike style mudguards curved in both directions ??

Mine is in 1/12 scale using Hummer wheels and buggy tyres.

Good luck with it. They are a very satisfying model to build and great fun to run

Peter

[BigPanzer]

Hi,

Just to whet your appetite, give you the enthusiasm to continue with a difficult subject to model and (maybe) just to show off a little  :-\

[septon]

that looks great hope my one looks as good how did you make the rear walking beems as i am useing tamiya truck axels would like to have them right but may be hard to do in 1\16

[BigPanzer]

Hi Paul,

Thanks for the complement. I've no doubt yours will look better because you will probably finish it !!

The walking beams would be very difficult to do in 1/16. I cut down the width of a Tamiya diff and bolted a bit of ally channel to each end. In each channel there is a bearing and a metal sleeve. The sleeve fits over the bearing and into the inner race of a larger bearing fitted into the inner face of the beam. The half shaft goes through the bearing within sleeve within bearing (if you can follow that) and right through the walking beam to another bearing in its outer side which is covered with a metal plate.

The half shaft carries two chain sprockets within the beam and there is one chain to each wheel. Chains are 3mm pitch stainless (as are the sprockets) and I had to get them from the good old USA. They cost a fortune and I'll never order from the USA again. It might be possible to do it using a gear drive, but there will be a lot more friction.

The beams themselves are moulded in glass/epoxy from a wooden master, and the outer side is an ally plate carrying the turrets for the wheel hubs. The beams are very crude (first ever attempt at moulding) but they work !!

If you wanted to do a working setup in 1/16 there is a company in Germany who makes specialist diffs but you will need to sell your soul to the devil to buy one. However I think they do one narrow enough that can also be fitted with a diff lock. If you have VERY deep pockets they also do a steerable front axle so the later Explorer (6x6) could be made. Think what that would pull.

There is one Pioneer still in existance with its original trailer, but I have no idea where it is, sorry. The REME museum have at least one HRV.

As far as running gear goes, I'm using standard Tamiya gearbox/motor/diff but there is a home made 5:1 reduction on the output end of the gearbox. Even so the speed range is much too fast though I've succeeded in twisting a Tamiya propshaft and the only limit on pulling power is tyre adhesion.

I started this project really as a maquette for a possible 1/6 model capable of pulling a 1/6 tank on a trailer and I even got in touch with Armortek about the possibility of making a rolling chassis for customers to make the bodywork of their choice, but they need a minimum run of 40. My personal feeling is that the engineering is too much for them though!

Keep working on it

Peter

[septon]

well i got some paint on the scammell to day its starting to look the part soon be time to start on the trailer

[grompix]

Wow! Excellent work Paul.

Cheers
Chris