I'm following this thread with interest 'cause I've got one of these to do, myself.

Regarding the rear truck, it looks to me as if the rear of the truck is too low. Comparing the top of the pony-truck frame with the lower edge of the ash pan and the generator support vs a photo I took of Port LIne. Unfortunately, I don't know how to add photos to a comment or else I'd put it on for you to see.

As you say, on the real thing, the rear of the frames pass between the truck wheels, but in a model this might restrict side play unless you use prototypical curves - or narrow the frames.

The rear end of the truck should bear up against supports extending out from the frames at an angle. There is a pad at each outer corner, so the truck frame has three-point mounting so it can move sidewaysbut not up and down. Of course the axle is sprung so it goes up and down within the truck, to accommodate track irregularities. I replicated this arrangement on my Taw Valley model and it both works well and looks very convincing - no daylight visible through the truck area.

I actually have the full size BR drawings for the modified MN frames & cab support but they're far too large to scan (generally 1.5"/foot scale) and I'm not keen to send them through the post (cast & risk of loss). I'll try and dig them out and sketch some details. The underside of the rear frames is 0.67 mm below thr driving wheel centre line and the bearing brackets 2.77 mm below. Allowinf say 1.5 for the bearing pads, that would put the top of the rear of the truck 4.27 mm below dring wheel centres or about 8 mm above rail.

I'll create an entry in my blog with the photo and some sketches in the next few days - but with the current problems you might have to dig a bit to find it!

Good luck.

Dave.

The Masokits tender chassis is very simple in essence.

Here's some photos of how I built mine recently:

http://www.rmweb.co.uk/community/index.php?app=gallery&module=user&user=6879&do=view_album&album=501&sort_key=idate&order_key=DESC&prune_key=*&st=20

(NB: copy the entire link and enter it in a separate window, as page linking doesn't seem to be working correctly at present!)

Your chassis will technically be even easier, since your tender has "only" 3 axles, compared to my 4!

Look forward to seeing the sketch/photo, sounds like it will be very useful!

 

Just had another look at the truck frame,I have a feeling I have probably glued the Hornby sideframes in the wrong place! Starting to think that my original plan of trying to source a set of castings for the axlebox/springs and using them along with a modified comet west country etch might work better. No idea as to the accuracy of the Hornby cast frames...

Either way I will cut the frames back off tomorrow and see if I can realign them to get the right position.

 

Thankfully curve radius shouldn't be an issue (the layout is straight), though I think making them slightly narrower might be sensible just in case I make that continuous run expansion...

Actually, the Horby truck sides look very good to me. Perhaps re-positioning rather than replacement is the answer?

Thats the sort of thing I like to hear!

Will have a go at repositioning them this afternoon and see how I get on.

Have just tried to put some photos and notes on my blog, as promised - but I get an error message and it wont upload the photo files. I'll try again later. I have managed to scan in selected sections of the BR drawings showing the rear of the loco frames and a half-view of the rear of the cab support. You'll have to scale from the drawings based on the visible dimension(s).

Alternatively, I could just e-mail them to you, although file size might be a bit big?

Dave.