adrian
Flying Squad
Nice one, didn't D1054 say the fans rotated at different speeds? Could you make one of the pulleys smaller than the other to achieve this effect?
7mm Loose Ends
- Thread starter 28ten
- Start date
28ten
Guv'nor
The thought had crossed my mind
I might just be simpler just to use 4 motors, the current draw is minimal, Im sure someone could tell me how to make them work off the decoder 
I need to draw up the motors and pulleys later this week.
28ten
Guv'nor
I had a quick look at the interior at 5.30 this morning 
the kits come with some nicely laser cut partitions, but if you want to fit glazing into the corridor partition then there is the problem of seeing glazing sheet inside the partition. Its a fairly common problem that you also get in some etched kits unless the designer has used an inner skin for the partition. So what can be done?
MDF partition and press fit glazing. using one of the little quirks of lasering ( a slightly tapered kerf ) the glazing can be pressed securely into the taper without needing glue. The crude diagram below shows what I mean
Applying the theory from the outside (only the middle partition is glazed btw)
Without the side
and from the corridor side, hopefully you can just see the reflection.
The downside is that the glazing is slightly prismatic, but Ill live with that, as I feel its worth it for being able to apply the no smoking transfers to the glazing. Im happy with the concept and it takes all of 10 seconds to glaze a partition.
the kits come with some nicely laser cut partitions, but if you want to fit glazing into the corridor partition then there is the problem of seeing glazing sheet inside the partition. Its a fairly common problem that you also get in some etched kits unless the designer has used an inner skin for the partition. So what can be done? MDF partition and press fit glazing. using one of the little quirks of lasering ( a slightly tapered kerf ) the glazing can be pressed securely into the taper without needing glue. The crude diagram below shows what I mean
Applying the theory from the outside (only the middle partition is glazed btw)
Without the side
and from the corridor side, hopefully you can just see the reflection.
The downside is that the glazing is slightly prismatic, but Ill live with that, as I feel its worth it for being able to apply the no smoking transfers to the glazing. Im happy with the concept and it takes all of 10 seconds to glaze a partition.
D1054
Western Thunderer
I really like the look of this, Cynric. I also think it will significantly reduce the sound problem with using the coarse nylon worm and gears I've been using
.
28ten
Guv'nor
I'll put you down for ten then !!I really like the look of this, Cynric. I also think it will significantly reduce the sound problem with using the coarse nylon worm and gears I've been using
It's JLTRT . The glazing is optical grade cast acrylic, expensive but they best you can get for glazing. Obviously the technique is applicable to any coach with a single piece partition. I'm not bothering with luggage racks, but some mirrors would be nice and possibly some lights.
Dog Star
Western Thunderer
Cynric, thank you for the details of the kit. Please let me check that I have this correct:-
* the kit is a JLTRT Mk1 coach;
* the "white" box contains compartment partitions / corridor screen as laser-cut MDF (2mm thick?);
* you have laser-cut some acrylic sheet to fit into the JLTRT MDF corridor screen.
Yes?
The "floor" looks like a typical JLTRT cast underframe with a brass overlay, how are the MDF parts attached to the floor? What do you get for the sliding doors of the compartments? How does you glazing idea work for the sliding doors?
Thinking (a) Easybuild Mk1s and (b) compartments and partitions of JLTRT Gresleys (which are all brass etch).
regards, Graham
* the kit is a JLTRT Mk1 coach;
* the "white" box contains compartment partitions / corridor screen as laser-cut MDF (2mm thick?);
* you have laser-cut some acrylic sheet to fit into the JLTRT MDF corridor screen.
Yes?
The "floor" looks like a typical JLTRT cast underframe with a brass overlay, how are the MDF parts attached to the floor? What do you get for the sliding doors of the compartments? How does you glazing idea work for the sliding doors?
Thinking (a) Easybuild Mk1s and (b) compartments and partitions of JLTRT Gresleys (which are all brass etch).
regards, Graham
28ten
Guv'nor
The kit has laser cut plastic(card) partitions. I just drew corridor partitions and compartment partitions (which I wont use the kit ones will work just as well ) For the doors I will use some 1mm rowmark and cut glazing to fit
The kit parts are fine, its just me being fussy. To get the tolerances required for a push fit I need to use my own parts and cut them at the same time. They will probably be attached with superglue or epoxy as there is plenty of contact area once the seats and partitions are added.
i have done some rowmark parts for Rob (Lancer) easybuild mk1s, but now with glazing. The alternative is two pieces of .75 rowmark sandwiching some clear glazing, good quality card will also work. Im a big fan of lasering high quality card the results are very good
The kit parts are fine, its just me being fussy. To get the tolerances required for a push fit I need to use my own parts and cut them at the same time. They will probably be attached with superglue or epoxy as there is plenty of contact area once the seats and partitions are added.
i have done some rowmark parts for Rob (Lancer) easybuild mk1s, but now with glazing. The alternative is two pieces of .75 rowmark sandwiching some clear glazing, good quality card will also work. Im a big fan of lasering high quality card the results are very good
28ten
Guv'nor
Im doing them all at the same time, imagine what my bench is like......BTW Cynric, how are you able to cope with several discussions going on at the same time? We have glazing... then there is the Wessie cab and fans.... not to forget the bogies. Just re-reading the posts on this page has the potential for confusion.
Otherwise -
28ten
Guv'nor
I think this is what you call 'bodge prototyping' but I chucked the dxf into the laser so I could see if things would fit the bogies and if I could use my highly technical method of checking spring deflection.....
An mdf etch the piano wire will be fitted to a guide soldered to the bearing but this is a quick way of testing the fulcrum points. Solidworks would do all this for me but you dont get a feel for the boing factor 
obviously the central fulcrum will be within the bolster
High tech weight simulation. I weighed the coach parts, divided it by two and found something the same weight...... I could go little thinker with the wire, but the main thing is that the action is quite nicely damped with a thicker wire, its just a question of cushioning the ride rather than climbing matchsticks
Next test, does it fit?
in a basic mk1
Commonwealth
and the delux etched version - yes i know its upside down)
Next step is to work out some brake attachment points and some 'pods' to attach the castings. Fingers crossed the etch will go off midweek and I can proceed with 9 pairs of bogies......
An mdf etch
the piano wire will be fitted to a guide soldered to the bearing but this is a quick way of testing the fulcrum points. Solidworks would do all this for me but you dont get a feel for the boing factor obviously the central fulcrum will be within the bolsterHigh tech weight simulation. I weighed the coach parts, divided it by two and found something the same weight...... I could go little thinker with the wire, but the main thing is that the action is quite nicely damped with a thicker wire, its just a question of cushioning the ride rather than climbing matchsticks
Next test, does it fit?
in a basic mk1
Commonwealth
and the delux etched version - yes i know its upside down)
Next step is to work out some brake attachment points and some 'pods' to attach the castings. Fingers crossed the etch will go off midweek and I can proceed with 9 pairs of bogies......
Phill Dyson
Western Thunderer
Looking good
28ten
Guv'nor
You wouldnt have an easybuild bogie lying about for some measurements?Looking good
Phill Dyson
Western Thunderer
I have some Commonwealths
Railwaymaniac
Western Thunderer
28ten
Guv'nor
That should do it the spring wire needs to be trimmed, but it should work
the spring wire needs to be trimmed, but it should work
From underneath. The U ends are not structural, and not needed for Commonwealth bogies
To make ride height adjustment a little easier, a couple of notches indicate midpoint, helping set the ride height and an extra hole will give a little pre load, but i need to calculate the exact amount needed
Dog Star
Western Thunderer
When you prepare the layout for the photo-tool you might wish to consider using the space between the solebars for some washers and rings to:-
(a) fix under the bolster to increase the bearing area of the bogie pivot bolt.
(b) increase the bearing area between bolster and underframe... washers on top of bogie and under floor for bearing surface.
(c) ring on top of bolster to provide lateral stablility to corresponding washer on floor ( or put another way, to transmit thrust between bogie and floor over a larger area than pivot bolt).
If the above does not make sense, consider how NQLTRT bogies are attached to the resin floor.... the threaded bolt wears the bearing hole in the etch frame / whitemetal bolster... the small surface area on the bolster in contact with the floor (hence does not minimise rocking of the body on the bogie).
Mr. Penn-Sayers has turned some shouldered bolts for me to minimise the wear of the whitemetal (from the thread of the supplied set screw)... and I have increased the bearing area on the bolster to circa 15mm diameter to reduce the tendency of the coaches to rock in motion.
regards, Graham
(a) fix under the bolster to increase the bearing area of the bogie pivot bolt.
(b) increase the bearing area between bolster and underframe... washers on top of bogie and under floor for bearing surface.
(c) ring on top of bolster to provide lateral stablility to corresponding washer on floor ( or put another way, to transmit thrust between bogie and floor over a larger area than pivot bolt).
If the above does not make sense, consider how NQLTRT bogies are attached to the resin floor.... the threaded bolt wears the bearing hole in the etch frame / whitemetal bolster... the small surface area on the bolster in contact with the floor (hence does not minimise rocking of the body on the bogie).
Mr. Penn-Sayers has turned some shouldered bolts for me to minimise the wear of the whitemetal (from the thread of the supplied set screw)... and I have increased the bearing area on the bolster to circa 15mm diameter to reduce the tendency of the coaches to rock in motion.
regards, Graham
Dog Star
Western Thunderer
I do not know how the JLTRT or Easybuild MK.1 BR1 bogies fit to the floor... in the case of the Gresley coaches the bogie has a w/m bolster with a hole for a 4mm set-screw, the set-screw goes into a nut-sert in the floor moulding.Don't worry Graham, I had spotted that! I shall also be bushing the pivot
The shouldered screws which have been made for me, thank you Paul, are 4mm x 1mm thread, with a shoulder of 5mm diameter and a head of 8mm diameter, hence there is a need to enlarge the hole in the bolster. The shoulder of the screw is long enough that the bolster can rotate free when the screw has tightended into the nut-sert.
The floor moulding has a flat area of around 1cm x 1cm surrounding the nut-sert, the corresponding area of the bolster is a ring, about 10mm ID and 13mm OD. I have put a 15mm diameter circle of styrene on the floor moulding to increase the contact area between bolster and floor - the thickness of the disk is that which is required to set the buffer height at the required dimension. As yet I have not been able to complete the job because I am not sure how to produce the necessary part in the required quantity. The ring on the top of the bolster is about 3mm deep and I intend to fit a styrene washer, of diameter to fit inside the bolster ring, to the underneath of the floor moulding. This disk shall not be thick enough to take any vertical load, the purpose of the washer is to act as a constraint on horizontal loads along the carriage centre line. Why? To limit any tendency for the bogie pivot bolt to rock for and aft when running.
regards, Graham