TLM and 7mm

Details and announcements about our expanding range of specially designed and produced kits of resin wagons, transfers and etched parts
Post Reply
John Duffy
Posts: 94
Joined: Tue Nov 05, 2013 11:02 pm

TLM and 7mm

Post by John Duffy »

The current availability of rolling stock kits for modellers working in 7mm is somewhat limited. The Association, through TLM, has done well to address the equivalent issue in 4mm, but there remains a real lack of provision for those of us who are working in 7mm.

The following comment from a post may be of interest. It was made my Mark Dobson who trades under the name of Pre-Grouping Railways (formerly Furness Railway Wagon Company) and already had a couple of CR items available;
I am a model maker, who manufacture kits that I enjoy building and want to share with other modellers. All of my kits are manufactured in limited productions runs, giving the customer a bespoke model without having to scratch build their own.
I am constantly increasing our range as many customers commission new wagons. I will look at manufacturing any prototype as long as the initial order is for at least the 8 kits. We now also offer a kit building service for any kits, not just our own. I can now offer a 3D printing service were I can either print your 3D CAD models on our HD3D printer or we can also design parts to your specifications "If I can draw it I can make it".


There are a couple of wagon types that I might get close to needing 8 of myself, but I wondered if this might be something that could be done under the banner of the Association? Is it worth trying to assess the demand for a run of wagons in 7mm?

John
jasp
Posts: 534
Joined: Mon Aug 20, 2012 5:40 pm

Re: TLM and 7mm

Post by jasp »

As former Chairman, I feel qualified to make comment here.
This has been discussed at Committee and elsewhere.
The 4mm wagons offerings were progressed by individuals making masters which could then be turned into TLM models. These individuals were volunteers, their reward being 2(?) finished mouldings.
Mike Williams was keen to progress the 7mm side and, as I understand, is in process of making a master for an open wagon.
7mm models could also be progressed by the method used for 4mm.
Come on you 7mm modellers what about it? I would, however, suggest that you contact Mike to ascertain the suitability of your chosen vehicle
Best wishes for Christmas etc
Jim P
caleyJim
Posts: 99
Joined: Tue Mar 12, 2013 4:10 pm

Re: TLM and 7mm

Post by caleyJim »

Prepared to discuss anything which is currently in the Caley Coaches range being made available in 7mm scale. Given sufficient interest anything is possible...

My best to all at this Christmas time.

Jim
tony brenchley
Posts: 344
Joined: Sun Aug 26, 2012 9:36 am

Re: TLM and 7mm

Post by tony brenchley »

I am the person nominated by the CRA to coordinate TLM and it is time to get involved in this discussion.

I have been asked many times over the years why we haven't extended the range to 7mm wagons. The answer is simple. Nobody has provided patterns for 7mm wagon bodies that can be used for resin casting following the method used for the 4mm models. There are other sources of 7mm Caley wagon kits and bodies, or have been in the past, but I do not know the current availability of these. Perhaps somebody can tell us.

TLM started as a private venture by Mike Williams and myself. Our initial investment was taken over by the CRA and we have since produced TLM on behalf of the CRA. Mike makes most of the patterns although other people have contributed and I source the components and handle mail orders. The only limitation we have is not to duplicate any wagons in the 51L Models range. That is fair enough as they supply a lot of the components we use.

I am happy to do the same for 7mm models, Somebody needs to make a pattern or patterns for the bodies and give me some advice of sources of appropriate components.

When that happens we can have 7mm kits also.

Tony B
David Blevins
Posts: 230
Joined: Fri Nov 16, 2012 8:26 pm

Re: TLM and 7mm

Post by David Blevins »

The "Patterns" for 7mm are probably beyond my expertise, but for a person with no knowledge of this technique, how do you make a Pattern?
Maybe others are asking themselves the same question, but if not, I would like to know what is required and the process in Pattern Making.
From a 7mm Modeller
David Blevins
John Duffy
Posts: 94
Joined: Tue Nov 05, 2013 11:02 pm

Re: TLM and 7mm

Post by John Duffy »

David Blevins wrote: Wed Dec 30, 2020 11:52 am The "Patterns" for 7mm are probably beyond my expertise, but for a person with no knowledge of this technique, how do you make a Pattern?
Maybe others are asking themselves the same question, but if not, I would like to know what is required and the process in Pattern Making.
From a 7mm Modeller
David Blevins
I'm really not sure why we need to be making patterns when there is an offer to make the kits. If you make a pattern for a mould that will allow you to produce wagon bodies but you then need to consider how you will do the strapping? Etched brass is probably the preferred method, so who will draw that up? How will you produce the brake gear? Again that would preferably be etched. How about the cast parts such as axle guards, springs and buffers? Some of these items are commercially available but the strapping and brakes are not.

Instead of doing it this way, would it not be easier to hand Marc Dobson a copy of the wagon book and an order for at least eight vehicles?

If you have a particular vehicle in mind send me a PM and lets see if we can get enough interest for an order for 8.

John
jasp
Posts: 534
Joined: Mon Aug 20, 2012 5:40 pm

Re: TLM and 7mm

Post by jasp »

John
I would look carefully at the cost of 3D printed wagons as it can be expensive. The design alone will have a significant cost.
That is why I mentioned resin casting.
Jim P
John Duffy
Posts: 94
Joined: Tue Nov 05, 2013 11:02 pm

Re: TLM and 7mm

Post by John Duffy »

Indeed Jim, the current costs are around £50 each which is pretty much in line with other similar kits. It does though mean that they are available. Personally I am not in the least bit interested in how the kit is produced, I am simply looking for a shortcut as an alternative to scratch building the more numerous designs.

John
tony brenchley
Posts: 344
Joined: Sun Aug 26, 2012 9:36 am

Re: TLM and 7mm

Post by tony brenchley »

My turn to chip in again. By pattern or master I mean the item you wish to produce in quantity. For resin moulding the mould is cold poured silicon rubber. The pattern can therefore be made entirely of plastikard with strapping and bolt heads from the same material. All our 4mm patterns are made this way. A metal pattern is as good but is very much more difficult to make.

Airfix kits used metal moulds for injection moulding in the early days which were good for 10,000 units. These moulds were machined from solid metal. The high cost of this could only be recovered by producing large batches from each mould and hence for some railway items like the wagon kits they would wait until demand built up to justify making a new mould and 10.000 batch. I guess this technology has moved on and the market has changed dramatically.

There are some things to consider for patterns for resin casting. The mould is reasonably flexible and will cope with small undercuts. Our 4mm wagons are cast with solebars and as far as I can tell up-side down in the mould so it copes with the undercuts from the strapping and other detail. It also copes with solid buffers on some wagons. For the cattle wagon we needed a different approach to reproduce the spaces between the planks and hence the 5 part body. Mike Williams is working on a pattern for a CR mineral bogie, and of course, our friends in the NBRSG have successfully produced a one piece body for a similar wagon so the moulding process can apparently cope with the inset between the framing.

If we have any doubts about what is possible we always consult CMA the manufacturer of our bodies. They are always willing to help and give advice when necessary and always produce samples for our inspection before starting the main batch.

They say that any shrinkage caused by the moulding process is limited to 1-2% so that is not a problem even in 7mm scale. The moulding process very accurately reproduces the pattern. There is an apocryphal tale of a finger print on a pattern that was copied on all the mouldings. That gives and idea of the potential for fine detail but is also a warning that the patterns do need to be sharp and clean in every respect.

I hope that encourages somebody to made some 7mm patterns. As we have already heard from Jim Pairman, Mike Williams has already made at least one pattern for a 7mm wagon. I am sure he wouldn't mind me volunteering him to give advice to anybody who wants have a go.

Tony B
Mike 1
Posts: 70
Joined: Tue Feb 12, 2019 8:46 pm

Re: TLM and 7mm

Post by Mike 1 »

I echo everything Tony.B has written. I am a manufacturer in Gauge 3, but don't have anything Caledonian yet. www.williamsmodels.co.uk All I would add is that somebody should co-ordinate this at the start to set certain standards. For instance, you will probably need a standard width between inner faces of the solebars so that common parts can be used under all wagons, and standard sized holes for things like buffers and coupling hooks. Believe e - there's nothing worse than somebody making a beautiful body for casting in resin, only to find that the W irons won't quite fit and you have to scrape away at the solebars (I know!).

If Mike Williams has made a 7mm pattern he has probably already decided on those standards, so if they were published then maybe others would have a go at making a pattern. That's how I started by making a pattern for Richard DeCamin in 7mm.

Personally, I'd use Plastikard for the pattern, resin cast bodies from CMA, etched W irons with cast axleboxes and buffers. I would not go for 3D printing the whole body, though others may disagree. Once some of the fittings are available it will encourage others to have a go. We already have members that have made solid printed parts and if cleaned up they can be used as patterns for casting - you are then half way there.

I sense there is some momentum to this 7mm TLM and it will happen.

Mike
jasp
Posts: 534
Joined: Mon Aug 20, 2012 5:40 pm

Re: TLM and 7mm

Post by jasp »

Not my field but others may know if Ronnie Cockburn’s casting masters, or even moulds still exist.
These, no doubt, included CR bits.
If available, or found, these could help the 7mm cause
Jim P
John Duffy
Posts: 94
Joined: Tue Nov 05, 2013 11:02 pm

Re: TLM and 7mm

Post by John Duffy »

There is the potential for Diag 46 wagons to be available by the middle of February. If anyone wishes to join me in ordering some can they PM me please.

John
tony brenchley
Posts: 344
Joined: Sun Aug 26, 2012 9:36 am

Re: TLM and 7mm

Post by tony brenchley »

John

That is potentially very good news. Have you had sufficient interest to progress?

I mentioned possible 7mm wagons in my AGM report.

Tony B
Post Reply