Member postings for Dave Smith 14

Stew

PM me your email address and I will send you some info I have which explains the process very simply.

Dave

I am involved at the moment in changing the status of the model railway club of which I am chairman and is currently a non incorporated organisation. The main reason for this is that our landlords are moving from a service letter agreement for our room rental, to a commercial tenancy. We have decided change to a Company Limited by Guarantee, having considered changing to a charitable status for a couple of reasons:

1 We are bunch of people who build model railways, we do do not anything which 'benefits the community' as charitable status requires you to do.

2. We have substantial assets and if the club is dissolved then the assets are distributed amongst the members. This is not permitted if you are a charitable trust, the assets must be passed to another organisation to use.

3 We think it is easier to take the potential hit on taxation of any profit than the additional hassle that goes with being a charitable trust brings.

We will classed as a micro entity which makes the annual accounting much simpler and does not require the accounts to be audited under the small company rules.

Acetone or IPA.

Dave

I am 6ft and have Warco stand. Height is fine for me. Without a stand I would set it at kitchen worktop height.

My experience with the castings on my Aspinall is unless they are lost wax from a known set of dimensions, I would only use castings if it there was no other choice (like wheels). I would either fabricate or machine from solid. For sure on my next loco that is the approach I will be taking.

There is a study that found Parsnips contain carcinogens! How many of us have stopped eating them. Seriously provided you use a suitable mask and disposable gloves, with the quantities you are probably spraying something else is going to kill you first.

Bob

Yes you just push the rail through the roller. Can be done by one person or with help. It is large scale version of this. The rollers are spaced relatively further apart though.

Make a base from plate, thick sheet or even wood about 400 mm long. Get three bearings about 20 mm OD M8 bolt. Bolt two bearings to the base at the ends of the plate. The centre bearing needs to be positioned centrally between the two outer bearings such that its position can be adjusted in the transverse direction. Place rail between the three bearings and adjust to put a gentle curve into rail. Run the full length of the rail through the bearings and it will put a curve into the rail. Continue adjusting until desired radius is achieved. If you over bend just reverse the rail and adjust it out. We use a rail bender like this at our club.

Phil

The joint is basically as per Don Youngs drawing. The only change I made was to the outer wrapper to include the little 'ears' that line up with boiler tube flange. The throat plate is double flanged, hopefully this picture will explain the joint, note the bottom of the throat plate and the wrapper have not yet been trimmed to length.. If you want more detail let me know.

I used plywood for the flanging on my Aspinall and 3D printed formers for outer and inner wrappers, which work a treat. I have also used a 3D printed former successfully to reshape one part when I got plywood shape wrong.

Hope the following photos may be of interest to some people.

First couple of photos show the 3D formers.

This photo shows the laser cut and 3D printed drill jig I made to get all the bits in the right place.

Where I am

Trial fir in chassis.

Michael

Ask the same question on MECH.

MECH

Dave

I did say in a limited way. I agree with 2D data that there are compatibility issues with fonts, drawing borders etc but the important bit which is the geometry does not normally have problems. It does not take long to recreate dimensions add a drawing border any way. With 3D models on the 'good' CAD systems 3D model transfer is not a problem. I transfer models between CATIA, SE and occasionally F360 without any issues. The first photo shows the boiler for my Aspinall which was modelled in CATIA, the second photo shows the boiler assembly after conversion to a STEP file and then imported into SE which took about 5 mins Depending on the system and how you create the STEP file it can be made to bring all the parts in their correct relative position.

So for Ian this may be useful to know if he needs to import a complete assembly.

I was not advocating people use multiple packages, just answering a question if systems can talk to each other which they can. I would always advise if possible to chose a CAD that does what you want of it and stick with it.

By the way I have used CAD systems continuously since the early 1980's where I was involved with the introduction of the first system into Rolls Royce, Computervision CADDS 3 if anyone remembers it. I then went onto to use CADDS 4, CATIA V3, V4 and V5 which is my current weapon of choice.

All the 'good' CAD systems can talk to each other in a least a limited way. This is either achieved using native translators embeded in the software or importing geometry using dxf for 2D and either IGES or STEP for 3D. STEP is the preferred file format for 3D. As Paul says with regards to 3D geometry you get a 'dumb' solid. This means it has none of the history as to how it was created, as this is unique to the parent software. However a dumb solid can be modified, have materials allocated etc you just cannot deconstruct it and it is still orrientated correctly relative to its origin axis. So although parts in an assembly may lose their relative positions, it is an easy task to reposition them. (I have the tee-shirt on a full model of a 5" gauge loco). STL files are not designed to be modified as such and are difficult to manipulate, some CAD systems have functions to change the mesh to a surface model, which in turn allows a solid model to be created (CATIA has this function).

This is what I use. It is simple scissor frame pivoted onto the lower frame and upper frame at one one. The other ends have sealed bearings run along the upper and lower frames. A car scissor jack provides the movement to raise and lower the upper frame and is arrange to give around a 2:1 motion ratio. No fancy machining needed, cheap to build, does not take up a huge amount of room and the loco can live on it in the workshop or garage which at present my Super Simplex does. If you want some more detailed photos let me know.

Edited By Dave Smith 14 on 11/10/2021 18:52:30

Ron Laden's Class 22 build thread will help you a lot as it discusses the choice of motors, batteries etc.

Class 22 build

Also look at the photos of this Charalatan Station Road Steam had for sale. It shows how the drive train is arranged.

Station Road Steam 08

For anyone interested a fairly comprehensive history of the origins of CAD.

Table of Contents: CAD History

I bought a 5kg bucket of it from Ebay for about £10.

Daniel

Also worth asking the same question on the Model Engineering Clearing House forum, which tends to have a lot more locomotive based people posting than here.

Why do so many model engineers knock anything that does not conform to the norm? I think it is a nice elegant piece of design, that has a practical use and if that is the value of the prize good on him, because it will pay off a huge amount of his university debt. Remember we are talking here about product design (he will probably go onto to design white goods) not mechanical design which is a whole different ballpark.

Caravan water pump (about £7 on the net) through the blow down? That is what I use on my Super Simplex and other clubmates do.