Timber

There are still a few areas where I want to improve the print, it needs the correct smokebox door and the headstock needs a slight tweak. However, rather than keep going over the same ground I am going to finish this model as a prototype and apply all the modifications in one go at the end brfore making the finished model. With this model I will produce a small set of etches. Included in this etch are two strengtheners that sit along the top of the cab side and support the cab handles. Without this etch the handles would just snap out of a plastic fitting.

With this print, the locomotive now benefits from some very simple compensation, basically there is 0.5mm of vertical play in the axles. This is very simple but the combination of the heavier motor, driving the back axle together with some vertical movement in the axles is now producing a very slow and smooth ride. A significant improvement over earlier test runs.

The revised motor and gear box all fit nicely in an updated print. I have also reduced the rivet size on the saddle, will be interesting to see if the detail is lost when painted.

I have fitted the motor unit to a simplified form of the print. Removing the footplate and cab so I can see how the motor fits. It runs nice and smoothly - much closer to what I am looking for. The wheels are temporary Scalelink products rather than damage my 3D printed Manning Wardle wheels for these test builds. Now need to see if I can fit the rest of the print around the motor,

I then decided to increase the locomotive weight by using a Hornby X7098 motor. It has an Iron Core and is considerably heavier than the High Level motor.

Thank you Stephen. In my experience all of High Level Models components are excellent and the customer service superb. That said I have made some adjustments to the engine. Something that included a motor swap. What I was finding was that no matter how well I could get the engine to run from the centre axle, it simply performed better when driven from the front or rear. With the centre axle I was pulling one wheel and pushing the other but from the rear everything was working in the same direction. Probably my poor modelling but that was what was happening. Rather than build something I was not happy with I have changed the design to run the locomotove off the rear axle. To achieve this I used a High Level HiFlyer Plus gear box

Less than an hour later I have a working engine. It is a bit lumpy but this should fix itself once run in, Next step is to rework the etchings required to finish.

Further enhancements to the design prior to taking another print this afternoon. I am following Rob's advice and simply top up the Vat rather than keep cleaning. It is a much better way of working, saving time and reducing the risk of resin spilling. I am also finding it helpful to lift the model much higher off the printer build plate, It is then easier to remove the print. With the additional space between the plate and print, I can use a razor saw to cut the supports off the raft and then carefully remove them after that,

I want to make three of these engines, Nos 58,35 and 49. I will probable take a break from MWs after that but maybe a K Class in the future.

High Level Gearbox and a High Level motor are used to power the locomotive. I have used a few of these motors and they are exceptionally powerful for their size,

Yes rivets are on the tank. Just noticed that I need two central columns of rivets rather than the one that I currently have. This is easily changed. My rivets may also be a little too big but I can easily make these smaller as I finish up

Thank you - This is the resin https://www.amazon.co.uk/ELEGOO-Washable-Printer-Translucent-Fast-Curing/dp/B08T19DTYS/ref=sr_1_5?crid=LO72CKHU295R&keywords=elegoo%2Bresin%2Bgreen&qid=1654446413&sprefix=elegoo%2Bresin%2Bgree%2Caps%2C65&sr=8-5&th=1

Another member asked me about the chimney. There appeared to be a number of differenty chimney types. This is the one I am copying. Maybe on my model the bottom collar is too high and the top too low. I will adjust for the next print,

Thank you Rosedale. I now have the connecting rods sorted and have been advised by one of our more experienced 3D printing members to try the green water washable resin. It is amazing. Almost too good as it is highlighting some errors in my artwork. On this model I have opened out the front and rear bearings so that there is a little bit of vertical play downwards. A small spring wire above will offer some simple compensation. The resin is really hard - I cannot imagine an axle wearing this out any time soon. Tomorrow I will print the version for the metal chassis.

Waiting on new etches for the connecting rods and to print some new wheel centres . Originally I had a simple compensation system but took this feature out to help get to the bottom of what was causing the binding. Once the new connecting rods are proven I will reintroduce the compensation. That said the engine runs well on a fixed chassis, the EM profile Ultrascale wheels seem to work well.

The motor is accessed via the saddle, it is now a clip fit.

Started to add some details this evening...

The connecting rods are modified to fix the binding issue. Once proven I will send for a fresh set, Push on now to fit some of the more detailing.

3D prints were an improvement. I have located the binding problem to the connecting rods .....once i have a working model I will go back and try and improve the print quality. But for now better to build something and find all the snags than keep messing around with the print.

Once I have a stable model that works I will post the STLs in the thread so that others can reuse,