Friday, July 1, 2022

Locked in the Vertical Position

Annoyingly although I had the day off today I only managed to grab about 10 minutes to work on Ivor. Fortunately that was long enough for me to sort out how to lock the gearbox in place whilst allowing it to still be removable.
It's a littly tricky to see in that photo, but essentially I took a short piece of brass strip and put a 90 degree bend in it. I then soldered that to the inside of the chassis with it pushed up against the gearbox. I made it big enough that with the geabox in the right place it can't rotate on the axle, but if you remove the axle you can work the gearbox out without too much difficulty.

You can see exactly what I added a lot better in this photo with the gearbox removed.
I know it's quite a simple solution but it seems to work so fingers crossed.

Thursday, June 30, 2022

We're Going To Need A Bigger Hole

As expected once I'd bolted the motor to the gearbox there was no way it would fit through the hole in the footplate, at least not when the gearbox was mounted on the axle as it was impossible to get the angle right, even with the gearbox free to rotate around the axle.

The solution was to use a jewllers piercing saw to lengthen the hole in the footplate by about 9mm at which point I could slide the parts together nicely. This was possible even with the gearbox held vertically with some masking tape; I still need to sort a more permanent way of holding it in place.
I know it's not the best of photos but hopefully you can see that the hole is longer now. You can also see that the motor shaft will certainly need shortening as currently it would protrude into the cab which would stop me fitting the body and chassis together. That means that as I expected a flywheel is probably out of the questions but we shall see exactly how much shorter it needs to be, once I've built the cab.

Just to prove that things do fit, here is a terrible video of me slotting the footplate over the motor and into place: it can't be that bad if I managed it one handed while holding the phone to film with the other hand!

Tuesday, June 28, 2022

You're Not Thinking Fourth Dimensionally

Having mentioned in a previous post that I'd carefully measured to ensure that the gerbox and motor would fit, I've now discovered a slight flaw in the plan.
That is the drawing I made which combines the plan of the loco from the instructions, the gearbox, and space for a nice chunky Mashima 1620 (16mm x 20mm) motor. As you can see it all fits nicely. Unfortunately not only was I not thinking in three dimensions, I wasn't fully thinking in four dimensions either.

There was nothing wrong with my planning and I could build the gearbox and the motor will fit inside the boiler just as shown. The problem is that I didn't consider how I would actually get from assembling the chassis with the gearbox and motor to the point where the body was fitted.

Yes, I'd checked that the gearbox would fit between the frames but the mounting lugs for the motor are wider than the gearbox. This means whilst I could assemble the chassis with the gearbox in place it would never fit through the hole in the footplate so I wouldn't be able to slot the body on. Fortunately the gearbox has two mounting points, so I could remove the lugs and it would fit through the chassis.
Except of course that the motor is also way too wide to fit through the chassis; in fact to make it fit I'd have had to cut off the rear of the splashers and left a much weaker chassis. Fortunately I have a Mashima 1215 motor in stock which will mount to the gear box and fit through the hole in the footplate... at least it will on an angle. I need to bolt it to the gearbox first and see if it will slide in or if I will still need to lengthen the hole slightly. It's a double shafted motor and while a flywheel would be nice I think I'll need to trim the extra shaft down to help fitting it in. We shall see.

Oh and I still need to work out how to keep the gearbox vertical as currently it will spin freely on the axle. Of course not being part of the kit there are no nice mounting brackets, but I think I have a plan to solve that problem

Saturday, June 25, 2022

HiFlier

Having got the chassis for Ivor to the stage where it rolls along the track, I wasn't entirely sure what to tackle next. This is complicated slightly because the step by step instructions (well series of photographs) don't include some elements of the build. Specifically they make no mention of motorising the model. This is because the kit doesn't contain a gearbox. The schematic view in the instructions suggests fitting a "Mashima 1015 or equivalent motor" vertically between the axles driving the front axle via a simple gearbox containing a single worm/gear arrangement. Unfortunately it doesn't make any suggestions as to where you might source such a gearbox.

After designing my own wheels I didn't fancy trying to design a gearbox myself (although I think I could probably have done so) so went hunting for an easy option I could buy. In the end found a gearbox from High Level Kits which seemed to be a good fit: specifically the HiFlier.
The photo shows the parts laid out ready for construction. As you might be able to spot this is a sligtly more complex gearbox than the one I described being shown in the instructions, and will place the motor horizontally inside the boiler instead of vertically. Given the good diagrams and measurements provided by High Level Kits for their gearboxes I'm fairly certain it should all fit, but it seemed sensible to make it up first so that if I do need to modify the body in anyway I can do that while I build it rather than afterwards.

So far all I've done is gently open out the holes in the etch to take the bearings and shafts, and gently reamed the bearings and final gear to fit the 1/8" axle I'm using -- the parts are designed for 1/8" axles but also point out that the parts are all designed as "finish-to-fit" so they all need opening out slightly to give a nice fit rather than being sloppy. So far so good, next step will be assembly and testing with the Mashima motor I bought (can't remember the size I went for but will measure it for a follow up post).

Friday, June 17, 2022

It Rolls!

So after the apparent success of turning one working axle I had a go at making a second. Amazingly all went to plan, and more importantly they fit next to each other in the chassis.
As you can see even with the smaller wheels than the instructions suggested there isn't a huge amount of clearance between the two axles.
More importantly they also fit properly, albeit only just, within the splashers and it rolls!

Thursday, June 16, 2022

Two Wheels, One Axle

Having messed up the first attempt at axle making I spent some actual time thinking through the process a bit and came up with a plan. This essentially involved keeping a long piece of 1/8" axle steel nice and straight on the lathe using a fixed steady (a recent purcahse and this is the first time I've tried it) and then lightly makring the sections for an axle on the rod using the cutting tool. I could then cut the axle from the rod and face and turn with just the end protruding from the collet chuck. Unfortunately I forgot to take any photos while marking up the axles, but here you can see the end result (after I roughly cut the two sections from the rod).
So if you look at those you can see I roughly cut them from the rod, so from each end I need to face off at the first line, and then turn down the rod between the first and second line. This will give me a stepped axle which should enforce the correct back-to-back measurement; although each end needs turning down differently to match the insulated and uninsulated wheels.

So far I've only managed to do one axle but......
And just to prove that they both fit on track and roll



And you have no idea just how happy I am with that!

Monday, June 13, 2022

Actual Progress

Whilst it looked as if the new wheels would indeed fit inside Ivor there was only one way to find out.... turn some axles and try fitting them.

I ended up messing up the axles, both sorting the back-to-back measurement and reducing the diameter slightly too far but....
To my eye that looks pretty good but.....
there is still very little clearance when viewed from beneath. I'd already bent the hidden part of the splashers when trying to fit the original wheels and I would have still hadto do the same for these wheels which just shows how little space there is and still brings into question how anyone is meant to build the kit given the instructions.

So next step is to re-think how to turn the stepped axles to get them the right size, but this small step feels like real progress, so I'm happy.