7mm Michaels odd new kit, a Prussian T18

Steph Dale

Western Thunderer
Michael,

Unfortunately it's pretty much indestructible once set...

So it's mechanical removal if you need to get rid of it. I've had good success shaping it with wetted dental carving tools before it cures (and then polish it smooth once set), but I don't know of anything that can soften or shape it once it's hard.

Steph
 

J_F_S

Western Thunderer
Is there any way to dissolve the white superfine?
Michael

I have never needed to do this, but if I had to, I would try Xylene. It is repulsive stuff but it will soften very many plastics. I don't hold out much hope, but it might be worth a go if you have not tried it.

The quickest way to get hold of it would be to buy a tin of "Hammerite" thinners.

No promises mind!

Good luck,
Howard
 

Overseer

Western Thunderer
As an epoxy it should be able to be softened. From past experience, Methylene chloride paint stripper will do the job but it could take a month or more in a plastic bag. Grinding would be quicker.
 

michael080

Western Thunderer
Thanks for all the proposals. I tried Butanol, Toluene, Xlyene, MEK and a few minor solvent without any success. Finally, I removed some larger chunks with a freshly sharpened scraper. A steel polishing brush in my Proxxon removed the rest. A nicely 3d-printed part looks quite OK now. Never again!

IMG_20210414_173029_sml.jpg

I won't fix this ring until later. There is a lot to be soldered onto the boiler.
Right now, I am preparing the major parts like cab, tanks, bunker for assembly.

Michael
 

Steph Dale

Western Thunderer
Michael,

That looks like a good result.

I've also had a good result - the chassis for the BR78 is finished. The problem is that the file is vast and I've had to order more RAM to be able to render it...!

Moving onto an Austro-East German test coach now. How exotic!

Steph
 

mickoo

Western Thunderer
Thanks for all the proposals. I tried Butanol, Toluene, Xlyene, MEK and a few minor solvent without any success. Finally, I removed some larger chunks with a freshly sharpened scraper. A steel polishing brush in my Proxxon removed the rest. A nicely 3d-printed part looks quite OK now. Never again!

View attachment 141787

I won't fix this ring until later. There is a lot to be soldered onto the boiler.
Right now, I am preparing the major parts like cab, tanks, bunker for assembly.

Michael
Sometimes it's necessary to go backward in order to be able to go forward :cool:

Nice result :thumbs:
 

michael080

Western Thunderer
I've also had a good result - the chassis for the BR78 is finished. The problem is that the file is vast and I've had to order more RAM to be able to render it...!


I would love to see more of it.

Moving onto an Austro-East German test coach now. How exotic!


what? That sounds really exotic.

Here is what I achieved today. The bunker, cabin and tank are one piece. Looks like it managed to fit it without too many bulges and wrinkles. Next step is to remove 95% of used solder.

IMG_20210415_215049_sml.jpg

The cabin is remarkably spacious.


Michael
 

michael080

Western Thunderer
Tanks are fixed. This gave me a bit of headache because of the 5.5mm radius it should have. I had to order a bit of brass to come up with a kind of die.

IMG_20210416_204441_sml.jpg

The rod is simply soldered to the square bar and the whole thing goes into the vice. I put a piece of thick rubber below the tank and this is how it came out.

IMG_20210419_202801_sml.jpg

Not too bad. I did like the idea with the bending die so much that I ordered material for a complete set from 1 to 7.5mm radius. These dies can be used to bend 180° angles as well as longer tabs on both sides.
I know, I need to fill the groove between tank and cabin. :oops:

Michael
 

Steph Dale

Western Thunderer
Michael,

I got the RAM on the machine today and what was proving impossible now takes seconds...

BR 78 DB loco, sb modellbau drive, from the front:
20210421 v19 DB sb front.jpg

BR 78 DR/DRG loco, High Level Kits drive, from the rear:
20210421 v19 DR HL rear.jpg

It doesn't even look too bad from underneath, most of what needs to be there is shown. It's quite tightly-packed, but will fit:
20210421 v19 DR HL underneath.jpg

Wheels shown are to RP25-88 standards (what Weinert describe as 'Fine-25'), although there is clearance for standard RP25-110 wheels. Anything chunkier will hit the frame, so I'm going to have to re-tyre my stock of Fleischmann wheels. Not a bad idea anyway - I hate traction tyres.

And the Austro-DDR test coach? It's the Oberbaumesswagen: Bahndienstwagen Bauart 289. I think (although not 100% sure) that I've worked out what the Beiwagen were in the 1970s, but it's taken me a while. Various bits and pieces (including the donor carriages) are on their way to help with that project, but I'm going to have to draw up various bits of it for etching and 3D printing as it was a unique vehicle.

I hope that's of interest. When I start on the build of the 78 chassis I'll continue on my workbench thread...

Steph
 

michael080

Western Thunderer
Steph,

78246 is probably the most frequently photographed German steam engine. As you say, it has some not so typical features, but then, after 50 years of service, they are all quite unique in their appearance.
There are lot of web sites showing Class 78 pictures. A great source for pictures not only for this class is Drehscheibe Online Foren :: 04 - Historisches Forum

Your CAD model is very impressive. As I already mentioned, a lot more detailling than my ancient kit.
Just one thing I noticed: Are you planning to cut the frame along the footplate? The 78 frame is basically a huge tank with some fittings for attaching the wheels. The frame stands some 40cm above the footplate. My kit is using this fact to align the footplate around the frame.

This East-German/Austrian coach is the strangest thing I have ever seen. The GDR was always short of convertible currency, so these coaches must have been very expensive for them. I would have thought they would rather buy it from an east European country.

Bad news for my kit. I can't proceed with the boiler before I fix the smoke box saddle. The smoke box saddle can't be fixed before the frame is folded. The frame can't be folded before I have the gear box attached. And the gear box has been ordered some 6 weeks ago at a very reputated UK supplier, but hasn't been sent yet.
Let's see if I find some intermediate kit on the shelf .... oh, look at that! :D

Michael
 

Steph Dale

Western Thunderer
Michael,
All the HO scale models split at the footplate, so this frame should fit most of them - it's actually designed around the Fleischmann model.

You may well be able to get your frame formed up without the gearbox. Most of the UK gearboxes are designed to mount on the axle, not the frame. If you're using one that has a published planner or diagram, you could make up a representative gearbox (even in plastic) to make sure you've got the clearances you need.

Steph
 

michael080

Western Thunderer
After a lot of forward and backward thinking, I decided to fold the frame hoping that the desired gear box will arrive soon. It is a massive piece, almost 30cm long and shaped as a closed bar. This makes sense, as the prototype frame was holding the larger part of the water supply. However, I hope that I won't have to add anything inside this frame at a later time. The axle bearings are slaters style, but the suspension is a little strange. The driven axle is fixed, the middle axis is cut out of the frame so that it can move in all directions, the front axle can move around the longitudinal axis.

IMG_20210428_185010_sml.jpg

I have received some brass parts to replace the poor white metal castings that came with the kit. They are looking very nice:

IMG_20210428_185628_sml.jpg

cheers,
Michael
 

Steph Dale

Western Thunderer
That sounds as though it's just scaled-up from HO; I've got a few ready to run models with chassis that work on a similar principal. Unusual to do it in 0-scale though, where there are so many other options.

Steph
 

michael080

Western Thunderer
weekend update!

I don't think that this kit was born in H0 scale. Obviously, Germanys brass kit manufacturers were not looking closely to their British counterparts. Nevertheless, I have to say, the frame design is strange, but surprisingly ridgid.
Axle bearings were simple brass style. There is no provision for any hornblocks, so I used a set of matching ball bearings I have already for some time.
They were glued into the frame with Stabilit Express.

IMG_20210430_182049_cut.jpg


The buffer beams and the wheels have been prepared today. I like to use M1.6 countersunk screws with matching threads in the wheels and bushes.

IMG_20210508_215703_cut.jpg

As expected, it rolls very nicely without any binding.

The big hole in the frame is for the gear box that has been shipped some time ago. It is still lost in space somewhere at a customs office.

Michael
 

michael080

Western Thunderer
here's a little update.

The gearbox arrived, charges for customs and local forwarder handling are absurd, but that is what it is.
IMG_20210516_214949_sml.jpg

this looks nice and tidy. The motor will pretty much disappear in the monster frame. There will be plenty of space for a DCC-chip and probably for some keep alive capacitors as well.

Next step is the outside motion and this will be tricky. The piston assembly location is not marked at the frame and after some playing around, I noticed that the parts don't match. The slidebars are 4mm too short and the reverser bar is too long. I will have to compare prototype and model geometry and try to figure out how to work with existing parts. If that won't work, I will have to rebuild some rods. I think I read the term "scratch build aid" once.
IMG_20210516_214904_sml.jpg


Michael
 
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