Live Diesel-Mechanical 1/12th scale

Sekim wrote:

Did you consider cone clutches where you have used dogs and have you any detail pics of the dog clutches you could share?  I have a chum with a working “Smiths of Rodley” model steam crane and this uses cone clutches for all the main actions/winches etc.  They engage, drive and disengage cleanly and with your gate gearbox should work a treat.  Perhaps a thought for your next engine!

 
Hi Mike,
 
No I didn't consider cone clutches.  I'm using two-dog dog clutches.  These gears aren't for changing on the move.  The flywheel has a tapered clutch.


 
I'm looking forward to moving on from the gearing now, and getting onto the other things like the rods and the bodywork, and perhaps new frames.
 
Best wishes,
Dave.

I've had to extend the frames forwards 10 mm.  The front of the carburettor was directly inline with the front buffer beam.  The engine couldn't go back any further...
 
The chassis with one side frame off for lengthening.

 

Now the frame is 10 mm longer.


 
The new graceful proportions.

 
Best wishes,
Dave

Can´t wait to see the finished product!

The rear suspension is far too bouncy.  Some things are good being bouncy but not this loco. 



As a trial I had used a gauge 1 inside frame type suspension, it doesn't look the best on this application. 

Here we are, I'm making horn plates for a new suspension arrangement on both axles.



Best wishes,
Dave.

Milling the axle box slots out of the first frame side.




Here's the new horn plates in position on one of the frames.

Front


Back


My project this week is to make some axle boxes.

Best wishes,
Dave.

Here are two new axle boxes.  I shall think about the springing and the keeper plate before I start on the other frame.



Best wishes,
Dave.

I had to use coil springs as I couldn't fit leaf springs in. 






Now I have to do it all over again for the second frame.

Dave.

That's just great Dave. Is the lever arrangement the final one or just for testing? Do you have an overflow outlet in your main transmission box to let the engine oil out? The idea with the horn plates is really interesting. How many leeway is there between the axle block and the horn plates? I'll keep watching

What a wonderful piece of mechanics! I am amazed! Are you a clock builder?

Tacbob wrote:

That's just great Dave. Is the lever arrangement the final one or just for testing? Do you have an overflow outlet in your main transmission box to let the engine oil out? The idea with the horn plates is really interesting. How many leeway is there between the axle block and the horn plates? I'll keep watching

Thank you Lorenz.  The lever is still temporary, I think I will connect it to a lever inside the cab.  I need to get the chassis rolling first. 
No overflow yet.
The axle boxes are quite a close fit in the horn plates, but have about 0.25 mm endways movement.

Saint-Oblas wrote:

What a wonderful piece of mechanics! I am amazed! Are you a clock builder?

Thank you.  No I'm not, these are quite chunky mechanics!    

Best wishes,
Dave.

Finally the chassis is rolling again...  I had to modify the clutch actuator shaft to allow full travel on the front axle boxes (the wheel flanges were contacting it) that took three days after I had worked out what to do!  I've switched the fasteners to mushroom headed screws, I think they look better.



I need to make slightly longer axles now as the axle boxes stand out further than previous bushes.

There are a lot of no longer used holes in the chassis that need filling...

Best wishes,
Dave.

Well, I've managed to fill four holes with some more screws.

Here's a cover for the lower gears, I imagined that line-side vegetation would get caught and crunched up by the large 1st gear.



The cover fitted.



Looking down on the cover, we could fill it with oil too.



Best wishes,
Dave.

Awesome engineering - can't wait to see the videos of it running 

GWhizz wrote:

Awesome engineering - can't wait to see the videos of it running 

Thank you!  Well, we are one step closer.

Here's the footplate, all one piece, lots of sawing and filing.





It weighs in at 3.4 Kg (7 lb 7 oz) now.

Best wishes,
Dave.

dtsteam wrote:

1. Your workmanship is absolutely pin-sharp and a joy to see. It will be one of those models which would be a shame to paint.
   

Thank you!  They never work as well after painting either.

I had a big shock when the cab was mocked-up in card today, it's enormous!





Best wishes,
Dave.

Hi Dave,
A real beauty. I wish I'm that far. Can you guess what pressure your clutch is working with? What servo have you planned to use?

Tacbob wrote:

Hi Dave,
A real beauty. I wish I'm that far. Can you guess what pressure your clutch is working with? What servo have you planned to use?

Thank you Lorenz.  I've just been pressing down on the kitchen scales, I'd say I was using a force of 5 to 6 N on the lever, the lever magnifies the force by about 3.5:1  So perhaps 18 N or 1.8 Kg in total.  I'm planning on keeping the loco fully manual with perhaps all the controls on the rear of the cab.

Best wishes,
Dave,

Hi Dave,
Many thx for your reply and your measurements. Do you have a loop track?

Tacbob wrote:

Hi Dave,
Many thx for your reply and your measurements. Do you have a loop track?

Hi Lorenz, yes, it's a simple loop.

Best wishes,
Dave.

Slow progress recently.  Ended up cutting out the cab pieces by hand after wasting time and money on a scroll saw.  Then spent a week waiting for a metre of 1/8" brass half round beading to arrive; to edge the window openings and doorways.  The metre length wasn't quite enough, but the front and both sides are done.  I've got some more on order for the rear sheet.  It's quite an enjoyable process soft-soldering the beading.  The most important part is annealing it first, otherwise it is far too stiff.

I need to have the superstructure finalised so that I can progress the exhaust, fuel tank, and controls.



Best wishes,
Dave.

Here we are.  The cab is well on the way to completion.  Soon it will be time to start on the bonnet.



Best wishes,
Dave.

A joy to behold. Hope we see it in action soon.

Here we are, I've bent up the bonnet in the wood vice.  I like the end-on view, it's got that menacing look of the truck in "Duel" (I could put some battered old engine nameplates along the buffer beam of victims, lol).







Best wishes,
Dave,

Just fantastic. You got a nice work shop.
Will you have space for the fuel tank in the loco?
How many castor oil do you add?

Really a nice piece of craftmanship! I assume you have a well-equiped shop, and sure you know how to use it!

I see that you too have difficulties in getting raw material. In France it is quite the same and I have sometimes been waiting months before being able to get some very common material, but I do not want to purchase 6m if I only need 20cm! I have sometimes to beg from craftman shops that are become rarer and rarer!