Wright writes.....

[1471SirFrederickBanbury]

yes, I was very much inspired by the Dynadrive system, with the difference being that I separate the flywheel and the actual screw clutch, with the flywheel being on the motor and the screw clutch being on the driving axle.  This allows the clutch to be far more compact, as its just a screw collar that interacts with the final drive gear, and I can use a sprung clutch plate to add to the smoothness, and allow stopping to be controlled by putting the thing in reverse so that there is just enough slip.  The reason they probably didn't make it this way is because its difficult to retrofit without knowing the exact models its being fitted to, which is something that I see about later. 

Edited 19 hours ago by 1471SirFrederickBanbury
to add the part about controllability

[St Enodoc]

4 hours ago, lezz01 said:

the weight issue didn't help with the stopping issue as the loco could plough through the buffers and keep going.

Quite prototypical for a class 40.

[Tony Wright]

More on the pair of DJH A1s.........

 

 

Basic tender bodies on and Cartazzi frames in place.

 

It's vital that further testing takes place at this stage (layout or curved test track) to ensure there's clearance between the Cartazzi frames and that the cab doors don't catch the front of the tender sides on curves. 

[Captain Kernow]

There's an amusing story that I associate with a Dyna-Drive fitted loco, but it may not have been the actual Dyna-Drive, but a home-brewed similar set-up.

 

The loco belonged to my friend and fellow club member Brian Harrap and was usually used on his lovely Quai 87 layout (P87). It certainly had (has) a large fly wheel and driving it takes a bit of getting used to, especially the stopping of it.

 

Brian was also friend with the late Iain Rice, who I understand was exhibiting his 'Bodesmeer' layout at the same exhibition.

 

I understand that Iain asked Brian to borrow this loco for a turn on 'Bodesmeer'. Brian tried to warn Iain about the nature of the flywheel drive but Iain apparently dismissed this, saying something along the lines of, 'oh, I can handle that sort of thing'...

 

The next thing that happened was that Brian's loco failed to stop when Iain rather rapidly shut the power off, as it approached a buffer stop. The loco kept going and demolished Iain's scratchbuilt Dutch buffer stop!

 

I gather the loco was then returned to it's owner and not requested again!

 

[lezz01]

3 hours ago, Captain Kernow said:

There's an amusing story that I associate with a Dyna-Drive fitted loco, but it may not have been the actual Dyna-Drive, but a home-brewed similar set-up.

 

The loco belonged to my friend and fellow club member Brian Harrap and was usually used on his lovely Quai 87 layout (P87). It certainly had (has) a large fly wheel and driving it takes a bit of getting used to, especially the stopping of it.

 

Brian was also friend with the late Iain Rice, who I understand was exhibiting his 'Bodesmeer' layout at the same exhibition.

 

I understand that Iain asked Brian to borrow this loco for a turn on 'Bodesmeer'. Brian tried to warn Iain about the nature of the flywheel drive but Iain apparently dismissed this, saying something along the lines of, 'oh, I can handle that sort of thing'...

 

The next thing that happened was that Brian's loco failed to stop when Iain rather rapidly shut the power off, as it approached a buffer stop. The loco kept going and demolished Iain's scratchbuilt Dutch buffer stop!

 

I gather the loco was then returned to it's owner and not requested again!

 

I too have heard this story from the lips of Iain Rice himself so I presume that it's true. We were at scale forum at the time and discussing the Dyna-Drive system and replicating it with a second motor instead over a cuppa along with others from our area group and he regaled us with the above story. The conversation arose because the Dyna-Drive system was also being demoed at the exhibition where you could have a go with it and no one trying it out could stop the loco on a mark. We had watched it and tried it out for ourselves for some time and whilst it was a nice idea and it did replicate prototype acceleration and deceleration we decided that it was totally impractical for end to end layouts. We also tried the second motor method at the club room and found it to be much more controllable but the problems came with the fact that the traction motor was a Lima pancake type motor bogie and the free motor was a sigami and after a while the Lima pancake began to cook so we gave up on the idea. We worked out that both motors needed to have the same sort of current draw to prevent overheating of the motor with the higher current draw. The idea was sound but needed better traction motor for it to work properly. Back then the only diesel loco with a good traction motor was the Lima Class 20 which only drove one bogie. Now of course we have the same sort of system in all diesels but driving on both bogies and DCC can replicate a load with ease.  

Regards Lez.       

[1471SirFrederickBanbury]

56 minutes ago, lezz01 said:

I too have heard this story from the lips of Iain Rice himself so I presume that it's true. We were at scale forum at the time and discussing the Dyna-Drive system and replicating it with a second motor instead over a cuppa along with others from our area group and he regaled us with the above story. The conversation arose because the Dyna-Drive system was also being demoed at the exhibition where you could have a go with it and no one trying it out could stop the loco on a mark. We had watched it and tried it out for ourselves for some time and whilst it was a nice idea and it did replicate prototype acceleration and deceleration we decided that it was totally impractical for end to end layouts. We also tried the second motor method at the club room and found it to be much more controllable but the problems came with the fact that the traction motor was a Lima pancake type motor bogie and the free motor was a sigami and after a while the Lima pancake began to cook so we gave up on the idea. We worked out that both motors needed to have the same sort of current draw to prevent overheating of the motor with the higher current draw. The idea was sound but needed better traction motor for it to work properly. Back then the only diesel loco with a good traction motor was the Lima Class 20 which only drove one bogie. Now of course we have the same sort of system in all diesels but driving on both bogies and DCC can replicate a load with ease.  

Regards Lez.       

sounds like a great use for working wagon handbrakes, and maybe loco brakes, perhaps activated by an undertrack electromagnet!  That would actually be really easy to implement, just put a magnet on a bellcrank attached to the brake rodding!  I've got to try that sometime around!  Eureka!