Author Topic: Failed reverser UJ  (Read 2983 times)

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Offline 454

Failed reverser UJ
« on: Apr 29 2013 16:38 »
Apologies for lack of sharpness as my camera does not do macro. :-[

It can be seen where the UJ failed & started to go clunkety clunk. :'(

Steel split pin replaces 2 tiny hex head screws. Fixed in a matter of minutes. :)

Dave
454

Offline AllWight

Re: Failed reverser UJ
« Reply #1 on: Apr 30 2013 15:43 »
Hi Dave

As you have a RC Brit which has controls on both reverser and regulator. Am I right in thinking that you can technically notch back from 75% to a 40% cut off once the engine is upto speed and thus conserving your steam from the steam chest of the boiler, just like the real thing.

I know at Johns the other day you set the speed so it was ok plodding along regardless of the gradient and it ran well, but can you actually drive it as if you were in the cab reducing the cut off of the piston stroke.

What I want to know is, is this a technique you would willingly try with the engine in motion.

Now I have lit the fuse on a debate for the steam operators out there on the potential for conserving the steam to get more steaming time out of your engines at no extra cost of water or heat source(gas or coal).

Mark

Offline 454

Re: Failed reverser UJ
« Reply #2 on: Apr 30 2013 19:44 »
Yes Mark that is the idea.

Would like to get the gas turned down, safety valves NOT blowing off, regulator & gear set to plod around the track with my coal wagons in tow around my curved but level track once it's laid properly. Still work in progress.

In the early stages of using the Brit's controls it was my intention to just using the reverser servo in lieu of the hand winder tool which is not convenient when the engine is running. Just using it with the loco stopped. As you saw when the loco was on manual control. But I now realise that there is so much travel on the gear that fine control should be eminently possible.  8 full turns from mid gear to full reverse or forward gear. 16 turns between extremities. That is why I would rather use RC on the reverser.

When operating the reverser servo though it is important to have line of sight to the radius rod just so that the servo works within its free range. If it was to drive against the end stop full gear reverse or full gear forward then there is risk of the grub screws on the UJ being forced loose as the servo has bags of torque.

AshleyW has been experimenting with his Brit on the rolling road, there are some videos on Youtube.

Just need to get some more running in fine weather without showers or hail. The downpour at Timperley had a negative effect on my transmitter i.e. made it buzz! :'(  & restricted the lever travel on the throttle when the Tx got swamped with rain  :-[

The weather sadly did not allow me to explore the loco's performance envelope thoroughly but gave me an opportunity to run it manually by simply removing the control module from the cab. I found it quite controllable which pleased me very much  :)

Dave
454




Offline AllWight

Re: Failed reverser UJ
« Reply #3 on: Apr 30 2013 22:15 »
You would need to have a limiter fitted that it cannot be flung into full reverse while travelling forward, or "poling" as is the technical but frowned upon term. This can be done on the larger full size engines such as the tank engines where only a lever is used to set the valves on the cylinders but should only be performed when very nearly at a stand or stationary as it puts a great strain on all the motion. The larger engines have the screw reverser and to fling one of those into the opposite direction whilst in motion would take a great deal of skill and courage.

Mark

Offline 454

Re: Failed reverser UJ
« Reply #4 on: Apr 30 2013 23:54 »
No it's purely manual. Not foolproof. Just got to be sensible.

Dave
454

Offline AshleyW

Re: Failed reverser UJ
« Reply #5 on: May 15 2013 10:15 »
you can control the cut off just like the real thing and poling is unliklley as the servo operates very slowly.