M Menu
b 0 Items s

SLNER P2

walkingthedog

19346 posts

After all the work you have put in it would be a shame not to persevere. 

WTD ........... Nurse, the screens.

RAF96

10995 posts


Community Moderator

Keep at it Ken.

Its only engineering, there is a solution out there, just needs finding.

Going to be out of the loop in a day or so as I decamp Cyprus back to UK.

I will make direct contact with a hotmail address as my cytanet email will die on me end of this week.

Rob

Halton Brat - Running Win 10, 64-bit - RM (Pro-Pack) with Elite as Controller-A, Select as Walkabout and E-Link as Controller-B - Locos are mostly TTS. http://www.halton96th.org.uk/page21.html

gowest

936 posts

Now with the new parts installed the engine was run once more and this times things were much better it was a bit stiff but as a fellow engineer used to say “its only the newness”And after setting and resetting the valve timing and letting the engine run for 30 minutes it soon showed that the extra work paid off and it had lots of steam and power the speed at full boiler pressure was great enough to run the engine off the curves despite its slightly smaller wheels.

Here you see it as I have just managed to catch it as it nips round my small track with 2 coaches on

I did add a set of rubber tyres to the third set of drivers these were the standard Hornby tyres for the A3 and A4 and appear to fit ok.

I still have the problem with the rear truck wheels and as you can see from these pictures just how far the rear end of the chassis swings over the rails making things hard to work as the full size engine with flanged wheels.

Another problem I found was the pivoting Hornby connecting rods these seam too flexible and would lend them selves to locking up the wheels and in some cases jam the quartering or slow the engine down so a quick fix was to solder the flexible link on the rear of the rod on the second driver this was the wheel set connecting to the piston and was therefore delivering all the power to the wheels especially the set with the rubber tyres on.

The fixing points were made to fit the body to the chassis this way I could get an idea as to how thing were working out and all looks fine the steam exhaust from the working chassis was almost directly under the hole in the brass body so no real problem there the only thing to change was the very front of the oil tank which needed more of an angel to match the angel of the front of the brass body so a little filing and this fitted better.

Still thinking on the working valve system for the model i came up with this idea which is to take the drive from the Hornby valve system and extend it out the front of the valve cover and with a small double pulley and 2 rubber o rings drive 2 small shafts above the cylinders and then down to the second drivers this way as the engine moved along the small shafts would rotate and look like the full size engine but we will see as there is still much to do on the chassis and body.

RAF96

10995 posts


Community Moderator

Superb Ken

Rob

Halton Brat - Running Win 10, 64-bit - RM (Pro-Pack) with Elite as Controller-A, Select as Walkabout and E-Link as Controller-B - Locos are mostly TTS. http://www.halton96th.org.uk/page21.html

walkingthedog

19346 posts

I knew you’d get it to work. Well done.

WTD ........... Nurse, the screens.

gowest

936 posts

i have a few parts now made to the above valve system so will try to explain it ...............

 

Here I have made up the main parts of the valve drive system that I hope might work from the drawings put here a few days ago.Starting from left to right the first part is the small black valve which rotates to send steam to the cylinders at the right time it also does the exhaust side of the cycle at the same time.This small valve has a steel pin set in it and its this pin that will drive the second shaft and drive the rotating valve shafts.

The next part is the second shaft which as you can see from the picture has a slot cut in it to take the drive pin.The 2 holes in this shaft boss are for locking the shaft so that the nut on the other end of the shaft can be tightened against the pulley wheel.

Next is the bronze washer followed by the spring that keeps the valve on the valve face and the second shaft in contact with the back of the valve.Next is the gasket and the valve cover with a hole drilled in it to take the bearing housing which is the next part and will be silver soldered in place.After this is the O ring seal then the glad nut then the double pulley and last of all the nut to lock the pulley to the shaft.

 

Now we come to the output shaft 

In this picture top right hand is the drive belt below this are the 2 screws and the bracket to fix to the top of the cylinder block.The output bearing housing will be solder in place on the bracket.The shaft its self has a wing nut look to the left hand end of it, it is this that will connect to the shaft and give a flexible joint when it revolves. I hope this all makes sense. I will build up just one side of the system to see if it works if it don’t then will opt for a static build and bin the parts.

RAF96

10995 posts


Community Moderator

Good progress Ken. I can just about imagine me trying to assemble those tiny parts, but making them in the first place is well out of scope for me.

For anyone wondering about those grooves, the steam valve unit pulley has twin grooves to drive the dummy valve gears as seen in the schematics earlier in this post. The dummy valve gear drawing immediately above only has a single groove to confuse those not paying attention.

Rob

Halton Brat - Running Win 10, 64-bit - RM (Pro-Pack) with Elite as Controller-A, Select as Walkabout and E-Link as Controller-B - Locos are mostly TTS. http://www.halton96th.org.uk/page21.html

Ericm0hff

6293 posts

A belt groove for each of the dummy valves, I presume (l and r).

if it works first time, you did something wrong!

gowest

936 posts

Ericm0hff

yes you are right and I should have pointed that out that the double pulley is for 2 drive belts one for the left hand side and one to the right hand side if the pulleys rotate at the same speed as the main drive shaft which turns at I think a ratio of 4 to 1 then the outside valve shafts will look to turn at the right speed to the original design 

Ken

gowest

936 posts

The parts have been installed on the engine which might make things a little clearer.By turning the wheels I managed to get the belt to drive the dummy valve shaft but only by crossing the belt to give it more contact on both the pulleys but as these are very oily engines I can see a problem with belt slip so even now this idea may not work as we still have the 2 shafts to build and a middle bearing block to connect the shafts down to the main driver and its gear box.Gears might be the answer any ideas?

This picture shows the layout of the valve system and should it work the model valve drive will be covered by brass sheets as the picture here so you will only see the small shafts rotating down to the driver.In this picture you might just also see the drive coming off the third driver via a crank to the 2 oil pumps on the running board. This appears both sides of the engine.

With the body in place the valve drive system has a nice lot of clearance with no problems there 

I will carry on with the assemble of the valve system and try to run it on compressed air if that works then a steam test one thing will need changing is the bracket as this is not strong enough to take the load of the drive belt.

I’m off to Lundy island to find the lost railway and 2 crashed Heinkel bombers so will not be online for a bit Ken

Please create an account or login to reply.

Forum Rules

  • The Hornby Forum is intended for discussion of all things model railways. Primarily a place for newcomers to ask questions and seek assistance from like-minded individuals, the Hornby Forum offers a user community for all those interested in railways.
  • Discussion of non-Hornby brands is allowed, however, active promotion or advertising of these brands is not permitted.
  • Please keep in mind that the Hornby Forum is a publicly viewable space and you should never post personal information (including email addresses). 
  • While every effort is made to contact you before any censorship, we reserve the right to amend or remove any content without explanation.
  • All customer service enquiries should be directed to Hornby Customer Services.

Useful Links

Forum Guidelines

Membership Restricted Product