keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Dec 9, 2021 16:55:37 GMT
Thank you to everyone for your help and suggestions , I have a question probably best aimed at Don9f as he has built his 9f to the Warnett plans… Should there only be a 1/8” gap at the end of the piston stroke ? Is that enough room for air to push it end to end ? Total stroke is 2 1/2” and thickness of the piston is 11/16” = 3 3/16” The gap inside cylinder end covers is 3 7/16” The air inlet at the top of the cylinder bore is 1/4” wide, so gets almost covered over by the piston at each end ! I have tried your suggestion of blowing up one cylinder at a time, still without any success ! I have been working on this problem for months now and am losing the will to live !!
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Dec 9, 2021 16:59:53 GMT
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Dec 9, 2021 17:53:53 GMT
One more quick question… which is forward and which is reverse on the reverser worm ?
|
|
|
Post by John Baguley on Dec 9, 2021 18:43:17 GMT
In theory you want as small a gap as possible between the piston and the cylinder end covers to reduce the 'dead' volume at the end of the stroke. Your 1/8" will be plenty. You need a bit of clearance as the piston will move backwards and forwards slightly as the axles move up and down and you don't want it to hit the end covers.
I'm wondering if the gaps in your piston rings and/or piston valve rings are excessive when cold and allowing air to leak through? It looks as though the rings are possibly carbon filled PTFE so will need quite a big gap when the cylinders are cold. The rings will expand and the gaps will close up when the cylinders get hot when run on steam so may not leak then. It would be worth taking a ring off and trying it in the bore to see just how big the gaps are when they are cold. You also want to put the gaps at 180° to each other to reduce the leakage.
Forward gear is when the lifting arm is in the downward position and reverse gear is when the lifting arm is in it's upwards position. In your photo the gear is in reverse.
John
|
|
don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
|
Post by don9f on Dec 9, 2021 19:41:50 GMT
One more quick question… which is forward and which is reverse on the reverser worm ? Hi Keith, just to clarify something, could you possibly post a photo looking square on to the centre driving wheel, with its big end, return crank etc. It’s not clear from the photo above, but the return crank might not be set correctly. I think my cylinder covers have a 1/16th shoulder that fits into the slightly bigger diameter at the end of the cylinder.....I don’t have the drawings these days but know someone that has if I need to refer to them. This would mean a piston to cover clearance at each end of the stroke of 1/16th inch? Cheers Don
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Dec 10, 2021 19:16:26 GMT
Hi Don.. photo of return crank as requested
|
|
don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
|
Post by don9f on Dec 10, 2021 20:03:19 GMT
Ok thanks Keith, that return crank on the RH side looks “in the ball park”. As I said, it wasn’t really possible to see the return crank on the LH side in your previous photo, but hopefully its ok too. Maybe you can look at the things John asked about and report back.....also possibly to my question about setting a valve bobbin in its mid position, when both valves should be closed and see what happens when you pressurise the steam (air) inlet to just that side? Maybe you could bring it to Staffordshire 😀
Cheers Don
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Dec 18, 2021 17:26:09 GMT
I am the happiest carpenter in the world 😊😊 Thank you to all members for advising me to take the cylinders off for closer inspection … I found that the spool valve was too tight, which I remedied, then tuned them up using a foot pump top of cylinders. I attached 2 pieces of rubber tube from the drain cocks and put the other end into a bucket of water to blow bubbles into! So I now have moving wheels finally ! I have uploaded a quick video on YouTube if you would like to see it working youtu.be/0e-GKPHYWqII am now getting into the pipe work !! Is there an art to silver soldering nipples onto copper pipe ? I tried 2 test pieces and both ended up with a blob on them, I can saw it off and file it down, but this doesn’t seem right knowing I will have about 40 more to do 😕 I don’t want to waste any nipples or pipes … does anyone have any tips or advise please ? Thanks again everyone
|
|
don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
|
Post by don9f on Dec 18, 2021 18:58:57 GMT
Amongst other things, successful silver soldering needs:- The parts clean The joints properly fluxed The right amount of heat “Blobs” suggest that maybe the silver solder melted before the materials of the joint themselves were hot enough. What size and grade of silver solder were you using? I find that a good grade for jobs like pipe unions etc. is 455, which melts at around 630 degrees C. It is available in small diameters (eg 0.5mm or 0.7mm) and this melts easily into the joint....if it is hot enough! Using larger diameter solder on small parts is more difficult as it is best to get the parent metal to melt the solder, not the flame. Check this out for hints and tips about silver soldering. Cheers Don
|
|
JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,907
|
Post by JonL on Dec 18, 2021 19:10:30 GMT
You don't need as much as you think
|
|
|
Post by coniston on Dec 19, 2021 20:56:15 GMT
The technique I use (and many others) is to mix the flux into a paste with water and a tiny droplet of washing up water (this helps the flux 'wet out' on the metal). Paint flux onto the pipe and fit into the nipple. Make a ring of silver solder from thin silver solder wire (0.5mm is good for nipples). place the ring on the pipe up against the nipple. Gently warm the pipe, NOT the nipple, Brass melts at a lower temperature than copper and you want the metal to melt the solder. I heat the pipe an inch or two from the nipple / fitting. when the flux has dried and stopped bubbling turn the heat up a bit, as the copper pipe becomes hot and starts to turn a very dull red move the flame of the torch closer to the nipple, all of a sudden you'll see the silver solder melt and flash round the joint, at this point you can then move the torch onto the nipple for a short time just to ensure the solder has flowed right to the bottom of the joint. Leave to cool until black then quench in water, this will remove most of the residual flux. Then to clean pickle it in your favorite pickle, usually weak solutions of Sulphuric acid or Citric acid.
Chris
|
|
|
Post by ettingtonliam on Dec 20, 2021 2:39:13 GMT
When quenching hot pipe don't stand in line with the open end, its possible to get a very hot jet of steam/water. Personally I leave it until cold, then pickle it.
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Feb 5, 2022 14:44:22 GMT
Auxiliary vacuum ejector Hi, not been online for a while but been getting on well with the les Warnett 9f build! I am well into plumbing now, but baffled with one item. The auxiliary vacuum ejector positioned on the left side of the smoke box is a bit confusing on my plans! I bought a ready made ejector valve which has 3 connections, steam in, exhaust and vacuum. My blower pipe connects from the wheel valve in the cab to one side of the double blast pipe jets in the smoke box 1 I assume steam in on the ejector from the other side of jets 2 vacuum to outside of smoke box open ended to a cowl 3 exhaust directed to open ended pipe underneath between frames I may be totally wrong… please help ?? Has anybody else built a 9f or shall I just throw the bloody valve in the bin Any advice would be greatly appreciated Cheers Keith
|
|
don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
|
Post by don9f on Feb 5, 2022 17:13:21 GMT
Well I’ll try to help but I don’t fully understand your three numbered points....
Point 1....If it is to be a “working” ejector, it would need a steam supply from its own dedicated valve, either in the cab, or like the real things, a valve just outside the cab but operated by extension spindles from within. (The real 9F ejectors had two steam supplies and therefore two valves, one for the “small” and one for the “large” ejectors....both contained within the same body).
Point 2....Sorry don’t understand what you mean by “open ended to a cowl”? The ejector vacuum would connect to the driver’s brake valve in the cab and the train vacuum pipework.
Point 3....Normally the “exhaust” steam from an ejector is piped into the smokebox and directed up the chimney along with the air it is exhausting out of the brake system pipework. Maybe the designer’s intention here was to pass the exhaust / air out via the second connection to the blower jets?
On my own model, that second connection to the jets is blanked off and the ejector itself is just a dummy as I have never needed to use vacuum for train braking.
Hope this helps, but as always, photos help in these situations.
Regards Don
|
|
tony9f
Involved Member
Posts: 95
|
Post by tony9f on Feb 6, 2022 10:13:16 GMT
Hello Keith,
From what you have posted, it sounds like there may be some confusion between the blower and brake ejector. What you have described in points 1 and 2 are very much blower and functionally could be called an 'auxiliary vacuum ejector' because it's job is to create a draught in the firebox when the loco is stationary. Live steam is piped directly down to the blastpipe and into the blower rings and the steam jets are directed into the petticoat pipes (cowls) which due to their shape creates a partial vacuum and draws gases through the boiler. On the 9F, the brake vacuum elector is placed on the left hand front end on the boiler. It is easier to picture the ejector as a tee shape where the steam in end and exhaust end are the top bar, and the vacuum is the upright leg. Live steam is fed in from the cab controls and its action through cones in the ejector create a vacuum that is pulled on the leg piece which goes down under the boiler to connect with all the braking system pipework and the resulting air/steam mixture (exhaust) is piped into the smokebox where it is discharged via the chimney. The point is that seeing it is very unlikely that you will ever use vacuum brakes I would just forget about them. It sounds like you have bought an ejector in error (not the end of the world, might be handy one day). The most important thing is making the blower work.
I haven't seen the Warnett drawings but am wondering if he didn't intend for the steam blower pipework to run to a dummy ejector then use the ejector exhaust pipe as a conduit to feed steam to the blower jets which is cunning but I see how it could cause confusion.
I hope I haven't trampled all over Dons reply but with any luck this will clarify the situation and I hope it didn't come across as too school teacherish.
Tony
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Mar 9, 2022 19:17:03 GMT
Hi again everyone 😊 and thank you for all your previous advice ! I am in the final stages of the plumbing now, but I am stuck on the whistle valve. I’ve fixed the cylindrical valve in the cab in the upright position with the plunger at the bottom at the top. There is a side inlet or outlet near the top end & one directly central into the bottom … my Les Warnett plan is a bit confusing as to how it is piped up, do I run the steam from the Turret into the bottom, & the pipe to the whistle from the side outlet, or vice Versa? I want to get it right the first time as this is a tricky manoeuvre ! Any advice would be much appreciated Thanks Keith
|
|
JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,907
|
Post by JonL on Mar 10, 2022 15:46:15 GMT
Can you apply an airline to it? Can you show us a picture?
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Mar 11, 2022 19:01:42 GMT
ibb.co/s27GjZwHi … I can’t connect it to air at the moment ! I have posted a picture 😊 Regards Keith
|
|
keith9f
Active Member
Enter your message here...
Posts: 19
|
Post by keith9f on Mar 11, 2022 19:02:30 GMT
|
|
don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
|
Post by don9f on Mar 11, 2022 22:29:09 GMT
Looks like steam in from the manifold at the lower connection, feed out to the whistle at the upper one.
Cheers Don
|
|