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Post by cplmickey on Jun 27, 2019 8:51:55 GMT
As I mentioned on Baggo's thread about the Winson Britannia I've been inspired by his work to start on my 9F again which has lain pretty much untouched for some time. Decided to start a new thread - one apology though, lots of words and only one picture (if I can get it to work) in this first post. In our club there are at least 3 Winson 9Fs and 3 Britannias all in need of improvements to the cylinders. The problems are well known I think. One of our clever chaps has made a shaped tip for the spark eroder to enlarge the steam passages between the cylinder and the valve chest, a jig made to hold the cylinder correctly and one cylinder has already been completed to show it all works. Yesterday was my turn. I mounted my cylinder on the jig and dropped a rod down the existing hole to find it was no where near vertical. So either the jig was wrong or my cylinder had been machined differently to the one already tackled. On getting home my measurements showed this ...  Hopefully this works and you can see the ports and passages relative to each other. The two outermost ports at the top are the inlets and they match with the 2 ports at the bottom in the sleeves. Similarly with the central exhaust port. However the transfer ports (small holes to the inside of the inlets) come nowhere near the annulars in the sleeves (shown hatched) so effectively those routes are blocked. No wonder it didn't run! The good news is that the jig used on the spark eroder would bring the port lower down the wall so more likely to line up with the annular on the sleeve. Next job is to measure the already completed cylinder and see if that is definitely the case. If so we can just crack on with the job and ignore the existing machining. Watch this space as they say. |
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tony9f
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Post by tony9f on Jun 28, 2019 5:22:10 GMT
When I was doing the cylinders for my 9F I found so many fundamental errors that I had to check every aspect of the machining as the bores didn't even run parallel to the rear face. I rectified this by shimming and grinding the rear face. As it turns out the cylinder faces were of acceptable squareness.
The steam ports were modified before the valve sleeves were fitted, I opened out the original ones and drilled an extra larger diameter one alongside.
I have to say that a lot of these problems were discovered gradually mainly because I was comparing against drawings of Britannia motionwork and came to realize that Winsons had moved the cylinders forward by 1/4" without compensating for the way it affects the valve geometry. The union links as supplied are also short and at mid stroke sets the valves back too far. In truth this probably doesn't make a huge amount of difference to the running of the loco but once you know its there it just looks wrong.
Winson also made the valve sleeves too short so they compensated with a modified valve bobbin. The designer must have confused himself at some stage because when I set the liners up at the correct positions, the original bobbin coincided with the valve ports. I put a spacer ring between the sleeves to achieve the correct positioning and widened the annular grooves to pick up the transfer ports. The original valve head width then appeared to give the correct steam lap. Anyway, I've had it running on air and it seems to work OK.
I don't think that there has been anything on this model that I haven't had to modify, remake or generally alter in some way to get it to a standard that looks acceptable and to think that it was sold as being something that could just be assembled out of the box...(Trades Description Act?)
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Post by simplyloco on Jun 28, 2019 7:43:51 GMT
SNIP I don't think that there has been anything on this model that I haven't had to modify, remake or generally alter in some way to get it to a standard that looks acceptable and to think that it was sold as being something that could just be assembled out of the box...(Trades Description Act?) You express a sentiment that has been aired many times! Precision engineers such as myself despair that the Company allowed such a poor product to reach the market place. Many years aago a friend asked me to look at his part built Winson A4. It was a mess and I gave it back to him untouched... John |
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Post by gwr14xx on Jun 28, 2019 12:35:27 GMT
I am the 2nd owner of my Winson 9F (Evening Star) - the previous owner was an ex-BR driver and he had fitted the updated parts supplied by Winsons. That was all to no avail, as the loco still performed weakly. When I bought it, I compared it to my other Winson loco (a 14XX)(I know, I'm a glutton for punishment!). On first steaming, I found the boiler capable of producing far more steam than the loco could use - so compared it to the 14XX. Even though it was supposed to be Evening Star, it only had a single chimney and blast pipe smaller than that in the 14. My first move was to open out the blast pipe diameter by 50% - then make it double chimney and blast pipe at the larger diameter. This made it perform better, but still not right. The next thing to get attention was the regulator (6mm dia, the same as the 14), mounted on a support bracket with just a 4mm dia feed port. The regulator was eventually opened out to 8mm dia on a bracket with an 8mm port. This resulted in the loco performing well at low speed but still didn't sparkle! Finally, I had to attend to the cylinders where I found the ports from the valves to the cylinders to be undersize - these were then drilled oversize and then 'squared off' by running a small long series slot drill down the corners. This work required the valve sleeves to be drawn out of the cylinders - then the main culprit was exposed - the ports that allow the exhaust steam to escape to the blast pipe were extremely small - in each case 5 holes 2mm dia. These holes were opened out to 3mm slots x 6mm long (the valves don't travel over these ports, so they don't affect the timing). My 9F now performs strongly with the larger blast nozzles providing a good draught and an ample supply of steam.
Eddie.
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tony9f
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Post by tony9f on Jun 28, 2019 13:22:04 GMT
John/Eddie,
You are totally correct about the quality of Winsons output and to be honest I did take a chance when I bought mine. I saw a part built loco that needed finishing. I have been working on it for about six years fairly steadily and with cunning and guile managed to make good most of the Winson parts. I think I have made a fairly good attempt at representing the 9F but it is absolutely not what could be called a scale model i.e. museum standard.
Regarding the cylinders, the steam port area has been more than doubled although I have left the exhaust ports as original. As I stated before, Winsons placed the cylinders further forward than they should be and that affects the position of the blast pipe. The original chimney has been modified into a double chimney scaled from BR drawings. Because the smoke box has been moved back to sit correctly in relation to the frames, I have adopted a method of securing it by a saddle clamp which will double as a seat for the blast pipe as well as sealing the bottom of the smokebox. The exhaust transfer is now through an ally block between the frames which engages the saddle clamp and seals with an o ring.
Working from the Britannia motion drawings (most of which seems to be identical to the 9F) and Greenlys book on valve gear I could see that with the Winson union link the combination lever was not perpendicular to the valve spindle at mid stroke in mid gear so these were remade. The combination levers were appalling and it was easier to make new ones.
When I air tested it, the motion turned over smoothly on about 20PSI although there was a bit of blow by (graphited PTFE valve bobbins). I have also used piston rings from a Stihl chainsaw engine as they have 44mm bores, two on each piston.
P.S. Eddie, I presume that the picture on the avatar is you. Is that a fore and aft Duggie you're riding? My brother sprints a Matchless twin in an Enfield chassis.
Tony
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Post by gwr14xx on Jun 28, 2019 15:09:37 GMT
Yes Tony - it is a Douglas - a 1929 600cc engine in a 1931 frame. Best time for the 1/4 mile standing start - 12.78 secs with 103 mph terminal speed.
Eddie.
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Post by fordfocus54 on Jun 28, 2019 21:30:03 GMT
My own Winson Brittania took almost three years and many hours in the workshop to sort out! Cylinder modifications included machining the liners to fit O ring seals, ptfe rings on the valve bobins and drilling out the ports to each end of the cylinder. The bores needed considerable honing to remove the tool marks before I binned the piston o ring and fitted cast iron ones.
At the recent spring rally at Gilling "Tornado" hauled the Thames Clyde express consisting of 11 mark one coaches for it's booked two hour slot with ease. Now I've said that it will probably fail at it's next turn!!
As an aside, It's really good to see someone who still sprints a motorcycle. 39 years ago I regularly sprinted a Methanol guzzling Lambretta, best quarter 14.5 secs at 92mph and was the holder of several British speed records. My scooter is a museum piece now but I still have it.
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Post by cplmickey on Jun 28, 2019 21:43:32 GMT
Always interesting to hear what others have done. In addition to those points mentioned I also remade the smokebox door hinges (large air gap with the originals) and a couple of rods (centres way out) and plan to do something with the drain cock actuating rod (bends rather than moves the cocks) among others. I bought the 9F when Winsons were in production as a quick way of getting a loco on the track - how wrong I was! Ian
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Post by fordfocus54 on Jun 29, 2019 10:27:39 GMT
I have heard of many faults with Winson loco's including a 9F with different sized driving wheels, a Britannia having different sized bores in the cylinders and several examples of the wieghshaft not being square to the frames. "Tornado" would not run properly until careful measurement of the valve gear revealed a 1/8" difference in the length of the return cranks!
Having said that, I now have a wonderful loco which has taken me three years to build rather than ten if I had started from scratch!
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cadser
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Post by cadser on Jun 29, 2019 10:33:06 GMT
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tony9f
Involved Member
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Post by tony9f on Jun 29, 2019 11:41:06 GMT
So the Britannias also suffered from the Winson curse. I remachined all the 9F wheels, they were terrible. They all needed boring out and new axles making as the fit was so poor, then having the tyres returned to the proper diameter and profiling. I used SMEE dimensions for this which seem very close to Southern Fed. Incidently, before all this I put the driving wheels on the mill and spent several weeks reshaping the balance weights and thinning down the spokes because I couldn't stand looking at them. 'My first little steam train toy' sprang to mind when I saw how crude they were.
The return cranks were remade to the LMS pattern and all quartering and crank setting done on the mill with the axle clamped under the spindle in a vee block and the crankpins clamped on slip gauge stacks. Trigonometry comes in very handy.
I fabricated my own slide bar brackets and used motion brackets from Model Engineers Laser. Again the Winson slide bar brackets were at different centres to the piston rods and just for good measure, the cylinders were inclined at 6 degrees and the slide bars at 7. Also the leading drive wheel coupling rod caps had very little clearance on the crossheads which means that they now have no side float.
As for drain cocks, I am using the Hewson steam operated ones as I am going to attempt atomizing lubrication to the cylinders as it all works off the same valve.
By the way, it's interesting just how many model engineers seem to be into bikes and stuff.
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cadser
Active Member
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Post by cadser on Jun 29, 2019 14:01:33 GMT
My bike days were over when i smashed my face up at the age of 13. Greaves 197 single cylinder. Wish i had it now
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Post by cplmickey on Jun 29, 2019 16:14:20 GMT
I've been into BSAs for 40 years and was secretary of the BSA Owners Club for 7 (I think). I always had a modern bike at the same time and I've had all sorts through my hands but just left now with 2 C15s. Funnily enough that's how I got into model engineering - I made all sorts of bits for the bikes including some stainless parts and when I ran out of things to make I started on a loco. Ian
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Post by cplmickey on Jul 3, 2019 21:18:55 GMT
OK one week later and it's time to sort out the first steam passage. Firstly to anticipate the question "Why use a spark eroder?". Well there are at least 7 locos in the club requiring this modification and using a small milling cutter (4mm) down a deep hole (1 inch) especially where the hole might not be in the right place is asking a lot of some of us. But also with 28 steam passages to do the spark erosion method gives repeatability with less chance of error. It takes a while but we've got time on our side. Here is the cylinder as made by Winson. Note the 4mm hole between the 2 cover screw holes (which in my case is at the wrong angle so the passage doesn't enter the valve chest in the correct position)  Onto the spark eroder. The cylinder is lightly clamped onto an angled base and the shaped copper tip is accurately set into position. You can also see a copper pipe to the right which floods coolant into the cutting area to try to clear material as it's removed.  The bath then raises and the entire workpiece is submerged in parafin. As you can see, it's difficult to see what's going on so we checked after a short time to ensure the outline of the cut was acceptable.  And here's the finished result. The passage is the shape of the copper tip and it has a superb finish.  In my case it took about 3 hours, previous ones have taken about 2. We had a lot of trouble with the eroded material not clearing and that's probably because the original hole was in the wrong place and so after the first 10mm or so the erosion tip was into a blind hole. Where the original hole was correct the waste material simply washed out of the bottom. 3 more to go. I won't bore you with more of the same so next will be the valves following Baggos procedure. |
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Post by simplyloco on Jul 3, 2019 21:49:24 GMT
OK one week later and it's time to sort out the first steam passage. SNIP 3 more to go. I won't bore you with more of the same so next will be the valves following Baggos procedure. Excellent result. No pun intended? John |
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