|
Post by keith1500 on Jan 17, 2021 22:30:19 GMT
Big nasty surprise today. Having got a satisfactory result with the expansion link bracket I thought I would go back to the prototype side and do that one. Started to do the convertion by drilling and tapping a 2 BA hole and surprise! Walschaerts valve gear by GL5Keith1500, on Flickr
|
|
|
Post by keith1500 on Jan 17, 2021 20:46:12 GMT
|
|
|
Post by keith1500 on Jan 16, 2021 15:57:20 GMT
|
|
|
Post by keith1500 on Jan 15, 2021 22:54:14 GMT
Very nicely done. Great series of photos.
|
|
|
Post by keith1500 on Jan 14, 2021 12:56:00 GMT
I fabricated a regulator and like you tuned the handle. Then upon parting it off I ended up with a short spigot which was rather useful. I drilled a small locating hole in the end of the lever and silver soldered it in place.
My handle was plane Jane in comparison to your nice bit of work.
|
|
|
Post by keith1500 on Jan 14, 2021 12:31:42 GMT
Having played around with the simulator and got some reasonable results I decided The next step is the measure some of the movements and compare them with the design. So the next logical step is the set the return crank. I made up a jig. The crank is located in one hole. The crank pin finds the other hole. One advantage of having made new crank pins for this project is I could allow a few thou for a witness. Finally the pin locates in the axial centre. It’s ambidextrous so can be used on the other side. Walschaerts valve gear by GL5Keith1500, on Flickr Walschaerts valve gear by GL5Keith1500, on Flickr
|
|
|
Post by keith1500 on Jan 10, 2021 21:03:40 GMT
Nice bit work. I am really inspired as my current project to sort Walschaerts on a friends chassis will lead me to sorting out the valve. The valve is so ridiculously wide that it really needs a guide similar to what your have identified.
Hope you post more soon.
Thanks Keith
|
|
|
Post by keith1500 on Jan 9, 2021 12:45:47 GMT
I am pleased to say I now have a nice rolling chassis or frame with which to play with and so I can now return to the original task of making a set of valve gear for it. Walschaerts valve gear by GL5Keith1500, on Flickr I was quite surprised how far out the quartering and also the throu between the cranks was, it was a wonder it went around at all! ....or may be that’s my lack of experience. Comparing the two wheel sets this was the difference. There is a fair gap between the engineers square and the brass ring which corrects the crank to be the same diameter as the other crank. Walschaerts valve gear by GL5Keith1500, on Flickr
|
|
|
Post by keith1500 on Jan 8, 2021 22:44:57 GMT
Well you have cleaned them up nicely.
I had forgotten about the marvels of Model Engineers Laser. Makes sense to crack on with something you do enjoy.
|
|
|
Post by keith1500 on Jan 8, 2021 21:41:33 GMT
Those links have a sweet shape towards the tail pin. Very nicely done.
|
|
|
Post by keith1500 on Jan 8, 2021 7:05:07 GMT
Wow that guy is an inspiration. Some amazing work. Thanks for sharing.
The first thing I am going to make is the leather soft jaws.
|
|
|
Post by keith1500 on Jan 7, 2021 22:12:40 GMT
Wheel with new crank pins and new axial. Walschaerts valve gear by GL5Keith1500, on Flickr I just have to pin the wheel to the axial. Should I do a completely fresh hole or gently open out an existing hole?. I am thinking a fresh hole and carefully paint over the old? Also took a leaf out of David’s book and cleaned up the spokes and excess flashing with a file. Two coats of Hammerite primer, ready for spraying. Keith
|
|
|
Post by keith1500 on Jan 4, 2021 9:17:08 GMT
The throw on the main cranks was out considerably when compared to the coupled wheels. I felt this had to be corrected rather than bodge the coupling rod holes which are already slightly elongated ! I set up a mandrel on the mill. I recall Roger using this method so took a leaf from his book. Walschaerts valve gear by GL5Keith1500, on Flickr I figured I could move the pin back by 12 thou and simply make a new crank to suit the hole. The hole was blued so as to show when the boring bar was cutting all around. Walschaerts valve gear by GL5Keith1500, on Flickr Then the cranks where checked on the surface table using the height gauge and a dial gauge to show when the surface gauge was being deflected upwards and by what amount. To do required a test pin fitting. The outside diameter matching the coupled wheels so as to keep maths to a minimum. Walschaerts valve gear by GL5Keith1500, on Flickr I wasn’t satisfied with one wheel and so had a second go. Fingers crossed all this theory works outs. I wonder how many measure their cranks before assembly or just hope for the best?
|
|
|
Post by keith1500 on Jan 3, 2021 23:01:32 GMT
I wouldn’t rush in to painting those bands. I think they look alright. Leave them a while the finish might grow on you.
|
|
|
Post by keith1500 on Jan 3, 2021 15:21:36 GMT
I have been making some progress with this project. Having tried out a few ideas and made some prototype components for the valve gear I became increasing frustrated with the way the chassis rolled. It had that horrible characteristic of binding every quarter. I suspected the quartering but, if my diagnosis is correct it’s the throw of one of the crank pins. Walschaerts valve gear by GL5Keith1500, on Flickr
|
|
|
Post by keith1500 on Dec 31, 2020 14:48:23 GMT
|
|
|
Post by keith1500 on Dec 31, 2020 14:38:57 GMT
Fitted new control board to central heating boiler. While in bits cleaned out flue ways in heat exchanger and cleaned burner tray. All working nicely again. Fan heater returns to workshop and so do I !
|
|
|
Post by keith1500 on Dec 25, 2020 17:31:15 GMT
Tried to fix the boiler pcb... check mate to the boiler!
|
|
|
Post by keith1500 on Dec 23, 2020 6:48:10 GMT
Question: are the offsets machined in or are the rods simply bent at either end.
|
|
|
Post by keith1500 on Dec 22, 2020 12:51:38 GMT
Just wondering whether or not a radius rod should have an offset of say 1/8 to 3/16 inch in it rather than be dead straight?
I recall The 2-8-0 Gresley design has a slight offset.
Any thoughts would be appreciated.
|
|