Having never really ventured in to the world of loco wheels etc I felt that a technique of using key ways located in the wheel using a jig relative the cranks would prove successful and easy. - Wrong !
Despite my best efforts i have found out to my cost that errors have crept in allowing each wheel set to be slightly different. Not sure how this has happened but there you are - experience.
I guess the only sure way when setting up driving wheels is to use a quartering jig to check or double check the alignment.
Just wished someone had warned me. But in hinds sight when you think about it, even a slight shift resulting in the crank being a few thou out, which in linear measurement sounds peanuts, is in fact to a coupling rod significant.
Any ideas how to demount wheels with out damaging them !!
Never-the-less to my amazement I have fiddled the bushes in the coupling rods allowing the wheels to rotate smoothly. If the loco runs ok it will be at Gilling. Mean time I will make new axles so any tips or suggests please fire away… Thanks Keith.
Quartering wheels - Whoops !
The conclusion of the re-wheeling of my 1500 is, I am glad to say, success! Just goes to show how tolerant a steam loco really can be.
The engine was steamed and given a new steam certificate for the coming year on Sunday. She run much the same as ever only much quieter as I hoped having rectified many worn bits and that’s with the quartering 1 degree out! Re-quartering and coupling rod bushes are on the cards for next overhaul.
Plus the brakes now work nicely too.
Look forward to running at Gilling soon.
Keith
The engine was steamed and given a new steam certificate for the coming year on Sunday. She run much the same as ever only much quieter as I hoped having rectified many worn bits and that’s with the quartering 1 degree out! Re-quartering and coupling rod bushes are on the cards for next overhaul.
Plus the brakes now work nicely too.
Look forward to running at Gilling soon.
Keith
Keith be interested in your experiences, I am in process of doing a crank axle from solid and will have to do key ways in the wheels and axles. Axles I have made a jig for it, save buying a index head, but the wheels how did you do those, I have some ideas including broaching in the lathe either using the lathe saddle itself and reciprocating and taking out a few thou at a time, or making a broaching tool.. like (http://www.homepages.mcb.net/howe/NewsBroaching.htm), how did you get on ?
Happy steaming
I used a commercial 4mm broach with a 17mm bush. That meant boring the hole in the wheel to 17mm. The broaching bush was fitted in to a jig with a corresponding hole that fitted over the crank pin. The jig had a pinch bolt to prevent the broaching bush from moving. The broach was pushed through using a press.
Now a variation on this that I gleaned from this weekend at Gilling is to. (It relies in the fact the crank pin had not yet been fitted)...is to put a pair of wheels back to back using the broaching bush and a pin through the crank pin hole to keep them aligned, then broach them in one. This will reduce any errors between pairs of wheels.
I would assemble one wheel on to the axle complete with key and then assemble the other dry and check the quartering using a jig. when happy assemble for real using the jig and fit the key last just to lock the wheel in place. This really is a case of lots of preparation and checking and double checking as you only do it once !
Some have said they don't use keys or pins as loctite is extremely good. As a precaution they ensure absolute cleanness and use a fresh bottle. I have followed some else's method of "priming" the two surfaces first by applying Loctite and then wiping it off so as to remove anything untoward. then applying a fresh lot and assemble.
My engine run quite well at Gilling certainly didn't let herself down. The steel tyres certainly had more grip and in fact i managed to push a heavy mineral train up the bank at Erimus using pretty much max boiler pressure and lots of cut-off only to find i had blown all the oil out of the lubricator !!
Reprimed, it worked fine again but I'll need to check the non return valve.
Hope that helps a little
Keith
Now a variation on this that I gleaned from this weekend at Gilling is to. (It relies in the fact the crank pin had not yet been fitted)...is to put a pair of wheels back to back using the broaching bush and a pin through the crank pin hole to keep them aligned, then broach them in one. This will reduce any errors between pairs of wheels.
I would assemble one wheel on to the axle complete with key and then assemble the other dry and check the quartering using a jig. when happy assemble for real using the jig and fit the key last just to lock the wheel in place. This really is a case of lots of preparation and checking and double checking as you only do it once !
Some have said they don't use keys or pins as loctite is extremely good. As a precaution they ensure absolute cleanness and use a fresh bottle. I have followed some else's method of "priming" the two surfaces first by applying Loctite and then wiping it off so as to remove anything untoward. then applying a fresh lot and assemble.
My engine run quite well at Gilling certainly didn't let herself down. The steel tyres certainly had more grip and in fact i managed to push a heavy mineral train up the bank at Erimus using pretty much max boiler pressure and lots of cut-off only to find i had blown all the oil out of the lubricator !!
Reprimed, it worked fine again but I'll need to check the non return valve.
Hope that helps a little
Keith
Thanks Keith certainly given me another idea, I think the key thing (excuse the pun) is to make sure that the keyway is broached in the same place on each wheel, and as in your case my wheels are being re-used so the crank pin is still in, hence some form of jig. I didn't want to go to the expense of buying a broach for one off job, so was trying to find another way. I did find a web site with a broaching tool on it that attached to the cross slide (http://www.homepages.mcb.net/howe/Minor ... pTools.htm) I have seen similar designs as well. Using this design you could use the saddle, for the odd one off job, wouldn't want to do loads this way but works on the same principle, the issue is getting the wheel set in the same position so would require another jig. I did think of putting the wheels back to back but again a case of aligning the crank pins as they are the datum point, but I have some ideas there...
Anyway I will let you know how I get on, could be some time before I get there.
Anyway I will let you know how I get on, could be some time before I get there.
Happy steaming
Crank Axle completed
Keith just to let you know the crank axle was finally completed end of 2008, now onto other jobs to get the engine back on the rails. The crank was turned and milled from a solid piece of EN3 (cold rolled) over a period of 2 years. The steel billet was 8 inches long by 4 inches diameter to start most of it becoming swarf..
Happy steaming