Tips for machining 5" gauge wheel sets.

[02jcole]

Hello All,

I am after any tips for maching the wheels and axles for my 5" gauge, 5 plank coal wagon. I am roughly following doug hewsons design but beefing up some of the dimensions so that you are able to sit on it!

I have already machined 4 blanks out of flat plate as this was the only materila I had. The wheels are quite plain and simple with 4 holes, a slight recess on the front and a boss on the back. I planned to machine the wheels oversize and then skim them up when they have been loctited on their axles. I plan to use the standards shown in Tubal Cain's handbook.

Has anyone got any tips for turning these wheels and axles?

Regards James.

[standardsteam]

Just to note that the GL5 wheel standards are on line if you are interested at www.gl5.org/pages/standards.php

At the moment I mainly kit-build so I can't offer sound advice, but when I last had access to a lathe I turned my wheels off the axles and ground up a separate tool for the tread and finished them all to size with a light skim (obviously some risk of chatter with a broad tool) by replacing each in turn on the mandrel for the final cut. Other more proficient builders probably turn to size on axles using a live/rotating center I assume. I just loctited mine on being only for a wagon, I didn't think the run-out would be all that critical.

[Tony K]

James, I'm not sure of your skills, but perhaps I could just kick this off and some of the others can then pick it up.
I think your plate will need to be something around ½" thick and the wheels will be something like 3" diameter. The axles will be something like 5/8" diameter, machined down to ½" at the ends for fixing the wheels on. I would machine the wheels before fitting them to the axles. I have used two methods of machining wheels of this type.

1) I machined a mandrel to support the wheel while machining, which was held in a collett chuck, but could have been a normal 3-jaw chuck. This was a holding hub simply 2” long, 1" round mild steel with the end turned down to ½" - to fit the wheel on - threaded to accommodate a nut and washer to hold it in position. I also tapped a hole in the outer end of the boss at about ¾" from the centre. This was to put a small bolt through the wheel blank to prevent it rotating - conveniently positioned where one of the holes in the wheel would be. Maybe this could be avoided by applying a slight taper to the shank and corresponding wheel centre. It is best if you can machine the mandrel and then do the work without removing it from the chuck - ensures concentricity.

2) On another occasion I machined a wheel by padding out the blank in the chuck to allow machining one side, then turned it round to machine the other.

Turning the wheels to the maximum measurements of the profile and then fettling them from there is my way. Finally, put the 2 degree profiling on each wheel, but do them all to about 2 thou over diameter, then set your final cut on one wheel, do it, leave your cross-slide set, and then do the final cut on the others - that way they will all be exactly the same diameter.

The axles are relatively easy, just turned between centres.

There we are James – there are much more qualified and able people on this site – perhaps they will chip in and we can both learn – I hope they will.

Added after: Sorry Standardsteam, I wrote this before I saw your post.

[jgb7573]

That's pretty much how I machined my 5" diameter cast iron wheels, though my mounting 'jig' in
the lathe was a piece of plate a bit smaller than the o/d of the finished wheel with a machined peg mounted in the centre. The wheels could be put on and taken off this at will with no unacceptable loss of conentricity. I relied on bolts between the spokes to hold the wheel blank to the plate.
I used a form tool foir the flange and root radius made from hardened and tempered gauge plate. I'm not sure how well this would work with steel.
The backing plate came into its own again doing the crankpin holes. The plate was fitted to the milling table with the peg under the axis of the spindle. I moved the table over the amount of the throw, mounted each wheel casting in turn and machined the hole for the crankpin.
I haven't fitted the crankpins or the wheels on the axles yet (I moved house and got married instead) but I'm hopeful that with the machining done with the wheel held against the backing plate and a well fitting peg, that I will not need to machine the treads with the wheels on their axles. We shall see.

[stuartthurstan]

I'm no great expert on machining wheels (I've done the grand total of twenty so far) but I've always machined on a mandrel as suggested by others.

I use a piece of 30 or 35mm bar about 100mm long in the 3 jaw chuck. The end is turned down in two steps, first to about 0.02 less than the wheel bore and about a millimetre shorter than the wheel thickness, and the final section I turn to about 11.9 millimetres diameter and thread M12.

The wheels need to be lightly countersunk on the rear face to accomodate the tool radius on the mandrel and are then fastened to the mandrel with an M12 nut and large washer. I have never used a fixing pin and with wheels up to about 4 inches in diameter have not yet had one slip.

The large diameter bar used for the mandrel ensures a minimum amount of flex and also provides a substantial square shoulder. I also mark the mandrel according to it's position in relation to the chuck jaws so that on subsequent use it can be placed in the chuck in more or less the same place.

I first turn the entire blank to 0.05mm over the finished wheel diameter. I then proceed to take off the tread to the finished diameter, but leaving an extra 0.05mm on the flange thickness.

Once this is done the cross-slide is rotated to turn the angle on the flange, working slowly inwards until the tool tip meets the tread diameter. I do this by eye - shock horror, such imprecision!!

Next I machine a 2 degree coning angle on the tread, taking light cuts until the tool nose arrives in the root of the flange - again done by eye.

Next step is to cut a light shamfer of 45 degrees between the wheel face and tread - usually about 1mm

The final step is where I cheat somewhat. I have a flange profile tool cut on the EDM wire cutter which I use to carefully complete and tidy up the flange profile until the wheel arrives at it's final diameter. This is the most nerve racking part of the job although (touch wood) I've not yet had this tool dig in and ruin the wheel.

I make no excuses for the use of the by eye methods described. I am a firm believer in accuracy where it's necessary and not just for the sake of it. These wheels are all used for riding wagons and by the time they've been round the track a half dozen times, clouted a few bits of pointwork or been derailed with a couple of good sized adults on them, I'm personally convinced that sub-0.02 millimeter accuracy at the machining stage would be somewhat academic.

Stuart

[chris vine]

To be fair John, if you must be critical, you really should be accurate.

The previous contributors, who were all helpful, have written 1318 words.

Politely
Chris.

[ausdan]

Dr john, I looked at that link and the pictures, doesn't make too much sense, but when I read the words as well I got a full understanding.

As normal, instead of sharing a view, you try to ram you righteous position in the world to any one who graces these pages..

[Myford Matt]

And this makes three of us who are getting a little tired of being lectured to.

Everyone’s help is appreciated - whether it's through words, pictures, links, magazine references or whatever.

However, much more important is the civilised nature of the communication. A hell of a lot of work has gone into setting up and running a very valuable resource, which we all enjoy for free. Forums such as these are very vulnerable to arguments, and personal slights can quickly be misinterpreted and turn nasty.

A style, which is boisterous can be entertaining, but it can also be hectoring and opinionated, as here. Your link was useful, the comments either side were unnecessary and ill-judged.

Please try and restrain your negative sentiments about other people’s postings or opinions.

As Chris said

Politely

Matt

[abby]

What took you guys so long ?

[steam4ian]

G'day All

Dr John's message and link seem to have disappeared so as a public service I will repost the link.

mokei-jouki.hp.infoseek.co.jp/e-Wiltop.htm

The whole site is worth seeing not just the wheel section.

Dr John, If you lead by the chin expect it to get the odd swipe ;D

We all need to be aware of our bed side manners.

Regards,
Ian

[waggy]

Dr John appears to have removed himself from the site altogether. He had a dig at the membership in the thread I started re "Unstreamlined Duchess". I replied early this morning, his post was there then.

Regards,

Waggy.

[chris vine]

Oh Dear

[spurley]

Gone but not forgotten

[steam4ian]

Long may he prosper a certian Scottish industry.

[ilvaporista]

I bought a few of those 2MT soft fronted arbors. Instead of making up a special faceplate held in the 3 jaw I use the normal faceplate with one of these arbors turned to size. Two bolts through the spokes holds the wheel to the faceplate with a small parallel packing piece to allow me to take the tool to the edge of the flange.

I'm just too mean to use a good bit of metal to hold something....

This way was explained to me by a chap at the Reeves shop in Marston Green with much added non politically correct language and in an accent thick as the fogs we get round here.

[Peter W.]

ilvaporista said:

I bought a few of those 2MT soft fronted arbors

Same here, except instead of using bolts, I used some thin hooks round the spokes
and threaded at the other end which goes behind the faceplate. That way you can
get at more of the wheel, which you need to sometimes.

Peter

[spurley]

Adrian

That's genius, just found these listed on ebaY, item 150054563441, if any one else is interested. So I'm going to get myself a couple I think, just the job. ;D

Cheers

Brian

[chris vine]

Morse arbours.

I made a general purpose arbour from an old reamer with a No 2 taper. It was quite easy to cut off the reamer and leave enough to machine to a 1/2" stub, sticking about an inch proud of the face plate.

To fit different size hole in work pieces, I have made up various sleeves as I need them.

My technique for holding wheels on is to push them on with a piece of bar from the tailstock, using a rotating centre. The drive is then just by friction on the faceplate.

I usually put a piece of cardboard between wheel and face plate to increase friction.

I like to do it this way because my way of working involves just doing one simple operation to each wheel at a time. All the dial settings can then be used without disturbing them for other operations. I think this may be called sequence turning?

Cheers and on topic!!!
Chris.

[AndrewP]

sounds dear to me Brian, rdg tools' are 4.50 when they have em, mind you 30 bob is a bargain to post a lump of metal like that so it might all come out even in the end.

[dscott]

Another lovely site, and what a difference getting the scales of the person to fit in with the engine. As with Conway Martin Evans lets down the design with the scale of the cab. In his defence of course having imposible dedlines with the magazine over the years to meet at the locomotives cost.
The cost of re-design being out of reach of most model firms these days, though Doug Huson has done a wonderful job with the Y4.

David.