7 1/4" Gauge Electric 0-4-0 Loco

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NickG:
Stew,

thanks, I never thought of buying a body but no doubt it would be the wrong size now anyway :doh:

I'm going to make a simple body folded / welded in steel I think.

Made some more progress but will post in a bit as wife is going crackers :bang: :bang: :lol:

NickG:
Right, despite even more moaning for her, here is a quick update - with some machining!

I thought I'd make a start on finishing the wheels off, which were just blanks at the moment.

To turn wheels, there's a sort of accepted method in the loco world and it makes sense. You face and bore / drill the blank in the outside jaws, then turn up an arbor to finish the tread / flange. Once the arbor is turned, you don't take it back out of the lathe so it stays true to the lathe axis, however, as you'll see, in this case I did because I made the bloomin' bits the wrong way around! :doh:

Anyway, here goes - it needs to be a fairly large dia to give the wheel some support from behind, another quick way I suppose you could do it is use some rod near to the right size, skim down then with a nut clamp the wheel up against the jaws of the chuck, but here is my method:

Found some suitable material and turned and faced one end for a nice datum:

Turned it around so I could grip the datum and turned a larger, new datum on other end which will be gripped in the chuck until all wheels are complete:

Opened the hole up then tapped it:

at this point I should have started bolting wheels on and turning them but I realised I'd made this part first instead of the bolt! :doh: So I scribed a line at one of the jaws and made a note of which jaw to ensure it was back in the chuck where it was before - this can't gaurantee zero runout still but I could hardly detect any.

Started making the bolt, face a bit of hex to length:

Turning down to size:

I hate finishing cuts, I took half a thou off but it was still not enough - that's when I get in patient then overshoot on the next cut! This one was ok luckily, maybe a tinsy bit looser than I would of liked but still ok:

Putting a shortish thread on the bolt, only thing I needed to do was make sure the plain shank was shorter than the thickness of the blanks so it will clamp up:

Then I realised I had been given a tailstock die holder for xmas and hardly used it - much easier / better result with this! :

Here is the finished bolt:

Actually it wasn't, I only left the head long because that's how it worked out - no point sawing, parting things for the sake of it but then as an after thought I put a centre hole in to support it from the other end, so it was a good job I left the head of the bolt long, gives me more room to get in:

Wheel mounted on the arbor and started truing up the OD:

Then turned the tread leaving the flange 1mm over-size. I will need to grind a tool with a 1mm rad to go in and form the radii, think I will get all wheels to this stage first though so only have to change tool once:

I'm sure many people have seen this sort of method before but thought it was worth showing. An other way is to turn down a longer piece of material to leave a spigot the right size sticking out, then thread and use a nut to clamp - just more work whittling down a larger diameter. Or, you can buy expanding mandrels, never tried these though.

Hopefully tonight I'll get the wheels finished and it'll be a rolling chassis of sorts, though not rigidly fastened together and I can't put fasten the wheels in place as the motor hangers & gears need to go on first.

Nick

raynerd:
Great work and good pics....!!

Look forward to seeing your updates later :D

NickG:
I've made a little progress on this but not updated for a while due to being away etc etc. I was doing a bit more tonight in the garage but I've come in in a bit of a huff ... :doh: will explain later!

I finished turning the wheels, thinning the flanges down and putting the 1mm radius in. I just ground the tool by eye and I think I had it set at a bit of a funny angle so they aren't that good but they'll do.

Also quickly made the draw bar. Not sure whether the height will be correct for our driving trucks at the club but I can correct that later with a bend in it or something.

My attention then turned to milling two bits of angle iron to length to fit between the frames to hold the battery and act as stretchers. I then welded them in - as you can see, not the neatest welding, need a lot more practice at this, never-the-less the joints seem strong.

I then started on the motor hangers, I thought I needed more flat steel for this but I decided to measure the bit I'd bought and there was just enough as luck would have it! :D

This was really a marking out and drilling exercise, I was holding the pieces by hand to drill them and being careful managed to get up to about 1/2" diameter - then when I was drilling one of the smallest holes I was too slap dash and didn't have a tight hold which sent the thing spinning and dug into my hand - hence the g clamp set up a bit further down. So there's a bit of a safety lesson to learn there, I thought I had some common sense but obviously not, I kept thinking I shouldn't be holding onto this really but I thought I'd cracked it then then it came back to bite me drilling the small hole :hammer: :wack:

The setup to bore the big holes was quite interesting. At first I thought I couldn't do it it my massive 4 jaw. It's really too big for the lathe in my opinion - so if I had all the jaws reversed, there was no hole in the middle to bore through, if I had them in the normal way, the jaws were extended out too far and caught the bed. Then I thought why not put 1 jaw in the normal way and use some packing pieces - to my astonishment it worked!

This is the setup I used for drilling the holes out bigger for the bearings - I didn't have a drill big enough but found a centre drill that did the job:

Here are the finished hangers minus the bushes which will need making and loctiting in.

I started making the brass bushes tonight but I drilled it with a 10mm drill as thought it would give a decent sliding fit, drill was really cheap and nasty though and it ended up way over-size! :bang: The best thing I've got is a 10mm end mill which should give a more accurate size although when I tried that on test pieces for the wheels I thought it was a bit sloppy. Maybe my tail stock is out of alignment.

Another thing that is bugging me is the lathe has started cutting out, the bi-metal strips are tripping it on the on / off switch. Anyone have ideas what that would be? it just started doing it about a week or so ago. The first time it did I'm sure the motor made some weird noise but it's sounded normal since, just when it's been running for a couple of minutes or put a decent load on it it trips. :( I wondered if it could be the start or run capacitor needs changing or something? Or would that stop it completely? :smart: don't want to :zap: so better get it sorted.

Nick

Stilldrillin:
Nicely shown Nick! :clap:

Re your 10mm hole. Always double drill, for a (more) accurate hole.

9mm, first. Then 10mm, held well out from the chuck, to allow it to centralise itself easier...... :thumbup:

David D

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