Loco wheels (and other issues) 7/8th scale

[Dave Cooper]

Good evening folks.
I have hit a snag which I am hopeful can be assisted/sorted by some (or one) the great minds here.
I am planning to attend the gathering of 7/8th modellers at the W&L later this year. To which end, I am working towards have at least working loco to be able to pull my meagre, but growing, stock of wagons.
However, the PDF LAT kit (I actually have 2 of these so double the trouble) appears to have a few curious 'issues'. The main one being that the steel wheels (which have plastic centres) come fitted to axles of 3.35 dia as opposed to the 3.175 (1/8th inch) bore of the drive gear supplied, plus they are not long enough to fit between the frames.
So, my solution, before I realised the diameters did not match, was to simply cut new correct length axles. Easy, thinks I, new 1/8th axles, no problem!
So now I am stuck!
The bearings provided for the frames are ok with both axle sizes (a little wiggle room is ok for this in my book), however, the 1/8 axles float in the plastic centres of the provided wheels.
I know, I though, I can buy some 30mm dia steel wheels with 1/8th axle holes.
The question is, can I, or is there another way of solving thus problem?
Please note, with the best will in the world, I doubt PDF would be able to help with this so I have not approached Leanne.
I just hope someone can offer some help
Many thanks

[GTB]

However, the PDF LAT kit (I actually have 2 of these so double the trouble) appears to have a few curious 'issues'. The main one being that the steel wheels (which have plastic centres) come fitted to axles of 3.35 dia as opposed to the 3.175 (1/8th inch) bore of the drive gear supplied, plus they are not long enough to fit between the frames.

3.35 mm is gauge 41 music wire (piano wire) size. A strange choice for axles.......???????

Do you have, or have access to, a lathe? I turn my own wheelsets and my reaction to this sort of thing would be turn replacement bushes for 1/8" dia. axles.

Commercially, IP Engineering was using 1/8" dia. axles with his 30mm wheels the last time I bought any, but that was 10+ years ago, so you'd need to check the axle dia. and length with Ivan. Peter Binnie supplies 3mm axles with his 29mm wheelsets and lists a range of axle lengths on his website.

No idea what other commercial offerings are out there.......

Regards,
Graeme

[ge_rik]

I've used Essel Engineering before now and he (Steve, I think), was happy to produce some steel disc wheels to my spec. He might be able and willing to help.

Rik

[Dave Cooper]

Since my original post I have discovered that the wheels 'may' be Sierra Valley items as they certainly look like them plus they have, what appear to be, the same plastic centres. Wether that has any bearing on the choice of axle size in this case is unclear as that specified now is entirely different from the 'Train Department'. As you say GBT, the 41 gauge piano wire size does seem very odd.
I can only assume that a decision was made at the time as to why such a choice made sense however it doesn't explain why the gear bore is clearly 1/8th. How one is supposed to marry the two is a mystery, to me at least.
I don't have a lathe so I expect to have to get someone to turn up some bushes to suit the adaptation needed, or I get someone like Essel to make new wheels. My feeling is bushes (metal I assume and then the whole ensemble 'glued' together?) would be easier as it would seem a waste to chuck perfectly good wheels for the sake of bushes.
More musing and investigation required I think.
Many thanks thus far gentlemen.

[-steves-]

Since my original post I have discovered that the wheels 'may' be Sierra Valley items as they certainly look like them plus they have, what appear to be, the same plastic centres. Wether that has any bearing on the choice of axle size in this case is unclear as that specified now is entirely different from the 'Train Department'. As you say GBT, the 41 gauge piano wire size does seem very odd.
I can only assume that a decision was made at the time as to why such a choice made sense however it doesn't explain why the gear bore is clearly 1/8th. How one is supposed to marry the two is a mystery, to me at least.
I don't have a lathe so I expect to have to get someone to turn up some bushes to suit the adaptation needed, or I get someone like Essel to make new wheels. My feeling is bushes (metal I assume and then the whole ensemble 'glued' together?) would be easier as it would seem a waste to chuck perfectly good wheels for the sake of bushes.
More musing and investigation required I think.
Many thanks thus far gentlemen.

Is it a brass drive gear? If so could you drill it out a bit to fit? Would that solve the issue? I know once I had a PDF kit and they supplied the wheels but also a new axle of which you had to remove the wheels from one and fit it to the other. Some pictures of the issues would definitely help come up with a fitting solution.

[Jbs]

My PDF 1/12th scale ruston kit came without axles and wheels so I used 3/16th axles and Essel wheels, easily regaugable between 32mm and 45mm. Wheel diameter I used is 32mm available in the Essel catalogue. They will also make wheels with wider treads for 7/8th and 1/12th scales.I bored out the axleboxes in the PDF chassis and inserted brass bearings for the axles and have had no problems so far. No connection with Essel other than as a satisfied customer.
I adopted the above method as I wanted more robust running gear after having had problems with long 1/8th axles in the past and the 3/16th axle diameter gives a selection of motor/gears readily available from 0 gauge suppliers.
John

[Dave Cooper]

Thanks a million gents, you have given me plenty to consider.
It did occur to me that James Hilton build one of these so I may ask him what he did.

More pondering any way
Cheers
Dave

[Dave Cooper]

Good evening folks
I finally got round to assembling the gearbox etc as supplied.
To be honest, it is a bit rubbish in my honest opinion.
Has anyone ever used the range of N20 motor/gearbox combo's. I can see that they have a range of available ratios and motor voltages so something will match my needs I think.
I know they are metric so I would have to risk drilling out the output shaft gear to 1/8th (only approx 0.2 different) but I think it would stand it.
The use of the N20 setup would at least give me a properly meshed gearset, which I certainly don't seem to have with the current one.

Many thanks
Dave

[philipy]

Yes, I have used a couple of N20 gear motors, most recently on a German "Gmeinder & Co" diesel:
https://gardenrails.org/forum/viewtopic ... t=gmeinder


They are fine for light duty loco's but not sure if I would trust them with a heavy hauler, and I have no experience of 7/8.

[Dave Cooper]

Oooh, I couldn't find one with long shafts! That might well do the job.
There is a chat in the states, one Charlie Lix, who has used them for years on his 7/8th loco's with apparent great success.
I agree, I wouldn't want to be putting them to too much stress, say a six bogie coach train, but most of my stock is pretty light.
I will order one (or maybe 2) and see what they come out like.

Would you mind telling all when yours arrives philipy? I would be interested to hear how it worked out for you.

Many thanks

[philipy]

Would you mind telling all when yours arrives philipy? I would be interested to hear how it worked out for you.

Sorry Dave, I'm not quite with you? I got one a couple of months ago and installed it in the Gmeinder loco, as per the thread I linked to. I don't have any more on order.

[Dave Cooper]

Oh, sorry Philip, my mistake.
How did you mount it and how did it work out in your model, successful I hope?

Dave

[philipy]

Oh, sorry Philip, my mistake.
How did you mount it and how did it work out in your model, successful I hope?

Dave

Dave, read through the link to my build thread in my earlier post and it will show you how I mounted it. Because of the cross-shaft output there are no fixing holes in the end, so I trapped it in a purpose printed sleeve as part of the chassis.