Dave Sutton
Active Member
I reckon you'll have to shorten those black and red pick ups....
I wanted some slack Dave! Ha ha you’re a tease ……….I reckon you'll have to shorten those black and red pick ups....
Thanks for the reply John no lathe here! The most basic of basic set ups all handrolic!The best system to set the holes is a little work, and more or less needs a lathe.
Take out the drivers. Make 2 replacement axles with the ends turned to crankpin diameter.
Take(or make) your 4 crank bushings and place on these axle ends.
Make holes in the siderods big enough to easily slide over the bushings. Then solder the bushings securely in the siderods.
In theory, you are now done.
You may wish to just start over siderods using N/S scrap from etchings.
Hello @AdeMooreummm well what happened was! When I pushed the chassis with the Jinty I resorted to opening up the coupling rod bush holes to make it run!
I now realise that was not wise!
So should I shim them out with brass to the right size, scrap them and start again or something else?
The coupling rods should set the axle centres I read but it was too late back then when I was starting out I‘d gone off the template.
Also the nuts on the front pair I filed down for clearance came loose so they came off to see what was what.
I need to investigate the reverse crank pin set up any photos or pointers to suppliers would be welcome.
I had to put the box and label there to get the mobile to focus in the van!
View attachment 174273
View attachment 174272
View attachment 174275
View attachment 174274
Cheers for looking in.
Just a few tags for those who have helped previously!
@Dave Sutton @adrian @simond @Robin @Ian@StEnochs @Overseer thanks in advance.
Hello @AdeMoore
Obviously the biggest issue is getting the axle centres accurately transferred to the coupling rods. This is not easy. This is the way I did it on the Y4:
Post in thread 'Jan's 4mm Workbench'
4mm - Jan's 4mm Workbench
If you were building this from a kit, then the frames would be built up using the rods as datum, If with some alignment jigs from London Road Models or Markits
http://traders.scalefour.org/LondonRoadModels/images/alignmentjig.jpg. There is another (better) version that has parallel ends the same size as crankpin bearings, but I don’t know where you can get them. In your application, these - used in conjunction with a tapered broach - might be handy in getting the connecting rod pitch the same as that of the chassis. The broach would maintain the concentricity of the hole and prevent it becoming oval - which would introduce binding.
So really - for me - it’s whether you can find some way to rework the pitch of the holes accurately.
Failing all that, i would start again, and open out the holes in the rods incrementally with small drills, ending with a tapered broach to maintain concentricity.
Cheers
Jan
The paralell end ones were perseverance. I don't think theyare available any more.
Thanks for all for the replies Jan I was looking in on the Y4 thread thanks.ooooh difficult one. I was able to build the frames and bearings with the rods in a jig.
Have you got any overlong axles/rod? You need to check if the bearings in the frames are parallel. I'll have a look in the 'bits' box and see if I've got anything, I moved house a while ago and we're in a rental while I build our new one so it may take a bit of time to find. I'll also look to see if there are any spares left.
Cheers Paul for the info. Yes great idea RE the rods on a fine flat file. I now remember I actually have the hornways! /guides for the hornblocks I bought 25 plus years ago. I wonder if I can find them!When I bushed my rods, I sliced off the tube with a piercing saw, leaving a small stub, then drew the rods along a fine flat file until the join was almost invisible.
Re. the hornways, Comet hornblocks require a slot 5.85mm wide - any good? Otherwise I'd solder in a compact hornblock & guide from High Level. Best of luck.
Time flies like an arrow, fruit flies like a banana...Good to see you back.Ah now where were we! time flies.
IIRC I was given a measurement for the horn blocks as I'd not used them. I did mine as a straightforward rigid chassis without problems (OO) I'm not 100% sure but I think Robin Gay (Rolvenden and Wantage layouts) also did his rigid in P4.Next the chassis the horn blocks have no guides! The slots are over size there’s a lot of movement!
..
Cheers Dave amazing your still tuning in after all these years! Thanks for the advice.Time flies like an arrow, fruit flies like a banana...Good to see you back.
IIRC I was given a measurement for the horn blocks as I'd not used them. I did mine as a straightforward rigid chassis without problems (OO) I'm not 100% sure but I think Robin Gay (Rolvenden and Wantage layouts) also did his rigid in P4.
She is a tricky wee beastie but you've done good so far.
Cheers Jon thanks as always for your support and advice along the way.Good luck!
Jon