Precious 1976 scratch built Terrier needing help, bearings etc.

[mikesndbs]

So just starting to try and open up the bearings ready for the bushes using the suggested broaches. I've selected the smallest that fits and have twisted it around.

Quite hard going.

Will it really self centre? 

[John Isherwood]

1 minute ago, mikesndbs said:

So just starting to try and open up the bearings ready for the bushes using the suggested broaches. I've selected the smallest that fits and have twisted it around.

Quite hard going.

Will it really self centre? 

 

No reason why it shouldn't.

 

CJI.

[micklner]

I doubt that very much. You need what LRM call Alignment Jigs which I believe are  1/8th axles with pointed ends place the bearing in the holes then the coupling rods on the pointed ends ( LRM have no photos of the  jigs).

Hold them on with elastic bands or similar only then . Then glue the bushes in place.  You  will have to check the rods are straight by eye , before you glue the bushes in place. I suggest glue at one end first (using the tightest best fitting holes)  On a kit with tight fitting bushes added they would be ok without the last check having to take place.

 

If you just glue them in loose they will will be all over place as a result. Nothing will ever self centre.

 

 

http://londonroadmodels.com/various_pages/components.php

 

Photo of the alignement jigs I use here.

 

http://philsworkbench.blogspot.com/2016/02/locomotive-chassis-jigs.html

[John Isherwood]

12 minutes ago, micklner said:

I doubt that very much. You need what LRM call Alignment Jigs which I believe are  1/8th axles with pointed ends place the bearing in the holes then the coupling rods on the pointed ends ( LRM have no photos of the  jigs).

Hold them on with elastic bands or similar only then . Then glue the bushes in place.  You  will have to check the rods are straight by eye , before you glue the bushes in place. I suggest glue at one end first (using the tightest best fitting holes)  On a kit with tight fitting bushes added they would be ok without the last check having to take place.

 

If you just glue them in loose they will will be all over place as a result. Nothing will ever self centre.

 

 

http://londonroadmodels.com/various_pages/components.php

 

Photo of the alignement jigs I use here.

 

http://philsworkbench.blogspot.com/2016/02/locomotive-chassis-jigs.html

 

My suggestion is based on the assumption that the wear in the frame holes is, near as dammit, concentric with the original holes.

 

That being the case, the cutting broach should simply enlarge the worn holes, to the point where the bearings will press in.

 

I would certainly try this method first - if the holes prove not to be concentric, then four of them can be enlarged a little more to allow some adjustment clearance.

 

Having acquired the jig axles, the bushes can then be SOLDERED (glued - really?) into the frames using the rods as spacers.

 

I do not believe in complicating a job unless it has proved to be necessary!

 

CJI.

[micklner]

This is someone who has never built a chassis of any description. Again from the description the axle holes are already oval/badly worn.

 

It will be hard enough for him to hold the whole thing together, let alone solder at the same time as well. If he wants to solder that is his choice.

 

 

 

 

Edited June 16 by micklner

[mikesndbs]

HI and thanks for the input.

Yes this is my first big modelling step.

The axel holes are slightly elliptical on the centre driven wheels.

Since fitting the new axels Richard kindly sent me with the bushes, it's clear I won't need to bush the outer wheels as they are now snug.

 

I've begun using the broach as suggested above, going very carefully indeed.

 

Given what's been said above I plan to uses one of the spare axles placed in the new bearings to try and ensure alignment.

 

Hope this works, it's scary stuff lol

 

[mikesndbs]

On 11/06/2024 at 19:21, cctransuk said:

 

The broach will self-centre in the worn frame holes.

 

Bushes : Product RM4 at Wizard Models.

 

CJI.

 

OO just re-read this so I should be ok anyway :)

[melmerby]

3 hours ago, micklner said:

You need what LRM call Alignment Jigs which I believe are  1/8th axles with pointed ends place the bearing in the holes then the coupling rods on the pointed ends ( LRM have no photos of the  jigs).

I made my own jigs for a frame where the holes weren't exactly the same centres as the coupling rods

Using the original coupling rods as a pattern I made another crude pair but with the same hole centres which were then opened out with a broach to snugly take the threaded ends of Romford axles

The chassis holes were opened out until the bushes were loose in the holes

I then using the Romford axles & nuts and duplicate coupling rods assembled everything, hence automatically aligning the bushes to the rods, the bushes were then one by one soldered in place.

Presto! A perfect fit.

[Barclay]

This is the primary concern when building a chassis up, that the coupling rods and the wheelbase match exactly. Ideally a set of jig axles, from London Road models, for example, will enable you to check this and make sure the bearings go back in the right place, if there is any ambiguity. At a push the Romford axles may do the job, depending on the size of the hole in the rods.

 

Example:

 

[uax6]

If it was only the centre axle holes that were slightly elliptical, I think I would have left them alone and just fitted a slimline gearbox that hangs on that axle. The reason? Well if they are the only ones that are elliptical, then its quite likely that they were built that way to give a tad of flexibility in the chassis (ie to allow it to go over slight humps in the track). I wonder if the coupling rods have the centre crankpin with a lot of slack to allow this movement to happen?

I've converted tri-ang chassis this way before, but I always put split rods on instead of a sloppy hole. 

 

Andy G

[mikesndbs]

Hi guys

 

So far so good. I'm pleased to report that as the broaches worked they did indeed make the hole perfectly round again :)

Bearing bushed were a firm push fit and have been soldered in place (after checking alignment of course) as suggested.

Used a high temp epoxy to fix the crank pins in place, dad had used normal epoxy after all.

And when it comes to resoldering the nuts on, I intend to use low melt point solder so the glue should be safe.

 

If this all works it will be time for the livery sort out.

 

Here are some photos from today's activities. 

 

[mikesndbs]

Click the picture to play the video! Welcome to part 3 and the continuing story of restoring my Terrier that dad made for me back in 1976. In this penultimate video we look at the detailed steps I had to undertake to get 2636 back in running order. Cutting broaches, press fit bearings, brass soldering and press fix transfers and paint are all used. Will she be ok? Watch now to find out. 

 

[mikesndbs]

Video goes live on Wednesday at 2 PM BST