Wednesday, 2 March 2011

Compensation units

One month has passed since my decision to enter the Armchairs Modellers Challenge was taken. With the holiday and a few other things going during February not a lot has happened. So over the last couple of evenings I've squeezed in some modelling time and started to look at a couple of wagon compensation units.

My aim is to try two or three different compensation units on the wagons. I've a couple of frets from Bill Bedford, some MJT frets plus some Exatroscale units. I've used an old D&S unit on the 7 plank wagon which did go together easily enough and seems to work OK. Unfortunately this fret was the only one I had so cannot consider this as an option for future projects.

First to try was the Bill Bedford units.........


Hmmmm....... Above is my first attempt at putting together one of Mr Bedford's compensation units. To be fair it was built a few months ago, the units were easy to fold and I ran a little solder along the internal folds to stiffen them a little, but as can be seen it is not a very successful attempt. The W irons are not square to the base and when the axles are depressed the W iron splay out a little further..... I couldn't see where I'd gone wrong and the unit was put onto one side for some thinking time. I was sure that, as these units have been around for some time, it was the way I'd put them together that was the problem.

In a subsequent discussion with one of the P4 area group members it was suggested that I use Exactoscale square axles with these units. This I did and the next unit I built.........




has gone together nice and square.....................


The MJT units are similar to the D&S units but again I'm not totally happy with my first attempt as the axle is a sloppy fit not as rigid as the D&S units. The rocking unit is shown below......


I'll persevere with the MJT units on one of my wagons but the jury is still out as to which unit I prefer. I have yet to pluck up the courage to build one of Exactoscale wagon chassis kits which do look a little more complex to put together than either of the above. No doubt once one is built they it won't seem that daunting.

4 comments:

Flymo said...

Hi Jan,

on the two BB units, it looks like there is a difference between the axle lengths. Is that really the case?

The other difference that it could be, and it's nothing to do with how you put the units together, is that the hollows in the bearings are different depths. People don't realise this, and it can make an enormous difference.

Flymo

Yan said...

I didn't realise about differing depth to bearings. Even from the same manufacturer?

The pin point axles in the first BB and MJT units are exactly the same length. Between the two BB units one axle is a Alan Gibson pin point the other a square ended Exactoscale axle which is 0.73mm shorter.

Mike Garwood said...

There was quite a discussion on E4um with this. (- run by Bill -) if you contact him I'm sure he'd send you a precise of the discussion with all the relevant measurements. I think it was Russ Elliot that took them, so they are probably gospel. I know in building my BB bogies I use Markits bearings, I don't like the Exacto ones and they are way expensive compared like for like.

Yan said...

Thanks Mike, I'll try and contact Bill.

I can only find pinpoint bearings for rolling stock in the Markits catalogue.... am I missing something?