7mm Sandy's Workbench Thread

Sandy Harper

Sandy Harper

Western Thunderer
Whilst the other models are at various stages of painting and detailing I have started on a LNER (GNR) 0-6-0 tank engine and have decided to compensate the front two axles of the chassis. The model already has a system of making the top hat bearings slide in the chassis frames but as I did not receive any top hat bearings as part of the 'kit' , and my spars box could not provide me with a matching set of six, I decided to use two that were similar for the rear, fixed, driven axle and 4 of Slaters 'square' bearings that I bought in bulk from them some time ago.

The chassis already had etched cutouts where the axles were located and these were removed but then left a space too large to take the 'square bearings. They were designed to take the larger cast horn blocks I think. So I fretted out four U shaped spacers/hornblocks to fit over the gaps and accept the square bearings.

The whole assembly was then set up in my chassis jig and the spacers soldered in place using the RSU.

The next job is to fit the chassis spacers.

DSCN4343.JPG

DSCN4344.JPG

DSCN4345.JPG

Regards
Sandy
 
spikey faz

spikey faz

Western Thunderer
Hi Sandy

Your chassis jig looks interesting. Is it commercially available or is it homebrewed?

I'm also interested in how easy you find the RSU to use. Do you have any pictures of it? I've never owned or used one and not sure if it's one those 'must have' tools.

Mike
 
Lyndhurstman

Lyndhurstman

Western Thunderer
Lancastrian

Lancastrian

Western Thunderer
spikey faz said:
Hi Sandy

Your chassis jig looks interesting. Is it commercially available or is it homebrewed?

I'm also interested in how easy you find the RSU to use. Do you have any pictures of it? I've never owned or used one and not sure if it's one those 'must have' tools.

Mike
Click to expand...

Mike,

Regarding RSU's, I wouldn't say a "must have" but once used, you'll wonder how you coped without it for certain jobs. Probably the same tenet as those with micro gas torches. I've not used one, but can imagine putting one to use if I did have one.

Ian
 
spikey faz

spikey faz

Western Thunderer
Lancastrian said:
Mike,

Regarding RSU's, I wouldn't say a "must have" but once used, you'll wonder how you coped without it for certain jobs. Probably the same tenet as those with micro gas torches. I've not used one, but can imagine putting one to use if I did have one.

Ian
Click to expand...

I'm guessing the RSU is ideal to getting a lot of localised heat to allow parts to solder quickly without the fear of adjacent parts becoming unsoldered?

Mike
 
Lancastrian

Lancastrian

Western Thunderer
Mike,

They are great for adding small detail parts. Tin one side of the item, a dab of preferred flux on the main part, position the detail part, the tip of one RSU probe holds it in place with the tip of the second probe close by on the main item, press the footswitch, fizz of flux, solder melts, job done and minimal cleaning.

Ian
 
Sandy Harper

Sandy Harper

Western Thunderer
spikey faz said:
Hi Sandy

Your chassis jig looks interesting. Is it commercially available or is it homebrewed?

I'm also interested in how easy you find the RSU to use. Do you have any pictures of it? I've never owned or used one and not sure if it's one those 'must have' tools.

Mike
Click to expand...
Hi Mike,
Thanks to Ian and Jan for responding, in addition I would also say that they are probably two of the most useful items I have ever bought for railway modelling. My RSU was purchased about 20 years ago from Mignion Studios. You will not find them anymore and their unit was IMHO the best ever on the market.
The chassis jig is great at assisting in the building of a square chassis but it is also very useful at identifying chassis that have been built badly!!!!
Stay Safe
Regards
Sandy
 
Lyndhurstman

Lyndhurstman

Western Thunderer
Sandy Harper said:
Hi Mike,
My RSU was purchased about 20 years ago from Mignion Studios. You will not find them anymore and their unit was IMHO the best ever on the market.

Stay Safe
Regards
Sandy
Click to expand...

I have a Mignon Models RSU too. £35 I paid, back in the 90s, I think. A benefit of being in the same Scalefour Area Group as the designer/manufacturer. I may be wrong, but I seem to recall Derek Russan (he of Eileen’s) being involved. Mine hasn’t had much use, but once the VANWIDEs are done, I have plans...

Cheers

Jan
 
Sandy Harper

Sandy Harper

Western Thunderer
Isolation update.

I am so glad I have a constructive hobby that I can do indoors!

The two chassis pictures are the present construction project. A GNR J15, LNER J54 0-6-0 Saddle tank. It has the wrong sized wheels on at the moment. The correct ones are on their way from Slaters. Bless them!

The Ugly Duckling double cab Sentinel is now complete and awaiting a coat of varnish and the Fowler is slowly making its way through paint shops .

Sandy

DSCN4347.JPG

DSCN4348.JPG

DSCN4349.JPG

DSCN4350.JPG
 
A

Allen M

Western Thunderer
Hi Sandy
Looking at your 0-6-0 chassis it appears to me to have 1 fixed axle at one end. The centre & other end then have compensating beams on each side. I have tried this a couple of time and been unsuccessful in getting good running, What happened was a wheel on 1 side would rise or fall, it's mate do the opposite. The wheels on the other side then did not know what to do and may lift of the track,
The chassis was checked on a flat surface and all the wheels were level and the compensated ones could raise and drop a little.
I solved the problem by going for a single beam on the centre line as described by Mike Sharman in his 'flexychass' book.
I wonder if you could suggest what I may have got wrong.

Regards
Allen Morgan
 
Sandy Harper

Sandy Harper

Western Thunderer
I don't know Allen. This is the first time I have tried this method and only because it was part of the kit. This is a sort of test build for the kit.
When I have attempted 'compensation' in the past, like you, I have used the central beam and it has worked fine. Did your beams work independently of each other?
Regards
Sandy
 
Peter Cross

Peter Cross

Western Thunderer
This system works well, they do need to work independently. I normally make the third axle rotate about the centre of the frames.

Nice work sandy.
 
simond

simond

Western Thunderer
“Four point” compensation simply cannot work as a means of keeping all the wheels touching the track all the time.

You can have a fixed axle and a single, central compensation beam for the other two, or twin independent* beams, and a rocking axle.

Like stools, three feet good, more or fewer, less good!

* if they are independent, you’ll always get 5 wheels touching the rails. If they aren’t, you might get 4 but you’re only guaranteed to get 3, same as a rigid chassis. That means only one wheel on one side supporting the loco, and that means a hair or a mote of dust can stop the loco picking up power.

Atb
Simon
 
Last edited:
Sandy Harper

Sandy Harper

Western Thunderer
Mmmmm! Sorry Simon but I need to challenge you on that assumption. With my simple understanding of mechanics I cannot see how you could end up with all wheels on one side failing to collect current.
The principle of the simple centre rocking beam in easy enough to follow and the use of twin beams is just a more controlled version of it without the wear and friction that you could get from a simple rocking beam.
Many kit designers use the twin rocking beam compensation system and I doubt they would have gone to the expense of including it in their kits if it didn't work!
I can't quite understand Allen's problem of the 'wheels on the other side did not know what to do and may lift of the track' as there should be nothing mechanical to cause them to do that unless he had introduced some other physical entity that reacted unexpectedly. IE bearings too sloppy, friction in the beam fulcrum etc.
Regards
Sandy
 
Ian_C

Ian_C

Western Thunderer
Sandy Harper said:
Mmmmm! Sorry Simon but I need to challenge you on that assumption. With my simple understanding of mechanics I cannot see how you could end up with all wheels on one side failing to collect current.
The principle of the simple centre rocking beam in easy enough to follow and the use of twin beams is just a more controlled version of it without the wear and friction that you could get from a simple rocking beam.
Many kit designers use the twin rocking beam compensation system and I doubt they would have gone to the expense of including it in their kits if it didn't work!
I can't quite understand Allen's problem of the 'wheels on the other side did not know what to do and may lift of the track' as there should be nothing mechanical to cause them to do that unless he had introduced some other physical entity that reacted unexpectedly. IE bearings too sloppy, friction in the beam fulcrum etc.
Regards
Sandy
Click to expand...
Simon's absolutely correct. And not all kit designers seem to understand the principles of compensation. However you arrange things there'll always be at least one wheel on one side in proper contact with the railhead. But that's the problem - if you rely on a single electrical contact and it's sat on a piece of dirt you're stuck (caveat 'stay alive capacitors' etc). In which case you may as well make the chassis rigid and save the trouble of springs or beams. Rigid works OK-ish on level, clean track, just not ideal.
 
You must log in or register to reply here.
What's New?
Top