Sandy's Workbench 7mm Scale

[Sandy Harper]

I have decided to have a go at a 'shelf queen' that I have had around for a while. I think it was an impulse buy on ebay some time ago and it has languished in the pile of 'jobs to do' since then.

A 'Mega' kit, from the late 'Home of '0' Gauge', with updated instructions. Now I know it has got its problems and discrepancies but I think I can live with them. I will add my own touches to it like split axle/chassis tender pickup and any other modifications I feel might improve it, short of a complete rebuild.

 

On checking the chassis dimensions against Peter Tatlows drawing in his book on Highland engines, I found that the wheel spacing was a bit out, but I can live with that. However these 0-6-0's were all built with Helical springs to the centre wheels, where as the kit chassis has etched leaf springs. That I will need to change. The footplate was also found to be short, according to the drawing, which also meant the valances would be wrong and, although I did not measure the boiler, it would follow suit. The cab side sheet was also missing a few mm's and only the smoke box seemed to match the drawing. I have no intention of attempting to correct these errors as it would mean an almost complete scratch building exercising, As long as the errors are in proportion to each other only I will now about them. Oh! and maybe you now as well!! Mum's the word.

 

Anyway on to the build. On opening the box I found the brass to be quite tarnished so the first job was to give the etches a good clean with a Garryflex block. This didn't take long and I soon had them nice and shiny again and ready for soldering.

 

The Tender chassis inner frames are very basic with half etched dimples where the axle bearing holes need to go and that is it!. No location for brake hangers or where the turned brass chassis spacers should be located, as in most other kits. This was not a problem for me, in fact, it was of great benefit as I am fitting Perspex frame spacers and a set of Slaters 'Square' axle bearings. Large axle bearing holes would have been a pain as I would have needed to consider another method of bearings and horn blocks, or scratch build new chassis sides.Instead it was just a matter of spending a few minutes measuring, and marking out, where I wanted holes drilled and the chassis cut.

 

The tender chassis sides marked out for cutting, along with the Perspex spacers.

 

 

Having first tack soldered the two chassis sides together, I cut out the horn guides with the piercing saw. I have stuck some wet & dry to the face of the cutting table to add a bit of friction between the work piece and the table to stop it slipping, when cutting, which can easily lead to a broken blade. Pilot holes were also drilled for the brake hangers and fixing holes for the Perspex spacers.

 

 

The spacer holes were opened out to accept 8BA bolts and countersunk. The Perspex spacers will be drilled and tapped 8BA

 

 

The easiest way to separate the sides is with a miniature blow torch.

 

 

The horn block apertures were cut under size and then opened up with a file to produce a nice sliding fit for the bearings

 

The spacers fitted to the chassis sides and checked for alignment. Although not very clear in the photograph, the spacers sit about 0.5mm above the top of the chassis sides to provide an electrical insulation gap between them and the footplate of the tender.

 

 

 

More to follow

Sandy

[ian@stenochs]

"Anyway on to the build. On opening the box I found the brass to be quite tarnished so the first job was to give the etches a good clean with a Garryflex block. This didn't take long and I soon had them nice and shiny again and ready for soldering."

 

Hi Sandy,

 

I find that a spray with Viakal removes the tarnish very quickly and without the risk of snagging the finer bits of etch on the Garryflex.

 

Ian

[Sandy Harper]

"Anyway on to the build. On opening the box I found the brass to be quite tarnished so the first job was to give the etches a good clean with a Garryflex block. This didn't take long and I soon had them nice and shiny again and ready for soldering."

 

Hi Sandy,

 

I find that a spray with Viakal removes the tarnish very quickly and without the risk of snagging the finer bits of etch on the Garryflex.

 

Ian

Thanks Ian, good tip. I could also have used the sonic cleaner but Mega etches don't usually, as a rule, have many 'fine' bits of etches to snag. More agricultural!

 

Regards

Sandy

[EKR]

Hi Sandy this looks another interesting build to follow.

 

What thickness of perspex do you use/recommend and how do you attach it to the frames?

How secure is it in use?

 

 

edit for not wearing glasses duh.

Edited November 16, 2015 by EKR

[Sandy Harper]

Hi Sandy this looks another interesting build to follow.

 

What thickness of perspex do you use/recommend and how do you attach it to the frames?

How secure is it in use?

 

 

edit for not wearing glasses duh.

The Perspex in this particular build is 5mm thick and 24mm wide. I obtain it from a local sign maker who is able to cut it into 24mm wide strips for me with a band saw. Again, in this particular case the spacers are attached with 8BA countersunk headed bolts with the Perspex being tapped 8BA. I have also used 4mm wide Perspex on some small tank engines. If you felt the need you could smear the threads of the bolts with some epoxy before screwing them in but I have not found the need as the Perspex tends to 'grab' the bolts anyway. One tip is only to use hand drills as even the slow speed of an electrical drill will melt the Perspex!

 

Regards

Sandy

[Sandy Harper]

I have now completed the footplate for the tender. This was a very easy construction as all the etched parts fitted perfectly. It is all very basic and you need to mark and drill the holes in the footplate yourself, to attach the inner chassis, as there are no indications of the position. This is quite good really, especially if you are wanting to modify things a bit! I also marked out and cut a space in the middle of the footplate to gain access to the inside of the tank area for locating a DCC chip.

 

The outer cosmetic frames, located 6mm from the edge of the footplate, end up exactly in the middle of the hole for the buffer shank extension that extends through the buffer beam. Usually there is a need to make a cut out in the end of the outer frame to accommodate this and, on GWR tenders, a large rear footstep usually disguises this but, on an HR tender, no such luck!

 

Fortunately, on this occasion, I have been lucky! The turned brass buffer housings supplied in the kit have a very narrow shank extension that just fits the thickness of the buffer beam and the sprung buffer head, which is permanently fixed to the housing, by having the steel end of the buffer operating rod flattened, and slightly splayed out, to hold it in position. I was able to trim the rod down to about half its width using a cutting disc in the Dremel so that it now just slides past on the inside of the outer frame with only a couple of mm cut out hidden by the turndown in the valance.

 

I am still awaiting the delivery of the wheels so there is not much more I can do to the chassis at the moment. I will continue with the tank part of the tender. This tender, by the way, is the HR 6 wheeled version with the full sized tank.

 

 

 

Sandy

[Barnaby]

Cor! Sandy........................again.

[Sandy Harper]

The tank for the tender is etched in two parts. The main tank, with a half etched area at the top to which the second half etched part is attached. I did this using the RSU and solder paste.

 

 

 

 

I now needed to bend the flare and for that I use my drilling table with a length of rod clamped to it.

 

 

 

To actually do the bending I use a steel straight edge with a chamfer on it.

 

 

 

 

Vertical bends were done free hand with a slightly smaller diameter of rod.

 

 

Regards

Sandy

[Sandy Harper]

As I mentioned previously, I was fortunate with the design of the sprung buffer housing. Here is a close up of the fitting.

 

 

...and with the spring depressed.

 

 

The arrangement of the bearings for the tender chassis. Rear bearings soldered in position. Centre bearings fitted with a sprung wire and able to move both above and below the axle centre line and the front bearings loose fitted with an L shaped brass wire soldered to the inside of the chassis side to prevent rotation and capture.

 

 

 

Regards

Sandy

[Londontram]

Hello Sandy, how did I miss this thread, excellent work and rather than go through 24 pages putting Craftsmanship/clever on every post I'll just say it here, I'll now be following this with interest Steve

 

                                    CRAFTSMANSHIP/CLEVER

[Sandy Harper]

Hello Sandy, how did I miss this thread, excellent work and rather than go through 24 pages putting Craftsmanship/clever on every post I'll just say it here, I'll now be following this with interest Steve

 

                                    CRAFTSMANSHIP/CLEVER

Thanks Steve, much appreciated.

Sandy

[Sandy Harper]

There are a pair of supports that run the length of the tender tank, for the tank top to rest on, and before fitting the top I took the opportunity to fill the spaces, between the spacers and the outer tank sides, with small sheets of roofing lead to give the tender a bit of weight.

 

 

The tank top and coal chute fitted extremely well with only a little trimming at the front end to get a good fit.

 

 

The next job was to make the rear, rounded corners, to the tender to flare. This is probably the job that I hate most in building these pre-grouping tenders. The kit designer, in this case, leaves you with a couple of 'fingers' of brass that you are supposed to 'fill with solder and file to shape'. No matter how often I have done this I can never get the solder to successfully 'fill' the gaps. And I have tried all sorts of solder but always resulted in failure. The only success I can claim to is by using a scratch built infill of brass and then using solder to fill in the much smaller gaps.

 

On this tender I first removed the useless 'fingers'.

 

 

....then I made a new corner to match, overly large, to be cut, back a bit at a time, until I got a good fit.

 

 

This was then soldered in using 188 degree solder

 

 

....followed by Carr's 100 degree solder to both the front and back to fill the remaining gaps.

 

 

Then out with the files, emery cloth, scrapers etc. to get the final finish.

 

 

There must be a better way to do this job, but so far this is the best I can come up with. Any one got any better methods, as I'm sure we have all struggled with this?

 

 

I then finished yesterday by adding the two sets of tool boxes to the front end, the footplate floor and a pair of front extension pieces that have the doors attached. I noticed that the door etches were identical with a cut-out half way down the door. This was needed to clear the tablet operating mechanism fitted to the left hand cab side of these engines but were not required on the right hand side! In good railway practice I 'sheeted over' the inside of the door, the only part that can be seen when in the open position, with a very thin sheet of brass before adding the door handle/locking lever.

 

 

Regards

Sandy

[Buckjumper]

Well done - it looks great. Tender flare corners are always a pain. I've found that the more fingers of brass the better the solder meniscus grabs and will carry over from one finger to the next, so if there's only one or two fingers supplied I'll instead make a splay of five or more, shape them and fix in place with 188. Then like you I use 100 to fill the joins, however, if the solder really won't play ball I'll clean up, make the initial pass with 145 (which is why I use 188 to fix the fingers in place) and then drop to 100 for the final filling of gaps. Then it's out with the burrs (in the mini drill for the inside), files, w&d cloth. As you say, it's one of the worst anticipated jobs in building locos, but despite the mental hurdle it invariably works out ok, and there's quite a feeling of euphoria when it's all polished up and done. I can't think of another way of achieving it.

[ian@stenochs]

Hi Sandy,

 

Those fingers splay out too much and it is very difficult getting the solder to fill the gaps. Plumbers solder is best but still leave a lot of fettling to get right. You have made a good job there.

 

I have scratch built quite a few tenders with curved and flared corners, the Drummond brothers were particularly keen on them and quite a few pre group railways had examples. I have a little former made by turning a taper on a piece of steel over which it is easy to form a piece of sheet into part of a cone which can be soldered into the corner. This shows the former, the taper is easily found from your drawing or off the model.

 

 

I use a piece of sheet slightly thicker than the side material, I usually use 15 thou for 10 thou sides, and fold it round with my fingers. I find that I can manage without annealing the nickel silver I use but with etched kits usually about 18 thou thick you may need to.

 

 

While you have a bit to hold onto it is easy to file the bottom curve while held on the former. You will see that the end of the former is flattened off to the diameter you need. It is now just a case of offering the blank up to the corner and scribing where you need to cut with a fine piercing saw. Leave it over high while it is fitted and soldered in place, the extra makes holding easier. The extra thickness gives you a bit of leeway as you don't need to get it exactly in line with the side and some metal to file away for an exact invisible match. The inside is easily done with a small rotary burr or stone, you can get some conical ones which almost match the flare angle. The surplus can be removed with the saw or even a cutting disc. If the edge is beaded I usually leave it over large until I have added the beading.

 

Hope this will be of use in the future.

 

Ian

[Sandy Harper]

Now that is a useful tip Ian. I'll need to make myself a 'cone bender'. Thanks for your informative response which has already attracted some other responses.

 

Kind regards

Sandy

Edited November 22, 2015 by Sandy Harper

[Sandy Harper]

Nearly complete. Time for a good clean up now.

 

 

 

[Sandy Harper]

I have made a start on the Loco chassis and footplate. Nothing to get excited about here. All very straight forward, although I modified the chassis in a couple of ways for my own benefit. The kit is supplied with two square brass spacers that are designed to be bolted on to the front and rear of the chassis.

 

First off, this results in a rather poor chassis that bends in the wind too easily, so I cut a couple of additional  L shaped spacers, from the spares box, that were more suited to my needs and fitted them at the front and rear. The rear one needed repositioning anyway as It was too close to the rear axle which I intend to use to mount the motor/gearbox unit. The rear axle is fixed, middle axle sprung, with both up and down movement allowed, and the front axle also sprung to allow downward movement only. You can see the steel wire springs soldered to the chassis sides and bent at a 90 degree angle to fit into a .9mm hole drilled in the  brass top hat bearing. Using this method also prevents the bearing from rotating in the chassis. (Thank you JAZZ for that tip) The chassis and bearings were all set up using my Holiday Hobbies Axle Jig using the coupling rods to set it up. Best investment I ever made, although other methods are also available. Just a satisfied customer.

 

Moving the rear spacer also required a new fixing hole location for the footplate. I used one of the original brass spacers in the middle of the chassis to give a bit more stiffness, and a location to fix the motor mount to, when I get around to adding it. I am picking up a motor and gearbox at Reading next Saturday.

 

Because of the pick up arrangement in the tender, there are none in the loco. Simples!

 

The coupling rods were simple affairs that needed  laminating and could be made to pivot, which I did,  with a rivet. The bosses were not very convincing, being the same thickness as  the rods, but a delve into the scrap box produced some left over etched bosses from another kit that suited. They look a bit better now.

 

The foot plate has had the valances added along with the front buffer beam and rear drag beam, all of which were very accurately etched and fitted perfectly.

 

 

 

 

Regards

Sandy

[Sandy Harper]

Ooops! Houston, I think we may have a problem!

 

There is no way I can stretch that flap to become the rear splasher top! What was the designer thinking? I will need to form another.

 

 

Fortunately there a couple of spare etches, that have no other apparent use, that I can use.

 

 

In the meantime I have continued with the rest of the cab.

 

 

 

 

Regards

Sandy

[Sandy Harper]

Don't Christmas preparations get in the way of modelling?

 

Not a lot done in the last 10 days except the brake gear added, a couple of splashers built, a roof detailed and a boiler!

 

 

 

Oh, and I picked this little beauty up at Reading from a friend who wants a bit of a paint job done on it!

 

CR Class 49

 

 

 

Sandy

[jim.snowdon]

A loco I know well, having had to reduce the width of the chassis one stretcher at a time in order to give it enough sideplay (in fact to give it any sideplay at all) to go round curves. Like our mutual friend, I shall be waiting with anticipation to see how impressive it looks once in its proper colours.

 

Jim

[Sandy Harper]

A loco I know well, having had to reduce the width of the chassis one stretcher at a time in order to give it enough sideplay (in fact to give it any sideplay at all) to go round curves. Like our mutual friend, I shall be waiting with anticipation to see how impressive it looks once in its proper colours.

 

Jim

N/S doesn't really suit it, does it? Runs nice though!

 

Is this the Mercian 'Cardeen' Kit or has it been scratch built? I cant see any markings on it that would give me a clue.

 

Sandy

Edited December 11, 2015 by Sandy Harper

[Sandy Harper]

I thought it was going to be a good day to get on with some serious modelling today, with the rain lashing against the modelling room window. How wrong can you be? Although I did spend most of the day in the workroom, I don't seem to have achieved a great deal as far as the Barney was concerned.

 

I started of by cutting out the fold-up etch to represent the piano door at the front of the smoke box. Well that was a joke! I think it was an aberration of the kit designers imagination on both what it was supposed to looked like, and what it was going to fold up into.

 

After a vain attempt at trying to fold the stupid thing I binned it, and scratch built one from the drawing Filed down hand rail knobs were used for the handles. The only other items added today were the front foot step back plate, and treads, and the rear footstep treads.

 

About an hour or so was also spent on the lathe turning down a lump of brass bar to make a pin to line up the tracks on the turntable fiddle yard for our club layout. It had to be a close siding fit at 6.8mm. That of course left me with a huge pile of brass chippings all over the lathe so a good clean down was carried out at the end of the job.

 

 

 

Regards

Sandy

[Sandy Harper]

Quite a good morning at the work bench today.

 

The upper works were all marked out and holes drilled for handrails, clack valves, feed water valves and whistle. You have to do this yourself from a drawing. No half etched hole marks!

 

The handrail knobs were all soldered in, without the rails at present.

 

Next I looked at the smoke box door casting but, after giving it a clean up, I was not too happy about the shape of the door. Fortunately a root through the spares box produced a much better shaped item and you can see the difference in the photographs.

 

 

 

 

 

 

 

 

I always feel that it is a seminal moment when the 'lum' is attached to the loco. A bit like the toping out ceremony performed by European builders when they get a roof on a new house. Ignoring elf and safety, they fit a Christmas tree to the top of the roof and then all go up for a bit of a party with copious amounts of beer! I'm off to my Granddaughters birthday party this afternoon, so no beer till later!!

 

[jim.snowdon]

Sandy,

 

Now that you have soldered in all of the handrail knobs, how do you fit the hanrdail where it passes across the front f the smokebox?

 

Second, and I won't claim to be an expert on these locos, but it appears that you have the handrail going straight over the top of the firebox washout plugs. I appreciate that it was not at all unknown for the draughtsmen in the Drawing Office to forget the practicalities of some fairly routine jobs, but I can imagine that having the plug directly under the handrail would have gone down a bomb with the shed staff from the extent to which it would get in the way of removing and reinstalling them on boiler washout days.Regards,

 

Jim

[Sandy Harper]

Sandy,

 

Now that you have soldered in all of the handrail knobs, how do you fit the hanrdail where it passes across the front f the smokebox?

 

Second, and I won't claim to be an expert on these locos, but it appears that you have the handrail going straight over the top of the firebox washout plugs. I appreciate that it was not at all unknown for the draughtsmen in the Drawing Office to forget the practicalities of some fairly routine jobs, but I can imagine that having the plug directly under the handrail would have gone down a bomb with the shed staff from the extent to which it would get in the way of removing and reinstalling them on boiler washout days.Regards,

 

Jim

Hi Jim

 

My method of doing such handrails is to make them in two parts with the join in the handrail knob above the smoke box door. I find it so much easier than trying to achieve the subtle curves all in one go.

 

The drawings and photographs of this particular loco clearly show the wash out plugs in line with the handrail. I agree, must have been a pain for the shed staff.

 

Regards

Sandy