Cherry's workbench - Connoisseur Jinty in Scale7

A quick precis of my Scale7 Jinty build as reported on the previous incarnation of RMweb. Unfortunately domestic commitments severely curtailed any modeling over the last few months so no more progress to date. However the bulk of house updates are now complete so hopefully I can get back to my workbench. It was a stark reminder when transferring this thread over that this "quick" kit build has taken over a year and it's still not finished. However I'm itching to get started on my next project so it's an added incentive to get this finished.

original page on Old RMweb

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??? posted on Sat Sep 27, 2008 11:11 pm

Time for a report I think on my next project - a 7mm Connoisseur Jinty built to Scale7 standards. Hopefully it'll prove interesting for someone. I don't intend to do a blow by blow account of the kit, more of a review of converting the kit to Scale7 standards and noting a few of the extras required to finish the kit.

So to start with the chosen prototype. I'm looking at building a few loco's round the Birmingham/Gloucester territory. A little bit of digging got this photo of 47276 from the Lickey Incline Photobook as a suitable subject to model.

Courtesy of http://lickeyarchive.photobook.org.uk/p31057401.html

The choice of loco was in part governed by the available wheelsets from the Scale7 group.

So the kit purchased was from http://www.jimmcgeown.com. The kit supplied as standard is a rigid chassis however I much prefer a sprung chassis which is the first modification. I've tried individual sprung hornblocks in the past but I always find them fiddly to set up accurately. Several of them use small coil springs and I've always struggled to fit them in and get a reasonable amount of movement without them being too soft. Compensation looks attractive as it was often used on the prototype but this was usually combined with the springing. So to cut to the chase, I intended to build this loco with "continuous springy beams", http://www.clag.org.uk/beam-annex3.html, a sprung chassis with compensation. It looks an attractive solution so this is going to be a bit of a test bed for me. So a set of fourtrack brass hornblocks were purchased.

The second modification are the connecting rods. For me valve gear is steel, the only thing that looks like steel is steel, no matter what you do to nickel silver it doesn't look like steel. I'd would have liked to machine the rods from steel but currently I don't have the necessary machinery. Also the etchings in the kit for the conn rods didn't look right. The diameter of the bosses looked much too big for me. After a bit of searching I settled on using a set of etched steel rods from Slaters. If anything they came out slightly "spindly" but capture the delicate nature of the rods quite well, plus they are the right colour!

All comments and questions are gratefully received. Also I'm hoping that this information will encourage others to have go a kit bashing and show that Scale7 isn't that difficult, so if I seemed to have glossed over anything then please ask for more details. I'll gladly fill in details as required because it really isn't that difficult.

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??? posted on Wed Oct 01, 2008 12:19 am

Next installment:

So progressing with the chassis first. I know some builders, including professional builders, that like to start with the body work first. Indeed the Connoisseur instructions start with the body first and finish with the chassis but I think this is the wrong way to go. Admittedly it's more glamorous than the chassis and you get something together quickly but I believe it causes problems further down the line. When you do get round to building the chassis it creates difficulties which could have been avoided, this usually seems to be solved by taking a slitting disc to the inside of the bodywork which I'm never comfortable with. Anyway off my soapbox and onto the chassis.

In this first photograph I have used a little bit of solder at each end to tack together the two frame etches from the kit. I actually used the bearing bushes supplied in the kit through the axle holes to locate the two frames. Once soldered together I then used a square and odd-leg calipers to mark out the cutouts required for the hornblocks. The one on the left has been cutout using a piercing saw. The photo also shows the Slaters coupling rods nearly complete ( more on that in a minute). Also the 3 hornblocks along the bottom have steel pegs in them. These are used to set the hornblock spacings, the finished coupling rods sit on these pegs. I turned these up on my lathe but similar chassis dowels are available from various 7mm suppliers.

The next photo shows the frame cutouts completed and the 2 frame pieces separated. Ive included this one to show the coupling rods. The Scale7 crankpins are supplied with a brass bush. On top of the crankpin this adds a bit to the clearance diameter required in the coupling rods. The right-hand boss on the top coupling rod shows how much had to be drilled out! This was a time to be brave as there isn't a lot of metal left! You have to be confident and quick drilling this out. As these rods are several etchings soldered together if you took it easy then the heat build up from drilling would melt the solder and separate the etchings as I found out.

The final photo shows the hornblocks ready for soldering to the frames. The coupling rods are finished and located on the steel dowels on the top frame. A nice 75 watt Weller soldering iron was used to sweat these to the frames. Note when soldering anything like this, a thin frame and a glorious heatsink of a hornblock use the iron to heat up the heatsink to get a good joint. If you put the iron on the thin frame then you'll never get enough heat into the brass casting to get a good joint. The lower frame has a bit of spring wire laid out to try and get a feel for how the springy beams are going to work.

So I'll try to cover the springy beams in the next installment. However I'm off to Leamington for a couple of days on a training course so apologies in advance but probably be the weekend before any more updates, or responses to any queries. Again I'll re-iterate if anyone is considered kit bashing or scratch building and feel that I've glossed over anything then please ask, I'll gladly expand on any part if required.

Regards

Adrian Cherry

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??? posted on Wed Oct 08, 2008 11:35 pm

Back to the kit, luckily the CLAG website has a set of dimensions for the 8'0"-8'6" wheelbase in setting up the pivot points, these were scaled up for 7mm. So on the top of each hornblock I soldered a small piece of brass angle. I then threaded a length of silver steel through adding in extra brass L-pieces for the pivots. I then set the hornblocks in position for the right ride height and then soldered the pivot points at the positions previously marked. I then replaced the silver steel with the spring wire.

This was surprisingly rapid once I'd decided how to do it. Probably 30 minutes to make the brackets and then an hour of set up and soldering completed the job. It was great to see very quickly a working system, pushing up on an outside hornblock, you could feel the springing and also see the centre hornblock move down slightly in compensation.

The frame spacers in the kit are far too narrow for S7 so I cut a strip of 18thou nickel sheet 28.5mm wide for the new spacers. Having put the kit together I think I could have managed with 29mm frame spacers. The nickel silver strip was then trimmed to length and folded similar to the kit supplied spacers and then soldered to one frame.

I was then ready to solder the frames together. Here's my super deluxe chassis alignment jig, three 12" lengths of silver steel. I've never used any of these fancy alignment jigs, too expensive for me, especially when I have a nice cheap solution that works fine for me. So the chassis is placed inverted on a glass plate to keep it square. The silver steel rods are pushed through the hornblocks. Now because of their length they will amplify any error in the hornblock alignment.

Looking along the length of the chassis all three should lie in the same plane. If one sticks up then it needs adjusting. Similarly in plan view the three rods should be parallel.

Once soldered up, I dropped in the wheels and added the coupling rods.

On the bench it all ran smoothly but running it down the test track revealed one slight tight spot. The usually trick to find which joint is binding is to waggle each coupling rod. I quickly found the culprit but when waggled the rod freeded itself up which was a little strange. It seems that the brass bush on the crankpin was a bit wider than the thickness of the coupling rods. As long as the rods were tight up against the wheels it was fine but as soon as the rod moved sideways on the crankpin it started to bind. So a little judicious filing to reduce the height of the brass bush stopped any lateral movement on the crankpin and resulted in a nice free running chassis.

So first impressions of the bendy beams is very encouraging, it was very simple and quick to build the suspension. I have what seems to be a sweet running chassis. Dropping the wheels out of the chassis is like a quick release system, because there are no keeper plates or retaining screws it's just a case of pulling out the the two wires and the wheels drop out. So I've still to finish the kit to test it in operating conditions but I think I'll be using the system on my next scratchbuild effort.

Regards

Adrian

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??? posted on Fri Oct 10, 2008 11:51 pm

Now you're into the mysterious art of jig building! Actually all I did was knock a couple of panel pins into a block of hardwood. These provided a stop against which I could push the various laminates with another smaller block of wood whilst I soldered them together, I used a couple of cocktail sticks on the holes to keep them aligned. The silhouette in the photo should illustrate where the rods were placed, the burn marks are where the iron was placed, pushing the rods onto the stops.

Adrian

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??? posted on Wed Oct 22, 2008 11:27 pm

The latest progress now I have a rolling chassis is to make a move on the footplate. With the wider frames in S7 if the footplate was left as supplied then it'll will overhang too much under the boiler. So as shown below a bit of the footplate is cut back, the lefthand side has been cutback whilst the righthand side is still as supplied, the marked line shows how much needs cutting back.

After pressing out the rivet detail the side valances and buffer beams were soldered on. This was all as per supplied in the kit, the only mod here was to move the rear chassis nut forward. This was something mentioned in a previous posting in this forum, if you put the rear chassis nut where indicated because of it's close proximity to the rear buffer beam then it leaves you a little short of space to fit in a sprung coupling hook.

I then started the main bodywork by tacking the inner tank sheets and front spectacle plate to the footplate. The front spectacle plate had a few extra rivets added. There aren't any half etched on the spectacle plate so I just worked off the photo's I had. This requires another mod for S7, with the wider wheel track the centre wheel is getting close to touching the inner sheets.

So before soldering the inner sheets they were cut back to give a bit more clearance for the centre drivers.

Adrian

??? posted on Thu Oct 23, 2008 11:12 pm

Thanks for the feedback, it's appreciated.

Yes I use a "proper" rivet tool, in fact I made my own! Many moons ago my Dad use to make tools for the scratchbuilder (Cherry Scale Models) one of which was a rivet tool. I spent many a Saturday making rivet tools and rolling bars to earn a bit of pocket money, so I made an extra one for myself. Although it's since been converted to "silent running". I have two young kids and the rhythmic tapping of the hammer was too noisy late at night so it got converted to lever press operation. My first attempt put the lever at the front in much the same way as many other rivet presses. This arrangement flagged up two problems, first pressing down on the lever tended to tip the rivet press forward, secondly the hand on top of the lever tended to obscure the the view to the punch and die.

So "mark 2" silent running moved the fulcrum point forward with the lever arm to the rear. This works a lot lot better, the rivet press doesn't tip up when in use, I can use it free standing and the hand on the lever arm is to the rear of the tool and out of the way of the punch and die.

If you're looking at getting a a rivet tool I suggest you try them first to find one that is comfortable for you.

Adrian

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??? posted on Sat Nov 08, 2008 1:21 am

A little more progress to report. The observant may have noticed that the loco I picked to model was one of the few batches built with the sand box filler on the top of the tank so there is no "keyhole" in the side of the tank. The etches in the kit have the "keyhole" etched in. I couldn't see any easy way of filling in the "keyholes" so I decided to make a new set of tank sides from a bit of 15thou nickel silver sheet. I cut a strip the same height of that in the kit, then rather than fold the nickel the front and sides were cut as separate items. Holes for the handrails will be drilled out later. So it's a little extra work but it makes it a little bit different to the standard kit.

After a bit of rivet detail the tank sides were tacked onto the footplate in position. I usually leave them tacked in position for a week or two so that I can see if it looks right. I find it usually takes a couple of days to see if something doesn't quite look right. Once I'm happy with it then I'll solder all the joints up, probably need to get the rear tank on first to see if it looks right.

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??? posted on Wed Nov 26, 2008 11:44 pm

Found a bit more time to make progress on the bodywork, this time making up the rear bunker. Looking at the prototype the folds in the rear bunker aren't sharp, so I have tried to put in a slight roll by folding it over some soft jaws in the vice and then stroked a bit with a hammer.

With these main body work bits I like to tack them in place and spend a few days looking the model to see that it looks right. On this photo the verticals at the back makes the bunker look like it is tipped forward. It might need a bit of tweaking before fixing properly.

I was going to crack on with the cab but I realised that the detailing around the cab doors is sparse. So I think I'll add a bit more detailing like doors first.

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Back to the Jinty. I've switched to the front as the cab will require some detailing before sorting out the roof. So to the smokebox, the basic unit went together without any problems.

I soldered together the inner wrapper on the frame, the edges were then given a nice large radius before fitting the outer wrapper with the rivet detail. It was only after rolling the outer wrapper that I realised there were 4 half etched rivets to be pressed out for the steam ejector ( or whatever it is ) on the right hand side of the smokebox. Fortunately being a thin wrapper it wasn't too difficult to get it in the rivet press. So the finished article, although still needs a bit of tidying up.

Adrian

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??? posted on Thu Jan 15, 2009 7:48 am

I've managed to make a little more progress on the boiler and firebox.

The firebox has a front and rear former, the front one has an extra etch for additional thickness to allow filing of the radius when complete. The firebox wrapper was formed around a piece of 3/16" steel bar held in the vice. The boiler was pre-rolled and only needed a little tweaking to get a couple of supplied formers fitted inside.

If you look at previous photos of the side tanks, the inside walls have little etched tabs which are bent at 90 degrees inward. These provide a little step to drop the firebox and boiler onto, so that's what I did to get an idea of what the loco would look like.

For some reason it didn't look right. After a few minutes looking I decided that it was slightly too low, the rivited beading around the firebox should almost touch the cab windows, and the boiler and smokebox step was too large.

Finally with the dome on, the top line from cab roof to dome top wasn't horizontal, it was pointing down. To test out this I cut a small bit of 1mm plasticard to rest on the tank tabs and jack up the boiler and firebox by 1mm. This looked a lot better to me, although I haven't fixed anything down yet. With the boiler raised by 1mm the dome is then closer to being the same level as the cab roof. I'll stare at it for a couple of days before tacking everything in place.

Adrian

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??? posted on Wed Jan 21, 2009 7:44 am

Whilst I'm sorting out the boiler height, I made a start on adding some detailing to the firebox.

The kit is supplied with a couple of white-metal castings for the mud-hole door bolts. The loco's seem to have had a cover plate, often circular although I have seen some square ones, over the mud-hole door. It seems that they often went missing are just weren't always replaced after a boiler clean. So it's one where we need to check back with the photo's of the loco we're modelling. The items supplied with the kit seem to be for modelling the case where the cover plates are missing.

I couldn't see anything in the etchings so I made up some cover plates. Basically I used 6thou half-hard nickel sheet, marked out 4 circles, 1/4" diameter. Before cutting out I pressed in a few rivets, I then cut out the discs using tin snips. A final fettle with a file to get a circular disc, which was then bent round a 3/16" steel bar, finished off by soldering to the fire-box.

Hopefully the photo shows the progression of the plates, one down three to go!

Adrian

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??? posted on Fri Apr 03, 2009 11:01 pm

After a long interlude I've been shamed into action and spurred on by the Ministers rapid progress. So time for a little progress update on the Jinty.

I finally sorted out the boiler height, deciding it was too low so it was was raised by 1mm and soldered in place. The looked a lot better but led to the next problem, the brackets between the boiler and the side tanks were mismatched. Also looking at the prototype photo's the step between the top of the tanks to the tank beading was less than the kit. So once again out came the nickel sheet an new tank tops were cut out and soldered on top of the existing tanks.

So it was all starting to come together when I hit the next stumbling block. the cab sides and roof. The prototype photos show a distinct roll from the cab sides over to the roof section. In the kit there are a couple of etchings for the cab sides and a whitemetal casting for the roof. On the etching there is a slot at the top of the cab side to aid folding, I couldn't see an easy way to get a seamless join from cab side to roof and so it got parked to one side to cogitate over.

There was nothing for it but to replace the cab sides. A piece of nickel was cut out the correct width but slightly over tall. I then folded the top part round a 1/4" steel bar, followed by the rivet detail. I find riveting close to the edge of a sheet causes a bit of distortion to the edge, so in these cases where possible I put the rivet detail in before cutting. So after the rivet detail was added the doorway was cut out in the cab sides finishing off with the beading. The rear cab spectacle plate was built as supplied in the kit.

Once again everything is tacked in postion, getting this looking right is important so I like to spend a few days looking at it from various angles to make sure I'm happy with it. I'll make the roof from another sheet of nickel sheet, the cab sides have been cut back to where there is a rain gutter which will hide the join between the roof and the sides.

So that's where I'm up to at moment. Once the cab is in place I can then crack on with the detailing as I think that is most of the superstructure sorted out.

Regards

Adrian

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??? posted on Sun Jun 07, 2009 12:42 am

Just been over to the Guild show at Halifax today. I bumped in to a really good friend that I hadn't seen for a while. He was asking about progress on the Jinty which prompted two thoughts, thanks Rob! The first was that it was nicw to think that some people are actually following this thread, second was the realisation that I hadn't posted any updates recently. Progress has been made on all the etched detailing, I like leaving the whitemetal castings to the end.

So for a few details on progress, more to follow once I've got the photo's sorted.

First up is the coal rails around the rear bunker. This is one area where you definitely need good photo's of the specific loco you are modelling. The coal rails seemed to have endless variations, I feel some sympathy for the kit manufacturers at this point for even something as simple as coal rails I reckon I've seen more than a dozen different variations on the Jintys when I start looking at the photos in detail. They can't possibly include every variation in the kit, so just to emphasise the changes detailed below are due to the prototype I've chosen to model rather than a reflection on the kit.

Any way with that caveat the following is the coal rail as supplied in the kit. The red makings indicating the bits I've removed from the supplied etching.

The top plate has chamfered corners rather than rounded corners and at the rear there was no vertical support post in the middle so this was removed. Once again refer to the prototype photo's - they were all different! The result, note I've also filled the half etched slot for the rear step in the middle of the rear tank with solder, again the rear step has several variations so check the prototype. As luck would have it my chosen loco has it over at the side above the pipework.

Moving forward I've added the beading to the top of the tanks and a bit more of the supplied detailing. This all went well and is just using stuff supplied in the kit. The only extra bit added here is the small bit of riveted angle at base of the cab side plates. This was just a bit of machined angle from Eileen's Emporium, embossing the rivets tends to distort it a bit so it was straightened with pliers. The machined angle often seems a bit on the thick side so it was then dressed with a file to thin down the thickness.

Moving forward I've added a bit more detailing in the shape of handrails and steps.

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??? posted on Thu Jul 23, 2009 10:28 pm

Been making a little progress on the tank detailing. Thanks to Mike for the photo - I thought I'd crack on with the fire iron bracket plus others. These delicate bits always seem a bit vulnerable to me, the obvious way of making it was just a vertical piece of wire with another curved piece butt jointed to the side but this seemed a recipe for trouble, it would probably fall apart when soldering it to the loco or be the first bit to get damaged when handling the loco. So first option considered was silver-soldering the joint but all that gear is packed up in the shed at the moment. So option two was to file a flat on two pieces of nickel silver wire so they were half round in profile, one was then bent through 90 degrees.

The two were then clamped together in a pin chuck for soldering.

Final cutting and shaping - hopefully fairly robust.

Then fitted to the tank, additional detailing includes the lifting plates, scratchbuilt from a few strips of nickel silver sheet, lubricators and pipework. The pipework was a pain, there was much cursing and swearing trying to fit the pipes into the lubricators.

Finally got the steps fitted as well so hopefully it's looking more like a loco.

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