alcazar
Guest
And ended up selling at least three pairs for whoever the stockist is, LOL.
7mm On Heather's Workbench - small and perfectly formed
- Thread starter Heather Kay
- Start date
Dave Bowden
Western Thunderer
I forgot to mention I have no association with the seller!!!
SimonT
Western Thunderer
Dave said
The photographs are very useful. The springs are a column of coils, not volute, and the loco has internal blackout shutters. Need to look at more books....
Simon
I know the theory, I have the tools and yet every time it ends up being a long process of tweaking to get all the bends in the correct place and in plane!
The photographs are very useful. The springs are a column of coils, not volute, and the loco has internal blackout shutters. Need to look at more books....
Simon
Heather Kay
Western Thunderer
Heather Kay
Western Thunderer
Well, that went well. 
Replacement etches are like hen's teeth, apparently. I won't go into the reasons I was given, but rather than wait on the off-chance Laurie finds a set lurking on a dusty shelf somewhere, I decided to fix the problem this end.
Let me explain. Basically, I had a complete brain failure on one side of the frames, filing off rivet and bolt detail that ought not be filed off. Thinking about it, most of what I had destroyed was essentially behind the wheels, and I could repair it by drilling out and soldering in wire of suitable diameter.
I spent a while carefully marking out the missing bolts and rivets, based on the frame overlay I hadn't messed up. Having centre-punched everything, I set up the venerable little Proxxon bench drill and set to with a 0.7mm bit.
Things went well for the first axle slot, but strange noises suddenly came from the drill. On investigation, the drive belt had begun to disintegrate. We've only had the thing a decade! Cue an hour searching for spares on the interwebs, without much success. I'll be on the blower to Chronos in Dunstable tomorrow to see if they stock the belt, or the one for the replacement model which I hope is the same size.
Ho hum.
Replacement etches are like hen's teeth, apparently. I won't go into the reasons I was given, but rather than wait on the off-chance Laurie finds a set lurking on a dusty shelf somewhere, I decided to fix the problem this end.
Let me explain. Basically, I had a complete brain failure on one side of the frames, filing off rivet and bolt detail that ought not be filed off. Thinking about it, most of what I had destroyed was essentially behind the wheels, and I could repair it by drilling out and soldering in wire of suitable diameter.
I spent a while carefully marking out the missing bolts and rivets, based on the frame overlay I hadn't messed up. Having centre-punched everything, I set up the venerable little Proxxon bench drill and set to with a 0.7mm bit.
Things went well for the first axle slot, but strange noises suddenly came from the drill. On investigation, the drive belt had begun to disintegrate. We've only had the thing a decade! Cue an hour searching for spares on the interwebs, without much success. I'll be on the blower to Chronos in Dunstable tomorrow to see if they stock the belt, or the one for the replacement model which I hope is the same size.
Ho hum.
Dog Star
Western Thunderer
Are Hen's teeth worth about the same as the JLTRT Platinum Guarantee?
Heather Kay
Western Thunderer
Like I said, I won't go into the reasons given, because I can't verify them at this distance. I'm prepared to accept them at face value, and Laurie tells me the company is looking at resolving the issue for the longer term.
Rob Pulham
Western Thunderer
You beat me to it Graham - it sounds like the HP warranty that guarantees next day fault fix until you read the small print which says "if the parts are in the country" it once to us 6 months to get a laptop fixed....
Heather Kay
Western Thunderer
I managed to achieve a rolling chassis in yesterday's afternoon session.
There's always a worry - especially with me - that critical things end up out of whack during this stage. Happily, the frames went together very smoothly. The spacers fit their slots neatly, and all I had to do was make sure the tabs were fully seated, check alignment with a small square, and run some solder along.
The other worry is where the etched bearing holes and springs have been lopped out to make way for the cast guides and springs. Again, some fettling was needed to fit the guides, followed by some filing to level things as the centre axle rode a little lower causing the chassis to rock.
Next step is to fit the suspension springs - no instructions for this bit, remember, so the brainbox is having to think things out. Once the suspension is sorted out, the cast keepers and springs can be fitted, then to motorise the beastie.
There's always a worry - especially with me - that critical things end up out of whack during this stage. Happily, the frames went together very smoothly. The spacers fit their slots neatly, and all I had to do was make sure the tabs were fully seated, check alignment with a small square, and run some solder along.
The other worry is where the etched bearing holes and springs have been lopped out to make way for the cast guides and springs. Again, some fettling was needed to fit the guides, followed by some filing to level things as the centre axle rode a little lower causing the chassis to rock.
Next step is to fit the suspension springs - no instructions for this bit, remember, so the brainbox is having to think things out. Once the suspension is sorted out, the cast keepers and springs can be fitted, then to motorise the beastie.
3 LINK
Western Thunderer
Morning Heather,
I can see from the picture that the horn guides are different to the one's supplied with my kit, and also I noticed in an earlier post that you said there were instructions as to what motor gearbox combination would fit, this was missing from my earlier kit so maybe there has been some updates.
If I could ask a couple of questions, did you use a chassis jig for alignment of the axles in the frames?, and did you mark out a datum line for the fitting of the horn guides into the frames?
I cannot help you out with the suspension springs as I replaced the horn blocks and guides with the Finney versions, but from what I remember there was an assortment of " various springs " included, and most of those have ended up being used for other projects
.
Regards,
Martyn.
I can see from the picture that the horn guides are different to the one's supplied with my kit, and also I noticed in an earlier post that you said there were instructions as to what motor gearbox combination would fit, this was missing from my earlier kit so maybe there has been some updates.
If I could ask a couple of questions, did you use a chassis jig for alignment of the axles in the frames?, and did you mark out a datum line for the fitting of the horn guides into the frames?
I cannot help you out with the suspension springs as I replaced the horn blocks and guides with the Finney versions, but from what I remember there was an assortment of " various springs " included, and most of those have ended up being used for other projects
.Regards,
Martyn.
Heather Kay
Western Thunderer
Hi Martyn.
I admit to not using a jig to align anything. Now, that's either testament to blind luck, or as to how good the original kit is.
As you say, the kit frame etch includes fixed holes for round bearings and flat etched spring detail. The kit included the cast hornguides and springs, and it seemed a shame not to use them. To mark out cutting the main frames to accept the hornguides I simply sweated the overlays in place and use them as the datum to cut and file to.
I have had to file back the inside top surface of each hornguide bearing surface on the centre axle to get things to sit properly flat at this stage. I know the suspension would probably cover the worst excesses, but it doesn't hurt to have a square and flat chassis to begin with. I measured the distance from the top of the frame to the bottom of the bearing surface (I'll photograph and explain later), and filed the centre ones down to as near as I could manage.
It seems to have worked. The chassis rolls quite smoothly, there's little sideplay, and I have high hopes it'll be a smooth runner when it's got the motor and gearbox.
Which reminds me, the motor and gearbox I selected isn't specifically mentioned by JLTRT. It is marketed by Slater's as "for JLTRT kits". The actual one is the GB40S, all metal, spur and crossed-helical gears and Mashima 1824 motor. All I have to do is drop it out of the box, fit it on the relevant axle and wire it up. This is the kind of engineering I like!
flexible_coupling
Western Thunderer
I'm very interested to see this build develop, as I'll need a 57xx to model 7754 for Mountain Ash (NCB). If you'd be so kind as to show a few clear snaps of the suspension springing when you complete it, the future version of myself would be grateful!
Dave Bowden
Western Thunderer
Hi Martyn.
I admit to not using a jig to align anything. Now, that's either testament to blind luck, or as to how good the original kit is.
As you say, the kit frame etch includes fixed holes for round bearings and flat etched spring detail. The kit included the cast hornguides and springs, and it seemed a shame not to use them. To mark out cutting the main frames to accept the hornguides I simply sweated the overlays in place and use them as the datum to cut and file to.
I have had to file back the inside top surface of each hornguide bearing surface on the centre axle to get things to sit properly flat at this stage. I know the suspension would probably cover the worst excesses, but it doesn't hurt to have a square and flat chassis to begin with. I measured the distance from the top of the frame to the bottom of the bearing surface (I'll photograph and explain later), and filed the centre ones down to as near as I could manage.
It seems to have worked. The chassis rolls quite smoothly, there's little sideplay, and I have high hopes it'll be a smooth runner when it's got the motor and gearbox.
Which reminds me, the motor and gearbox I selected isn't specifically mentioned by JLTRT. It is marketed by Slater's as "for JLTRT kits". The actual one is the GB40S, all metal, spur and crossed-helical gears and Mashima 1824 motor. All I have to do is drop it out of the box, fit it on the relevant axle and wire it up. This is the kind of engineering I like!
Hi Heather
Was an ABC G/B and Canon motor not an option for this kit?
Dave
Heather Kay
Western Thunderer
Probably. I didn't really look too far, because like DCC gearboxes make my head spin. The simpler things are for me, the better.
For reference, and I'm possibly repeating something from earlier in this thread, the kit's instructions refer to Markits motor code 1833, gearbox code 1240, and Slater's wheels. Since the kit is about ten years old, and the instructions still show the London fax number, I assume this is old information. Slater's have a specific motor/gearbox "for JLTRT kits", so it seemed ideal for the job. A quick inspection and trial fit (read "holding various components up in relationship to each other") shows things seem fit quite nicely for driving the rear axle with motor sitting in the space cast behind where the backhead goes.
Not much building going on here today, but plenty of thinking about brake gear, pickups and springing.
3 LINK
Western Thunderer
Hi Martyn.
I admit to not using a jig to align anything. Now, that's either testament to blind luck, or as to how good the original kit is.
Hello Heather,
The only reason I asked was because I noticed there was no crankpins in the wheels, and I know there are other ways of setting up the alignment of the axles but a lot of folk use the coupling rods method, so being the nosey s*d I had to ask
.Like I said in the earlier post, the only option that I knew would fit regarding the motor/gearbox situation was the Markits " foldy uppy " etch type. Not my gearbox of choice by any means, but saying that I have still got the loco and it does run smooth and quietly.
Keep up the good work,
Martyn.
Heather Kay
Western Thunderer
Ah, yes, I haven't got as far as crankpins and coupling rods yet. I expect all kinds of pain, followed by the traditional methods of fixing it.
I expect all kinds of pain, followed by the traditional methods of fixing it.
Dave Bowden
Western Thunderer
Hi HeatherAh, yes, I haven't got as far as crankpins and coupling rods yet.
I've recently started to use Derek Mundy heavy duty loco crankpins, £10 a set of 6. Which ever type of rods you chose these are a better fit in the coupling rod holes, they also don't have nuts on the ends, a nice flat face.
See the attached photo.
Dave
Steph Dale
Western Thunderer
Dave,
The Derek Mundy crankpins do work well, I agree. The 'nice flat face' is, however, no more prototypical than a visible nut...!
Steph
Heather,
I venture that you'll find getting the chassis to run smoothly under power will be tricky if you haven't jigged the hornblocks to the coupling rods. You won't need the expense (and considerable showing-off ability) of one of the chassis jigs, but a set of Metalsmiths or Meteor axle jigs would seem to be a 'must'.
Steph
The Derek Mundy crankpins do work well, I agree. The 'nice flat face' is, however, no more prototypical than a visible nut...!
Steph
Heather,
I venture that you'll find getting the chassis to run smoothly under power will be tricky if you haven't jigged the hornblocks to the coupling rods. You won't need the expense (and considerable showing-off ability) of one of the chassis jigs, but a set of Metalsmiths or Meteor axle jigs would seem to be a 'must'.
Steph
Eastsidepilot
Western Thunderer
Agree Steph, Heather I have never used an expensive chassis jig just the rods and a set of axle jigs, I turned my own set with parallel ends that fit the pre-reamed holes in the rods.
Col.