Sorting out the accumulated part done and not yet started things workbench

simond

Western Thunderer
Point 1 - I think it should be flush. Previous advice, or deepen countersink in the axle, or a couple of strokes of a file across the axle end.

Point 2 - you will need a washer to move the rod outboard, or it will catch on the screw head, a/o the boss.

Point 3 - I do. You don’t need a milling m/c. Second hand Duchess. But the little jig helps lots.

Atb
Simon
 

Steph Dale

Western Thunderer
Martin, you.may need to shorten the square section on the end of the axle if the screw won't tighten down fully. If that's one of the old blackened screws I'd also check it's formed properly, many weren't and the new bright steel ones are much more consistent.

Steph
 

Allen M

Western Thunderer
Hi Martin
Two things to check for the screw head being high.
First - drop the screw into the wheel and see if it is flush. If yes OK, if no then a bit more countersink is needed.
2nd - screw the screw into the axle without the wheel. Make sure the distance from the inner edge of the square to the end of the outer screw head is less than the thickness of the wheel. If yes then OK. If no the the hole will need to be made deeper or easier the screw shortened.
I would check both even if the problem appears to only one of the conditions.
Hope this helps.
Regards
Allen Morgan
 

Martin Shaw

Western Thunderer
Many thanks for all the helpful comments, I was going to do something today but the weather was such that gardening beckoned, even if that does sound unlikely.
Regards
Martin
 

Martin Shaw

Western Thunderer
Firstly I read everyones contribution and then I followed the instructions and it all pointed to the countersink being insufficiently deep. Very careful measurement suggested that I only had about 10 thou to play with before the screw was fully home so I very careful took a scrape out with a sharp countersink, with as you can see significant improvement. I can always turn a gnats off the axle end if necessary but it looks in this case as though it will be ok. All useful when I turn my attention to the other Slaters wheeled locos in due course. Thanks very much chaps.
Regards
Martin
IMG_0732.JPG
It should be obvious but in case, the modified one is on the right.
 

Martin Shaw

Western Thunderer
Hi Folks
I'm sorry there hasn't been an update recently, I've been rather unwell although thankfully not with this wretched pestilence, but it has kept me away from the bench. I'm better now.
Picking up from 6 weeks ago crankpin bushes were bought and then modified. Firstly mount the bush in a collet in the lathe and then with a 10BA tap in the tailstock rotate at 50rpm and thread them. This sounds scary but in fact worked well, I wouldn't do it in steel but I suspect the major issue is alignment rather than power, anyway no broken tap.
The collet is then transferred to a collet block held in a vice on the mill, this allows easy 180 deg rotation to cut two flats. A 10BA steel screw is used as a mandrel, it seemed to resist sideways pressure.
IMG_0784.JPG
Then it's all transferred to the lathe to skim the length
IMG_0785.JPG

This is done using a bit of brass rod threaded 10BA as a sacrificial mandrel and a 1.5mm drill shank to estimate the finished length that I wanted to be around 1.6mm. Out of 8 tries I got 6 usable ones. Bushes and other bits in hand it was re-assembled and surprisingly for me worked first time. It still runs better in reverse than forward, a slight growlyness that I can't actually be bothered with, it's sweet enough.
There is a slightly philosophical question though,
IMG_0787 (2).JPG
A rebuilt one, pro, probably looks more prototypical, con, a lot of effort
IMG_0788 (2).JPG
12BA standard, a lot less work and is it that noticeable. I don't know the answer and had I found the dry joint before I pulled it all apart I wouldn't have changed it, some food for thought.

IMG_0789.JPG Anyway she's working again and here awaits a green flag for the afternoon service. I really must paint the d*** thing.

To this, which you'll have seen before
IMG_0790.JPG
When I built it I filled the tanks with lead shot which since they are open internally hasn't shown any sign of problems. The boiler, forward of the motor compartment is also filled with shot, although in this case just inserted and the hole in the boiler former sealed with plasticard so I can extract it. All up it weighs 2lbs or 900grams if you wish and after prolonged running the firebox is as warm as the full size one. Do the collective think this is due to excess weight or lack of ventilation?
My best wishes to you all
Martin
 

Martin Shaw

Western Thunderer
I ventured into the workshop at about 10am to find the temperature was already 23 deg C, and since the weather forecast was suggesting the hottest day in the West of Scotland since Dante I put the C15 into ponder mode. It probably wasn't the hottest day, but it was b***** hot for this part of the world, so instead I started re-reading L.T.C. Rolt's Landscape with Machines which is a very fine read if a bit idiosyncratic. Under the parasol with the odd glass of something passed the day well. Maybe tomorrow.
Kind regards
A slightly reddened Martin
 

Martin Shaw

Western Thunderer
Generally the West of Scotland is a pleasant enough place to live all be it the winters are usually long and wet, the last one was, but 4 consecutive days with the temperature in the mid twenties and nary a cloud to be seen has somewhat sapped the energy even if there was a will to go into the workshop. Earlyish this morning I ventured in to plan the next project, the C15 is in full running order and I don't have any desparate need to do anything to it so it went back in it's box, which I exchanged for another one that contained this,
IMG_0791.JPG
A SECR C class, presumably from a Shedmaster kit originally but with a beefed up drive train. It was another of the coarse scale models that came my way and I rewheeled it some while ago, and yet again never quite got round to finishing.

Taking the bodies off reveals,
IMG_0793.JPG

the locomotive chassis with standard worm and gear on a drive shaft running in ball races, meanwhile the tender chassis
IMG_0792.JPG
has this muckle great Crailcrest and large flywheel leading to the universal coupling for the loco. Apart from the wheels all I have added is the pickups. The reason for this arrangement is that the boiler is solidly filled with lead from the firebox to the smokebox door, it was intended to pull long heavy trains which it did. The downside is firstly that the tender is carrying a lot of weight as this graphically shows.
IMG_1366.JPG
A badly worn tender axle bearing, the rest were no better. I managed to replace the bearings but there wasn't a lot of spare material so it's a bit of a bodge.
The second issue is that the lead in the boiler is fixed and removing it requires major surgery. I could squeeze a motor/gearbox in to the firebox space but it would be on the small side and I think probably not man enough for the weight of the thing. Therefore the plan is at the moment, make a new tender inner frame with probably bronze axle bearings for wear, refit the Crailcrest and do any necessary titivation to the tender. Strip the drive train out of the loco. fit a remote gearbox and driveshaft, fit the loco brake gear which I have now found and again titivate to taste. Rather than rush in I'm going to leave it all assembled until I've collected all the new bits together, it does actually run as it is.

A question for Steph, do you think your remote gearbox would work satisfactorily in this application?
Kind Regards
Martin
 

Steph Dale

Western Thunderer
A question for Steph, do you think your remote gearbox would work satisfactorily in this application?

Martin,

Hmm. Well, it's the sort of job it was designed for; you need to be careful to mesh the gears well due to the acetal worm, but it should work fine. We do a 26:1 version as a 'special' that would probably work well. But, I've got to ask what's wrong with what you've got? If the gears are okay (they look it), then I'd have a think about replacing the universal joints and have done with it.

Steph
 

Martin Shaw

Western Thunderer
Thanks Steph, I appreciate your thoughts, they do make sense and as it works maybe there is a point in leaving well alone. Somewhere I 've got some drive components so I'll look them out and see what's best.
Regards
Martin
 

simond

Western Thunderer
I think model boat suppliers will have UJ’s in stock, or the r/c car suppliers, perhaps?

Atb
Simon
 

Martin Shaw

Western Thunderer
Simon
Thanks for that, after a hunt through the myriad of boxes I couldn't find any UJ's so I did end up looking at aero/car/boat suppliers where there is an overwhelming selection. I reall need to replicate the current fittings to allow separation of the tender and loco, I have found a possible unit from Roxey models which might do or I might make a new cup joint from a bit of steel, I fear brass might be too soft.
Regards
Martin
 

Martin Shaw

Western Thunderer
I need to take some measurements of what I've got, it looks like it was cobbled together, but thanks for the idea Steph.

Martin
 

Martin Shaw

Western Thunderer
I've come up with a plan. It's not going to be a complete reconstruction that I initially thought but neither is it the minimalist intervention that Steph advocated. The locomotive, apart from refitting the brake gear has nothing done to it. The tender by contrast is going to be changed a bit. I had a discussion elsewhere about flywheels and the general concensus was that they aren't all that beneficial, so the flywheel goes. The Crailcrest motor is vastly overpowered and was originally used because the weight of all the loco gubbins plus the desired haulage capacity demanded it, it goes as well. A new inner frame designed and made, fitted with brass bearings since the weight has dropped. A can motor mounted between the frames and arranged to drive horizontally via a new cup joint onto the loco drive shaft. Some pickups, possibly plunger and new couplings front and rear. It all works in my head, what could possibly go wrong. Right stuff to order, designing hat on.
Regards
Martin
 

Martin Shaw

Western Thunderer
The weekends work, doesn't seem very much, some doodles, two bits of NS soldered together and a half done CAD drawing, however it's coming together. I'm rather keen to finish the design work before irrevocable decisions are made, been caught out before.
IMG_0798.JPG
The choice of motor proved slightly problematic, a Canon EN22 would fit easily but at 1.4W is a bit underpowered, an 1833 would also fit but only about 2W. I had an older JH gearbox and whilst I could sacrifice the gearbox, the motor was just a bit too bulky so in the end I ordered a 1532 from MSC. This is rated at 2.9W and with overall dimensions of 20.3w by 15.4h will easily fit. It does run at a higher speed than the Crailcrest so it may well be that the loco will need regearing, I'll worry about that in due course. I think I might fire up the milling machine this afternoon.
Best wishes
Martin
 

Martin Shaw

Western Thunderer
Just to show the DO has been busy. The blue outline is obviously the motor, drive coupling and mounting plate. There are one or two critical dimensions relating to the loco to check and I may well add a centre frame space, and then dimension it for manufacture. Tis going quite well he said cautiously.
Best wishes
Martin
SECR 13ft wheelbase tender inner frames.JPG
 

Martin Shaw

Western Thunderer
I'm making the axle bearings for the tender and I have two routes to the end product. I can ream the bearings to size individually before parting off, or leave them undersize and ream them in situ once the frames are assembled. The second course does require a means to accurately hold everything, which I have, and does mean that at least in theory the axles end up at 90 deg to the frames. Am I making this more comples than it needs, thoughts welcome.
Regards
Martin
 

simond

Western Thunderer
Martin

I'd drill to size or marginally undersize and part off, install bearings and then just run a reamer through by hand to ensure that each pair are accurately aligned. I don't think it's a big deal either way, you can always stick a bit of suitable bar through the holes to align them before soldering.

I would not want to have a 6-wheeler chassis without at least some vertical play in the middle pair, however.

atb
Simon
 
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