Geoff's G3 Workbench

Spitfire2865

Western Thunderer
Any chance you could possibly fit most or all the RC bits under the frame around the motor? From pictures of the Y11, it looks pretty dark and busy under there. Probably wouldnt be able to see much of it.
 

AndyB

Western Thunderer
Trevor - it's not so much the RC gear that takes up the space (RX boards and speed controllers for the power that this loco needs are pretty small now) , it's the batteries!
Andy
 

geoff_nicholls

Western Thunderer
Andy's hit the nail on the head. I only need about 5 volts to power this thing at a crawl, but I believe it needs a lot of mhA's, which PP3's don't seem to have. In the meantime, I fitted the chain drive recommended by Steph Dale (www.motionco.co.uk), which works very well, and seems appropriate, given the way the real thing was powered.
However, that small motor isn't up to the job. Even with a 500gm weight it wasn't happy pulling three GRS wagons, there was a lot of buzzing before there was any movement. The loco does run quite happily with the motor from a GRS 02 or the MSC XL motor.
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This is okay for anyone modelling the LNER or GWR simplexes with there enclosed bodywork, but it would be nice to be able to model it with the open cab, especially as I've made a good job of etching the cab roof brackets.
Any suggestions for tiny powerful batteries and motors would be appreciated.
 

simond

Western Thunderer
Geoff,

I'm very surprised that you need such a monster motor - some (many!) years back I built a 16mm Baldwin gas mechanical - I think it was from the Wrightscale stable but could be wrong here. It was a lovely kit, with laser steel frames, etched brass and whitemetal cab and engine covers & (dummy) gearbox. I powered it with a 7mm Portescap motor/gearbox, and a 4-pack of AA batteries. The Portescap drove a vertical shaft which drove the rear axle via a pair of conical gears. Unfortunately I cannot recall the ratios of either the Portescap or the final drive, but it handled several wooden wagons competently.

I'm not sure what it is that appears in your earlier photos, but I'd expect a 6V coreless motor on an ABC or similar gearbox should be entirely enough for a few wagons. Regarding mAh, your options are dry cells, nickel metal hydride, or lithium.

NiMH are the safe option, Lithium cells of all sorts need care and respect, and a reliable battery management system and can burn your house down if things go wrong. I know the plane boys use them very successfully, and the Lipo cells can be quite a bit more compact for the same capacity, but I'd tend to the NiMH option for simplicity.

Hope this helps.
Love the work you've done on the wagons!
Simon
 

simond

Western Thunderer
Just a thought and please forgive if teaching granny, but you haven't got the chain too tight?

Best
Simon
 

geoff_nicholls

Western Thunderer
This is the first time I've fitted chain drive to a loco, so I might have made it too tight. As it is in the photo, there is slight give if you stand something light like a biro on the chain. If I add one more link, the chain almost drags on the ground. I have included a slot for a chain tensioner on the frame, but I'll stick with it as it is for the present, until I get show it to someone who has more knowledge of these things. However, if I've done it right, then fitting chain drive is a doddle.
I'm beginning to admit to myself that the problems with the motor (a canon EN22 with helical gears) are actually problems with my early wagon construction. My first wagons were from GRS. When I built them I didn't put enough effort into ensuring they ran freely. The Williams Models wagons run much more freely and the shunter copes with them. There was also a problem with a check rail causing longer wagons to get jammed.
(Cue for shameless plug of LNWR diagram 42 glass wagon which I persuaded Mike to include in his range, I feel guilty about lumbering him with it, so please buy one)
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There is now room for a four-pack of AA batteries under the footplate. And now I need to re-examine all my early wagon building. There's still 31/2 months until Lea Siding is exhibited...
 

Arty

Western Thunderer
chain3.jpg

I've used Delrin chains on my Ruston - as prototype, usually I found link addition or removal didn't give a fine enough adjustment, so slotting the motor bracket mounting on the frames, vertically gave adjustment to both chains.

chain4.jpg

batt3.jpg
AA NiMh batteries squeezed into the bonnet and a Deltang receiver/esc being so small, fitted between the frames leaving the cab clear.
 

simond

Western Thunderer
My experience in chain drives derives from teenage motorbikes, so probably not turbo-relevant, but I'd suggest that there should be a little slack. Not a link's worth, but definite movement when you prod it gently.

If you can undo the final drive gear, so the axle can rotate freely, does the chassis run free? If so, your chain isn't a problem.

If not, and always assuming the axles aren't binding in the bearings, I'd guess your chain might be a little tight. If you have a tensioner slot, I'd add the extra link and try it with that. Otherwise, an appropriately curved piece of wire might make a spring tensioner which can act gently on the upper run of the chain - though this will add a little friction, I guess.

Hth
Simon
 

geoff_nicholls

Western Thunderer
Simon, I like you're suggestion of a piece of curved wire.
Richard, I'd been tempted by that Ruston in the past. Is the kit still available?
 

Mike W

Western Thunderer
Just from the look of the chain it does look a bit tight Geoff. Based purely on the lack of droop in the picture. I have no experience of Delrin, but steel chains (also teenage motorcycles!) stretch in service, so maybe it will be OK when run in?

Mike
 

simond

Western Thunderer
Mike

I concur that it looks a wee bit tight, hence my initial query, but I doubt that the links will stretch much, which was the usual failure mode of bike chains. I guess the Delrin chain might loosen a very little, if there's any moulding flash to wear off on the gears or where the links pivot on one another, but otherwise, I'd not expect a significant change.

Best
Simon
 

Mike W

Western Thunderer
Looks good Geoff. With hindsight maybe I should have had them cast in nickel silver as they will wear in use. Otherwise very nice and can't wait to start my own kit.

Mike
 

geoff_nicholls

Western Thunderer
Just finished soldering the Y11 frames together. The rivets are not just cosmetic, they also hold everything in place while soldering. I made an error in the artwork for the backets which fasten the buffer beam to the sideframes, it will be corrected for the kit, but I'll be filing them down for this test build.
It won't be finished by then, but I'll be displaying it on my stall at the gauge 3 soc AGM/show at Biggleswade, 25th Feb.
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CAD work has started on the other building on Lea Siding.

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Mike W

Western Thunderer
Thinking back to your comment about nickel silver. The caster you use is very good, but only recently mastered casting in nickel, which may be why he didn't mention it before.

Mike
 

geoff_nicholls

Western Thunderer
I've made the pattern for the bonnet out of plastikard, and hope to have it cast in resin. I've soldered one set of roof supports together to check they're correct. They're fine, but I made the cutout for the bonnet lip too large.
I now need to make the patterns for the axlebox, spring and chain tensioner, and solder the brake hangers together.

The other photo shows a Great Eastern Railway standard tool box, which I'm having cast in resin, and a GRS class 121 DMU kit, which has been sitting on the shelf for a long time. Unlike the G3 kits from Slaters or Williams, where you can chuck the bits in the air and they land made up, GRS gauge 3 kits need quite a bit of effort from the builder. The buffer beam and steps were etched from my own artwork. It is coming along nicely, I had it painted by Charlie King.
Anyone considering modeling gauge 3 would find this DMU a good place to start. If you add a GRS pannier (or better still, scratch build your own, using the parts available from GRS) plus a Toad brake van, and you've soon got the makings of a western region branch line, without breaking the bank.
The class 121/122 is not just a boring DMU shuttling back and forth. If you check my thread in the WR action forum, you'll see they were used to haul a variety of non-passenger stock.
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