waggy
Statesman
Posts: 744
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Post by waggy on Nov 16, 2020 9:33:03 GMT
Good morning all,
Be careful using that photo as a guide to building your loco. It’s a photo of “Tommy”, the prototype build. The production loco’s were slightly different, I’d advise comparing photo’s of the two versions, you’ll see the changes.
I served my time on these loco’s so if you need further info, ask away.
Waggy.
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lesstoneuk
Part of the e-furniture
Retired Omnibus navigation & velocity adjustment technician
Posts: 373
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Post by lesstoneuk on Nov 16, 2020 9:44:03 GMT
I'm proud to say that I was lucky enough to go on a rail tour from Didcot to Dinting many moons ago. The last few miles were class 76 hauled. I will continue to examine as many pics as I can. This pic shows just how large the sandboxes are too. To simplify those, I think resin castings will be a pretty easy solution. Anyone have thoughts on that on a 5" gauge loco.
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Post by delaplume on Nov 16, 2020 16:33:31 GMT
I'm proud to say that I was lucky enough to go on a rail tour from Didcot to Dinting many moons ago. The last few miles were class 76 hauled. I will continue to examine as many pics as I can. This pic shows just how large the sandboxes are too. To simplify those, I think resin castings will be a pretty easy solution. Anyone have thoughts on that on a 5" gauge loco. Whereabouts are you in the UK ??..........just the town will do..... Hello Waggy-------didn't we meet at a recent Manchester show ??.........Give me a PM for an Ex-BR Fitters chin-wag ...
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Post by coniston on Nov 16, 2020 21:22:50 GMT
I'm proud to say that I was lucky enough to go on a rail tour from Didcot to Dinting many moons ago. The last few miles were class 76 hauled. I will continue to examine as many pics as I can. This pic shows just how large the sandboxes are too. To simplify those, I think resin castings will be a pretty easy solution. Anyone have thoughts on that on a 5" gauge loco. I don't see any reason a resin casting cannot be used, or 3D printed in either resin or FDM? they seem simple enough shapes to be laser cut a single folded flat in brass or steel with fold guides lasered in would be easy to bend by hand and solder up? Looks an interesting project Chris D
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waggy
Statesman
Posts: 744
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Post by waggy on Nov 16, 2020 21:56:51 GMT
If you want to use resin castings, go ahead and use them! The rear sandboxes on my B1 are milled from mahogany, filled and sanded, they look fine. Obviously dummies but very noticeable by their absence! If you’re concerned what others may say, tell them to bring theirs so you can compare! In my experience you’ll wait a long time! Good luck with the EM1. Waggy.
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lesstoneuk
Part of the e-furniture
Retired Omnibus navigation & velocity adjustment technician
Posts: 373
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Post by lesstoneuk on Nov 17, 2020 1:41:37 GMT
I'm living in Cilmaengwyn, just up the valley from Pontardawe and ultimately, Swansea. Speak nice and I'll tell you how to pronounce it. Well done for using Mahogany, inventive and original. After all, we don't belong to a "metal working society". Wood was used to make full size mock-ups of some aircraft in days gone by. The twin spitfire comes to mind there.
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dscott
Elder Statesman
Posts: 2,437
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Post by dscott on Nov 17, 2020 2:54:43 GMT
Here is my Something Quick to get round the track Beast. I did do a workshop visit last year to buy some 1500 Cylinders all machined. Only to be shown a superbly built and weathered 50 by his son. The son being in his early 20s getting a job on his passion for things machining! There was a house but that just made the distance to the workshop longer. David and Lily.
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 17, 2020 8:34:23 GMT
Those cables, especially the red one between the batteries, look a bit thin David.
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Post by delaplume on Nov 17, 2020 8:43:45 GMT
Hi David,
I like the modular concept-------- you could keep on adding more power cars if you wanted.........
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jackrae
Elder Statesman
Posts: 1,333
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Post by jackrae on Nov 17, 2020 9:52:36 GMT
Is relying upon coning via a single axle sufficiently secure for the leading power bogie. I know a coned axle is self aligning but it just seems a little bit iffy. I like the idea of using rose joints as they permit roll, pitch and yaw all in a single fitting.
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Post by delaplume on Nov 17, 2020 10:17:41 GMT
Those cables, especially the red one between the batteries, look a bit thin David. Possibly a 24v system ??
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 17, 2020 17:13:04 GMT
Those cables, especially the red one between the batteries, look a bit thin David. Possibly a 24v system ?? Certainly it is best to use a higher voltage, and as David has two batteries, I am sure that is what he is doing. However, the current will be at least in the region of 10 amps (240 watts), and quite possible much higher. That red cable looks light - even for 10 amps.
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lesstoneuk
Part of the e-furniture
Retired Omnibus navigation & velocity adjustment technician
Posts: 373
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Post by lesstoneuk on Nov 17, 2020 17:42:27 GMT
Before I commit, I will be using two 12v batteries. Is it better to have 12v with a high amp/hr or 24v with a lower amp/hr.
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Post by andyhigham on Nov 17, 2020 19:13:59 GMT
Higher voltage lower current is always best
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Post by delaplume on Nov 17, 2020 20:13:06 GMT
Higher voltage lower current is always best International overhead electrical supply is}--------- 25Kv @ 50cps AC--------- and as with the National grid you can't have overhead cables which are 2ft or more in diameter.......Conversely the Southern Railway 3rd rail system is nomanally rated at 750v DC........two different approaches for the same end......... Hi lesstoneuk--------- grab a cup of hot coacoa this evening and have a read of this}-------- www.jons-workshop.com/wedge/wedge.html
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Nov 17, 2020 20:22:47 GMT
Before I commit, I will be using two 12v batteries. Is it better to have 12v with a high amp/hr or 24v with a lower amp/hr. The selection of the A/hr capacity of the batteries will be influenced by the physical dimensions that will fit within the body shell. My Class 25 batteries came from Halfords, rated at 45A/hr and weren’t expensive. To enable them to fit the Maxitrak chassis plate, I had to grind off the tapered lower edge of one side of each of them. This would be used in a car to clamp the battery in place, so it didn’t affect the structure of the actual battery in any way, but no doubt invalidated the warranty! These were the biggest I could fit in at the time and have worked well. The higher the A/hr rating, the better the voltage should be under load etc. Also, heavy duty cabling for all connections to speed controller/motors is very important to minimise volts drop, as has been mentioned above. Cheers Don
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jackrae
Elder Statesman
Posts: 1,333
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Post by jackrae on Nov 17, 2020 21:03:52 GMT
Be aware that battery discharge rate versus specified capacity cannot be considered as a linear function. For example a 50Ah battery (normally based on a 20hour discharge) is rated to deliver 2.5amps for 20 hours. But the actual capacity diminishes if the discharge rate exceeds the 20hr rate. Say you want to load at 20 amps. Rather than being capable of supplying this for 2.5 hours, the battery may only supply this for 2 hours, ie 40Ah capacity. The higher the discharge rate the lower the actual Ah capacity. Therefore using 24volts with batteries of capacity "X" is always preferable to operating at 12 volts with batteries of capacity "2X"
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 17, 2020 21:59:12 GMT
It is also worth mentioning that it is a good idea to use batteries designed for full discharge - e.g. for golf buggies or invalid carriages. Car batteries are designed to be kept fully charged, so are not ideal for battery loco usage.
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Post by steamer5 on Nov 18, 2020 1:40:13 GMT
Hi, My Toby tram uses 2 x 12 volt, 40 amp/hr marine batteries. Why 40 amp/hr....well that’s as big as would fit, unlike Don I didn’t have to grind anything off them but there’s not a lot of space around them. I chose marine batteries as they are cheaper than deep cycle ones, but they come with fiberglass mats between the plates to prevent plates touching, figured that if they can stand up to being bounced around at sea then they would be fine in a train! The motor is X wheel chair, 24 volt 7.5 amp I get 4 to 6 hrs run time out of them. I have a custom built charger made by an electronic guru friend, it’s 24 volt & charges at 4 amps max, ie charge time is 10 hours which he told me is the recommended rate /time for charging which also help prevent battery damage due to fast charge.
Cheers Kerrin
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dscott
Elder Statesman
Posts: 2,437
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Post by dscott on Nov 18, 2020 1:46:40 GMT
This view shows the putting together one of the drive units. You get into the Quick Experimental mode and roughly guess the size of belts and what they have to transmit. Do note the resting upon 2 of Jessies front Sandboxes. Going through the gearbox was far too slow. This is the first version without the bogie... The problem was lifting them up to attach. Several hours spent on a single bogie that I got for £50. New bearings and a coat of paint and we were flying. Lily made it to the front cover of our club magazine that month. The cables seem to work well and yes I have been thinking of adding another wrapped round to strange effect. The batteries are the ones specially made for Buggies. Expensive enough even with £8 back on the failed ones each. The new charger you can fit into a big pocket!! David and Lily.
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