It occurs to me that construction of a power bogie would be much easier if someone made a motor, with built-in epicyclic gearbox, that would replace the axle of a pair of bogie wheels. Do you get my drift? The output shaft of say 5 or 6 diameter would pass clean through the motor/gearbox and have a wheel fitted to each end. Obviously the overall length of the body would need to be short enough to fit within the B2B dim, and outboard bearings used.
Regards, Tim
Design one please Tim, I will have 6 of them.
Not too late to rebuild the Peak bogie as only one nearing completion at this time.
Would be an easy retrofit when loco completed.
Mine would require 8mm journals though.
Dave
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ABC gears have produced an axle hung motor/gearbox for gauge 1, which uses the same axle diameter as gauge 3. Has anyone tried using that? If it is not sufficient, then we need a gauge 3 version, something you can use straight out of the box. My view is it should assume an inside framed bogie,which would be easier to compensate or fit springs.
For an axle hung motor in a bogie it has to be able to be used with wheels outside bogie like a Western or with wheels inside frame like a Peak. Or driving an external crank. Like on a shunter.
I am well on now with my Peak diesel bogies with all 6 off axle hung geared motors assembled into wheelsets.
Dave
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thank you dave 454, I hadn't thought of westerns, that helps my argument for a setup suitable for inside frames. My aspiration is for a supplier to start producing an traction motor suitable for any loco (or DMU), you just buy two, four or six depending on what you're building. Preferably cheap as well!
Geoff.
Hello All
At the Reading '0' Gauge trade show last weekend David White of Slaters had just the thing for Gauge 1 on display, I inquired about a version for Gauge 3, the reply was positive so I invited him if possible to have a sample of a G3 version at the AGM, watch this space.
Regards
John
Here is my latest photo of a completed traction motor ready to be fitted into a Class 44 Peak diesel bogie frame.
There are 6 of them exactly like this one. The wheels are turned from BMS, the inner bearings are steel flanged PTFE impregnated phosphor bronze. The outer are machined brass to slide in horn blocks. The axle is 10mm silver steel with 8 mm journals. The Gears are from HPC gears & are Delrin material. The two motor suspension brackets are laser cut.
The motor is MFA Como drill motor with an integral 4:1 gearbox. There is a retaining collar from Technobots. The motor is suspended from the frame using a coil spring (not shown) but the mounting hole can be seen in the pic.
Dave
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Error "The outer are machined brass to slide in horn blocks".
Correction:
Should have read " The outer bearing horn blocks slide in frame mounted horn guides."
Apologies.
Dave
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Dave,
That looks very nice - so simple and so small it should be extremely adaptable. The motor looks quite small diameter, have you tested its slow running capabilities yet?
Mike
Mike,
Runs nice & slow & very controllable, but will also have a good turn of speed (hopefully). Will not be able to test traction until I get the first completed bogie on the track. I calculated the revs & gear ratio to wheel size will give a scale 60 MPH. The Class 44/45/46 were capable of 90, but it is not a speed that I would relish at a GTG. Mine will be hauling loose coupled coal trucks at a scale 20 mph.
Another hope is that the Delrin gears will give near silent traction & not sound like a coffee grinder & that the sound card will drown out any gear noise when out in the garden.
The power & traction I am hoping for will be derived from 6 of them all working together in unison.
The weight is climbing as I add parts & build up the supply of bits & pieces. Just hoping that this gives a traction benefit rather than a detrimental hindrance.
The bogie seems to have a smooth roll-ability with little drag on the friction bearing surfaces.
For me Mike this is purely an experimental exercise to generate traction like the 12" to the 1 footers do it, rather than adapt the approach by many in the smaller scales.
I will report back progress in the Peak diesel thread I set up earlier with performance appraisal of the first bogie, photo & Youtube link. This will be a simple rolling & powered chassis but self contained with all the gubbins taped to it.
Plan is for a track test in Jan 2014.
Dave
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Thanks Dave.
My personal opinion, based largely on 7mm experience, is that weight is a good thing. Some of the famous huge 7mm layouts (e.g. Norris, Rose, Corner) had locos as heavy as possible - literally stuffed with lead - and Mike May had the same ideas with his locos and stock.
Mike
I do admire Dave's neat axle hung arrangement and the dedication of using one motor per drive axle (6-off !!!), but can't help thinking it a laborious approach when all the brackets have to be home made and gears & bearings sourced and fitted. That's why I'm hoping someone would produce a commercial assembly to fit a power bogie. We may find out at the AGM if Slaters do manage to table a prototype.
Can I ask if anyone has experience of the alternative approach of having a single motor in the bogie, arranged fore-aft with bevel gears at each end to drive a pair of axles? I have a few chunky motors in my scrap box rescued from cordless drills, car tyre pumps and the like. They have a body diameter of around 35 - 38 mm. It strikes me that these could fit inside a bogie, and because they are intrinsically large and slow running, will not require a large gear ratio to be engineered.
Regards, Tim
Hi Tim
Discussions with another member at a GTG revealed that a source of other motors was to look at cheapo angle grinders these include the bevel gears. Or use kiddies electric scooter motors.
My motors are heavily modified Chris Barron design & used my laser cut parts & commercially sourced bearings & gears.
They were not at all laborious to make but quite easy & worked without to much fiddling. They will be at the AGM for inspection on the Midlands Group table. OK so there was a cost. None of the items were from scrap bins. This often creates hybridised designs that cannot easily be replicated. The only scrap bin material used were metal hex & round stock for spacers.
I think that i would use this approach again with EM2. Thats another story.
Cheers
Dave
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Tim,
The best method is to drive the central axle and then take power off to the fore and aft axles with either chains or toothed belts "Maude" uses same system to power her D0 axles. The £2 "RF POTTS" motor is geared down 1:12 and the output passes to the axles below via a chain. Note that the minimum number of sprockets for ideal transfer is 16 -8 can be a bit jerky.
(http://www.cabbagepatchrailway.co.uk/smotorpic32.jpg)
regards
ralph
Moving my "bogie" question back to this thread Dave.
Like the look of your axle-hung unit (very neat) and need Qty4 similar units for a project. I've been looking at something similar but all spur gears. So questions?
How rugged do you think that 4:1 gearbox will be - and where did you get your MFA unit from?
IanT
PS Of course we can also chat on Saturday!
Hi Ian, look forward to meeting you on Saturday.
The MFA Como motor/gearbox unit 4:1 ratio is from Technobots (member discount applicable).
The weak link as I see it is the radio suppression capacitor supplied with the motor. I have blown 2 so far, but this was due to setting up testing. A bit of careful reaming of the outer bearing brass horn blocks improving the fit cured the snag.
Although, might have been due to working with 14.4 volts on a 12 volt rated motor, but I do not know as I cannot prove it at the moment.
Once set up time will tell how reliable they are.
Cheers
Dave
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Well folks, at & since the AGM show at Biggleswade I have had various questions asked of me.
The most onerous was "Will you be making these commercially?" The answer is no. There are reasons for this. Primarily, I do not consider myself as a competent professional manufacturer just an enthusiastic amateur. The other reason is that I do not believe a once size fits all approach to traction motors is such a good idea. To use readily available parts is a good idea since wear & tear may be repaired at a future date due to having fitted "quality" components. To adapt them to a particular motor bogie just needs a bit of thought. The design I have used is an adaptation from the design depicted in Chris Barron's Class 45 Peak drawing set. The laser cut motor frames were redesigned to take a different bearing type from that shown in his design.
The gear ratio needs to be re-assessed for a shunter, mixed traffic loco, express top link loco. So does the motor type.
The axle diameter was a key issue for me since I used some 10mm diameter ground silver steel stock. This enabled me to use commercial flanged bearings without worrying about precision fit. It just fitted & worked. Not everyone will be using the same axle diameter or material so this factor could vary.
My bogie has outside frames, some may have inside frames.
Although we are not a model engineers society as such, we are a railway modelling society. The construction techniques are relatively simple & very "kitchen table" & should be within the capabilities of those who want to undertake the construction of a bogie powered loco type. It is just a matter of sourcing the parts & doing a bit of assembly. Must admit I had a Drill press & a Unimat but this can used on a "kitchen table", so I stand by my claim that a fully equipped workshop is not necessary.
I do not know what the copyright implications are of copying & adapting the design of others would be when it comes to writing up an article for the magazine, if I were to produce a drawing.
Would such an article be of any value?
Dave
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Yes Dave, certainly. And I'd go further and suggest that if it was available, with drawings and parts list, somewhere on the web site, that might encourage non-members or those without an archive of backnumbers, to have a go too.
Mike
I would certainly be willing to place it on www.G3MadeSimple.org.uk
John.
I don't think there would be an issue if you used your own drawings Dave.
From what I saw (at the AGM) it is a fairly 'generic' design, that I've seen used in various guises previously but in other scales and gauges. So we are not exactly in 'patent' territory here, simply one of possible copyright. So use your own (from scratch) drawings and I cannot see a problem.
However, I agree that the real value in your 'design experience' is not really the generic layout of the axle-hung unit (it's been done many time before) but more the practicality of the motor/gearbox combinations used and how they will perform (in our gauge/size) given different axle/bogie/weight/speed combinations - essentially as you state below.
So yes please - very keen to hear more.
IanT