Does Anyone Have a Slaters GBG3 Gearbox Unit?

[Peaky 556]

Morning all,
The reason I'm asking is because I need some running data for it.  Slaters can't directly help, but have decently offered me one on a sale or return basis so that I can take the data.  The unit has a Mabuchi motor, but I just can't register on their website for whatever reason. 

As some will know, I have characterised motors in the past using a tachometer and DVM, and that's all I need to do on the unit.  IMHO the manufacturer doesn't provide enough data to help us know how it will perform in various models.  For instance does the output shaft turn so slowly that to get up to mainline speeds we need 7' driving wheels?  Could it be useful as a drive unit for a more modern diesel electric with only 3'9" wheels and still turn a realistic speed?  For the purposes of beginners advice in the G3info pages, to be hosted by John, I just need to understand it a little better.
Regards, Tim

[hornbeam]

Hi Tim,

I can't help but I thought they used Piko G motor's. Must have changed spec I guess.

[Doddy]

No further information than Mabuchi? Model Numbers etc

From Mabuchis website Slaters G3 30:1 Ratio Spur Drive Gearbox motor looks identical to the Mabuchi RS-425PV-13233

https://product.mabuchi-motor.com/detail.html?id=105

Here is the spec . . .

[Peaky 556]

Simon, the Piko motor is an alternative, is 18V nom and looks smaller than the Mabuchi 24V motor and probably less powerful, so I am ignoring this one for the moment.

Bob, the Mabuchi motor is marked RS-545SH-3055, and I cannot find it on their website.  Maybe you will have better luck??

Cheers, Tim

[Peaky 556]

Bob, that's a different version of the same size of motor, suffix is different, so has different thickness wire, number of turns, etc.  These make a big difference to current draw, free running speed etc.  Come Monday I might get a reply from Mabuchi to let me access their website and answer queries. 

[Peaky 556]

Hi all,
Latest is that I've had a response from Mabuchi about this particular motor as used by Slaters, which is what they describe as a "special" and not normal stock.  They rate it at 26V, slightly greater than the Slaters 24V, and from the shaft speed given at 26V under load, I have looked at the typical loco speeds achieved.  The good news is that a steam outline with 80 mm wheels would motor along quite readily at ton-up speeds, so a reduced voltage should keep it all under control and stay realistic.  Otherwise the 50:1 gearbox option would be a better choice.
Less good news is that if we fitted the 30:1 unit to a 'modern outline' diesel or electric with wheels of around 50-55 mm, it will struggle to reach a scale 70 mph.  Thus it wouldn't seem suitable for a mainline express, but fine for one of the modern 'railbus' types or suburban DMUs.
So there we have it, some predictions for this unit over and above the very limited info supplied by Slaters.
As always, any results in practice would help us.

As an afterthought, who else supplies ready made motor-gearbox units suitable for G3?

Tim

[IanT]

Walsall Industries do one with a choice of two gear ratios....

IanT

[MikeWilliams]

Tim, is 70mph not enough for a model?  I suspect few prototypes regularly exceeded that?

Mike

[Peaky 556]

Mike, if you ever measured the speeds I think you would be surprised how high they are.  Don't forget that at a brisk walking pace of 4 mph we are doing a scale 90 mph!  At the bigger tracks I've attended (e.g. Alan's), I have to break into a jog to keep up with many!  Keeping speeds scale-like is probably one of our harder tasks, and it spoils so many video clips. 
Regards, Tim

[Peaky 556]

Walsall Industries do one with a choice of two gear ratios....
IanT

Ian, I can't find anything resembling a gear, gearbox or motor on their website, so do you know any more?

All supplier info appreciated as I can try and summarise it on the G3 info pages.

Thanks, Tim

[John Candy]

Tim,

The unit Ian refers to is that as fitted to the Sentinel locos (Plantagenet and Arthur).
The motor fitted is the same "Powermaster" as that which I sourced for members (at a couple of Quid a throw) a year or two back ... from recollection, Walsall were able to supply with 30:1 and 50:1 ratios (cannot now recall which is fitted to Sentinel but Ian may since he obtained them).

Since Mike is responsible for the production "run" of Sentinels, he will also know the answer.

John.

[MikeWilliams]

Keeping speeds scale-like is probably one of our harder tasks, and it spoils so many video clips.

Totally agree Tim, which is why I thought a limit of 70mph might not only be acceptable, but a good thing.

Mike

[MikeWilliams]

Sorry, just seen John's post about Walsall gearboxes.  Walsall have a lot of things not on their website.  Give them a call - very helpful.

Mike

[IanT]

From memory the ratios were 1:36 and 1:50 John - achieved by using either a single or two start worm (otherwise the two gearboxes use exactly the same components).

I think we originally planned to use the 1:50 g/b in any production model. At the time though, I already had two 1:36 motor/gearboxes and I used them in the two prototype engines. They seem to run well enough, so I think I'd stick with 1:36 now. However, because of the gearbox commonality, it would be possible for someone to change the ratio up to 1:50 if they wanted to, by simply changing the worm. I'm happy enough with the way 'Arthur' runs though, seems about right....

Spoke to Walsall at the AGM/Reading ALSRM earlier this year and they still had the gearboxes available then - but I agree with Mike, it's easiest to just give them a call.

Regards,

IanT

[IanT]

This is the beastie in question....





Regards,

IanT