Smiths Heater Motors

[peterseager]

The Smiths heaater motor is a well regarded basis for a loco blower fan. The problem is that they are fetchingg collectors prices.

There are new motors available intended for model boats and cars. I am trying to find one that matches the Smiths motor and so I need to find the characteristic for the Smiths motor. Can anyone help please?

Characteristics at 12V

Current

Revs/min

Body diameter and length

Spindle diameter and length

Peter

[SteveW]

Would suggest the old Smiths Heater Motor is a bit on an over-kill. Years back I made a very serviceable blower (sucker) using an ex-Electrolux vacuum cleaner centrifugal fan and the smaller brother to one of these : "MABUCHI RS-755VC-9012 DC 12V-18V High Speed Drill&Screwdriver/Garden Tools Motor" at 15 quid on Ebay.

The only complaint was from the club pain in the arse that it sucked too hard. It worked fine at 6 volts.

[lesstoneuk]

I'm using ZY6812/MY6812 motors, 12v:2500rpm:68mm diameter, 95mm long (105mm in some cases so be careful if this dimension matters. Don't ask me how I know. Available with chain cog, toothed belt or blank drive fitted.

[doubletop]

These motors are fairly standard these days



Max efficiency 69%
No load RPM 9700RPM
Full load torque 6000g.cm
Max. efficiency current 5.3A
Full load current 57A
Max efficiency RPM 8500RPM
Shaft diameter 5mm
Motor Type High Power
Motor Nominal Voltage 12V
Max efficiency power 63.5W
Shaft length 19mm
Maximum efficiency torque 709g.cm
No load current 1.3A

The only problem it is too good and needs a speed controller or, as Steve says, run it on 6V. The speed controller does allow for slow speed to get the fire starte and then speed up to get the fire to draw better.



Pete

[peterseager]

Thanks for your imfo. 

Was my lucy day. A club memneber prented to me q Smiths motot he dad laying around in his garage.

I measured rhe current drawm bt the Smiths motor and by the current blower. This was initially for use on my Simplex where it performed satisfactorily but is very slow at raising steam on the Manor.

Current Blower at 12 V        0.26 A  Operating in free air

Smiths Motor at 12 V          3.5 A

There is one Smiths motored blower in the club that often get called upon ro start various loco and does it every time,  I will try and copy its details. 

Peter

[steamer5]

Hi Peter,
I used the fan, sucker, from a vacuum cleaner, just make sure it’s a metal one! The fan is fully enclosed I shaped the housing so that I could get a vertical stack on it….. just don’t grab it by the stack once you have steam up! The stack pushes the smoke vertically rather than spreading it thru the steaming bay!!

Cheers Kerrin

[peterseager]

And make sure the metal fan is riveted together. My current fan was originally soft soldered. Big mistake as I found out when I left the blower running too long.


Peter 

[Boadicea]

Jun 29, 2022 23:29:31 GMT peterseager said:

Thanks for your imfo. 
Was my lucy day. A club memneber prented to me q Smiths motot he dad laying around in his garage.
I measured rhe current drawm bt the Smiths motor and by the current blower. This was initially for use on my Simplex where it performed satisfactorily but is very slow at raising steam on the Manor.
Current Blower at 12 V        0.26 A  Operating in free air
Smiths Motor at 12 V          3.5 A
There is one Smiths motored blower in the club that often get called upon ro start various loco and does it every time,  I will try and copy its details. 
Peter

Good to see you got fixed up Peter. Yes, there's one of those at my club too - does the job without a lot of noise and fuss.
A bit like the difference between all the fuss made by a midland pacific as compared to a southern one.
Light-hearted comment - shame nobody read your original question.

[JonL]

I use RS540 style radio controlled car motors on mine, then use a cheap chinese speed controller. Works very well. It's so handy to be able to drop the speed down while lighting up.

[JonL]

Just to add a bit to this... when I'm initially trying to light the boiler having no draught at all makes lighting difficult. Having the blower full chat sucks the flame out... With a variable speed control at its lowest speed there is enough draught to evacuate the burnt gases without sucking the flame out, then you can whack it up when its established. Saves me having to muffle the output with my flat cap all the time!