Steam Raising Blower

I am interested in making the Steam Raising Blower described by Brian Baker in recent Model Engineer magazines. However, a comprehensive internet search has failed to find a 12 volt fan motor suitable for a 7.25" loco as featured in Part 2. can you, Brian, or anyone else please advise where I can buy such a motor. Many thanks, Mike

Not seen it, but 12V and blower usually conjures up thoughts of car heater fans.

Haven't seen the article but isn't it more usual to mount a sucker on the funnel rather than using a blower? You then need a fan that is impervious to smoke and heat.

Where can you fit a blower?

Russell.

I'm not a loco type, but you could use a blower that doesn't involve a fan on the chimney, instead a blower line through a venturi, seen one like that used as a workshop vacuum. It could probably operate with the air from a 12v car heater fan.

Ian S C

hi Michael,

thanks for your interest in my fan design, and sorry to find the problem with sourcing a suitable motor.

I looked on Ebay and found about a dozen, when I built my blower back in June, but today not easy to find. The motor I used was normally used to operate a radiator cooling fan or car heater fan, made by smiths 7 fitted to many UK built cars in the 70s, 80s, & later.

However, ebay item 162175639784 may well be suitable, or, perhaps try a car breakers.

I will look into recommending a suitable motor, when I can find a reliable source.

hope this helps, and please let me know how you get on.

regards

Brian

Try breakeryard.com, and request quotes for a fan blower motor

http://www.breakeryard.com/partfinder

You may need to spoof a reg number so you can manually chose a suitable donor car.

A few points.

I know nothing about electric motors.

All my steam raising electric blowers use ex WD 24V motors. Most clubs have 12V and 24V supply on the steaming bays. If they have air lines via a compressor I much prefer this with a tube dropped down the chimney that has a 'U' bend on the bottom.

The car Smiths type heater fan doesnt work well on 12V but ok on 24V. However the fan itself is usually plastic.

The temperature of exhaust gases via the smokebox will eventually be well above what the fan can cope with. And the ex auto type motor will also get very hot.

I would much prefer clubs to have air lines instead of having to rely on electric motors on top of the blower vanes.

I havent seen the article yet in ME.

Cheers,

Julian

Greetings Julian, thank you for your comments.

In my experience, the compressed air system can use quite a lot of air, and just when you need the most, someone else opens up, thus reducing the supply, just what you need.

You are quite right about the plastic fan being next to useless, and my design was to provide a laser cut replacement for the fan & casing.

Above all, it was meant to be simple to construct, with a view to encouraging someone who has purchased a locomotive, to start making some thing simple, and thus beoming converted to this wonderful hobby of ours.

Regards

Brian

Hi Brian.

I followed your directions and have a motor on order, so now I can make a start on the steam raising blower, what all miniature loco people call them ! Many thanks. It's for a 7 1/4" William Dean Armstrong Class 4-4-0 "Gooch", the most beautiful express passenger loco ever built (see J.N Maskeleyne, A Further selection of Locomotives I Have Known p. 36) !!!

Thanks Neil for your helpful comments, I will follow up breakeryard site for future use.

Mike

Hi Micheal, that is a most beauttful loco that you have picked, and coming from a dyed in the wool LNER man,, thats saying something. I have seen several running. I had one my self, but my son in law pinched it.

Good luck with your build.

regards

Brian

For the record, I got 6 or 7 responses from breakeryard,. I put in my old Vectra's registration so a fairly hefty fan. Prices came back from nearly £60 down to £20.

I have a suspicion that a high-torque (with a soft steel outer wrapper) 540 'buggy motor' would do the job just fine is matched with a smaller but faster fan.

Neil

I'd started making a blower along the lines of the article, prior to it being published. I needed a motor and realised I had one of these laying around.

**LINK**

Its more than adequate and needs a speed controller otherwise you'll be sucking coal down the firetubes !!

**LINK**

Seriuosly this motor makes such an effective blower. I was using it for the first time the other day and once I'd got steam up one of the guys wanted to try it. He said "put it on full" as he only had about 10 psi on the guage. He went from 10psi to safety's blowing in less than a minute.

OK Jaycar is Oz/NZ but these are Chinese products so I'm guessing Maplins (are they still around?) will do similar, otherwise its Ebay or Alibaba.

Pete

PS - 7.25" guage locos. The tube for the chimney is 2" I'll do some photos if more details are required.

Edited By Doubletop on 11/12/2016 10:22:03

Just a thought when Blackgates first designed Charlatan (5" 08 diesel shunter ) they used 4 smiths motors, still listed at £42.50 each but I do not know if they are he same, worth a phone call?

Paul

Here's my nearly finished blower for a 7.25" loco (Dart) with the Jaycar motor (see link above)

The rotor was supposed to be just some flat baldes welded to the two plates. i don't have welding kit so made a hub and copper plades and silver soldered it all together. The other plate is held on stand offs like the main body. Rather than spending time making standoffs I used 1/4" stainless tube and 4ba bolts

By the way the direction of rotation is with the sweep of the blades trailing. I felt that the leading face would swash the air outwards and a vacuum would be created in the concave cavity of the trailing face. The combined effect drawing air from the center

This blower (sucker) is cabable of lifting something the size of a book off the table.

And the speed controller

Hope that helps somebody.

Pete

Edited By Doubletop on 13/12/2016 09:41:29

Not quite as efficient, but the blades will work even if they are just straight flat plates set radially.

Ian S C

I wasn't sure that would be the case or whether flat blades should be offset from the radial axis. A bit of googling indicated that any would work to some degree or other. However as I had no way of welding on the flat blades I'd been given with the disks I had to seek an alternative.

I did consider the tabs similar to those used by Brian or tabs a push fit into holes in the discs and the whole lot clamped together as a sandwich with the spacers and bolts.

In the end I went for the copper blades and silver solder. Adding the curved blades wouldn't be a problem. They were just annealled and bent by hand around a 3in tube.

Pete

Hi Pete,

I built a sucker a while back, I used the fan out of a vacuum cleaner, no idea which as I nicked the fan off dad! I enclosed the fan and attempted to make an involute ( well I think it is) put an chimney on it so the smoke is directed up, not much fun breathing up coal smoke, espeacally if it's got sulphur in it! Like the idea of a speed control, have to go to Jaycar & get one.

Cheers Kerrin

Kerrin

When you read the instructions you'll see that you will need a diode across the motor to protect the unit from back EMF. Its a 1N5404 so order one at the same time.

I found out too late.

Pete

Greetings, Doubletop is quite correct to say that curved trailing fan blades are more efficient & would be used in industry, but, please remember that this blower is designer to tempt locomotive purchasers into becoming builders, and the use of straight blades makes it easier to construct for a beginner.

The suggested motor seems fine, thanks for that, and as stated a speed control really helps to stop pulling the fire out in the early stages of steam raising.

regards

Brian