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[BarryM]

My intention is to fit an electro-feeder system to the current work-in-progress as described here:- http://www.modelboats.co.uk/news/article.asp?sp=&v=1&uan=70

Noting that the motor shown in the article does not feature in Maxon's current lists, I took details from the photo and emailed the company. Back came the answer that the motor shown is no longer made but a modern equivalent is available for £153.35 incl. P&P!!!! 

Thus, having crossed Maxon off my list, can anybody recommend from personal experience, a similar geared motor (200:1) or thereabouts which is suitably robust and does not need a second mortgage to purchase?

Thanks,

Barry M

[flashtwo]

Hi Barry,

Try Maplins N03BQ  100:1 motor  @ £22.99 or MFA Como on  http://www.mfacomodrills.com/gearboxes/940d_series.html.

I use them with my boiler feed pumps on my flash boiler. They operate upto 120 strokes/min (12volt supply) with a 1/4" plunger and 1" stroke into 60psi.

Mine are computer controlled (via Electronic Speed Controllers) with strokes/min feedback to give a specified flow rate essential for flash boiler control.

Ian.

[BarryM]

Thanks Ian - that's an interesting set-up you have. Have you thought of using it as a new steam topic?

Barry M

[flashtwo]

Hi Barry,

Yes, I have thought of starting a topic on the flash boiler control, but feel it is too computer (actually PIC micro-controllers) orientated to be of much interest.

I am about to build a very simple 5 foot hull and mount the boiler and the Stuart D10 engine (and controller) in it for pond trials. Currently the D10 is connected to a generator and I suspect that the load characteristic of a large 4.5inch prop will be a little bit different!

Do you think there would be much interest?

Ian

[derekwarner]

Hi Ian....I am new here on this site ....but have [1000+] postings on Paddleducks

This concept of a geared electric boiler feed pump motor has been discussed a few times on PD's but without resolution

Naturally some steam engines have the built in facility of fixed make up water boiler feed pump & with displacement relative to engine speed......however many do not..& such steam driven boiler feed pumps also consume energy when pumping over a relief valve setting etc 

I am sure many here & on other Forums would be interested in such a thread.....Derek   

[flashtwo]

Hi Derek,

The pumping system I use on the flash boiler depends on the feed flow being maintained independant of the back-pressure from the boiler, i.e. if the boiler pressure increases the displacement pump has to pump harder (not faster) to maintain the required flow.

In order to achieve this, I measure the speed of the pump (strokes/min) by means of a small magnet inserted into the arm of the pump. As the magnet passes a detector, a pulse is sent to a PIC micro-contoller which calculates the speed, compares it to the desired speed, i.e. feed flow, and adjusts the PWM signal to the Electronic Speed Controller (ESC). The ESC then powers the electric motor of the pump.

The actual desired speed (flow) can be manually set or varied automatically according to the steam engine RPM required.

Photo Pump_B.jpg shows the general arrangement of the gearbox, ram and pump and Pump_B1.jpg shows the detail of the magnet detector. Please excuse the un-tidiness but it is an experimental set up.

Ian

[SteamboatPhil]

Hi Ian, welcome to the forum, I knew you would find me,have PM'd you. 
Phil

[derekwarner]

Thanks Ian....... ....your concepts are a little higher level than I has assumed....flash steam is one & PIC micro-contoller of the feed water is another.......the Cheddar Company from UK....[now defunct] a number of years ago manufactured a model steam boiler control system which I believe used similar parameters as you are using

Good luck.......I will watch & read with interest.....Derek

[Bernhard]

hi.........I have 2 off this,,,and they work with aut eny problems,,,can be made to work wia a servo to,,,
regards Bernhard

[Martin (Admin)]

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