[modeleng] Re: Motor requirements

Tony, how about a motor out of a cordless Screw
Spanner for a power plant?

Al
--- Tony Wells <oaksfield@xxxxxxxxxxxxxxx> wrote:

> Well, I have finally surcumbed to the lure of the
> loco, and gone loco! My 3.1/2" gauge train now has a
> chassis, and both front and rear bogies, all in wood
> in true Richard Blizzard fashion though, so perhaps
> I should not be mentioning it here .... <VBG>
> It is a scratch built 4-6-2, with 3-axle tender, all
> to be made from polished hardwoods, and not "hard
> words" as I just mistyped - they will come later! As
> I am working from the bottom up, I need to decide on
> the drive train next, so as to be able to design the
> body around it. The idea is for it to look like a
> steam loco, but be electrically driven, but more
> Basset Loake than Hornby Triang, hopefully! With an
> overall length of nearly 30", at least I have given
> up on the Basselt Loake clockwork motor idea though
> .... I am therefore thinking of putting a battery
> (or batteries) in the tender, with a disguised power
> cable through to an electric motor in the loco
> proper.
> 
> Chatting to Al and Tel off list, I have come round
> to the idea of either a cordless electric drill or a
> recycled windscreen wiper motor, though whilst out
> shopping today, I saw some of the big 6-volt zinc
> lamp batteries, the ones (very) approximately 2"
> square and 3" high, for only £2 each and so may look
> into a 6-volt motor as well. I had thought about
> trying to find such as a small motocycle battery to
> fit into the tender, but decided that the additional
> weight made matters worse, not better, taking me
> into the lands of diminishing returns, incidentally.
> My problem is that while I have the bit of garden
> where the fruit trees are for some track, it is only
> 30' x 40' at the most, and so it would be a very
> twisty one at this size, round those trees, and so
> what design speed should I aim for please, so that I
> can determine how powerful a motor will be required?
> 
> From my working days, the clearance times for
> pedestrian crossings were based on 1.2 metres (4
> feet) per second, so should my train go faster or
> slower than that, bearing in mind the lack of long
> straights where an express could be wound up to
> maximum speeds? Should I be able to keep up / catch
> up with it in the event of an accident, such as when
> Unka Jesse fell off his and could then only watch it
> disappear into the distance until it (literally) ran
> out of steam ? As my driving wheels are 2.1/2"
> diameter, I did a bit of mental arithmetic to work
> out that at 3mph, a brisk walking pace but not
> rushing, the wheels would be doing around 225rpm.
> 
> If I was to use a cordless drill with a natural
> speed of 900rpm to 1,000rpm, it would need to be
> greared down rather than using the standard sort of
> speed control, as these are inclined to over heat if
> used for a prolonged period of time. I would need a
> pulley ratio of 4:1 if I was to use the flexible
> drive belt that I am looking for. 1" to 4" would
> give me problems in housing the 4" pulley, whereas
> 1/2" to 2" might well give me slippage problems on
> the 1/2" one, however. Physical gears has (for me)
> the problem of achieving alignment as well as
> maintaining it due to possible moisture movement of
> the timber frame and chassis. This as well as being
> far noisier, though nylon gears might get around
> that if they could take the loadings.
> 
> I am open to any help, ideas and suggestions that
> the Group may come up with, please, but precision
> engineering is just not possible for me I am afraid,
> as bittter experience has shown far too often.
> 
> Thank you,
> 
> Tony.
> 
> MODEL ENGINEERING DISCUSSION LIST.
> 
> To UNSUBSCRIBE from this list, send a blank email
> to, 
> modeleng-request@xxxxxxxxxxxxx with the word
> "unsubscribe" in the subject line.
> 



       
____________________________________________________________________________________You
 snooze, you lose. Get messages ASAP with AutoCheck
in the all-new Yahoo! Mail Beta.
http://advision.webevents.yahoo.com/mailbeta/newmail_html.html
MODEL ENGINEERING DISCUSSION LIST.

To UNSUBSCRIBE from this list, send a blank email to, 
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.

Other related posts: