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Tinkerbell by who ?

3 Ducks

Joined: 30-01-15

Topics: 2

Replies: 9

Posted: Mon 2nd Feb 2015, 11:04am
Tinkerbell by who ?

I'm thinking of making a 7 1/4 tinkerbell, what i would like to know if there is more than one designer for this model if so any to avoid or recommend.
Any comments would be appreciated.
 

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WembleyLion

Joined: 1-01-87

Topics: 2

Replies: 34

Posted: Mon 2nd Feb 2015, 9:15pm

Tinkerbell was designed by Roger Marsh over 30 years ago now; Roger also designed the Romulus.

The design is very adaptable and there are very few of the original open cab, marine firebox type built today as nearly every builder has altered Roger's original design to suit his/her own needs. This has now resulted in an almost universal closed cab design, of various styles and sizes, and a depending firebox boiler is fitted as the original marine boiler, designed to save money on the boiler build, did not steam too well. The depending firebox boiler has also allowed for the cylinders to be bored out to a larger size.

Chris Fincken at Bromyard used to supply the drawings and castings but I don't know if they are still available from him.

Hope this helps. John
 

3 Ducks

Joined: 30-01-15

Topics: 2

Replies: 9

Posted: Mon 2nd Feb 2015, 9:29pm

HI John,
Thanks for your reply, i have read that sometimes the bores have been opened up to 2.75 and 3 inches but the boiler / fire arrangement struggles to feed the steam sufficiently.
I was also wondering if the drawings valve gear geometry was right to drawing its self, i know on some models there are errors, not wanting to get into the geometric progression (i think that's what its called).
I have seen Roger Marsh drawing for sale on CD disc, so might treat my self,
thanks once again - 3D
 

WembleyLion

Joined: 1-01-87

Topics: 2

Replies: 34

Posted: Mon 2nd Feb 2015, 9:42pm

Roger used Greenly Improved Valve Gear and if you want to split hairs, as some people do, it is not perfect but Roger was happy with it.

The marine boiler would certainly have had trouble with opened out cylinders but the loco (depending) boiler should be ok with bigger cylinders although 3" might be a struggle but then it all depends what sort of gradients and passenger loading the loco has to deal with.

John
 

3 Ducks

Joined: 30-01-15

Topics: 2

Replies: 9

Posted: Mon 2nd Feb 2015, 10:01pm

Thanks for your information John, you have answered all i needed to know.
regards 3D
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Tue 3rd Feb 2015, 8:36am

Tinkerbell - the original - is now 47 years old. The Roger Marsh drawings are mainly OK, but, as has been mentioned, have a marine boiler for economy (of the construction phase). The marine boiler is OK but can be difficult to fire. The vast majority built these days use a locomotive boiler, and there are several professional steel boiler makers who will make you one to a vaguely similar design. Being short and stubby, it steams like the proverbial witch, you will never need to worry about poor steaming.

I have built 3 "standard" locos so far, I would suggest boring the cylinders out to 2.75" diameter, although I did do one at 3" and I had no problems running that.

As drawn, the cab section is far too short for use, my design has added 6" to the length, which also allows me to put a small bunker at the back as well, which, in my opinion, makes for a much better looking loco. Use roller bearings throughout - in this day and age there is no excuse for using old fashioned plain bearings which don't last 5 minutes. I laser cut almost everything in flat plate to speed up build time, also get the driving wheels (8.5" diameter, anything bigger and she'll go like a scared cat!!) CNC machined for about £60 each.

If you want to know anything else just get in touch or visit my website.
 

3 Ducks

Joined: 30-01-15

Topics: 2

Replies: 9

Posted: Tue 3rd Feb 2015, 11:23pm

Hi Peter...
great reading, im away from home for a few days now but will have a look at your web page and make a few notes when i return, i cant see any link, is it some where else?
i have done a bit of engineering in my time but any help or advice is most appreciated indeed and kind of you to explain the above in your reply.
regards 3D
 

MartynRedfearn

Joined: 1-01-94

Topics: 16

Replies: 107

Posted: Wed 4th Feb 2015, 9:42am

3D Peter's website http://www.beevers.org.uk/pbe/pbe.htm
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Wed 4th Feb 2015, 8:38pm

A build log of the pair I built a couple of years ago: http://twotinks.blogspot.com/
 

3 Ducks

Joined: 30-01-15

Topics: 2

Replies: 9

Posted: Sun 8th Feb 2015, 1:05pm

they certainly look very well..
 
 
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