Brian’s 1″ Minnie Traction Engine

[Brian AbbottParticipant @brianabbott67793]

Thanks Dan.

You've just hit the nail on the head, don’t know why i didn’t see it myself.

As explained in the book, leave a little room for the slide block to move.

Just need need to check the valve travel.

Update!

Much better but still happening, problem is i don’t think i have enough through to open the valve correctly.

Never kind, keep looking

 

 

Edited By Brian Abbott on 18/06/2020 14:20:41

[Paul KempParticipant @paulkemp46892]

Brian,

Are you sure your eccentric rods are exactly the same length? Easy way to check is stand the strap half and rod on a surface plate with the rods vertical and try passing a pin (drill shank even of the right size) through both clevis's. If they are different lengths it can play havoc with valve events in general. I don't have any experience of Minnie and looking at the video it's hard to judge but the crank centre line seems markedly higher than the valve spindle centre line? Might be worth rechecking everything is to drawing such as distance from crank to centre of weigh shaft, throw of the weighshaft arm etc. It's not unusual with Stephenson's gear to have some kick through the reach rod to the reverser but yours does sound a little excessive. Jason B is probably best qualified to comment having built one.

Paul.

[Brian AbbottParticipant @brianabbott67793]

Thanks Paul.

I have re-read the book tonight, and he does clearly say that this arrangement suffers from "link slip" and to leave a little free space in the link slot beyond the die block ( his words ).

As suggested by Dan I have tried clamping the reach rod with a couple of mm clearance in the link slot and it does seem ok (ish) so I think I need to finish all the reverse lever assembly and set everything up properly.

I am fairly sure everything is made correctly, I know when I made the eccentric rods I did take care, but costs nothing to check these things.

Thanks for the advice.

[Paul KempParticipant @paulkemp46892]

Brian,

No worries, these snags can sometimes be a b*****r to find. In general TE valve gear is usually a fairly inefficient compromise, the road engine boys never really seemed to catch up with their rail brethren when it came to valve gear! Wallis and Fowler probably came closest.

Paul.

[JasonBModerator @jasonb]

Your finger on the far side holding the arm is moving which is allowing the lifting links to move up and down, once reverser is in it's notch that can't happen, Try clamping it solid while you turn the engine over.

Also not quite low enough to get full forward and too high in reverse.

Edited By JasonB on 19/06/2020 07:01:11

Edited By JasonB on 19/06/2020 07:04:19

[Brian AbbottParticipant @brianabbott67793]

Thanks all for your help and advice.

[Roger BestParticipant @rogerbest89007]

Great thread – you have covered a great many issues over the years.

Fabulous work Brian!

[Brian AbbottParticipant @brianabbott67793]

Thank you, i didn’t think anyone followed this build,

Progress is slow admittedly, work and family take priority, but it’s getting there.

[Jeff DaymanParticipant @jeffdayman43397]

It's looking great Brian! I see you are starting the beading around the tender, looks like. Tricky, but looks great when done.

[peter hobbs 2Participant @peterhobbs2]

looking good brian i have finally steamed my minnie successfully using charcoal and it steams well .the only thing now is the pump will not work against the boiler pressure,when the engine is cold it works fine.

anyone else had this problem

pete

[JasonBModerator @jasonb]

The pump does not worrk as well when it get shot, some builders mount the pump down on the horn plate or at least space it off of the boiler.

[peter hobbs 2Participant @peterhobbs2]

thanks jason for the info i think i will try moving it to the horn plate and also fit a back up hand pump

pete

[Brian AbbottParticipant @brianabbott67793]

Hello all

Just working on the Minnie water pump,

Anyone know what size hole should be through the check valve seating.

7/64 or 1/8 ?

Thanks

[Harry WilkesParticipant @harrywilkes58467]

Looking very nice Brian

H

[Brian AbbottParticipant @brianabbott67793]

Thanks Harry.

[Richard S2Participant @richards2]

Hi Brian, Sorry for the delay. 7/64" bore for the valve seatings for 5/32" valve balls. Are you changing the pump layout/location ?.

[Neil WyattModerator @neilwyatt]

Nice to be reminded of this build!

Neil

[Brian AbbottParticipant @brianabbott67793]

Good afternoon all.

Could I ask any Minnie builders what thickness gasket they used between the cylinder and the boiler?

The reason I ask is when I machined the base of the cylinder I took great care to make sure it matched the boiler, unfortunately, I forgot all about the gasket.

Really, to make things right I should re-machine the base of the cylinder to allow for a gasket,

Thanks,

Brian

[Paul LousickParticipant @paullousick59116]

If there is no allowance for the thickness of a gasket and the surfaces are flat and mate well with each other, a coating of graphite based sealant will work. (used on the end cover on the steam cylinder of my 6" engine).

[Brian AbbottParticipant @brianabbott67793]

Hello all

Progress has been very slow of late but thought i’d post a quick update picture

Regulator’s done and the water pump is taking shape.

Still lots to do but the end is in sight 😀

[Jeff DaymanParticipant @jeffdayman43397]

The engine's looking really good Brian! keep going with the last bits. Did you use sealant under the cylinder or did you machine a bit out for a gasket?

[derek blakeParticipant @derekblake72550]

Looks great Brian, well done 👍

[Brian AbbottParticipant @brianabbott67793]

Thanks Derek,

Hello Jeff, never got that far,

Plan now is to write a list of all the half finish bits I need to do then strip the engine and sort all the gaskets so I can get it running,

Im not planning on painting it so just need to clean everything.

Be good to get it finish, I’ve really dragged my feet with this and I’m lucky I have never lost interest.

[Brian AbbottParticipant @brianabbott67793]

Hello everyone

I am working on the ash pan, damper and hinge arrangements.

I have made the hinge that attaches to the front of the boiler but am having trouble picturing the 2 small hinges that solder to the damper.

Would anyone have a clear picture?

Thank you

[JasonBModerator @jasonb]

Last two in this album of mine

[Author]

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