Brian’s 1″ Minnie Traction Engine

[Brian AbbottParticipant @brianabbott67793]

Thank you both for the reply’s

 

[PlasmaParticipant @plasma]

Brian,

I’m new to this thread but I think that looks amazing my friend!

The piping to the tender looks fine to me the way you did it.

Things takes as long as they take, I know Django is concerned about having enough time to complete a mini.  But if you have to put in full shifts every day the hobby will soon start to feel like a job.

I’m building a kit model which could be completed from box to unpainted built in 24 hours. But I’m modifying and making new parts so it’s going to take me at least a couple of years of hobby tinkering to finish it off.

You’re doing a fantastic job, can’t wait to see her finished.

Mick.

[Brian AbbottParticipant @brianabbott67793]

Thank you Mick

Paper template made for the cladding, need to transfer onto the brass.

 

 

 

[Brian AbbottParticipant @brianabbott67793]

Wondering if you could offer me any help regarding the riveting on the wheels?

I am just starting on the fronts but the problem i am having is this,

When i originally built the wheels, each spoke was drilled 1/16 for the rivet, the second hole was then opened up to suit a 10ba screw.

The problem i am now having is the oversized hole won’t rivet very well, i think the rivet is just swelling in the oversized hole.

Wondering if anyone has any tricks ?

I did think maybe fill the hole with solder and re drill the correct size.

Thank you

Brian

[JasonBModerator @jasonb]

You might just have to start with a longer rivit so that there is enough material to fill the larger hole and still leave enough to form a head.

This may require the making of an intermedial rivit snap so you can start to form it without the shank bending over, think of the shape like an upturned bucket.

I don’t recall enlarging any holes on the Minnie or the Fowler’s tender, I think that although a screw could not be pushed into  a1/16″ hole it could be screwed in and once done a few times the screw lost a bit off the crests.

[Brian AbbottParticipant @brianabbott67793]

Hi Jason

I think it was down to my own inexperience, i will try what you suggested as this would swell the rivet filling the hole without it bending,

Thank you

[Brian AbbottParticipant @brianabbott67793]

Hello Jason,

Could i ask how you clamped the boiler banding on your engine?

Did you drill and bend the ends ?

Thanks

[JasonBModerator @jasonb]

looks like I soldered a couple of 1/8″ square blocks to the ends of the banding.

[Brian AbbottParticipant @brianabbott67793]

Thanks Jason,

I have made some small angle brackets but i am really not happy with them, will follow your example i think.

Thanks again.

[Brian AbbottParticipant @brianabbott67793]

Hello All,

Anyone any tips on how to make the ratchet wheel on the Minnie Lubricator ?

Thank you.

 

 

[JasonBModerator @jasonb]

Make a small flycutter/single point tool with an acute end and proceed as if you were gear cutting.

[bernard towersParticipant @bernardtowers37738]

Can also be done with a standard end mill, just change the shape of the pawl

[Andy StopfordParticipant @andystopford50521]

I think I used a dovetail cutter on the centre line

[Clive Brown 1Participant @clivebrown1]

Here’s my 40t Allchin wheel, 1/2″ dia. Cut by grinding an angle on a 1/4″ square hss toolbit which is held in the lathe toolpost and using the carriage as a shaper. The lathe spindle was indexed using a changewheel. Quick and done in one chuck setting.

[Andy StopfordParticipant @andystopford50521]

Having had a look at it, I think I set the edge of the dovetail cutter a bit below the wheel centre line to give a slightly hooked effect to the teeth.

[Brian AbbottParticipant @brianabbott67793]

Thank you everyone for your help and advice, and sorry for the slow reply.

 

[Brian AbbottParticipant @brianabbott67793]

Hello everyone,

So i have completed the lubricator,

Decided on a 33 tooth ratchet wheel bit doesnt seem to ‘click in’ on a short stroke so need to make a new wheel with more teeth.

What have other people used ?

Thanks

 

[bernard towersParticipant @bernardtowers37738]

could you incorperate a miniature one way clutch bearing into the design leaving your ratchet in situ giving you the best of both worlds?.

[Glyn DaviesParticipant @glyndavies49417]

Before making a new wheel, it may be worth unbolting the lubricator from its mounting and moving it back and forth slightly while running the engine on air to see if there’s a position where it will work. Then either slot the pump mounting holes or move the actuating arm on the valve rod.

[JasonBModerator @jasonb]

The main problem is the top pawl has so little weight that it can just ride up and not engage the ratchet so the moving pawl’s spring just keeps it engaged in the same tooth rather than moving to the next. The top pawl really needs an extension towards the rear to give it a bit more weight.

Try it fully notched up to get the most arm movement with light finger pressure on the top pawl and see if it works then.

Easier than making a new gear is to extend the slot in the arm closer to the pivot and make a longer bent arm, that way you will get mor erotation for the same amount of valve rod movement when not fully notched up.

[Andy StopfordParticipant @andystopford50521]

As Jason says; in the photo below I’ve fitted a spacer to raise the bent arm, and given it a fore and aft bend to get the best possible action and as you can see this brings it up to the top of the slot, and it still doesn’t reliably deliver at all cut-offs.

I’m going to extend the slot as far as possible and make a new bent arm after a bit of test running to confirm the best dimensions.

For what it’s worth, the ratchet wheel has 36 teeth; here’s the drawing:

[Brian AbbottParticipant @brianabbott67793]

Sorry its taken so long to reply.

So i did try making a new rachet wheel with more teeth but didn’t really make any difference.

Had a play and adjusted the arm which seems to have done the trick.

Thank you

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