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Bill Dawes13/02/2022 19:33:11
534 forum posts

Hi guys.

I am attempting to finish my 5" gauge Emma Victoria but on the point of admitting defeat on the mechanical lubricator.

Made all the bits but finding it challenging to get the accuracy required, tiny pawls, springs, ratchet wheel, very fiddly,

Got it all assembled but the pawls don't engage with the ratchet wheel properly, suspect I didn't mill the teeth deep enough and/or not got the correct tooth angle.

So my question is, do you make your own or buy a proprietary one.

Bill D.

Former Member13/02/2022 19:58:15
1085 forum posts

[This posting has been removed]

Paul Lousick13/02/2022 21:35:00
2043 forum posts
722 photos

Made all parts for my lubricator.


duncan webster13/02/2022 22:19:14
3990 forum posts
65 photos

If the pumpy bits work, you could get a pair of sprag clutches and ditch the ratchet/pawls

Paul Lousick14/02/2022 05:24:48
2043 forum posts
722 photos

Where do you get miniature sprag clutches ?

Paul Lousick14/02/2022 05:51:52
2043 forum posts
722 photos

The ratchet wheel was machined much longer than required and a slice cut off to length (spares for next project or if it wears out). A dovetail milling cutter used to make the teeth.

53-5 lubricator.jpg


Nigel Bennett14/02/2022 08:58:36
457 forum posts
20 photos

Arc Euro sell non-return clutches; a type of needle-roller bearing.

Chris Gunn14/02/2022 10:15:09
430 forum posts
27 photos

Paul, the Bearing Boys sell them as well, 6mm bore about £8 each. I used them on my 4" and 6" Garrett lubricators I made, they work OK, but over time the thick steam oil gets in between sprags, and fills up the gap so they do not engage. A bit of a squirt with maintenance spray and a jiggle about gets them going again. I used them on a silver steel shaft, unhardened, and after 6 years no signs of wear.

Chris Gunn

Paul Lousick14/02/2022 11:07:13
2043 forum posts
722 photos

Thanks. I have a use for them on another project


Bill Dawes14/02/2022 11:27:52
534 forum posts

Looks a nice job Paul, from pics appears to be a bit more substantial than mine which is bordering on swiss watch size components.

Thanks for info guys, I will leave it a few days to get my head round whether to remake the bits or buy one.

Hate giving up anything I am trying to make/do but we all have our limits I suppose.


Bill D.

Bill Dawes23/02/2022 18:55:56
534 forum posts

Having pondered for a suitable length of time, I decided I wasn't going to give up and buy one but to have another go.

When I made the ratchet wheel I tried an experiment (well it is model and experimental engineering after all) I did not have a suitable milling cutter so tried making the wheel with a small slot mill set off centre, it did the job after a fashion but obviously not good enough, now have a dovetail cutter to try.

I am also going to try to make wire springs for the pawls, I could not not get the flat brass shim springs specified to position properly to exert enough force onto the pawls.

Onward and hopefully upward.

Bill D.

Clive Brown 123/02/2022 19:34:25
828 forum posts
42 photos

I've made my small lubricator ratchet wheels in the lathe. The process requires a means of indexing the chuck using, say, a change-wheel attached to the back-end of the mandrel and a plunger detent.

Turn the end of a piece of silver steel to the required diameter. Drill and partially part off. With the silver steel still in the chuck set up a suitably ground HSS tool at centre height in the tool-post and cut the ratchet teeth by traversing the lathe carriage as with a shaper and indexing for each tooth. Works very well giving accurate, well formed teeth for wheels of a range of diameters.

Finally part off and file or broach square centre hole then harden.

Didn't W. Hughes suggest this method for the Allchin?

duncan webster23/02/2022 21:06:49
3990 forum posts
65 photos

If you're making ratchet by dovetail cutter and some kind of indexing device, make a long length. It won't take any longer, and you can then part off as many as you like for your next project

Clive Brown 123/02/2022 21:23:25
828 forum posts
42 photos

Here's a ratchet wheel made as I described above. It's 7/16" dia.allchin lubricator.jpg

Bill Dawes26/02/2022 18:44:40
534 forum posts

Yes got a length ready for making several wheels.

Bill D.

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