Author Topic: Strictly.... Hot Air  (Read 31927 times)

Offline Jasonb

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Re: Strictly.... Hot Air
« Reply #360 on: November 27, 2018, 06:38:03 PM »
Could have got them next day from forrest, and more choice of Size as it matters and they also have the smaller No3 which you will need :facepalm:

https://www.forest-classics.co.uk/ceramic-burners/gas-essentials-and-jets

Cheaper via their e-bay site but slower postage


https://www.ebay.co.uk/itm/NEW-NO-3-GAS-JET-1BA-THREADI/202067603909?hash=item2f0c2af1c5:g:~y4AAOSw3~5ZzQYV:rk:2:pf:0
« Last Edit: November 27, 2018, 06:45:28 PM by Jasonb »

Online Jo

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Re: Strictly.... Hot Air
« Reply #361 on: November 28, 2018, 08:44:17 AM »
And even cheaper from Jeremy  ;)  They should be in the post later today then we just have to wait for Royal Snail  :disappointed:

Why do I need the little No 3 jet :headscratch:

Jo
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Offline Jasonb

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Re: Strictly.... Hot Air
« Reply #362 on: November 28, 2018, 08:52:07 AM »

Why do I need the little No 3 jet :headscratch:

Jo

I thought the whole reason for making a burner was that your hob was too big and your torch bigger still :facepalm2:

A No8 would be what you would use on a burner for a 3" vertical boiler but you don't want to be getting anywhere near that much heat so the smaller jet is the better bet.

Did you see the size of the flame on Norman's burner he was using for his Polly, not much more than a large candle flame, and mine runs on a similar flame without the base, the only reason I went with the ring was because it draws in air lower down and even then I can't set the flame as low as I would like without it going out.
« Last Edit: November 28, 2018, 09:05:58 AM by Jasonb »

Online Jo

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Re: Strictly.... Hot Air
« Reply #363 on: November 28, 2018, 09:01:19 AM »
My hob burners are a larger diameter than the hot pot on the 1/2 sized Robinson so they heat the stand rather than the pot. The torch needed a better mount but was only for a quick test. So the plan is to make a long term solution for each engine.

But it will all have to wait until I get some time... there is so much to do when you are retired  :facepalm:

Jo
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Offline Jasonb

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Re: Strictly.... Hot Air
« Reply #364 on: November 28, 2018, 09:14:12 AM »
Regarding that old camping gas ring you had. the 5.8mm dia thread is most likely to be the Euro standard M6 x 0.75 if you wanted to use that, not the BA size I thought.

Happens to be the same thread as that hose I had on my engine, had you mentioned it before I could have brought my taps along with me for you to borrow.

Online Jo

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Re: Strictly.... Hot Air
« Reply #365 on: November 29, 2018, 04:10:35 PM »
The ceramic proved to be easy to cut and file  :)

The bigger burner is finished and a second has been started. I didn't get far as it is Thursday  :naughty:  :wine1:

Jo
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Offline Bluechip

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Re: Strictly.... Hot Air
« Reply #366 on: November 29, 2018, 05:53:53 PM »
Ah :)  That's cute ..  does anything stick the ceramic in or just a close fit ??


it is Thursday  :naughty:  :wine1:

Jo

Yeah, me too after this mornings escapade. I feel I owe it to myself ....  :facepalm:

Dave

Offline ettingtonliam

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Re: Strictly.... Hot Air
« Reply #367 on: November 29, 2018, 08:54:08 PM »
I'm boring the Robinson cylinder and have just noticed that the drawing shows a 1/8" wide semi circular groove undercut at the end of the bore. Doing it isn't a problem, but I'm just curious what its purpose is.

Offline Jasonb

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Re: Strictly.... Hot Air
« Reply #368 on: November 30, 2018, 07:18:07 AM »
I would have thought it allows the piston to clear the end of the bore so you don't wear a ridge at the end, same sort of thing you see on cross head guides etc. Also makes it easier to lap as you are not working into a corner.

Offline Alyn Foundry

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Re: Strictly.... Hot Air
« Reply #369 on: November 30, 2018, 10:46:00 AM »
Good morning Richard.

If you look closely inside the cylinder you should see the grove " as cast " at the bottom end.

It's sole function is to allow the tip of the cutting tool to clear before bottoming.    ;)

Cheers Graham.

Offline ettingtonliam

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Re: Strictly.... Hot Air
« Reply #370 on: November 30, 2018, 11:23:47 AM »
Thanks Graham
I've only taken one roughing cut through as yet, with about another 1/8" to go. I did notice that the boring bar started cutting fresh air towards the end of the bore, but didn't realise that was deliberate!

Jasonb has a good point about it giving clearance when honing towards the end as well.

Online Jo

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Re: Strictly.... Hot Air
« Reply #371 on: November 30, 2018, 01:42:09 PM »
I have finished off the smaller burner just in time as the nice lady from Royal Snail has just dropped off those exceedingly cheap jets from Jeremy  :cartwheel:

This morning I started tackling the Hot cap and the Displacer which come as flat pieces of brass  :thinking: the first job was to turn them round using a super glue chuck and a safety tailstock support. I tried knocking the corners off the piece of brass before turning but I came to the conclusion that that was a waste of time.

We have discs  :) I need to make a hole in one and decide if I want a displacer or regenerator  :noidea:

Jo
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Online Jo

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Re: Strictly.... Hot Air
« Reply #372 on: December 01, 2018, 02:57:59 PM »
There is a little too much bonking going on around here   :embarassed:


I am going to have to sort that out but once it had cooled down I thought I may as well try a tea light  ;)


Must stop that bonking it is not good  :disappointed:

Jo
« Last Edit: December 01, 2018, 03:12:30 PM by Jo »
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Offline Gas_mantle

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Re: Strictly.... Hot Air
« Reply #373 on: December 01, 2018, 03:17:28 PM »
Great stuff, well done  :)

It runs fast on the tea light, you got me interested in making one now  :)

Offline Alyn Foundry

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Re: Strictly.... Hot Air
« Reply #374 on: December 01, 2018, 03:31:37 PM »
Well worth the wait Jo.

Very well done!   :ThumbsUp:

Have you been able to ascertain where the knocking is coming from? At this moment I think Andy's engine is the quietest I've ever heard running.

As a " by the way " I have 3 sets of castings left if anyone is interested.

Cheers Graham.