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Author Topic: Blackgates Oscillator rebuild  (Read 9645 times)

southsteyne2

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Re: Blackgates Oscillator rebuild
« Reply #25 on: January 15, 2016, 10:47:22 PM »

Hi Ramon I have been watching your build with great interest and find it difficult to comment on such great work but I do have one question that is the construction of the steam distributer box (not the regulator also George ooya/2 advice is spot on but make sure you use viton rings for pistons ,can't wait to see in action
Cheers
John
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ooyah/2

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Re: Blackgates Oscillator rebuild
« Reply #26 on: January 16, 2016, 04:25:22 PM »

Hi Ramon I have been watching your build with great interest and find it difficult to comment on such great work but I do have one question that is the construction of the steam distributer box (not the regulator also George ooya/2 advice is spot on but make sure you use viton rings for pistons ,can't wait to see in action
Cheers
John

Hi John,
Here is the reason that I don't use Viton "O: rings in pistons, they are potentialy dangerous. They have been discussed on this forum and others.  read on !!!  (http://www.modelboatmayhem.co.uk/forum/index.php/topic,26332.msg258594.html#msg258594  )

George.
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Ramon

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Re: Blackgates Oscillator rebuild
« Reply #27 on: January 16, 2016, 08:14:36 PM »

Hello Trevor, George and John, thanks once more for your input

Trevor - I'm familiar with Balsa cabin having visited them many times over the years - all the timber for the Huntsman build (elsewhere on here) came from them but thanks for the thought. I can truly commiserate with you on the radial - I began a Bentley Br2 in 1992 and like you have a collection of many machined parts sitting idly under the bench. Despite putting in so much work off and on over the years I have, I'm sorry to admit, little inclination to resume work on it.
As an aside Trevor, as you live in Norfolk, are you aware of the Forncett Steam Museum just south of Norwich. They hold a very good 'Model Engineers Day' each October which is well worth a visit - lots of stationary engines, steam boats, traction engines etc . Maybe see you there this year?

George, again thank you for your observations. When I re-assemble it after painting I will take your advice and replace the O ring with a small spring. I was totally unaware that silicone O rings could grow by such an amount. I will bear your comments in mind once final test runs on steam are carried out.

John, I assume from your comment you are referring to the 'make up' of said distributor block. I did not take any pics but basically there were two holes drilled right through from each side at the correct angle (18 degrees). Two further holes were drilled, one from from the top the other from the lower surface to break into each of these holes. (These two holes were opened slightly to take small plugs which were silver soldered in place when soldering the pipework). Two further holes were drilled from the cylinder end to break into these plugged holes. The whole was then set up with the pipes cut to just protrude into the block by about 2mm and held on the jig as shown - once the unions were tightened this was all 'self holding' ready for the soldering. Once soldered all four unions screwed onto their respective points on the engine without any stressing.

Hope that resolves your query John.

Thanks again guys, your comments are much appreciated.

regards - Ramon

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Crossie

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Re: Blackgates Oscillator rebuild
« Reply #28 on: January 16, 2016, 10:16:28 PM »


 Hi Ramon,
                      thanks for the reminder about the Forncett Steam Museum, I had past it several times , always when it was closed, some years ago on my way to or from Old Buckenham,  but I had quite forgotten about it but now that I have the spare time I shall be able to make a visit, October you say?
                 
                                                    Trevor
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Ramon

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Re: Blackgates Oscillator rebuild
« Reply #29 on: January 16, 2016, 10:55:19 PM »

Hi Trevor - yes it's always the first Sunday in October. You'll find various model engineers mostly with working exhibits tucked in all the nooks and crannies around the museum both inside and out along with the top floor given over to a display area. Last year there were something like sixteen or so large model traction engines outside all in steam and driving off around the village in a long convoy. Of course all the full size stationary engines in the museum are in steam too so it's certainly a 'Modeller's Day Out' all right.

I'm usually at the top of the stairs with stationary and IC engines so please come and say hello if you remember the date.

Regards - Ramon
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rhbrook

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Re: Blackgates Oscillator rebuild
« Reply #30 on: January 18, 2016, 04:24:27 PM »

Good afternoon Raymond,

I was wondering why you chose silver solder in preference to Lead/soft solder for the various elements of the engine?
Roger
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Ramon

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Re: Blackgates Oscillator rebuild
« Reply #31 on: January 18, 2016, 05:02:47 PM »

Hello Roger,

The main reason is strength with of course much greater temperature resistance. Soft solder, unless of the higher melting point may, and I stress may, soften. Many years ago I made a pair of oscillators of my own design with similar piping and manifolds. I used a high melting point soft solder on those which survived the steam at 40 psi from a boiler with a reasonable 'super heating' element fitted so it can be used but with caution.

One other good reason to bear in mind is once something is soft soldered - if it proves inadequate - it will not be able to be silver soldered until all traces of the soft solder has been removed. As in the case of this engine that usually means re - machining the surfaces affected.

Hope that answers sufficiently

Regards - Ramon  (There's no Y or D by the way  ok2 - that's my mother's choice not mine ok2 ok2)
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ooyah/2

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Re: Blackgates Oscillator rebuild
« Reply #32 on: January 18, 2016, 06:15:22 PM »

Good afternoon Raymond,

I was wondering why you chose silver solder in preference to Lead/soft solder for the various elements of the engine?
Roger

Roger,
Another reason is if you go back to Ramon's quote that he had to redrill the block as there was a blockage and then re Silver solder.
If the block had been Soft soldered the whole assembly would have fallen apart when re soldering.

Silver solder with 42% Silver needs 25% extra heat to remelt so there is a better chance that things don't fall apart when re soldering a pipe into an existing fitting.

When working with steam engines it's always better to Silver solder and only practice will get you better at it.

George.
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KNO3

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Re: Blackgates Oscillator rebuild
« Reply #33 on: April 09, 2016, 01:12:25 PM »

I've only now discovered this thread and must say, very beautiful work! You basically made a new engine.

If it is still useful, i can confirm that PTFE / Teflon tape works perfectly to seal glands and pistons in small steam engines. I have used it in several engines and had no problems. Yes PTFE swells a little bit, but this is actually an advantage because it improves sealing when on steam. If it should make the piston rod move too tight, it is easy to replace the PTFE with a smaller quantity or less tightly wound.
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Ramon

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Re: Blackgates Oscillator rebuild
« Reply #34 on: April 09, 2016, 08:27:32 PM »

Thanks for your input KN03  :-))

I originally rebuilt this engine intending to sell it in order to fund something else. My wife thought that having spent the time on it I should keep it so I guess it will only run on air. However I am currently rebuilding a Double Ten which will be steamed and as per usual trying to decide between no packing (as per the original build) PTFE or graphite packing or the silicone O rings as so keenly recommended by George (OoYah)

Regards - Ramon
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KNO3

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Re: Blackgates Oscillator rebuild
« Reply #35 on: April 09, 2016, 10:26:33 PM »

I guess it's have a matter of availability and preference. Ptfe tape also has the advantage of being useful where not suitable oring size is at hand.
Have you started a thread about your D10?
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Ramon

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Re: Blackgates Oscillator rebuild
« Reply #36 on: April 09, 2016, 11:17:13 PM »

Hi KN03 - I have various types of packing but I've heard that twisted tape makes for good packing too. Thanks for the input though  :-))

Re the engine thread-  well yes but not on here. The D10 is destined for a Wide a Wake open launch, the build of which, including the boiler rebuild and now the engine is described on the Model Engine Maker forum which is the main forum I post to - there simply isn't time to do the same on others I'm afraid.

It's now at 33 pages with a lot of pics but if you fancy a look it's here http://www.modelenginemaker.com/index.php/topic,2851.0.html

The work on the engine is only a recent addition so is on the last couple or so pages of the thread.

Regards - Ramon
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KNO3

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Re: Blackgates Oscillator rebuild
« Reply #37 on: April 10, 2016, 01:43:37 PM »

Oh, I know your Wide-a-wake build already :-)
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