Author Topic: Retlas  (Read 67964 times)

Offline Roger B

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Re: Retlas
« Reply #225 on: December 19, 2016, 11:16:34 PM »
Excellent  :praise2:  :praise2: The valve gear is interesting with a huge amount of lost motion  ::) I have been looking at similar concepts for my fuel injection sytems.
Best regards

Roger

Offline Chipmaster

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Re: Retlas
« Reply #226 on: December 20, 2016, 07:40:03 PM »
Hi Graham,
Yes, the Retlas has quite a kick, in the video you can see it has to be held down to stop it bouncing around. The bouncing also affects the governor makes it swing when I dont want it to. I understand your point about the name of the governor. The plans call it a Holts Inertia governor which is the same as the Gardner 0 type. Id like to know more about the origins of these governors but I cant find any information about the Holts Inertia or Pendulum governors on the Internet or my books, who was Holts ?
I can see the pendulum hanging beneath the Robinsons valve gear in your post  so I look forward to a video of the pendulum governor in the new year if you can find one.
Meanwhile there is much for me to do, including,
   Make up a cooling system.
   Make an exhaust system.
   Finish the governor properly.
   Open up the air intake which is only at the moment.
   Make a sump - it hasnt got one so I have been placing layers of tissues under the engine to soak up the oil that passes through the engine.
   Running in the engine.
   Make a smaller electronic ignition timing disc that houses the neodymium magnet and hide it on the crankshaft between the flywheel and  main bearing.
Andy
« Last Edit: February 13, 2017, 10:53:26 PM by Chipmaster »

Offline vcutajar

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Re: Retlas
« Reply #227 on: December 20, 2016, 07:45:34 PM »
Nice runner Andy.  Congratulations.

Vince

Offline Chipmaster

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Re: Retlas
« Reply #228 on: December 20, 2016, 07:58:52 PM »
Hi Dave, Achim, Kim, Roger and Vince.
Thanks for your posts.
The 'lost valve motion' is the consequence of using eccentrics. I chose to position the rod end bearing further away from the pivot to reduce the amount of travel on the inlet side yet there's still enough action to give the governor a sharp kick! I'm interested in making the engine as docile as possible.

Andy

Offline Alyn Foundry

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Re: Retlas
« Reply #229 on: December 21, 2016, 08:17:44 PM »
Hi Graham,
Yes, the Retlas has quite a kick, in the video you can see it has to be held down to stop it bouncing around. The bouncing also affects the governor makes it swing when I dont want it to. I understand your point about the name of the governor. The plans call it a Holts Inertia governor which is the same as the Gardner 0 type. Id like to know more about the origins of these governors but I cant find any information about the Holts Inertia or Pendulum governors on the Internet or my books, who was Holts ?
I can see the pendulum hanging beneath the Robinsons valve gear in your post  so I look forward to a video of the pendulum governor in the new year if you can find one.
Meanwhile there is much for me to do, including,
   Make up a cooling system.
   Make an exhaust system.
   Finish the governor properly.
   Open up the air intake which is only at the moment.
   Make a sump - it hasnt got one so I have been placing layers of tissues under the engine to soak up the oil that passes through the engine.
   Running in the engine.
   Make a smaller electronic ignition timing disc that houses the neodymium magnet and hide it on the crankshaft between the flywheel and  main bearing.
Andy

Hi Andy.

I too have trawled the internet for reference material but to no avail. It would require painstaking study of the patent records to find relevant information.

When Vincent first showed his Retlas to the public it was an " Old hand " who said " that's a holts style governor " on that engine. It stuck !!

The Pendulum style might be a Robinson ( H ) not ( AE ) patent as I have only seen it on Robinson patent engines of the 1895 era.

It's very simple in operation, as the swing of the pendulum increases the arm attached to the pivot puts a " Sprag " on the closing exhaust valve and the engine slows down. ( Hit and miss )
Engines fitted with this style of governor DO need to be firmly anchored to the ground as vibration causes havoc with their delicate operation.

All the very best for Christmas and the New year, Graham.

Nadolig llawen a blwyddyn newydd dda   ;)

Offline Chipmaster

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Re: Retlas
« Reply #230 on: February 13, 2017, 10:50:59 PM »
I haven't been able to do much work on the Retlas since before Christmas when I could only run it for short bursts without a cooling system.

I managed to return to the job a couple of weeks ago when I made up a temporary wooden mount for the engine, fabricated a brass cooling tank and assembled them so that I can run the engine for prolonged periods and work out how to finish it properly.
I filled the cooling system with something called 4-Life that a friend gave to me some time ago. The 4-Life coolant container has lost its original label, it just has a piece of masking tape with 4-Life and 2002 written on it. It has been kept in unopened 5L plastic containers but I have no idea whether its effective or perhaps hazardous, the colour is red.
Im keen to minimise corrosion in the engines water jacket and cylinder head and had considered central heating corrosion inhibitors as Im not concerned with anti-freeze. I have also searched the internet and looked at inorganic versus organic additives but can't see an obvious product for model engines
I would like to hear of any additives other members can recommend to protect model engine cooling systems or perhaps Im just being too fussy?

P1060118 by Andy, on Flickr

P1060135 by Andy, on Flickr

P1060143 by Andy, on Flickr

P1060147 by Andy, on Flickr

P1060115 by Andy, on Flickr

Here's a poor quality un-edited video of the engine running this afternoon. I keep an expendable 12 year old Sony digital camera in my workshop but the images have deteriorated to the point I reckon it's time to get rid of it. Perhaps tomorrow I'll be able to use my regular camera to record a better video of the engine.

Click on this picture and you'll be taken to my flickr album where another click on the picture will start the video.

Retlas with cooling tank by Andy, on Flickr

Andy
« Last Edit: February 13, 2017, 11:09:30 PM by Chipmaster »

Offline Dave Otto

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Re: Retlas
« Reply #231 on: February 13, 2017, 11:57:11 PM »
Very nice Andy.

I enjoyed the video too! I would also be interested in what people think about cooling water additives. I would like to find something preferably clear that would stop the corrosion of metal parts and also be kind to painted finishes.

Dave

Offline Jasonb

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Re: Retlas
« Reply #232 on: February 14, 2017, 07:39:19 AM »
Looking good Andy

I wonder if one of the boiler treatments would work at the lower temperatures, something like the TS (treatment steel) that Heritage Steam do.

https://www.heritagesteamsupplies.co.uk/water-treatment/boiler-water-treatment.html

I have also heard of people using a very light weight oil in the cooling system.

Offline vcutajar

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Re: Retlas
« Reply #233 on: February 14, 2017, 08:22:22 AM »
Nice one Andy. :ThumbsUp: :NotWorthy:

Vince

Offline Steamer5

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Re: Retlas
« Reply #234 on: February 14, 2017, 08:32:03 AM »
Hi Andy,
 That is looking so nice! Runs well as well, just love the sound!

Have you got a paint scheme sorted yet? Sure if you haven't then you'll get any amount of suggestion here!

On the water treatment front, I would go to your auto parts store hunt out radiator coolant that's compatible with cast iron. Given the number of aluminium engines out there you might have to hunt around, guessing that the formulation will be tailored to suit materials. Follow the instruction for mixing strength, 5 litres of the concentrate should out last most of us!

Cheers Kerrin
Get excited and make something!

Offline Roger B

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Re: Retlas
« Reply #235 on: February 14, 2017, 11:19:52 AM »
Nicely done  :praise2:  :praise2:  :wine1:

Have you had any problems with corrosion? I have always just drained the water off while then engine was still warm/hot so it dried out.
Best regards

Roger

Offline Chipmaster

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Re: Retlas
« Reply #236 on: February 14, 2017, 06:35:01 PM »
Heres a better video of my Retlas taken with a more recent handycam. The ignition timing was advanced a half way through the video little.


I usually supply my gas engines with propane from a small cylinder fitted with a sensitive variable two stage regulator that will maintain a steady low pressure normally psi. This is rather a bulky arrangement so I tried out a Cadac EN417 regulator that fits a C500 disposable cartridge containing a 70% butane 30% propane mix.  The fixed regulator delivers gas at 29mbar ~ 1/2psi. The arrangement seems to work and is preferable to carrying heavy propane cylinders about. I may try it out with a C250 cartridge that could be concealed about the model.
Building Retlas 815 by Andy, on Flickr
Building Retlas 816 by Andy, on Flickr
Building Retlas 817 by Andy, on Flickr


Hi Kerrin, for the paint job I have chosen Graphite Grey, still thinking about anti corrosion additives.
Graphite Grey by Andy, on Flickr

Andy

Offline Chipmaster

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Re: Retlas
« Reply #237 on: February 14, 2017, 07:40:56 PM »
Anti corrosion additives....

Hi Roger I always drain the water from my engines as soon as I have finished running them like you. Excluding the Retlas I have three with water jackets, an Alyn Foundry Gardner 0 Type, plus two hot air engines, a Heinrici  and a 1/4 scale Rider Ericsson. I haven't had any problems with them so far, the Heinrici has an aluminium jacket anyway. Since I made the Gardner nearly 20 years ago I have occasionally flushed out the  model and it takes a few minutes before the flushing water runs clear. When I ran the more recent Rider Ericsson hot air engine (which pumps water around a cast iron cylinder liner in an aluminium block) clear water always got to look mucky quite quickly due to rust so I started using the old 4-Life coolant in that model. It looks attractive - raspberry red but it may be hazardous and like Dave Otto I'd prefer a clear coolant. However, the 4-Life hasn't been unkind to the paintwork.

Tannin boiler water treatment as suggested by Jason might be a possibility that I'll look in to, perhaps I can get somebody in our club Black Country Live Steamers to donate a small quantity for me to try out.

Andy

Offline Dave Otto

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Re: Retlas
« Reply #238 on: February 15, 2017, 12:42:11 AM »
My friend Max has a Stickney model that has a pump jack attached to it; he runs mineral oil in it (the pump only). It is crystal clear and because of the viscosity it doesn't splash around and make a mess. I'm not sure how it would work in an engine though.

Dave

Offline Chipmaster

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Re: Retlas
« Reply #239 on: February 15, 2017, 05:35:28 PM »
Hi Dave.
A friend and I would like to build water pumps for our model engines to drive. We're not aware of any castings for pumps available in the UK. As we can't find a source for the pump jacks seen with several model engines in the USA could you suggest anybody selling water pump castings please?
Andy