Author Topic: Retlas  (Read 89939 times)

Offline Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 6133
  • Switzerland
Re: Retlas
« Reply #210 on: October 22, 2016, 04:08:15 PM »
Reading the instructions closely the white battery wire my be for the advance/retard system mentioned. At the speed the Retlas will operate it can be safely ignored.
Best regards

Roger

Offline Alyn Foundry

  • Full Member
  • ****
  • Posts: 1653
  • North Wales, Great Britain.
Re: Retlas
« Reply #211 on: October 22, 2016, 05:30:32 PM »
Hello Andy.

We will be playing with almost anything we can get our hands on! Don't worry if you can't make it, I know it's a long haul from the Midlands.

Regarding that electronic ignition unit is there a part number on the Hall effect transistor? We might be able to establish what the White wire does.

I was always " old school " where HT ignition was concerned. I built many from the coils of old Suffolk lawnmowers. A simple attracted Iron armature with some auto ignition points and a " Buzz box " was born!

Really looking forward to seeing the first run on video..... I remember well the first pops of life from my Sphinx engine, actually in front of quite a large audience. Vincent and I decided to complete the engine at the Hanmer steam rally, he had a portable generator so we had some power for the few tools needed to finish it. The feeling of satisfaction was immense!

Kind regards, Graham.

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 988
Re: Retlas
« Reply #212 on: October 22, 2016, 05:54:00 PM »
Hello Roger,
I set up the RHC electronic ignition unit with a three AA cell battery box and it worked briefly with or without the white wire connected as you expected. However,  the spark was far too weak, it would just about manage a ten thou gap but couldn't manage an arc across the RHC miniature spark plug points. Incidentally, I could only get a result by using the neodymium magnet from the Minimag, it wouldn't fire using the little bar magnet provided with the RHC. Perhaps the unit is past it's use by date. Not to worry it didn't cost much.

In stark contrast minutes later the Minimag was producing strong sparks that jumped a 0.125" gap and also fired the RHC spark plug with ease.

Hi Graham, you posted as I was finishing off the above. The RHC unit appears to be a failure, I reckon the Retlas would snuff out any sparks it managed to produce. There are no discernable identification marks on the Hall Effect Trigger but as you can see from the above it worked with or without the white wire connected.
"Old School" - I have used a 12v Lucas coil from an old Triumph motor bike with great success on my other engines equipped with 'old school' contact points and condenser. That produces sparks that jump half an inch but I think it kills the CM-6 spark plugs I use so I keep a good stock of them.

I bought a trembler coil for my Economy engine which is very effective, there are a couple of videos of that engine within my build log.

Andy

Andy

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 988
Re: Retlas
« Reply #213 on: November 09, 2016, 02:17:25 PM »
I haven't made much progress over the last week because of supervising some building work at home and being mauled by my dentist  :'(
However, I have been able to do some work on the inertia type governor, this is the plan,
221 Retlas Holts Style Inertia Governor by Andy, on Flickr

And to show what I'm trying to achieve here's a photo of the valve gear on a completed Retlas taken ten years ago.
Valve operating gear by Andy, on Flickr
The geometry of the governor had to be improvised because the valve chest casting is deeper than normal and I had to tailor make other parts to fit each other.

So I started off with a 9/16 square steel bar and milled, shaped, sawed and filed it to shape. I wanted to keep the little tripping ramp part of the trigger as solid bar but if needed I can file it down and solder on a new ramp in the optimum position. A pieces of scrap aluminium was made into a temporary tripping point.

Building Retlas 752 by Andy, on Flickr

Building Retlas 755 by Andy, on Flickr

Building Retlas 756 by Andy, on Flickr

Building Retlas 757 by Andy, on Flickr

Building Retlas 758 by Andy, on Flickr

Here are a couple of videos to demonstrate the action of the governor which opens the gas valve which will be timed to open about 1/32" behind the inlet valve. The gas valve will only be opened a minimal amount, the governor only has to miss the valve stem I don't intend to have it pushing against the valve spring collar when the engine is running.

These two videos are on Flickr, clicking on the image opens my Flickr album where you click on the play arrow in the centre of the screen.

Holts Governor MP4 by Andy, on Flickr

Hotls Governor on Retlas by Andy, on Flickr

By the way this is all jury rigged at the moment.
Andy
 

 
« Last Edit: November 09, 2016, 02:36:31 PM by Chipmaster »

Offline yogi

  • Full Member
  • ****
  • Posts: 450
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Retlas
« Reply #214 on: November 11, 2016, 12:32:42 AM »
Nice progress Andy!  :ThumbsUp: :ThumbsUp: :ThumbsUp:
Inertia governor are fascinating to watch. Well done!

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 4693
  • Boise, Idaho USA
    • Photo Bucket
Re: Retlas
« Reply #215 on: November 11, 2016, 12:40:16 AM »
Nice progress Andy!
I do like the pendulum governors.



Dave

Offline fumopuc

  • Full Member
  • *****
  • Posts: 3231
  • Munich, Germany, EU
Re: Retlas
« Reply #216 on: November 11, 2016, 04:52:21 AM »
Hi Andy, thanks for taking the time to show the function of this governor. Will be good to see the engine running soon.
Kind Regards
Achim

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 988
Re: Retlas
« Reply #217 on: December 18, 2016, 10:19:35 PM »
Last Monday 12th Dec I decided to try the engine out for a few short runs without a cooling system but with plenty of oil. It started with the first turn of the crank. However, a knocking sound developed and was apparent that the gib key securing the flywheel to the crank needed to be a better fit. I tried the engine out again this afternoon, here's the edited videos I uploaded onto YouTube....

<a href="https://www.youtube.com/watch?v=GlAti3CkX_0" target="_blank">http://www.youtube.com/watch?v=GlAti3CkX_0</a>

Some basic and fine tuning is necessary together with a cooling system so the engine can bed in. Once the engine is running smoothly I'll work out how to present it and decide on the paint job.

Andy

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9466
  • Surrey, UK
Re: Retlas
« Reply #218 on: December 18, 2016, 10:44:37 PM »
Looking good :pinkelephant:

Offline yogi

  • Full Member
  • ****
  • Posts: 450
  • Duncannon, PA USA
    • Yogi's Workshop
Re: Retlas
« Reply #219 on: December 18, 2016, 09:34:45 PM »
Fantastic engine Andy!!!  :ThumbsUp: :ThumbsUp: :ThumbsUp:
I love the motion of the valve gear. Well done!

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 988
Re: Retlas
« Reply #220 on: December 18, 2016, 11:58:13 PM »
Thanks for the comments Jason and yogi.

I reckon it will take me a few months to finish it off, my biggest problem will be choosing the colour scheme!

Andy

Offline fumopuc

  • Full Member
  • *****
  • Posts: 3231
  • Munich, Germany, EU
Re: Retlas
« Reply #221 on: December 19, 2016, 01:45:13 AM »
Looking really good. A very interesting motion of these hit and miss cycels.
Kind Regards
Achim

Offline Dave Otto

  • Full Member
  • *****
  • Posts: 4693
  • Boise, Idaho USA
    • Photo Bucket
Re: Retlas
« Reply #222 on: December 19, 2016, 02:49:16 AM »
Hey Andy

Congrats on the first pops! The engine is larger than I had thought; looks to be a nice size lump of iron.
I like the pendulum governor and the interesting valve linkage; also how slow she runs.

Very nice!
Dave

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 7862
  • Portland, Oregon, USA
Re: Retlas
« Reply #223 on: December 19, 2016, 07:54:46 AM »
That's really cool, Andy!  I'm not familiar with a pendulum governor.  I'll have to look into how that works.  Congratulations on a runner!
Kim

Offline Alyn Foundry

  • Full Member
  • ****
  • Posts: 1653
  • North Wales, Great Britain.
Re: Retlas
« Reply #224 on: December 19, 2016, 10:20:56 PM »
Well done Andy!!

Very much " alive and kicking " !  You must be very proud ?

She seems a little tight at the moment but should improve with a few runs.

May I be a bit pedantic ? The Retlas employs an inertia governor this should not be confused with a Pendulum governor. I had hoped to provide a video of a Robinson HA engine which has such a governor but it will have to wait until the New year. I have, however attached a picture of a model Robinson for clarification.

Kind regards, Graham.


 

SimplePortal 2.3.5 © 2008-2012, SimplePortal