Author Topic: RLE questions!  (Read 22269 times)

Offline Manorfarmdenton

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Re: RLE questions!
« Reply #75 on: February 14, 2016, 02:55:31 PM »
Assembled crankshaft.
John Fearnley

Offline Alyn Foundry

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Re: RLE questions!
« Reply #76 on: February 14, 2016, 03:20:33 PM »
Hello John.

I hope you have better luck with glued cranks than I did !!

I tried 638 when it first appeared on a couple of RLE contracts ( fully built option ). They lasted less than a few hours. I must admit I didn't pin them as the product info suggested 3 Ton shear strength on a 1" dia shaft.

Still, you have had success with your Redwing's, fingers crossed.

Kind regards, Graham. 

Offline Manorfarmdenton

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Re: RLE questions!
« Reply #77 on: February 14, 2016, 06:05:39 PM »
Hello Graham.

You have worried me now but I'm pretty confident that, given suitably cleaned interfaces the Loctite should be ok.  I wouldn't trust it without the pins though.  I drill parallel holes, ream with a taper-pin reamer, then clean the holes thoroughly and treat them with Loctite before hammering in the pins and filing off the protruding ends after curing. 

I'm a great believer in Loctite - amongst other things, I used Loctite metal filler to relocate and hold a cam follower guide which had come loose and badly worn the block of the 22 litre Diesel engine in my Caterpillar D8, and it provided a permanent cure.

Fingers crossed!

Kind regards, John.
John Fearnley

Offline Manorfarmdenton

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Re: RLE questions!
« Reply #78 on: February 21, 2016, 05:24:50 PM »
Has anyone any strong views on the best way to provide the electrical timing?  Another 52 tooth gear below the cam gear, or a disc with magnet on the crankshaft on the other side?   Presumably if I use the latter arrangement wasting a spark every other rev doesn't matter?

John.
John Fearnley

Offline Alyn Foundry

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Re: RLE questions!
« Reply #79 on: February 21, 2016, 05:50:40 PM »
Hello John.

On every RLE I built I fitted a small tube of Steel with a flat milled on it. Right in the centre of the flat a 6 BA threaded grub screw retained the cam in the correct position. I then used the smallest set of contact breaker points I could find, oh by the way this was fitted to the non geared side. ;)

Having a mostly raised cam meant that the battery was only pulsed for a short period of time and would last a whole day on the rally field.

Wasted spark is now normal even on multi cylinder engines.

Kind regards, Graham.

Offline Jasonb

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Re: RLE questions!
« Reply #80 on: February 21, 2016, 05:52:32 PM »
You could probably get a magnet into the existing 52T gear and have the sensor on an adjustable bracket to pick up teh magnet towards the botton of the gear, the adjustment will allow for a bit of advance & retard.

With a bit more room on the opposite side of the crank you could use a magnet or simple contact again making one part adjustable. Either the disc holding the magnet/contact can be moved by loosening a grub screw locking it to the crankshaft or the sensor can rotate, if you are using bearings then the flange could be extended to allow the sensor/contact to be rotated about that. Would not be a problem using waste spark.

Offline Chipmaster

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Re: RLE questions!
« Reply #81 on: February 21, 2016, 06:01:42 PM »
Hi John, have a look at my RLE running in a video that I posted this morning in an article headed Two Alyns and a Schoenner. At some point in the video you will be able to see the contact breaker which relies on a small domed screw in the back of the half time gear to make the brief contact required in a 12v HT system. That was the system suggested by Graham Corry in the plans I had. I built my engine around 20 years ago and it has never failed. I improvised the insulated mounting for the contact breaker which used Tungsten points and materials bought from Woking Precision Models, now available from Hemingway.
If you are interested I can take close up pictures for you.
Andy
« Last Edit: February 21, 2016, 06:15:54 PM by Chipmaster »

Offline Manorfarmdenton

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Re: RLE questions!
« Reply #82 on: February 21, 2016, 06:11:51 PM »
Many thanks Graham, Jason, and Andy!

Graham, the flat on the tube you mention actuates the points then? 

Jason, I'm still hazy about the magnet and sensor.  If I go that way I'd better buy a sensor so I can see what's involved.  Is the magnet ok set in a steel gear then? 

Andy, I'll look at the vid.  Thanks.

Kind regards, John.
John Fearnley

Offline Alyn Foundry

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Re: RLE questions!
« Reply #83 on: February 21, 2016, 06:26:04 PM »
Many thanks Graham, Jason, and Andy!

Graham, the flat on the tube you mention actuates the points then? 

Kind regards, John.

Hello John.

Yes, very much the same as in an " old school " car distributor only there's one flat instead of 4,6,8.

I'm pleased to read Andy had used the original system, I changed mine after noticing sparks flying on an evening event, ah Astle park they were remarkable firework displays and open to the public till 10 pm. Fond memories.........

Kind regards, Graham.

Offline Jasonb

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Re: RLE questions!
« Reply #84 on: February 21, 2016, 06:53:10 PM »
As you don't have a sensor I'd be more inclined to go with simple contacts, the last few engines I have done have all used them only got the hall & magnets on the aero engine and Hoglet

This pic is of the Gade, behind the large gear is the cam and then behind that a ring with the grub screw in it for adjustment, you can just see sticking out the back of the ring a 3/16" stud with screwdriver slot. This is what makes contact with the insulated live contact to the left. Basically the same as Andy describes but with a bit of advance & retard adjustment. It also has a spark saver but best not worry about that now.



The Allman that I'm making at the moment is very similar except the contact stud sticks out the side of teh ring



J


Offline Chipmaster

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Re: RLE questions!
« Reply #85 on: February 21, 2016, 06:55:22 PM »
My RLE spark plug tends to get oiled up and sooty. However, the old 12v Lucas coil I use coupled with a 12v battery ensures a massive spark. I tried a 3.6 volt model i/c engine coil but it didn't provide a spark sufficient to overcome sooting up - had to keep cleaning or changing plugs. I think the miniature coil was called a Cracker or Kracker.
Andy

Offline Chipmaster

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Re: RLE questions!
« Reply #86 on: February 21, 2016, 07:00:43 PM »
Another consideration, The points on my RLE are entirely insulated from the engine frame and self contained so that there is no electrical arcing between moving parts of the engine that might lead to problems caused by pitting.
Andy

Offline Alyn Foundry

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Re: RLE questions!
« Reply #87 on: February 21, 2016, 07:01:20 PM »
Jason.

That's some nice looking engineering !!   :ThumbsUp:

You'd have thought that with all those emoticons above there'd have been a " hats off " one !! 

Kind regards, Graham.

PS. As our posts crossed, Andy she needs a little work to do. I had the same problem with fouled plugs until the dragsaw, can't remember changing one since.

Offline Jasonb

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Re: RLE questions!
« Reply #88 on: February 21, 2016, 07:29:10 PM »
I know a man with a set of Dragsaw castings ;) and the matching Hercules too :) :)

Thanks Graham, it was a nice one to build, wrote about it here if you are interested
http://www.modelenginemaker.com/index.php/topic,4863.0.html

Offline Manorfarmdenton

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Re: RLE questions!
« Reply #89 on: February 21, 2016, 09:55:13 PM »
Very helpful photos Jason.  Thanks.  An unconnected point of interest is the bearing-type cam follower, supported on one side only (unlike the Red Wing which sits in a fork).  I had decided to do this with the RLE, so its encouraging to see it in the photo.

I'm very impressed by the quality of the photos too!  From the lack of shadows it appears that you aren't using flash?  What camera do you use Jason? 

John.
John Fearnley