Rays Latest Engine - AKA Alyn Foundry RLE

[Jasonb]

tipex should do the trick

[RayW]

Tippex did the trick! Both gears now modified. I have made the cam on the large gear rather more rounded that shown on the plan, but the lift is still 1/8" as specified. I painted the teeth of the smaller gear with Tippex before soldering on the larger boss. This worked pretty well, with only minimal solder getting into the teeth, and this was easily cleaned out with my Dremel.
Next job is to drill and tap the hole for the large gear spindle.

[Alyn Foundry]

Hi Ray.

I have just noticed your recent posts. Don't forget that the valve opening duration isn't just cam related. The follower also has a bearing. On the R.L.E. the follower is a very shallow semicircle so the opening time with a wide cam will add to the duration of opening.   

On 103 I opted for a 1/16" peg, set in the crankshaft as it leaves the main bearing. By putting the gear on a piece of 7/16" diameter round bar I then carefully drilled a 1/16" hole on the centreline to create a little pocket. The crank gear can then be simply slipped over the peg and an " invisible " drive achieved. As there's little to no load on this component there's no need for a more " robust " form of fixing.

Cheers Graham.

[RayW]

Hi Graham,
Do you think the longer valve opening will be a problem? If so, I will have to try and re-profile the cam or, alternatively, I could make the cam follower a tighter radius.
As regards fixing the small gear to the crankshaft, the reason that I soldered on a larger collar than the one that the gear had originally was because when bored out to 7/16"there was very little metal left at the root of the teeth ( not much more than 1/32") and there would have been no room for a pin drive like you suggest. If I fit the gear with the collar facing towards the side of the engine, the gear would be too far out.
The new collar will also provide sufficient wall thickness for a small grub screw.

[Alyn Foundry]

Hi Ray.

Well....

Ideally you'd like the exhaust to open a little before BDC and then be fully closed at TDC for the next intake stroke. I'd suggest to try it and see what " actually " happens when fully assembled. The " half moon " follower was made to stop the round pushrod from rotating, a very simple solution. Being made from Brass it also acts as a bearing too.

I seem to recall using a file to get the right profile after " fine " fitting the assembly.

Regarding the crank gear my own 40 DP wheel might have a little more " meat " to it than yours but was just a suggestion for an alternative fixing.

Cheers Graham.

[RayW]

I have now fitted the gears, using Graham's suggestion of an eccentric bush for the large gear spindle, which allows fine adjustment of the meshing. The eccentric bush is locked in position with a grub screw once the correct meshing has been achieved.

[Alyn Foundry]

Looking good Ray.   

I recently came across some old photos, amongst which was one of the prototype R.L.E. number 103.

Taken some time around 1986/7. Note the original " air cooled " format and MK 1 carburettor with high mounted " Three Nuns tobacco tin " fuel tank. This engine would also have the original Meccano gears fitted.

Cheers Graham.

[RayW]

I am really surprised that you say the air cooled one did not prove popular and that sales only took off after the hopper was added. To me, the air cooled one was a nice looking engine and something a bit different. What would be interesting to see is a picture of your air cooled RLE alongside your little Leek to show the similarities (and differences, of course!). Having just fitted the RLE gears, I was pleasantly surprised to find the the gears on my Leek are exactly the same in size and number of teeth so I will have no problem replacing the badly worn ones, subject to being able to get the flywheel off.

[Alyn Foundry]

A " side by side " would be a little difficult Ray, in fact young Alan was asking about the cylinder. I'm pretty sure I put it on another engine for a commission build.

Yes, despite several adverts placed in the various periodicals not a single air cooled engine was sold. The R.L.E. was loosely based around the Associated Manufacturers ( Amanco ) Chore boy, I even put a pad on the side of the cylinder for additional fan cooling.

After several months a good friend suggested the water hopper and, putting his money where his mouth was, bought the first set of water cooled engine castings. The rest is history, the R.L.E. went on to outsell every other kit we marketed with over 400 kits sold to date.

[Jasonb]

Same goes for the Associated models and Redwings, the hopper cooled ones are far more common than the air cooled, I've a water cooled Hired Man set of castings knocking about under a table 

I have made a start drawing up my own 24mm bore open crank design but am thinking of drawing three options - tank cooled, hopper cooled and air cooled all using mostly the same common fabricated/cut from solid parts along the lines of a Senior. I think I know which one will prove to be the most popular if I write it up ad do working drawings.

[RayW]

I drilled the two brackets today for the push rod. Despite taking great care with squares and height gauges to get everything in line with the centre of the cam, I ended up with the end of the rod just hitting the teeth of the large gear.
To rectify the problem, I firstly moved the gear fractionally closer to the side of the engine by grinding away some of the sloping side, but this was still not enough. Next step was to enlarge the hole in the cylinder bracket and glue in a brass guide bush, then fill the small gap around it with JB Weld.
The result is a nice free moving rod, which I will also help by adding an oil hole in each of the brackets.

[Jasonb]

Maybe that's why the gear is shown half the width on the plan view from what it is individually dimensioned

[RayW]

Yes, I had noticed that too Jason. I may see if I can reduce the thickness of the gear slightly just to move the pushrod more central to the cam.

Had a fun day yesterday making probably the most awkward shaped piece of the whole engine, the governor arm, not helped by the fact that several important dimensions are missing from the drawing, eg, location of the pivot hole, the 2BA threaded hole, and the 1/2" wide cutouts. Fortunately, my guesstimates on all of these worked out fine and the arm operates smoothly with the governor spool on the crankshaft.

Apart from milling  the 1/2" cutouts, all other shaping of this fiddly little component was done with my Dremel and with an assortment of files. Not a quick job, but I think the finished product looks pretty close to the drawing. As per Graham's notes, the end which engages with the latch on the pushrod was made flat, and not rounded as drawn, to ensure good latching when operating in the miss position.

[Alyn Foundry]

Good afternoon Ray.

The part looks great.

I realise that several dimensions are missing and also know that taking measurements from drawings is frowned upon. Back in the day the drawings were supplied, not as photocopies but taken from the original tracings by a process who's name I've forgotten.

Having been drawn at a 1:1 ratio the plan was to check out your measurements directly from the paper with either dividers or a rule. Obviously with the advent of photocopies all sorts of discrepancies can occur as any ratio of picture size can be entered for the print.

You're getting closer now, cheers Graham.

[Jo]

..... Back in the day the drawings were supplied, not as photocopies but taken from the original tracings by a process who's name I've forgotten.

Dyeline copying