Copper star reeds for Babe Bees with circlips

If you could take a grinding tool and deepen the face if the boss under where the reed sits, the circlip in its groove would then be slightly higher over the reed. This would allow free movement like the new retainers do. I may to try and find a grinding or sanding wheel for the Dremel that would do it. Worth trying anyway. I'll put it on my list of things to experiment with.

I talked to a guy who had some hand held paper hole punches made in china that punched out reeds (said it would only handle mylar or other soft material) and a punch that punched out .049 crankcase gaskets. He said it cost him around $1000 to have 10 of each made. He asked me if I would like to buy a set for $350. Sometimes I wish I would have taken it but at that time 2 punches for $350 sounded like A LOT! I tried to make a reed punch out of a sharpened metal rod with the sides filed off to give the reed that "oval" shape. I took the rod and hammered it into a piece of wood and then hammered it into a thin piece of sheet metal to make a "reed shaped" hole. It did not work as well as I thought it should. I later went back to cutting the reeds by hand. If I can still find the punch laying around here, I may start to work on it again. I was making reeds out of mylar floppy disc material. I did not try any metals with it yet, that may actually work better. I currently only use the factory reeds in my engines but I do like to mess around with other reed materials. I think the bending came from actual engine use over time as I have opened up new slightly used Babe Bees that did not have any edge bending to their reeds but I did open up well used engines to find the reeds had bent edges.

Yes I agree that the slight bending of the beryllium copper occurs over time. New ones are perfectly flat.

I had discussions with Larry Renger a few years ago about reeds. He said that the newer disc style reeds were more efficient and out of all the different materials he preferred stainless steels ones for reliability. The nylon, mylar and teflon ones are supposed to be better because they are lightweight and move easier but they don't last as long because they become warped easily.

Cheers

warrenlead wrote:he preferred stainless steels ones for reliability. The nylon, mylar and teflon ones are supposed to be better because they are lightweight and move easier but they don't last as long because they become warped easily.

I do like the stainless steel ones even though most people think Estes junk when you bring up stainless reeds. I have had good luck with the mylar but my '90 Black Widow came with a mylar reed that warped from being in the reed retainer for about 12 years before it actually ran. It did run with that reed but I replaced it with a star shaped mylar reed that boosted its rpms by 2000 or so.

the problem with the airflow explained at the top is just what i experienced with my black widow.
it had a mylar reed. but what i've actually noticed is that there is much less pressure buildup in the
crank case when the piston goes down, so much less fuel gets into the actual piston.
i noticed the same thing when i disassembled it and gave it the old suck in draw out routine. the
mylar reed never held entirely shut. that's why i'm running all of them on copper star at the moment.

Was probably the most common problem.

Back in the day when you bought a Cox model and it didnt work ie wouldnt, start you could take it back and they would give you another.

Back to the Cox factory they had these 44 gallon drums full of various 049 product engines. Every one of these engines supposedly did not run.

A guy I know here in Oz, went an purchased 2 drums of these motors for a Public Schools model building and flying program he was doing back in the 70s and 80s.

The majority of these engines ran with no problem. Some either had stuck reed valves, two reed valves, no reed valve or a bent reed valve. We used to sit around at the club house before he would go on one of his trips and fix up and test 30-60 motors... it was a lot of fun, but always either the reed valve or glow plug if anything.

I hope one day I find a drum that size of "faulty" tee dee .010s.

If there s a point to "pre-stressing" a reed in either direction what is it?

"Curious minds want to know"

SD

id bend it towards the venturi. might not be right, but thats what i would do.

GermanBeez wrote:the problem with the airflow explained at the top is just what i experienced with my black widow.
it had a mylar reed. but what i've actually noticed is that there is much less pressure buildup in the
crank case when the piston goes down, so much less fuel gets into the actual piston.
i noticed the same thing when i disassembled it and gave it the old suck in draw out routine. the
mylar reed never held entirely shut. that's why I'm running all of them on copper star at the moment.

When I use a new mylar reed, the first thing I do is probe the edges with a fingernail and feel for a rough lip around the edges, rolled over from when it was stamped out. Some have it, others don't. They are the ones that leak or squeak under pressure. I scrape it off with a razor blade and then they usually seal so hard and fast that I can't detect any back flow(flipping it upside down would probably fix it too). That's what I use in my BWs. They eventually warp outward a bit, so if the engine seems to be a little less fast it's time for a new one. Mine have been running all Summer and might be starting to drop off a little, but still good enough so far.
I have some steel reeds but I have yet to put any serious run time on them. The added weight of steel could conceivably make it a little slower to react to the pressure changes, but that's just one of my wild speculations.