Pressure controlled 2 stroke jan ridders

[brazza]

Hi everyone i've been building jan ridders Pressure controlled 2 stroke now
for about a year , (sorry haven't documented build).

All the mechanicals are now done , except some finishing of the fly wheel , and a wooden base to mount it apon.

I attemped to copy jans blokker ignition idea with a similar
battery operated candle lighter , but after many hours spent scratching
my head wondering why it won't spark , and replacing almost every component on the board still to no avail , i have given up on the idea, i have decided to buy a cdi instead of making one. I keep seeing people mention
the name RCEXL cdi , and was wondering if anyone would be able to help me out on which one will run my little 2 stroke , using hall effect sensors( I plan to embed a magnet into the fly wheel)

sorry about the photos i don't own a good camera

cheers Brayden

 

[AussieJimG]

Look at www.cncengines.com. I have used these on a couple of IC engines including Jan Ridders "Debbie" two stroke and they work well. There may be cheaper ways to do it but when I consider the time and effort that goes into these engines, the price is worth it.

BTW That's a nice looking engine. I hope it runs as well as it looks.

Jim

 

[brazza]

Cheers Jim ,
Have ordered one and will see how it goes , also ordered a 6" vertex rotary table to rough out the rest of the flywheel (takes way to long on a mini-lathe ). Then to buy some wood for the base , some shellite to make it go bang , then hopelfuly she'l be good as gold

cheers Brayden

 

[brazza]

Hi everyone,
finaly finished my little engine after just over a year since commencing.
At first it would not run on it's own , it would fire when aided with an electric drill , but was not self sustaining , extremely similar to how other's "simple 2 stroke" builds would act that were not quite running. At first i was quite shocked considering how much care i had put into making sure things were acurate ( most parts were within .01mm) and the piston and cylinder fit i thought were quite exceptional. I couldn't seem to find any major faults , so i assumed my problem was the same as others , COMPRESSION RATIO.

So i machined .5mm off the head , and removed 1mm from the cylinder , assembled it back together , gave it a couple of spins without spark to prime it , turned on ignition flicked the flywheel and off she went , infact it revved so hard i thought it was going to self destruct so i quickly turned it down ( it hasn't run this fast since) .
Well it runs well now but it can take 5 mins or so from a cold start to get it running because the vapor carb is so sensitive to different fuel levels , and the mixture has to be at it's sweet spot from a cold start (takes a little fiddling to find)

here's some pics and a very average video which i apologise for

Happy building

cheers Brayden

 

[AussieJimG]

Onya Brayden, that is a nice looking engine and one that will doubtless be in the family for a long time.
The compression problem is common, as is the sensitivity to fuel level and the whims of fate. No worries.

Jim

 

[cfellows]

That's a really nice running engine, one of the better 2 strokes I've heard. What did you use for the ignition?

Chuck

 

[brazza]

That's a really nice running engine, one of the better 2 strokes I've heard. What did you use for the ignition?

Chuck

Hi chuck , i used an RCEXL ignition designed for RC engines , may be considered expensive to some , but it eliminates alot of problems and works a treat, well worth it. It runs utilizing a hall sensor and a magnet embedded into the flywheel .

Brayden

 

[brazza]

Well today i was playing with my little engine ,
just for the sake of it, and i managed to arr .....BREAK IT:wall::wall:. F#@k!!!!
Long story short while it was running i was adjusting the mixture screw , i undone it too far and it dropped out of it's thread and decided to land between the moving conrod and it's bottom plate at a few thousand revvs . End result a broached plate , a spun flywheel (cold welding it's self onto crank) and a sheared brazzing joint (the crank on the crankshaft ) DAM IT!
No pictures as looking at it makes me want to cry

Well i'm building me another crank now

 

[cfellows]

Well today i was playing with my little engine ,
just for the sake of it, and i managed to arr .....BREAK IT:wall::wall:. F#@k!!!!
Long story short while it was running i was adjusting the mixture screw , i undone it too far and it dropped out of it's thread and decided to land between the moving conrod and it's bottom plate at a few thousand revvs . End result a broached plate , a spun flywheel (cold welding it's self onto crank) and a sheared brazzing joint (the crank on the crankshaft ) DAM IT!
No pictures as looking at it makes me want to cry

Well i'm building me another crank now

Oh Boy, I know how you feel. Just gotta get back on that horse and keep going!

Chuck

 

[AussieJimG]

That's really tough luck but the engine is so nice that it is worth saving. And by the sound of it, it will have a couple of interesting scars as conversation starters.
Don't give up. And show us the engine when it is renewed.

Jim

 

[JaamieG]

Found this thread right now. Sorry to hear you damage it, I hope you have managed to restore it.
I wish mine will run sweetly like yours.
Cheers,
Giacomo

 

[brazza]

Sorry i haven't got around to updating this thread.

Well i filled off the burrs , put some fine lapping paste where the damage was and shined it up enough to make the dents look unnoticeable , i then re-made the crankshaft , removed the siezed flywheel , and reamed out the flywheel again , assesmbled it all back together ,oiled it up , put fuel in the
tank and off she went again , this was all on the day after i broke it (got the day off work).

Since then i have added a port to plug in an rcexl tacho and killed two brand new lipo batteries because i forgot to charge them after using the motor.
Brought a new lipo which will stay inside the base, and added a stero socket which i will use as a charge port (i have wired the balancing charging wires to the socket)

I wil post another video , a better one this time when i get around to it .

I envy all you retires getting to spend large amounts of time model engine building ,Toolmaking is my job , but it's just not as fun as making model engines , i guess i only have to wait 40 years unless i win the lotto.

Cheers Brayden

 

[cfellows]

Sorry i haven't got around to updating this thread.

Well i filled off the burrs , put some fine lapping paste where the damage was and shined it up enough to make the dents look unnoticeable , i then re-made the crankshaft , removed the siezed flywheel , and reamed out the flywheel again , assesmbled it all back together ,oiled it up , put fuel in the
tank and off she went again , this was all on the day after i broke it (got the day off work).

Since then i have added a port to plug in an rcexl tacho and killed two brand new lipo batteries because i forgot to charge them after using the motor.
Brought a new lipo which will stay inside the base, and added a stero socket which i will use as a charge port (i have wired the balancing charging wires to the socket)

I wil post another video , a better one this time when i get around to it .

I envy all you retires getting to spend large amounts of time model engine building ,Toolmaking is my job , but it's just not as fun as making model engines , i guess i only have to wait 40 years unless i win the lotto.

Cheers Brayden

You want to be careful about putting off too much until you retire. Now that I've retired, I have plenty of time, but now I have no where near enough energy or enthusiasm to get all my projects done.

Chuck

 

[brazza]

Hi everyone ,
just thought i'de give a little update as it's been a while. I did get around to fixing it , and also made a few improvements , and additions.

Well I originally didn't use gaskets because I naively thought my finishes were good enough to not need them , but decided gaskets could possibly make it better so I made up a full set of gaskets out of non-stick baking paper (works a treat), This gave instant results and the compression went way up than before.

To aid in my attempts to achieve better sealing , I acted upon one of Jan's suggestions , which was to ditch the Teflon seal , and replace it with an O-ring compression plate (kind of like a mechanical seal).
This involved a bronze bush same as the Teflon seal , but with a counter bore in it to suit the O-ring , then a plate of some sort (I used aluminium) Which has the same counter bore as O-ring, plus the 5mm hole for shaft. this plate then fixes underneath the bottom cylinder block and compresses the o-ring against the piston rod forming a seal. This worked remarkably well. The engine now feels like it has plenty of compression.

Also to finish it off I added a port for the tacho to plug into , and also a charging port , End result, the engine is now more reliable , and doesn't embarrass me in front of people (it used to take 15mins to get going).

Here's a video I made , sounds a bit rough mainly because of the echoing of the shed , and some pictures

Cheers Brayden

 

[AussieJimG]

That's a nice looking engine Brayden and it is nicely balanced too; my Debbie (similar Ridders two stroke) jumps all over the place so perhaps I need to do some more work on it.

And the shed looks good as well.

Jim

 

[Philjoe5]

Like others have said..you made it once, you can get it going again. By the way the video and pictures are great. Glad you got it fixed.

Cheers,
Phil