Jan Ridders 2 takt Debbie

[hacklordsniper]

This is my first "serious" machining project. Until now i done only simpler lathe things, and assembled my mill. The engine will be made mostly by scrap since im surely going to make some mistakes in the process. This thread is more interesting for a beginner, than for experienced people (but i will welcome their advice if they stop by). There will be quite alot of pictures here.

First part i decided to make is the head of the engine. There is more than 1 record here, as this is the largest diameter part i ever turned in my lathe.

First i faced the aluminium scrap obtained from a machinists trash can, turned it down to required diameter, turned the front face, drilled and tapped. After that i cut it off, and since this was my first so deep cut i was quite surprised how well i did.

Since i like tiny allen screws i decided to have 8XM3 on the head instead 4XM4 and this was a great excuse to buy a rotating plate. However i got a lemon white quite of manufacturing faults, stripped threads, rusty bottom and full of casting sand. Since it was last one they gave me another 25 % discount if i keep it, so i did!

Made thread shells to repair threads, replaced all screws, cleaned a small bucket of sand, cleaned rust and mill out the blocks that go into the table (they were too large for my mill table), so my first milling operation

And then the head of the engine:

This weekend i plan to make quite more, stay tuned...

 

[Herbiev]

Looking good. Keep the pics coming.

 

[hacklordsniper]

Well i posted 2 times already quite alot of photos and text and they disappeared from forum, it seems i forgot to post after preview

This is no more a Jan Ridder 2 takt Debbie since as beginner i decided to use various scrap materials and i never like following a plan completely, i like to add my personal vision and force myself to do thinking and math (instead just copying a drawing) to learn more.

Second im a beginner, some of my machining methods are unsafe and wrong. I could not do it other way at the time i was doing it, and i considered it was enough safe at 90 rpm and 0.05 mm power feed speed. But if you are a beginner like me ignore my unsafe setups (especially faceplate)

The first problem arose at flywheel. Cast iron is unavailable, i dont like it anyway so i decided to go the aluminum route. Here is a nice chunk of alluminium dreaming all life to become a flywheel.

Unfortunately it is too big for my lathe (and to remember i bought a micro lathe before my mini lathe). So i took a face mill and straightened the bandsaw marks:

After that i indicated it in rotary table and milled the ring on the left side (where the magnet for a CDI will be). I forgot to take a picture

Then with little math i drilled a center hole on my drill press and hammered a m10 center-drilled screw in undersized hole and put that up in my chuck. I still needed to various methods to reach all the way since the part was rotating a hair from my ways.

Soon i was getting even, sweet swarf:

Some odd setups

After milling, turning here is my flywheel:

To rest on simpler things i made the brass fork

I acquired these 2 scraps of aluminium, one will be a flywheel support:

Before and after, face mill rocks!

Time to do the bearing hole and on oposite side will be clutch for starting the engine with a drill:

In the last mounting hole the dril broke (stupid cheap import drills). I milled it out with only carbide endmill i have and cut a M14 thread to insert a threading sheel:

White the glue was drying i made the base legs. This is a good example how a cheap DRO helped me to quicky make 4 parts identical in length. I usually dont use the DRO except in such situations. This is why i mounted the cheapest DRO, and not the expensive ones from OEM.

I was lazy and here is how i punched the holes for bearing block, with cup point screws

Bearing in place, quite hard to press it in

A scrap piece of aluminium (end of stock) was face milled and turned the bearing hole

And bearing installed:

Now it was time to make the flywheel pulley to which the fork will attach. I made this from mistery non magnetic steel i found. This almost made my lathe explode, its harder than anything i tried to turn (and trust me i tried some pretty weird materials, like hardened steel).

It made half of screws in my little lathe to fall out, there were sparks, purple swarf and what not. Even chipped my two inserts (original inserts with cheap holders, so its okay)

Since im stubborn i decided to finish what i started and promised my lathe a nice massage with plenty of Vactra oil, then she started flying!

Digging trough the parts bin i found a nice bearing from a hard disk that can be adopted to my need

And flywheel is completed:

Hope to get it running soon...

 

[hacklordsniper]

Did some more work today and thats enough for now, my machines, floor and everything else are so full of swarf i need to clean them this weekend.

I hope to build the cylinder and piston next week. This weekend if i will manage i will mill out the CDI PCB

 

[hacklordsniper]

Only today i managed to finish the board for a CDI i designed. After building it and having a few bugs i understood that i started a building a CDI that is an overkill for my tiny engine.

So i designed another one, much simpler and working the same.

Mounted and ready to go

Here is bad utube video of it in operation

http://www.youtube.com/watch?v=pHq65SDq7wo&feature=youtu.be

The build has gone very slow route since the time is restricted at work and i have a 1 year old daughter who waits me all day in front of door, preventing me to go in my workshop when i return home

 

[hacklordsniper]

Almost no machining time, i have an half of hour in evening when all go to sleep.

All is finished except the petrol tank (vapor carburetor) and clutch i will use for starting it with a drill. I got nice compression, the ball valve works perfectly. The blue hoses are there just to hold the ball valve, i need to go and buy proper hoses tomorrow.

Considering the amount of scrap spent in this engine im quite happy how it came out. Long time ago i decided that learning and using scrap will be the way in this engine, the esthetic's were neglected. I learned quite many things, did mistakes and most important learned how can i correct that mistakes and not repeat them in future

So excited to get it running, possibly this weekend

First picture shows how i honed the cylinder (ok it cant be called honing but it worked quite good)

 

[JaamieG]

Looking forward to see how it works and congrats for the quick progress.
I am building the same engine but planning to stick as much as possible to the original dwgs of Jan Ridders.
Cheers,
Giacomo

 

[hacklordsniper]

What i nice day i managed to get from work very early and work on my engine.

I built it completely except the vapor carburetor (i built one with a jar as seen on this forum to test my little engine as soon possible).

I brought it into garage not to stink the house with petrol and gave it a spin with my drill. In 5 seconds it goes pop-pop-pop and starts working nicely.

After about 30 seconds while i was admiring my engine it stopped. I tried to run it again but no luck, it would not start again whatever i did. I dismantled it few times, tested everything but no luck. I was worrying i have weak compression so i made a new piston with rings, that didn't help. I made another new piston with better tolerances and got a quite strong compression ( i could not hold the finger on spark plug hole while turning they flywheel) and again no luck.

I rebuilt the ball valve, replaced the spark plug, tested and just for sure built a new CDI.

After 10 hours spent in unheated garage i gave up on this engine. I feel somehow bad that this project ended like so after spending 100 + hours on it

 

[AussieJimG]

Don't stop now, if it ran once it will run again. And it looks good too.

Mine took 6 weeks to build and 5 weeks to get it running. They can be sensitive to the fuel level in the tank.

Jim

 

[hacklordsniper]

This weekend im alone at home and i will devote it to this engine.

I have found out that some of the grinding paste somwhow (left in intake valve ) came into my cylinder at the last try (now i can see some marks on first piston too). I turned the cylinder to 24.5 mm to remove all marks and honed it all night to do it "perfectly"

Tomorrow im making the piston and hopefuly during the day i will give it one more shot before spring/summer

 

[JaamieG]

This weekend im alone at home and i will devote it to this engine.

I have found out that some of the grinding paste somwhow (left in intake valve ) came into my cylinder at the last try (now i can see some marks on first piston too). I turned the cylinder to 24.5 mm to remove all marks and honed it all night to do it "perfectly"

Tomorrow im making the piston and hopefuly during the day i will give it one more shot before spring/summer

Good luck and don't give it up.
Cheers,
Giacomo

 

[hacklordsniper]

Hello, thank you. I looked your engine with envy but my 2 takt debbie is saved for some other days. I'm building it again from new but this time with vertical cylinder placement (looks nicer). Debbie taught me all the things i did wrong and hope a next one will run like a charm.

However i need to wait for my new lathe 2.5 months...

 

[AussieJimG]

Hacklordsniper: when you get back to the Debbie, have a look at John Somers' website: http://start-model-engineering.co.uk/category/jan-ridders-simple-two-stroke/

There is a photo of a modified piston that gives higher compression (and a slight change in port timing). John and I had been trying for weeks to get our engines to run and this piston was the answer. I think others have also found that a higher compression ratio helps.

Jan is a real expert and his engines have very little friction. They run on a low compression ratio. We all aspire to Jan's standard but in the meantime our engines have a little more friction and the bigger bang helps.

Jim

 

[hacklordsniper]

Thank you, i did try the cutout on the piston but it did not help. I will tackle this engine in spring/summer again. The biggest problem is petrol smell and i cant bring it back in.