69LikesOS FS26S-C 4-stroke development
06-10-2010 | 11:05 PM
#1126
Tech Initiate
Joined: Mar 2010
Posts: 42
From: Copenhagen, Denmark
DP, I also have a question for you regarding flywheel and collet.
What collet did you use, when you ran the OS FS56a?
All collets are typical 7mm in inside-diameter. But the crankshaft on the OS is 6,5mm. I fired it up for the first time yesterday, but the flywheel came loose (I tried a solution, that obviously didn't work out). So I need to find a better solution, to secure the flywheel.
I'm considering a 6mm collet (from Xray for Picco/Novarossi engines), which I can grind to 6,5mm.
Please let me know what you did?
Thanks!
What collet did you use, when you ran the OS FS56a?
All collets are typical 7mm in inside-diameter. But the crankshaft on the OS is 6,5mm. I fired it up for the first time yesterday, but the flywheel came loose (I tried a solution, that obviously didn't work out). So I need to find a better solution, to secure the flywheel.
I'm considering a 6mm collet (from Xray for Picco/Novarossi engines), which I can grind to 6,5mm.
Please let me know what you did?
Thanks!
06-11-2010 | 08:43 AM
#1127
I ended up making a custom flywheel for my kits for the FS26C. There's no difference between version 1 and 2's crankshaft as far as I know. On my first prototype, I had a steel flywheel for the GP Kyosho Ultima ST that I used. It was a little larger than the crank, so I wrapped some aluminum tape around the crank to keep it centered, then just clamped it between the thrust plate (the aluminum piece that goes behind the prop on most airplane engines) and the pilot shaft. That's enough to keep a flywheel on the small engines.
On the 52, I made a custom flywheel that had a keyway in it and I used the key that comes with the engine. That kept it in place perfectly fine. The downside is you have to be able to make your own flywheel with some sort of fan belt drive pulley machined into the back of it, and making the keyway with a broach on a manual lathe is a real pain in the butt, not to mention drilling the clutch pin holes JUST where they need to be... Without a CNC machine or an experienced manual machinist at your disposal, it's very tricky.
On the .56 I was in a hurry, so I used its thrust plate for its keyway and pulley groove, and modified an existing flywheel that I had for the .52 to just clamp between it and the pilot shaft. I found out very quickly that the .56 has more than enough torque to pop it loose, so I drilled a hole in the front of the thrust plate and the back of the flywheel, inserted a short pin to lock them together, and it held up nicely. **Don't drill the holes all the way through either piece - the pin needs to be held captive so it doesn't tear up the front engine bearing, or fall out the front of the flywheel**
Oh, and I've never used collets on any of my 4 strokes. I never found one that's the right size - It would probably work if you could find one.
On the 52, I made a custom flywheel that had a keyway in it and I used the key that comes with the engine. That kept it in place perfectly fine. The downside is you have to be able to make your own flywheel with some sort of fan belt drive pulley machined into the back of it, and making the keyway with a broach on a manual lathe is a real pain in the butt, not to mention drilling the clutch pin holes JUST where they need to be... Without a CNC machine or an experienced manual machinist at your disposal, it's very tricky.
On the .56 I was in a hurry, so I used its thrust plate for its keyway and pulley groove, and modified an existing flywheel that I had for the .52 to just clamp between it and the pilot shaft. I found out very quickly that the .56 has more than enough torque to pop it loose, so I drilled a hole in the front of the thrust plate and the back of the flywheel, inserted a short pin to lock them together, and it held up nicely. **Don't drill the holes all the way through either piece - the pin needs to be held captive so it doesn't tear up the front engine bearing, or fall out the front of the flywheel**
Oh, and I've never used collets on any of my 4 strokes. I never found one that's the right size - It would probably work if you could find one.
06-11-2010 | 12:44 PM
#1129
I sure would! Check the instruction manual on my website (thumprc.com) and see if you think it would work for you. The instructions show the flywheel pretty good on page 2. Feel free to PM me for any parts you might need.
06-11-2010 | 02:51 PM
#1131
Tech Initiate
Joined: Mar 2010
Posts: 42
From: Copenhagen, Denmark
I ended up making a custom flywheel for my kits for the FS26C. There's no difference between version 1 and 2's crankshaft as far as I know. On my first prototype, I had a steel flywheel for the GP Kyosho Ultima ST that I used. It was a little larger than the crank, so I wrapped some aluminum tape around the crank to keep it centered, then just clamped it between the thrust plate (the aluminum piece that goes behind the prop on most airplane engines) and the pilot shaft. That's enough to keep a flywheel on the small engines.
On the 52, I made a custom flywheel that had a keyway in it and I used the key that comes with the engine. That kept it in place perfectly fine. The downside is you have to be able to make your own flywheel with some sort of fan belt drive pulley machined into the back of it, and making the keyway with a broach on a manual lathe is a real pain in the butt, not to mention drilling the clutch pin holes JUST where they need to be... Without a CNC machine or an experienced manual machinist at your disposal, it's very tricky.
On the .56 I was in a hurry, so I used its thrust plate for its keyway and pulley groove, and modified an existing flywheel that I had for the .52 to just clamp between it and the pilot shaft. I found out very quickly that the .56 has more than enough torque to pop it loose, so I drilled a hole in the front of the thrust plate and the back of the flywheel, inserted a short pin to lock them together, and it held up nicely. **Don't drill the holes all the way through either piece - the pin needs to be held captive so it doesn't tear up the front engine bearing, or fall out the front of the flywheel**
Oh, and I've never used collets on any of my 4 strokes. I never found one that's the right size - It would probably work if you could find one.
On the 52, I made a custom flywheel that had a keyway in it and I used the key that comes with the engine. That kept it in place perfectly fine. The downside is you have to be able to make your own flywheel with some sort of fan belt drive pulley machined into the back of it, and making the keyway with a broach on a manual lathe is a real pain in the butt, not to mention drilling the clutch pin holes JUST where they need to be... Without a CNC machine or an experienced manual machinist at your disposal, it's very tricky.
On the .56 I was in a hurry, so I used its thrust plate for its keyway and pulley groove, and modified an existing flywheel that I had for the .52 to just clamp between it and the pilot shaft. I found out very quickly that the .56 has more than enough torque to pop it loose, so I drilled a hole in the front of the thrust plate and the back of the flywheel, inserted a short pin to lock them together, and it held up nicely. **Don't drill the holes all the way through either piece - the pin needs to be held captive so it doesn't tear up the front engine bearing, or fall out the front of the flywheel**
Oh, and I've never used collets on any of my 4 strokes. I never found one that's the right size - It would probably work if you could find one.
I tried with the aluminium tape around the crankshaft, that turned out a mess. Also tried to file the slot in the collet a little wider, so it would clamp the crankshaft a little tighter, but then it startet sliding between the collet and flywheel, as the outer diameter of the collet became too small.
It's a learning process, but it's funny and more rewarding when you finally find a way to make it work.
06-12-2010 | 05:59 AM
#1132
Tech Master
Joined: Oct 2006
Posts: 1,758
I bought a bunch of tool heads to my Dremel; it looks like I got the flywheel modified to fit well enough to the cranck, I locks pretty neatly on it's place.
I have other issues now though like two speed HPI pinion gears not aligning with the Spada spurs. No problem making it single speed but I don't yet give up having a two speed transmission. I will order a couple of more gears to see if I can get a suitable alignment there.
I have other issues now though like two speed HPI pinion gears not aligning with the Spada spurs. No problem making it single speed but I don't yet give up having a two speed transmission. I will order a couple of more gears to see if I can get a suitable alignment there.
06-13-2010 | 09:39 AM
#1134
Tech Master
Joined: Oct 2006
Posts: 1,758
Short video of the 1st run
Testing it on the starter box I cannot get it shifting, I need to work more on that. Anyhow, pretty good so far.
I will install a new 2nd gear to see if it shifts; if it does there should be a mark left on the gear from changer finger. If it does not, there shouldn't any wear on the spur.
Testing it on the starter box I cannot get it shifting, I need to work more on that. Anyhow, pretty good so far.
| + YouTube Video | |
I will install a new 2nd gear to see if it shifts; if it does there should be a mark left on the gear from changer finger. If it does not, there shouldn't any wear on the spur.
Last edited by MikaR; 06-13-2010 at 11:02 AM.
06-15-2010 | 11:18 AM
#1138
Tech Master
Joined: Oct 2006
Posts: 1,758
Ok, I put a new spur gear and marked the "pin" with some white paint, it's definitely changing gear which is good. just need to get on the track to test more. But it's raining again :/
Raman, you were correct; the new head won't benefit of DGS2. It definitely helps in starting but that's it. I may remove it since it just adds weight. It isn't so difficult start with a separate ignitor either. Well, it all testing & learning.
Raman, you were correct; the new head won't benefit of DGS2. It definitely helps in starting but that's it. I may remove it since it just adds weight. It isn't so difficult start with a separate ignitor either. Well, it all testing & learning.
