w8ye

My Feedback: (16)

Ron,

That looks about right for the residue. You still have the APC 18-10?

Enjoy

Tmoth4

My Feedback: (1)

Ron,

Those are sweet engines, aren't they? [sm=thumbup.gif] When I get mine converted I'm going to mount them both on the stand and get them running together!

That amount of goop doesn't look bad at all for 70 min. of flight. You have to expect some residue.

You did 25 min. flights. I don't think my fingers could take it!! [&:]

Jim

rsjr

Thanks w8ye and Jim for the input. I ran the APC 18x10 prop for all three flights, seems to work fine. I changed the landing gear from the plans built music wire to the shorter aluminum job a while back. I need to measure the clearance to see if a 20" prop will clear but I doubt it will.

Jim, these engines are sweet! I've been day dreaming about twin conversions on an r/c plane a lot lately. I'll keep a close eye on your ME 110 project! Two 33's running together has got to be awesome... Meanwhile I'm going to try and master a single, from what I've read the twins are a whole different ball game.

When I flew the hawk today it was 33 deg. F with a light breeze from the north. Not bad at all really.

Hopefully tomorrow I'll get to make some more exhaust "goop".

Tmoth4

My Feedback: (1)

Ron,

I already have a twin, a Cessna "Bamboo Bomber" with two Homie 25s in it. It weighs 30# and they haul it around great. I never even considered a twin for years because I don't trust glow engines that much. I've seen too many twins with glow engines spin in because one quit. When I got into gas engines twins became more feasable for me but then there was the cost of two gassers. Then I started hearing about guys doing conversions so I went out and got a cheap Homelite blower, took it apart, and just stuck a prop on it without doing the complete conversion (in case I wanted to make it back into a blower) ...and it worked!

The Cessna twin flies great and I only had one engine-out experience with it (scary), which had nothing to do with the engine reliability. A loose piece of fuel tubing got stuck in the flywheel! Other than that the engines have always run and have never missed a beat. Then recently I tried the 33cc Homie chainsaw conversion that I heard about here on RCU and that engine's even better! Now a twin warbird is a possibility without spending a small fortune on engines.

Jim

rsjr

Jim,

I have thought about building Wendell Hostetler's 119" Cessna Skymaster. 1.8 cu.in. minimum each engine is recommended. Ryobi 31cc engines may work because they are narrow but I'd rather use the 33cc homelites. Since this is an in-line twin, I thought it would be a good choice for a "rookie" such as myself. And like you've pointed out, there is no way I'm going to spend 600+$ on store bought gassers! A scratch- built, fixed gear twin would be a good project for next winter...

Ron

Tmoth4

My Feedback: (1)

That sounds like a good one. I would definitely go with the Homie 33s. That plane would look cool as one of the FAC planes in Vietnam.

Jim

rsjr

Thats exactly what I was thinking, Jim.


Ron

rsjr

Hooker 53 brought up a good question about Homelites "ZipStart" technology. I've looked over all the paper work that came with the saw and there's no info at all.

One homelite dealer on the web has this information;

"1999 Homelite introduces ZipStart effortless starting technology on gas-powered string trimmers. ZipStart makes starting 2-cycle engines easier because it requires less effort to pull the cord, resulting in quicker starts"

I'm assuming they are talking about the pull start mechanism, not some sort of special compression relief or flywheel mods.

Any thoughts?

Ron

Tmoth4

My Feedback: (1)

Ron,

The Homelite 25s that I've gotten from blowers and weadies have a small hole just above the exhaust port that lowers compression. Maybe that's what they're talking about. I plugged the holes with a set screw on the 25s and the compression goes way up. The 33cc chainsaw motors don't have the hole.

Jim

rsjr

Thanks Jim for the reply.

The box that my bandit saw came in has "ZipStart" on it and I was just curious.


Ron

rsjr

I made an exhaust stack today out of 1/4"x1" aluminum bar and an old aluminum elbow. After bolting it on to the homelite I started it up and reset the carb. It idles really low and smooth with nearly instant transition to full throttle. I wish I had a tach so I could post some numbers.

Ron.

oops, I hit ok b4 I was done.

Tmoth4

My Feedback: (1)

Ron,

That's a neat looking stack. I guess you know how to do aluminum welding. That's something I wish I knew how to do. I have to use a muffler because of noise restrictions at the field, so I usually modify the stock muffler to fit inside the cowl.

Jim

rsjr

Thanks, Jim. There's no welding involved on this little noise maker. The flange is chamfered on the engine side and the elbow end is flared out to match. A little J B weld on the joint makes for a gas tight seal.

The sound is unreal... the homelite really "pops" compared to the ryobi. I've got one neighbor within a 1/2 mile, and luckily they don't mind loud r/c planes!

Ron

Tmoth4

My Feedback: (1)

Ron,

I'm in the process of tearing down the two 33s that I have. I was thinking about posting some pictures in a new thread as I go along for others to see how it's done. Think that's a good idea?

I was also thinking of turning down the flywheel the way that you did using a drillpress. Does that work well? I have an old engine that I can get the crankshaft end off of.

Jim

rsjr

Jim,

A step by step how-to on the 33cc homelite would be a great idea! I'm sure it would be helpful for anyone who is contemplating useing this engine.

Turning down the flywheel with the drillpress worked for me on the ryobi, but I guess it depends on the prop hub that would be used. You may come up with a better idea, once you get started.

I'm looking forward to seeing your conversions mounted on the ME110!!

Ron

Tmoth4

My Feedback: (1)

Yeah, I'm at the point where I have to test mount the engines, figure out the throttle hookups, and fit the cowls. There's still a ways to go yet but the major construction's done.

Jim

rsjr

Thats fantastic Jim! Now you can start doing the "fun" stuff.

Ron

rsjr

I put another 70 minutes of flight duty on the Hawk today with the custom "goop" diverter installed. Once the plane is up in the air and throttled back a little it's really not that loud. Keep in mind that I am just experimenting with this set up and I will eventually put the modified Ryobi muffler back on.

I am very pleased with this conversion and I plan on using it for my next project, a BUSA Fokker DVIII. Thanks all for the input, It's been very helpful.



Ron

Tmoth4

My Feedback: (1)

EEEwwww!!! Yuck!!

Jim

rsjr

I got a good chuckle out of your reply Jim.[sm=lol.gif]

Ron

Tmoth4

My Feedback: (1)

Ron,

It looks like your engine has a cold! [sm=lol.gif]

I got the engine mounts from Tower today. They're the Great Planes giant adjustable ones made of the black fiber-filled nylon. They seem pretty hefty. Now I have to make the adapter plates. Tonight I also turned down the flywheels using the method you described...worked great![sm=thumbup.gif] They look much neater than when I did it using a hacksaw and file.

Once I get them mounted I'm going to try running them, hopefully tomorrow. Sunday's temp. is supposed to be in the single digits and I don't want to do it outside then.

Jim

rsjr

A pair of homelite conversions! Right on, Jim![X(]

I think you will like the glass- fiber mounts, I'm using the .60-120 size and they are are holding up well. Did you use the crankshaft stub to modify the flywheels?

Are you going to mount your engines on the plane for testing or ?

Ron

Tmoth4

My Feedback: (1)

Yeah, I used the crank from the Ryobi that I could never get to run right. It's been sitting on the shelf for two years, so at least it was useful for something!

I test my engines by mounting them to a board and clamping them in my Black&Decker "Workmate" bench. The plane doesn't have any primer or paint on it yet. it won't be til Spring when I can paint the plane. Then I will mount the engines and taxi it around the back yard.

I used G10 material for the adapter plates on my last one, but I used the glass-fibered stuff, and it dulled my bandsaw blade. This time I'm going to try the brown G10 board, which has softer fibers in it. It's still real tuff material. How did you make your adapter plates?

Jim

rsjr

I used a chunk of 1/4 x 1 aluminum bar that I had laying around. I cut two pieces the same length as the crankcase, drilled 4 holes, did a little grinding for crankcase clearance, and I had a set of adapter plates. My local Loew's also carries thinner aluminum stock in different widths that would work as well. If the G10 board works for you I'd say go with it.

How do you like the GP motor mounts? I'm already re-thinking my plans for the D8. I may go with the giant fiber mount and the Wacker hub on the D8 to save money.

Do you plan to run both conversions on the Workmate at the same time? That might be a good way to work any bugs out of your throttle set-up before you mount 'em on the 110.

Heres a pic of the adapter plates. I had to work around an existing hole in my piece of scrap aluminum, so the one on the right is a little funny looking. I will make a couple more soon.

Tmoth4

My Feedback: (1)

I decided to go with the 3/16" G10 with the glass fibers in it. I checked the ones I made for the 33 that's in the Triplane and they've held up just fine. I'm Afraid the G10 with the softer fibers in it might crack later on. I don't use aluminum because I don't have a good way of cutting it other than by hand with a hacksaw.

I haven't got to trying the GP mounts yet. I'm still making the adapter plates. I would like to run both engines at the same time if I can.

JIm