cwoodyfly2001

My Feedback: (7)

I am trying to find any info on the electric jet factory's Rafale. I am wanting to use the Toki fan unit and .18 sized engine. Do you think I could fit 2?
I hate electrics so I think this would be a great project.
Do you think 1 fan would be enough to power this plane.
I also have a O.S. 21 rz Marine engine that I have machined the head for D.F. use and was considering replacing the .18, and going with the 21 that will turn 35k to 40k instead of 20k by the .18.
Is anybody using a .21 sized car motor in a Toki fan unit.

Please help I think this could be a very cool plane

Rahlberg13-delete

I'm using an Ofna .21 Hyper with great results. You might need to reinforce the shourd a little due to the increase in power. Wrap a couple layers of light oz (.5-1.5) glass cloth around it and on the mounts.

Is your .21 RZ a pull start? If not, you'll have to fab up a starter probe. I did this and had more problems than it was worth. Unless you can put your starter right up to it, I'd keep with the pull start style engines.

Let us know how yours works out.

JWN

My Feedback: (42)

A couple of questions.

First, how did you manage to get the carb to clear the fan? Looking at pictures of the Ofna engines, the carb sits so far forward it would be in the way of the fan.

Second, what did you do for a drive washer. Again, all of the pictures show the engines without drive washers.

Thanks,
John

Rahlberg13-delete

I should clarify something first, that I'm not using this engine in the Toki fan, but rather in a Kress RK-720 fan unit.

To use the Ofna engine, I had to do a few modifications to it and make a few pieces on a metal cutting lathe.

1.) I didn't use the large head that came with it. There'll be pleanty of air flowing over the head w/o that extiension. Take it off, and then you'll need to make a seperate piece to bolt down to the top (inplace of that extension) so it holds the glow plug plate in place. If you have access to a lathe, it's nothing more than a disk with a hole in the center and 4 holes around it for the screws

2.) To get the carb to clear the fan, I pulled it out of the fan and used an extension. Check out my gallery. Look at the close up pict of the mirage-fan. This is kind of how I did it (this is a Kress unit with MVVS engine, but the process is still the same). I had to machine a small aluminum sleeve that fit into the engine where the carb goes. Then I run a piece of plastic tubing about 2" long up and out of the fan shroud. Then I plug the carb into that. Did that make sense? Basically you extend the carb out of the fan. Then you can attach you throttle, clear the fan, etc... Let me know if you need a detailed pict of it.

3.) As far as a drive washer, I don't have one either. What I did was machine up a third part. Since the diameter of the hole in the Kress fan was bigger than the OFNA shaft, I made an addapter that screwed onto the shaft, then I could slide the fan onto it. The adapeter is just a bolt (to fit through the center of the fan) with a hole through it so it screws onto the OFNA shaft (6mm thread I think). Then I just throw on the fan and a nut and it's done.

Let me know if that makes sense or if you need detailed picts of descriptions.

Good luck

Russ

JWN

My Feedback: (42)

Darn, I was hoping you were going to provide us with some brilliant insite on how to get a .21 sized engine in an .18 sized fan

John

Rahlberg13-delete

Sorry John,

I've got a friend in Asia that has heard of guys shoehorning a .21 into the Toki .18. He said that at full power the shroud twisted. That's why I recommended adding the glass to it for strength. You'd probably have to play with the bolt pattern to get it to work, but I don't see why you could do it.

I was also looking into retrofitting the Kyosho .15 fan unit for a .21 engine. That fan unit is pretty cheap and easy to get.

I say go for it. Let me know if I can help. I can do machine work if you need certain parts done.

Anyhow, let me know. Email me and we can talk.
Russ