Ryobi 31 conversion short shaft

[flysrc]

This is my first engine conversion. It was pretty straight forward and is almost finished. All I have left is to build/cut the prop adapter. What should I make it out of and what diameter should it be. I have both steel and aluminum. If I should use the steel, what kind of drill bit should I use. Titanuim, cobalt or something else? Please help!!!!!!!!! :shock:
Thank you all in advance....
Dave

[Vulcan1]

Dave,
I have converted a few and changed all my adapters and prop nuts to this. My shaft adapter is 1 1/4" long with a 1 1/2" front flange machined on it. The base is to match the flywheel front. I chuck a piece of alum.(1 1/2 dia.) and machine the base, drill and tap right through. Mine are 5/16-24. If you keep the center accurate then you can machine the contour to what you want. I keep my main part at 1" and after cut or file two flats so I can use a wrench. Don't like plyers on it. You can also use a knurling tool on the face for a grip on the prop. Also I use an alum. turned spinner drilled 5/16" and countersunk to fit a 5/16" allan head bolt. The bolt you can change lengths of because all the props are not the same thickness. Makes for a neat installation and easy for my starter. Bolts can be purchased from any bolt supply. Usually not found in a hardware store as they are fine thread.
If you have any problems let me know and I can post a picture.
John

[flysrc]

John,
First off how is your wife I hope she has/is recovering from her illness.
I think I have a good Idea but if you had a picture to post it would more than be appreaciated. So aluminum is sufficient for the adapter. I hope thats what the concensus would be. Steel is a !@#$ to drill let alone tap. I have the drill bit, bolt and tap and yes it is the same thread as you have mentioned. Good ole Canadian tire had it all. Canadian tire money does come in handy. :D
Dave

[Cecil Marshall]

Dave:
I have the same setup as John, basically. Aluminum shaft adapter. My flange is 1-1/4" dia. I make my adapter last, to suit the plane (application)
I use a I-1/2" long 5/16" fine thread hex. head cap screw drilled and tapped for an 8-32 socket head screw to hold the 18x8 dynathrust prop on (different props, different hub thicknesses)(thus different bolt lengths)
On my 4*120 I use a 3" CB plastic spinner held on with an 8-32 socket head cap screw.

[Vulcan1]

Dave,
The wife is still in the hospital. Had her home for 4 days about a month ago and developed a fever and back she went. She is on an IV now for the last 3 weeks and has this vac pump still on. The wound now in her stomach is about 4.5 x 5" and coming along. She so far has an ostomy which should be fixed later but as you probably heard we just about lost her. One of the nurses in icu was really happy to see her Sat. night as they did not think she would make it. She is a fighter and this has just proved it to me. Going back after this.
This is a couple of shots of 2 of mine. One 25cc and 46cc, they are both Homelite. You can use a bolt and drill for a spinner as Cecil mentioned but I went this way. It is up to you. I also made an exhaust (25cc)from leftover ss from my turbine adventure. The spot welder sure makes it a lot easier. Just a touch of silver solder to finish one seam.
John