Okay, I have a Graupner speed 300, a MP Jet 4.5 to 1 gearbox, and a Master airscrew 9x6 prop. I'd like to put a spinner on my plane. I bought a DuBro 1 3/4" spinner, but can't seem to figure out how to attach the thing.

Any ideas on how this goes together?

Thanks

Yeah, the spinner backplate goes between the propeller and the propeller adapter's drive surface, then you just install the spinner cone over the top of the propeller with the supplied screws.

Are you having specific issues someone might be able to help you with?

I think I may just have either the wrong prop adapter or wrong propeller.

Starting with the adapter shaft, I slide the tapered backplate on. Next, I put the spinner backplate through followed by the propeller. Then I put the washer on. The last thing is the nut, but there isn't enough room to even begin tightening it down.

The propeller seems to have a pretty thick center section, should this be thinner?

An alternative way that I tried to attach it is:
Slide the adapter backplate onto the adapter shaft. Put the spinner backplate on, put the washer on and use the nut to screw this down. Place the prop in the spinner top (it's very tight), then try and screw this onto the spinner backplate. Going this route, there isn't enough room between the prop and the adapter nut to actually get the spinner on to the backplate assembly.

So, which part should I replace?

Thanks!

You simply need a prop adapter with a longer shaft. The order should be:

gearbox shaft --> propeller adapter --> spinner backplate --> prop --> nut --> spinner cone

This is a common problem, especially with glow engines.

Thanks for the help, at first I thought I was going crazy.