Most of my airplanes are measured and fitted with an aluminum spinner,i have several plastic ones around that came with ARF kits,
i can't however use these plastic spinners because they are "stepped" on the back or recessed and when i try to use one of these,it will hit the cowl.
What is the best way to take up about a 1/4" on the prop shaft to make these fit?
Thanks

Move the cowl back. You don't want to add spacers, besides, if you did that...you wouldn't be able to get the spinner nut on.

Or, buy spinners that are not recessed on the back plate.

Gary

Moving the cowl back is not an option,the holes drilled for the needle valve,muffler and engine head would also have to be relocated making the cowl look pretty bad with all those new holes...I guess i will have to buy flat backplates as you mentioned.
Thanks for you're reply!