PA51 Spinner

[Luis Strufaldi]

Hello Everyone

I recently acquired a PA51 and I wanted to try to get some of those carbon fiber spinners at Hobbyking.

Can anyone tell me, from the top of their heads, what diameter prop nut adapter I should get for the PA?

Thanks!

Luis S

[Paul Taylor]

What is the link to the spinner?


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[Luis Strufaldi]

http://www.hobbyking.com/hobbyking/store/__10185__Carbon_Fiber_prop_Spinner_51mm_2in_diameter.html

[Steve Thomas]

While we're at it, any suggestions on the best way to make the prop blade cutouts in these? I'm thinking maybe a Dremel with cutoff wheel, but am open to ideas.

Steve

[Randy Cuberly]

I'm not sure exactly what you're asking for but the PA51 as all of the PA's has a 5/16 (.312) diameter shaft!

Randy Cuberly

[Paul Taylor]

Thanks Luis!😉

[Alan Buck]

the pa40 u/l has 1/4'' shaft not 5/16''

[Steve Helmick]

the pa40 u/l has 1/4'' shaft not 5/16''

Well...it is a .51, so it's a 5/16-24. The PA .40UL has a 1/4-28 thread, and is the only PA that does, other than the Aero Tiger .36, which is only sort of a PA. I haven't looked at the Hobby King link yet, but for me, there always seems to be some machining/adapting required. Probably bring it on myself?  Steve 

[Luis Strufaldi]

Almost all the prop nuts Hoobyking have are metric ones (M3, M4, M5...)

http://www.hobbyking.com/hobbyking/store/RC_PRODUCT_SEARCH.asp?strSearch=brass+nut+for+spinner

I have found the following site showing how inch threads relate to metric threads (this is frustraiting!!!! )

http://m3service.com/metricinch-comparisons/

So, basically, I'd need an M8x1.0 nut, right? Or am I the nut??

[Randy Cuberly]

Almost all the prop nuts Hoobyking have are metric ones (M3, M4, M5...)

http://www.hobbyking.com/hobbyking/store/RC_PRODUCT_SEARCH.asp?strSearch=brass+nut+for+spinner

I have found the following site showing how inch threads relate to metric threads (this is frustraiting!!!! )

http://m3service.com/metricinch-comparisons/

So, basically, I'd need an M8x1.0 nut, right? Or am I the nut??

No and M8X1.0 is an equivalent size and strength but the thread is slightly different in pitch a dn root diameter, and will not fit on a 5/16-24 UNF thread!

Randy Cuberly
PS:  the original PA 40 (large case) also had a 5/16-24 shaft.  I have two each of all the PA engines except for the 40 UL.

[Brett Buck]

So, basically, I'd need an M8x1.0 nut, right? Or am I the nut??

  I don't think that will work. I also don't understand why they would have metric, almost all engines, even those from metric countries, have UNF threads. And UNEF glow plugs.

     Brett

[Steve Helmick]

I'd suggest a close inspection of Dave Brown and Tru-Turn spinner accessories on the Tower Hobbies site. They will not have a metric thread for the coaxial mounting screw, but it's a start. On second thought, you might check the Hobby People site for Magnum spinner accessories...they may very well have metric threads for the mounting screw. Maxx Products is another place to look for metric adapters. The url's for these sites are as close as your Model Aviation magazine...or Google...but if you need help, I probably can dig out the links.  Steve

 

[Steve Thomas]

Luis, they sell a couple of different types of carbon spinner. If you get this one:  http://www.hobbyking.com/hobbyking/store/__25680__2_Inch_Carbon_Fiber_Spinner.html
the cone is held on with a couple of screws and you won't need an adapter.

Steve

[Chris Wilson]

While we're at it, any suggestions on the best way to make the prop blade cutouts in these? I'm thinking maybe a Dremel with cutoff wheel, but am open to ideas.

Steve

Hi Steve,
           a Dremel cut off wheel is a thin high speed disk only suitable for cutting straight lines slowly. There would be no way I would use one to arc out a spinner cone as it could shatter and become dangerous. (And yes I have used a Dremel quite extensively.)

Quote from the Dremel web site -
"User Tips
The cut-off wheel cuts only along its edge. Do not attempt to sand or cut curved holes with them."

In the past I have used a finger gauge to mould the prop hub shape and then traced and transfered that shape onto a masking tape coated spinner using a pencil held as horizontal as possible, repeat of course 180 degrees for the other side - then hogged it out with a Dremel grinding stone and finished off with an old prop of the same type coated with wet and dry around the hub area to duplicate the correct shape.

Cheers.

[Luis Strufaldi]

Luis, they sell a couple of different types of carbon spinner. If you get this one:  http://www.hobbyking.com/hobbyking/store/__25680__2_Inch_Carbon_Fiber_Spinner.html
the cone is held on with a couple of screws and you won't need an adapter.

Steve

Thanks Steve!
This one will work for the 2 blade prop, but not for the 3 blade, because of the position of the bolts.

I was planning on saving a few bucks, but this will most likely end up costing more in terms of man-hours to put everything together and aggravation than it's worth. Probably much better (and perhaps safer) to go with Steve Helmick's suggestion and go for the tried and thrusted Tru-Turn.

Thanks a lot to all of you guys that took the time to reply!

[RandySmith]

HI

The PA 51 is an 8mm shaft with 5\16 x 24 threads, so you will need the spinner to have the ability to fit those dimensions

Regards
Randy

[Steve Helmick]

"Probably much better (and perhaps safer) to go with Steve Helmick's suggestion and go for the tried and thrusted Tru-Turn."

What I was actually suggesting was to look at the Dave Brown, Tru-Turn, etc., spinner adapters and prop nut options. I have had to re-tap a brass Chinese (Magnum, I think) adapter to a suitable SAE thread...and then found out the screw head didn't fit into the counterbore in the tip of the spinner, so had to figure out how to open that up (glued the spinner to a chunk of aluminum that I machined a groove into to index the spinner cone, did my machining and the used the heat gun to make the epoxy release.)

Randy Smith's Aero-Spinners are my favorite, but come with an aluminum adapter...and I would be too worried about stripping the threads out. Maybe he makes steel adapters, but I dunno. I know he has some magnesium pieces, but I always seem to need nose weight.   Steve