VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 01-01-2018, 09:37 PM
Graham Graham is offline
 
Join Date: Mar 2012
Location: New Zealand
Posts: 35
Default Cummins Spinners

Folks,

I am fitting a Cummins aluminium spun spinner to my almost completed RV6.

The Cummins installation instructions do not require the spinner to be checked for "tracking" of the nose as the Vans instructions do. This is presumably because there is no need to trim the aft edge of the Cummins spinners, whereas the Vans spinners need trimming.

Can those of you who have fitted these spinners please advise whether they bothered checking the tracking prior to drilling the spinner backplate & fwd plate.

Thank You
Graham
New Zealand.
Reply With Quote
  #2  
Old 01-01-2018, 10:57 PM
Ironflight's Avatar
Ironflight Ironflight is offline
VAF Moderator / Line Boy
 
Join Date: Jan 2005
Location: Dayton, NV
Posts: 11,689
Default

Ours was dead on, without any need for adjustment.
__________________
Paul F. Dye
Editor in Chief - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
Reply With Quote
  #3  
Old 01-02-2018, 07:37 AM
Larco Larco is offline
 
Join Date: Mar 2005
Location: DVT Phoenix
Posts: 1,061
Default

Same here, dead on. We love our spinner! :-)
__________________
Larry
Reply With Quote
  #4  
Old 01-02-2018, 08:33 AM
pilotkms pilotkms is offline
 
Join Date: Mar 2007
Location: WARNER ROBINS, GA
Posts: 207
Default

I mated the back edge of the spinner to the back edge of the backplate. In addition to appearing properly centered visually, I subsequently Had my prop dynamically balanced and the balancer advised it had no impact and he had to remove the VERY thin shim-weight that was installed on the prop by the factory to remove the SMALL amount of vibration.
__________________
Keith
RV 7A RV #9700
N325KS the Flying “K”
Built in SoCal KCCB, now @ KPXE
120 Hours in Year 1 & 4x cross the USA
2018 OSH - yes
Reply With Quote
  #5  
Old 05-29-2018, 12:49 PM
Hangar 1271 Hangar 1271 is offline
 
Join Date: Nov 2013
Location: Orlando, FL
Posts: 68
Default All those screws!

I am installing a Cummins spinner on my RV-8. The installation instructions call for 7 screws in the forward plate and 14 in the aft plate. Well, why does one need the 7 forward screws? Certified planes with aluminum spinners don't have them. Does anyone have experience and an informed opinion that might answer this question?

Thanks,
David
__________________
David
305h@mazergroup.net
Reply With Quote
  #6  
Old 05-29-2018, 12:55 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 2,436
Default

I also like to know the measurement for the front screws. The instruction says 9-3/16" but my measurement doesn't put that right in the center of the front spinner. Also, I think there is 6 screw in the front and not 7. The instruction youtube video says 7 but if you follow it and mark it, you will come with 6 screw.
__________________
Mehrdad
RV7A - IO360M1B - SOLD
Dues paid
Reply With Quote
  #7  
Old 05-29-2018, 01:12 PM
Hangar 1271 Hangar 1271 is offline
 
Join Date: Nov 2013
Location: Orlando, FL
Posts: 68
Default

You know, I just finished the drawing for the forward screws and hadn't even realized I drew 6 following their instructions but heard, and remembered, 7. Very good point.

I don't think the goal is to put the forward screws in the middle of the spinner but in the middle of the forward mounting plate.
__________________
David
305h@mazergroup.net
Reply With Quote
  #8  
Old 05-29-2018, 02:09 PM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 9,609
Exclamation

Quote:
Originally Posted by Hangar 1271 View Post
I am installing a Cummins spinner on my RV-8. The installation instructions call for 7 screws in the forward plate and 14 in the aft plate. Well, why does one need the 7 forward screws? Certified planes with aluminum spinners don't have them. Does anyone have experience and an informed opinion that might answer this question?

Thanks,
David
My Tiger has 16 screws in the aft prop bulkhead and 6 in the forward prop bulkhead.

Early models only used screws in the aft bulkhead but were soon replaced by a Service Kit that has the screws and forward bulkhead described above.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #9  
Old 05-29-2018, 03:23 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 2,436
Default

Quote:
Originally Posted by Hangar 1271 View Post
I don't think the goal is to put the forward screws in the middle of the spinner but in the middle of the forward mounting plate.
This is what I mean, in the middle of forward mounting plate FLANGE.

Please let us know how your measurement jibs down with this.
__________________
Mehrdad
RV7A - IO360M1B - SOLD
Dues paid
Reply With Quote
  #10  
Old 05-29-2018, 06:52 PM
pilotkms pilotkms is offline
 
Join Date: Mar 2007
Location: WARNER ROBINS, GA
Posts: 207
Default 30 degrees

I made my back plate mounting holes every 30 degrees. An easy measurement for 12 bolts. Good luck with 14 back plate screws.
Also makes 6 bolts for the front plate rather easy.
Yes, u want the holes to be in the center of the front plate flange. I followed the directions and they worked.
As to why - someone else with an engineering degree can calculate the force being exerted as that thing spins at 2700 rpm. I wouldn’t leave them out. I have seen some RVs without the front plate bolts but the builder did much more engineering and added substructure in their assembly that was way beyond me.
__________________
Keith
RV 7A RV #9700
N325KS the Flying “K”
Built in SoCal KCCB, now @ KPXE
120 Hours in Year 1 & 4x cross the USA
2018 OSH - yes
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 01:06 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.