|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

08-29-2017, 07:39 AM
|
|
|
|
Join Date: Nov 2009
Location: Boston
Posts: 154
|
|
Lucky for me, lycomings have a "flywheel" with 12 perimeter holes, 30 degrees apart, where I can mount the optimal bolt/washer/nut counterbalance. An earlier post mentioned that balance was effected by directly modifying (e.g., spot painting) the prop. I guess on engines without a flywheel nor spinner backplate, this is the easiest route toward dynamic balancing....if you happen to be lucky enough that the rotational inbalance is along the length of the prop. Otherwise, I don't see how you can satisfy a polar plot inbalance by just working on the prop.
|

08-29-2017, 08:25 AM
|
 |
|
|
Join Date: Mar 2006
Location: Eldridge, Iowa
Posts: 75
|
|
Our chapter recently bought the ACES 1015. I've helped do three planes so far, all Lycoming. It's very easy to use, just follow the instructions on the screen. As was mentioned it allows you to split the weight to two angles. So if it wants weight at 78 degrees, you say you want to split it at 60 and 90 degrees and it gives you the amount of weight at each of angle. Like I said, just follow the instructions.
__________________
Paul A. Fisher
RV-7A N18PF
Q-200 N17PF
APRS track
|

08-29-2017, 08:30 AM
|
 |
|
|
Join Date: Nov 2005
Location: Tellico Plains, TN
Posts: 561
|
|
Thanks for the report. I had a 2020 years ago, and it looks like the 1015 works the same for standard dynamic balancing. It lacks a second channel, and doesn't have any vibration spectrum analysis, but I don't recall ever using those anyway. The 2020 was really impressive if you do your part, and by that I mean giving it correct angles and measuring the weight you add precisely.
Cheers,
Rusty
__________________
RV-8, SN-80587, built, flown, sold.
RV-3B, SN-10751, rotary engine, built, flown, sold
RV-8, SN-82470, built, flown, sold.
RV-3B, SN-11351, purchased, , flown, sold
A&P - 2018
|

08-29-2017, 09:40 AM
|
 |
|
|
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
|
|
Quote:
Originally Posted by Radioflyer
Lucky for me, lycomings have a "flywheel" with 12 perimeter holes, 30 degrees apart, where I can mount the optimal bolt/washer/nut counterbalance. An earlier post mentioned that balance was effected by directly modifying (e.g., spot painting) the prop. I guess on engines without a flywheel nor spinner backplate, this is the easiest route toward dynamic balancing....if you happen to be lucky enough that the rotational inbalance is along the length of the prop. Otherwise, I don't see how you can satisfy a polar plot inbalance by just working on the prop.
|
In general, for metal two-bladed props, isn't the imbalance always along the length of the prop since that is where the longest moment arm is?
__________________
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
|

08-29-2017, 11:11 AM
|
|
|
|
Join Date: Sep 2014
Location: Maple Valley, WA
Posts: 273
|
|
Quote:
Originally Posted by az_gila
In general, for metal two-bladed props, isn't the imbalance always along the length of the prop since that is where the longest moment arm is?
|
Not necessarily, as you are balancing the prop and engine together.
|

08-29-2017, 05:33 PM
|
 |
|
|
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,686
|
|
You can't balance the engine by balancing the prop.
If you're bored I have lots of good info posted on my webpage about prop balancing toward the bottom of the page under "Theory":
http://expaircraft.com/PropBalance.htm
__________________
Walt Aronow, DFW, TX (52F)
EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
|

08-30-2017, 08:03 AM
|
|
|
|
Join Date: May 2009
Location: Greenfield, IN
Posts: 123
|
|
Stupid balancer questions
I'm planning to balance my prop soon and have some basic questions.
I'd like to use the "flywheel" holes to add weight as needed.
1. Should I use 1/4" hardware? If yes then if the weight needed is less than the weight of a bolt/washer/nut, I would add a similar combo 180 around then fine tune with washers or is it acceptable to use smaller hardware in the 1/4" hole in the flywheel.
2. Is it OK to do full power runups with only the lower cowl on? I've seen photos of runs with just the upper cowl off and some with both halves removed. I've looked at prop balancing videos but haven't found any that go into the, dare I say "nuts and bolts" of the operation 
Thanks, Gunther
__________________
Gunther
2002 RV-9A 150hp
|

08-30-2017, 08:44 AM
|
 |
|
|
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,686
|
|
Quote:
Originally Posted by GWZ
I'm planning to balance my prop soon and have some basic questions.
I'd like to use the "flywheel" holes to add weight as needed.
1. Should I use 1/4" hardware? If yes then if the weight needed is less than the weight of a bolt/washer/nut, I would add a similar combo 180 around then fine tune with washers or is it acceptable to use smaller hardware in the 1/4" hole in the flywheel.
2. Is it OK to do full power runups with only the lower cowl on? I've seen photos of runs with just the upper cowl off and some with both halves removed. I've looked at prop balancing videos but haven't found any that go into the, dare I say "nuts and bolts" of the operation 
Thanks, Gunther
|
I have used 3/16 hardware when the weight of the 1/4" is to much, when doing this I make sure to tighten down the bolt at the edge of the hole so it can't migrate outboard on its own with the centrifugal force. I generally balance at 2400 which is a good cruise RPM but less than full power. I've not had any problem leaving the bottom cowls on an RV.
__________________
Walt Aronow, DFW, TX (52F)
EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
|

08-30-2017, 11:51 AM
|
 |
|
|
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
|
|
Quote:
Originally Posted by Walt
I have used 3/16 hardware when the weight of the 1/4" is to much, when doing this I make sure to tighten down the bolt at the edge of the hole so it can't migrate outboard on its own with the centrifugal force. I generally balance at 2400 which is a good cruise RPM but less than full power. I've not had any problem leaving the bottom cowls on an RV.
|
My mechanic used 1/4 inch AN4 hardware on my flywheel. Installed identical nuts and bolts at two holes 180 degrees apart.
Final balancing was done by adding either AN960 or AN970 washers to the light side only.
__________________
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
|

08-30-2017, 12:49 PM
|
 |
|
|
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,686
|
|
Quote:
Originally Posted by az_gila
My mechanic used 1/4 inch AN4 hardware on my flywheel. Installed identical nuts and bolts at two holes 180 degrees apart.
Final balancing was done by adding either AN960 or AN970 washers to the light side only.
|
I've tried this as well, and theory says that should work, but the reality is balancing with 3 positions vs 2 (as is normal) does not work very well and most often leads to additional run time to get things tweaked with the end result being no better. The bolts don't carry any load other than their own weight, they just need to stay in the holes.
__________________
Walt Aronow, DFW, TX (52F)
EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 02:32 AM.
|