VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.






VAF on Twitter:
@VansAirForceNet

  #101  
Old 03-23-2016, 09:41 PM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 173
Default

Maybe for those with the more common larger alternator pulley a ring similar to this set up from Lightspeed could be fitted to the inside of the flywheel after having the required teeth cut in it? This would have the added benefit of mitigating some of the risk of a broken belt flying outwards and taking the reluctor and or wiring out.
I really like the ideas so for in this thread. I think you guys are onto a viable DIY ignition system here

Last edited by airtractor8 : 03-23-2016 at 10:39 PM.
Reply With Quote
  #102  
Old 03-24-2016, 07:57 AM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 11,236
Default

Quote:
Originally Posted by airtractor8 View Post
Maybe for those with the more common larger alternator pulley a ring similar to this set up from Lightspeed could be fitted to the inside of the flywheel after having the required teeth cut in it?
Sure. Depends on enough physical space between the nose of the engine case and the ID of the pulley for reluctor mounting. Easy to check, and as noted previously, there are lots of different reluctors available.

Here's an example from our old friend Bob Japundza. It has 60 teeth minus 1 because he intends to use an old Electroair brain box. Material is 0.125" 4130. Computer-driven waterjet and laser cutters are just grand, eh?



Lot of ways to skin this cat. For example, it would be easy to simply embed 35 solid steel dowel pins in the rear face of the aluminum flywheel, inboard of the ring gear, similar to the way other systems embed magnets. What is the OD of the belt pulley and the ID of the steel ring gear anyway?
__________________
Dan Horton
RV-8 SS
Barrett IO-390

Last edited by DanH : 03-24-2016 at 08:04 AM.
Reply With Quote
  #103  
Old 03-24-2016, 12:49 PM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 173
Default

What is the OD of the belt pulley and the ID of the steel ring gear anyway?


I don't have a flywheel assembly lying around but found this on the net. Looks like 9-3/4 OD for the pulley & 10-1/4 ID for the ring gear. The shiny edge on the outer edge of the pulley is a machined edge so looks a bit deceiving at first



Last edited by airtractor8 : 03-24-2016 at 01:07 PM.
Reply With Quote
  #104  
Old 03-24-2016, 01:59 PM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 11,236
Default

Quote:
Originally Posted by airtractor8 View Post
Looks like 9-3/4 OD for the pulley & 10-1/4 ID for the ring gear.
Ok, so only 1/2" to work with there, and it's outside the belt, thus a belt failure might take out the reluctor(s). A toothed wheel inside the pulley makes more sense.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Reply With Quote
  #105  
Old 03-24-2016, 11:47 PM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 173
Default

Quote:
Originally Posted by DanH View Post
Ok, so only 1/2" to work with there, and it's outside the belt, thus a belt failure might take out the reluctor(s). A toothed wheel inside the pulley makes more sense.
I may have made a mistake there with the diameters but it makes little difference.
I think the guy that took the picture was trying to illustrate the diameter of the pulley only not the ring gear so we are probably looking at something like 10-3/4 instead for it not 10-1/4 .
There certainly seems to be more than 1/2"on some of them. The list of different part numbers is huge http://www.skytecair.com/RingGearTech.htm

Last edited by airtractor8 : 03-25-2016 at 12:02 AM.
Reply With Quote
  #106  
Old 03-25-2016, 05:00 AM
Kirk Harrell Kirk Harrell is offline
 
Join Date: Mar 2016
Location: Montgomery, AL
Posts: 13
Default

Mike, what do you want for that trigger ring?
Reply With Quote
  #107  
Old 03-25-2016, 05:47 AM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 173
Default

Quote:
Originally Posted by DanH View Post
A toothed wheel inside the pulley makes more sense.
Here are some bolt hole dimensions for mounting an inside wheel to the larger pulley that I lifted from the Lightspeed site
4&6 cylinder bolt orientation in relation to the missing tooth would be 30deg. different as shown in the pic




If the wheel was made with the teeth on the OD (the same as a car) and the reluctor was mounted clock wise 90deg. from the TC mark there would be plenty of room to mount the reluctor with a bracket mounted on the 2 crankcase through bolts similar to Ross & Robert's design shown in this photo.



The ID of the wheel would just have to be bigger than the crankshaft flange to allow it to slip over in one piece. My verniers are not large enough but I think the crank flange on my engine is somewhere around 6"or so.

Getting really interested in this

Feel like drawing something up for us Dan? I don't have access (or the knowledge) to do a CAD drawing for it.

Last edited by airtractor8 : 03-25-2016 at 07:24 AM.
Reply With Quote
  #108  
Old 03-25-2016, 05:53 AM
Kirk Harrell Kirk Harrell is offline
 
Join Date: Mar 2016
Location: Montgomery, AL
Posts: 13
Cool

Quote:
Originally Posted by Kirk Harrell View Post
BTW, my flywheel has the small dia alternator drive pulley. Have not determined if the large diameter drive pulley is a factor
We now know it is.
Reply With Quote
  #109  
Old 03-25-2016, 07:42 AM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 11,236
Default

Quote:
Originally Posted by airtractor8 View Post
Here are some bolt hole dimensions for mounting an inside wheel to the larger pulley that I lifted from the Lightspeed site
4&6 cylinder bolt orientation in relation to the missing tooth would be 30deg. different as shown in the pic

If the wheel was made with the teeth on the OD (the same as a car) and the reluctor was mounted clock wise 90deg. from the TC mark there would be plenty of room to mount the reluctor with a bracket mounted on the 2 crankcase through bolts similar to Ross & Robert's design shown in this photo.

The ID of the wheel would just have to be bigger than the crankshaft flange to allow it to slip over in one piece. My verniers are not large enough but I think the crank flange on my engine is somewhere around 6"or so.

Feel like drawing something up for us Dan? I don't have access (or the knowledge) to do a CAD drawing for it.
Sure. This would be the 4-cyl orientation, slip-over-hub style. A variation would be like Bob's 60-tooth above, a split ring with additional tooth support.



No warranties gentlemen. You're welcome to a .dwg file, but it's your project. Check dimensions, output waveform, etc.
__________________
Dan Horton
RV-8 SS
Barrett IO-390

Last edited by DanH : 12-05-2018 at 09:25 AM.
Reply With Quote
  #110  
Old 03-25-2016, 07:53 AM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 173
Default

Quote:
Originally Posted by DanH View Post
Ok, so only 1/2" to work with there, and it's outside the belt, thus a belt failure might take out the reluctor(s). A toothed wheel inside the pulley makes more sense.
Quote:
Originally Posted by DanH View Post
Sure. This would be the 4-cyl orientation, slip-over-hub style. A variation would be like Bob's 60-tooth above, a split ring with additional tooth support.



No warranties gentlemen. You're welcome to a .dwg file, but it's your project. Check dimensions, output waveform, etc.
You are a true Gentleman Dan. Thanks I would love to have a copy of the file for it.
I will send you a PM with my email address
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 02:57 PM.


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.