"1/2 A" & "1/8 A" airplanes These are the small ones...more popular now than ever.

Throttle Sleeve, ACE OR COX Setup??

Reply

Old 01-08-2012, 05:22 AM
  #1  
astronomer1
Member
Thread Starter
 
Join Date: Jan 2007
Location: Loveland, CO
Posts: 62
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Throttle Sleeve, ACE OR COX Setup??



I am building an ACE Whizard using a Dickybird TD.049 engine
that is working very nicely. 5.5K to 18K RPM. I am having a problem
with the servo pushrod binding whether I use a Z-bend or a small nylon clevis
with fuel line keeper. On the test stand, I’m using a piece of .032 safety wire
and actuating it by hand and it wants to bend. I want to use ridged
piano wire with the servo.

What is the most effective way of hooking up a servo pushrod
to an ACE or COX throttle ring? I have tried using Z-bent piano wire keeping
the Z-bend tang as short as possible but it still binds with the throttle ring and
the pushrod wants to fall off. The small Nylon clevis with fuel line keeper, binds
either at the fuel line keeper part or the end of the clevis where I have filed it
shorter in an attempt to eliminate binding. I am afraid to file more for fear of
further weakening it.

Perhaps the attached sketch will help further illustrate my problem.
Sorry about the crudeness of the sketches, it is the best I can do using Microsoft Paint.


Attached Images
File Type: jpg
Ig12170.jpg (1.77 MB, 23 views)
astronomer1 is offline  
Reply With Quote
Old 01-08-2012, 05:46 AM
  #2  
Rendegade
Senior Member
 
Join Date: Mar 2003
Location: Perth, AUSTRALIA
Posts: 1,881
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

Ok, here's a few things that you might want to try.

Firstly, Z bends don't always have to be axial, so to get around your fouling issues, maybe you could bend the toe of the Z bend away from what it's hitting to alleviate the problem, or rotate the toe 180˚ to make a U bend instead. The toe on the Z bend is merely there to provide a means of keeping the pushrod attached. If you think about the first bent leg of the Z as doing all the work, and the second as the keeper, I'm sure you'll come up with a satisfactory solution.

Also, nylon clevises and searingly hot exhaust systems are an accident waiting to happen. Don't use it unless you don't really want a throttle after all.
Rendegade is offline  
Reply With Quote
Old 01-08-2012, 10:50 AM
  #3  
Mr Cox
 
Mr Cox's Avatar
 
Join Date: Jul 2007
Location: Karlstad, SWEDEN
Posts: 3,790
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

Yes, the tip of the z-bend can be made in almost any direction if the pushrod is locked from rotating at the servo-end.
Mr Cox is offline  
Reply With Quote
Old 01-08-2012, 11:55 AM
  #4  
rrragmanliam
Senior Member
My Feedback: (1)
 
Join Date: Oct 2003
Location: Arvada, CO
Posts: 1,228
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??


ORIGINAL: Mr Cox

Yes, the tip of the z-bend can be made in almost any direction if the pushrod is locked from rotating at the servo-end.
I agree rotate the "end" of the z bend 90 deg. counterclockwise. Also with a throttle ring you realy don't need alot of throw. The engine will hit max rpm way before the exhaust ports are completly uncovered.

rrragman
rrragmanliam is offline  
Reply With Quote
Old 01-08-2012, 09:07 PM
  #5  
skaliwag
My Feedback: (1)
 
skaliwag's Avatar
 
Join Date: Jan 2003
Location: Corralitos CA
Posts: 2,468
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

Pic of a connection.

Edit .. RCU says the file too large' Gets clunky and slow sometimes.
Attached Thumbnails Click image for larger version

Name:	Lj23960.jpg
Views:	35
Size:	66.6 KB
ID:	1711806  
skaliwag is offline  
Reply With Quote
Old 01-09-2012, 09:57 AM
  #6  
av8rsodt
My Feedback: (23)
 
av8rsodt's Avatar
 
Join Date: Jan 2003
Location: Kernersville, NC
Posts: 587
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

One thing to also keep in mind is the adjustability the c-ring on the throttle sleeve (moving the location). For some reason I always forget this until I run out of other options.

I take a flat head screwdriver, with engine held firm in other hand, and place the screwdriver head into the opening of the c-ring pushing to make small adjustments.

This has helped so the pushrod is in a better location that works with the entire throttle ring movement needed.

Just be careful of the screwdriver slipping and hitting your hand / arm.

Brian
av8rsodt is offline  
Reply With Quote
Old 01-09-2012, 01:57 PM
  #7  
Boomerang1
 
Boomerang1's Avatar
 
Join Date: Jun 2005
Location: Sydney, AUSTRALIA
Posts: 2,870
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

Adjustment of throttle sleeves brings back memories.

I built this years ago using 09 & 049 Medallion engines.

Let's just say getting the engines running & reasonably synchronised was 'challenging'!

I used Z bends to hook up & adjusted by slipping the circlips around the sleeves. - John.
Attached Thumbnails Click image for larger version

Name:	Yw68835.jpg
Views:	24
Size:	64.9 KB
ID:	1712109  
Boomerang1 is offline  
Reply With Quote
Old 02-19-2012, 09:45 AM
  #8  
proctor
Junior Member
 
Join Date: May 2002
Location: tain, , UNITED KINGDOM
Posts: 25
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

From the very nice clear sketch of your set up it would appear that if you removed circlip and reinstalled
other side up you would most likely avoid jamming at attachment point.
john

PS you guys call them snap rings not circlips
proctor is offline  
Reply With Quote
Old 02-19-2012, 10:58 AM
  #9  
bps
My Feedback: (3)
 
bps's Avatar
 
Join Date: Oct 2002
Location: Indianapolis, IN
Posts: 1,342
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Throttle Sleeve, ACE OR COX Setup??

Also nothing wrong with adding a slight bend in the wire to get it out further from the center line of the motor. I would use the smallest diameter wire you can get by with. If the throttle sleeve is binding at all the burr that is creating the bind must be removed. This throttle sleeve does not have to fit tightly to have the effect on rpm.
bps is offline  
Reply With Quote

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service