REFLECTOR: Fixes for Stick Slop

Fri Jan 7 16:53:58 CST 2011

Great questions.

I installed the turbo, and ran the engine with wastegate wide open.  The 
performance was 50RPM static better than a carbureted/magneto Franklin 
with identical propeller.  I am very happy with the performance.  First 
flight I calculated a 20 degree climbout angle.  I was at 900 feet when 
the engine failed, about 2500 feet from where I took off.  I don't know 
what that is in FPM, but I got there stinking fast.  I kept pulling back 
on the stick to keep from overspeeding the engine.  The plan was to 
increase prop once I reached 1000 feet.

The initial configuration was a bit complex, so this second time I am 
removing complexity and will add back those features later.
To control the wastegate and throttle, I built some linear stages, 
actuated via an embedded controller.  This could be overriden by the 
pilot by using the friction lock on the knobs.  These stages have been 
removed, and I'm waiting on a new set of throttle/turbo cables from AS&S.

Since the primary fuel system is electronic injection, I fabricated from 
scratch a completely redundant injection system.  It actually performed 
quite well, but tuning on the ground is difficult.  I am removing the 
automated actuating part of it, and am instead installing a needle valve 
that is manually operated from the pilots position.
The original backup EFI is nice, because in an emergency, it monitored 
for a power failure and engaged on that event, or a pushbutton.

At this time, I am gated on several things.  The cable install really 
needs to happen before I mount the intercoolers, which prevents 
induction or cowl work.
Wings are ready to mount, but we are waiting on primer.

I think three weeks after the parts are in that we'll be ready for an 
engine start.  Optimistically, I'm saying March for another flight, but 
reasonably would me more like June/July.

I checked the runout on the crank, and was very pleased to measure 
.0005" TIR.  The manual says I'm allowed .008" so that's pretty good.

On 1/7/2011 4:17 PM, Bob Jackson wrote:
>
> Sorry, Brian!
>
> I forgot about your first flight adventure.  Don't feel bad, almost 
> all of us have done something.  I had engine problems (turned out to 
> be my own engine control mis-management) and ran off the end of the 
> runway when doing simulated power off landings.  And my A/C partner 
> collapsed the nose gear (poor technique and a suspect weld) and slid 
> down the runway a 1000 feet grinding away the bottom of the nose!
>
> I'm sure your fix would do the job, I'm just concerned about the 
> small-area steel-to-aluminum contact space.  But probably for no reason.
>
> I remember you also had a pretty fancy turbo design.  How is that 
> working out?  When do you think you might get back into the air?  We 
> fiddle-farted around for ten years to complete, then another half-year 
> off repair the hole in the nose after the NG collapse.  Nobody likes 
> the 'when are you going to fly' question!
>
> Thanks for all you do operating and maintaining the Reflector,
>
> Bob
>
> ------------------------------------------------------------------------
>
> *From:*reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] 
> *On Behalf Of *Brian Michalk
> *Sent:* Friday, January 07, 2011 4:20 PM
> *To:* bobj at jaxtechllc.com; Velocity Aircraft Owners and Builders list
> *Subject:* Re: REFLECTOR: Fixes for Stick Slop
>
> I think it's safe to say I have about .05 hours of airtime on it.
>
> That would be the first flight, and subsequent off field.  However, 
> over years of airplane work, it's been tight.
>
> On 1/7/2011 12:35 PM, Bob Jackson (Jax Tech) wrote:
>
> Nice design and approach!  How many hours do you have on it?
>
> Don't you still have concerns about the effect on the softer aluminum 
> of the hard steel bolt?
>
> ------------------------------------------------------------------------
>
> *From:*reflector-bounces at tvbf.org <mailto:reflector-bounces at tvbf.org> 
> [mailto:reflector-bounces at tvbf.org] *On Behalf Of *Brian Michalk
> *Sent:* Friday, January 07, 2011 1:02 PM
> *To:* Velocity Aircraft Owners and Builders list
> *Subject:* Re: REFLECTOR: Fixes for Stick Slop
>
> There has been little discussion on a fix.  My solution involves 
> making a saddle, I'm not sure if it's what the factory does or not.
>
> I think the tubes are 1/2", so I bought some 1/2"ID, .25" wall 
> aluminum tube.
> With about 2" of stock, I first machined a flat on opposing side, 
> leaving about 1/8" thickness.
> Next, cut the tube in half along a plane parallel with the two flats.
> Take the two halves, and place them flat to flat, drilling a hole for 
> the bolt.  The tubes can now be cradled in the saddle.
>
> The flats help support the torque transmitted to the two tubes at 
> right angles.  For extra smoothness, use a thin teflon washer(or 
> sheet) between the flats.
>
> On 1/7/2011 11:13 AM, Bob Jackson wrote:
>
> We've been flying for a couple of years and now have 300+ hours on the 
> plane.  When we started doing some formation flying recently I began 
> to be aware that we're developing stick slop -- it's not what you want 
> flying close formation, or when landing or anytime you need small 
> corrections and fine attitude control.
>
> When we built the plane we were leery of the standard _steel_ AN3 bolt 
> that joins the bottom of the _aluminum_ stick stub and the 
> aileron/elevator torque tubes) -- even when improved with the U-shaped 
> steel reinforcing collar that the factory started shipping.
>
> In our case, we know that nearly all of our stick slop comes from this 
> mechanical connection between the stick's torque tube and the aileron 
> and elevator torque tubes.  We've been on the Reflector for 12 years, 
> but haven't heard much, if any talk about this problem and 
> improvements that builders have made.
>
> The _question_ is:  do any of you have good fixes for this connection 
> that eliminates stick slop?
>
> Thanks,
>
> Bob Jackson
>
> N2XF
>
>   
>
>   
> _______________________________________________
> To change your email address, visithttp://www.tvbf.org/mailman/listinfo/reflector
>   
> Visit the gallery!www.tvbf.org/gallery  <http://www.tvbf.org/gallery>
> user:pw = tvbf:jamaicangoose
> Check new archives:www.tvbf.org/pipermail  <http://www.tvbf.org/pipermail>
> Check old archives:http://www.tvbf.org/archives/velocity/maillist.html
>
> ------------------------------------------------------------------------
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 10.0.1191 / Virus Database: 1435/3365 - Release Date: 01/07/11
>
>   
>
>   
> _______________________________________________
> To change your email address, visithttp://www.tvbf.org/mailman/listinfo/reflector
>   
> Visit the gallery!www.tvbf.org/gallery  <http://www.tvbf.org/gallery>
> user:pw = tvbf:jamaicangoose
> Check new archives:www.tvbf.org/pipermail  <http://www.tvbf.org/pipermail>
> Check old archives:http://www.tvbf.org/archives/velocity/maillist.html
>
> ------------------------------------------------------------------------
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 10.0.1191 / Virus Database: 1435/3365 - Release Date: 01/07/11
>
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20110107/57a29e32/attachment-0001.htm>