slk23

Amazon photos changed the file type. Will convert and repost. 

Thanks for the encouragement. I’m only a couple hundred hours in so what the heck 😕

Other canard drivers have reported improved ground cooling with a smaller gap. I’m hopeful.

An oil flow test showed significant airflow separation with the old cowling shape.  The new shape will definitely improve that; we’ll see if it leads to airspeed improvements.

And yes, I do hand prop like all self-respecting VariEze pilots. 

I think most people are replacing their vacuum-powered instruments with electric versions, or better yet a full EFIS.

Can anyone tell me how to make the attached photos display inline?

This covid-lockdown project has been going on for awhile; I hope to get the airplane flying again in the next couple months. 

The goals:

• Better ground cowling by reducing the distance between the cowling trailing edge and the prop from 4" to <1".
• Less airflow separation (drag) due to more gentle contours, especially at the lower trailing edge.
• Increase groundspeed (how fast it looks like it's going while parked).

2020-11-15_16-53-12_743.heic 2020-11-28_17-15-55_839.heic 2020-12-05_16-26-13_975.heic 2020-12-05_18-29-25_959.heic 2021-01-10_17-20-00_996.heic

On my VariEze I installed a push-pull cable (custom length, ordered from Aircraft Spruce) for the throttle.  I left the bicycle cables for the mixture and carb heat.  At the control quadrant (which is designed to use the bicycle cables) I made a throttle lever and sandwiched it in-between the existing spools (for Mixture, etc.).

I'm planning on making molds from my current, somewhat heavy engine cowlings and making new ones with carbon fiber.   Does anyone have advice on the number of plies of 5.7 oz. CF cloth are needed to get sufficient strength?  I'm using the U.S. Composites 635 epoxy.  Three plies would seem enough, but I'll go with two if I can.

TIA.

On 3/15/2021 at 12:40 AM, Bugstrider said:

Thank you for that info.  Did you get the foam at the local fabric shop, Hobby Lobby or an online source?  I will do a search for online sources and thicknesses.

Cheers

Trevor

I bought mine from McMaster-Carr but that was 20 years ago.  There are many online sources these days.

Someone posted the original article about using Confor foam for added safety on this site or in the Cozy Builders Mailing List (Google Groups). 

On 3/10/2021 at 7:07 PM, Bugstrider said:

Does anyone have any suggestions to obtaining some seat cushions for the Var-Eze?  I see OregonAero sells just the cushion uncovered pads, but did not know if they were worth the cost of $380 per seat.  Upholstery for the cushions would be an additional expense.

Any used seat cushions for sale out there?

I made my own from pieces of polyurethane foam (aka "memory" or "Confor" foam). Two layers if I remember correctly: firm on the bottom and a softer one on top. The foam cuts very cleanly with a band saw. I sewed the covers myself but next time I'll probably have a pro do it.

If my memory is correct the change to the cuff-less wing was documented in the Canard Pusher newsletters. Marc Zeitlin may be able to advise you on the effort and cost to convert to cuff-less. 

@Bellancabrian 

Just to confirm, the exhaust system is for a Continental O-200? 

@wockda : I think the improvements you're planning are all worthwhile.  Before first flight in '03 I changed my cowling to use a NACA scoop (from Lightspeed Engineering) and a boat tail.  I used a Van's airbox turned toward the rear and later replaced it with a custom version that provides a little more clearance.  Around '06 I switched out my Hendrickson prop for one from Gary Hertzler.  It performs better and just as importantly for me, is safer since it's unlikely to catastrophically fail if a fuel cap went through it.  Now I'm working on extending the trailing edge of the cowling with the hope that I will get better ground/taxi cooling by reducing the gap between the cowl opening and the prop disk.  There's also a side benefit of smoothing out the curves leading to the trailing edge and keeping the airflow attached longer during flight. 

You can reshape your cowling to reduce airflow separation and reduce drag but it's a big job.  I'm in round 2 of that and it's taking months to get the shape to my satisfaction.

If your exhaust system will be needing replacement anytime soon you could go for in-cowl design.

24 minutes ago, Marc Zeitlin said:

The first sentence is incorrect. The Varieze was the first implementation of the "Whitcomb" winglet, and Whitcomb's original design included the small lower winglet, so when Burt adopted the Whitcomb design, he included the lower winglet as well.

As it turns out, unless you're cruising around at the Max. L/D speed (which we never do, because it's very slow or unless you're very high), it does, in fact, contribute little to aerodynamics. But the lower winglet was NOT put there as physical protection, but as an aerodynamic feature.

With the anhedral in Varieze wings, runway contact of the lower winglet is not unknown, but is purely a cosmetic issue, as the lower winglet is not structural.

Regardless of the original intention, the lower winglet serves almost no aerodynamic purpose, as you acknowledge.  It does, however, provide physical protection from a wing strike.  So I stand by my statement that its purpose (now) is the latter.  If you're not worried about hitting the wingtip then remove the lower winglet as many have done (speaking about the VariEze only). 

By the way, assuming that data was available at the time, it seems likely Burt knew that the lower winglet wouldn't contribute much aerodynamically in normal operations.

Wingtip protection is the purpose of the lower winglet on the VariEze.  It contributes little, if anything, to aerodynamics.  The larger lower winglet on the Long-EZ is a different story.

1 hour ago, Cmead said:

Here's some pics of the light install.

Looks exactly like mine.  I still haven't found plans for it.  I wonder if it was a Ken Brock part?

I got a long length of aluminum tubing from Aircraft Spruce.  I think it was 1/4" diameter and I measured the distance from the aileron corner to the wingtip to determine the length of tubing needed.  I filed small teeth on one end of the tube.  I don't remember which side I drilled from but the length of the tube made it pretty easy to sight down and aim where it needed to go.

In the corner of the aileron cove I removed a 1"x1" (approx.) piece from the vertical shear web to gain access to the foam core.  After the cove-to-tip hole was done I drilled from the wing root to the cove corner, following the vertical shear web just inside the wing foam.

The VariEze project I bought already had the flip-down landing light installed. I don't know where that design came from (Debbie Iwatate?) but it works well.  The lever can be seen next to the nose gear crank: