Harbinger Build

[kjkavaney]

looking good David. following along...can't wait to see it in the air this season...

[Sled-Works 1]

Back at it now and making progress on the right wing. Is has been great to be in the shop again. Basically decided to begin glueing the darn thing together.



Used wood glue for the 1/16" sheathing. Gave me time to get everything weighted down and pinned in place.



Compartment for the spoilers. As discussed earlier...will fab spoilers separately as a stand alone piece that can then be mechanically fastened into this compartment.


Starting to look like something. Will add the leading edge blocks next and rough into shape. Ailerons will be up after that.

[Sled-Works 1]

I found this inspiring photo recently . Unfortunately I don't know who took the photo or whose model is in the image. It certainly is beautiful.

[Sled-Works 1]

Started roughing out the canopy plug last night. Have a long way to go on this one.

[Tango Juliet]

Nicely done.

[Sled-Works 1]

Stab covering.

[Sled-Works 1]

Got in some good shop time lately. Covered the stab and built a stand for the fuse. The stand is made w scrap basswood from the model shop, a fiberglass bed formed over the fuse, and then sprayed with 3M-77, and covered with an old blue shirt from the rag bag. The fuse fits seems to love it. The stab is covered with Solartex white and natural. Seems to look okay.

[Sled-Works 1]

Hello Len - Well, life has gotten in the way here a bit but I've gotten back on the horse recently. Also took some time to work on a few other ships for the flying season. More to follow!

[lenb]

Hey Dave,
Where ya been?
We want to see this plane out flying this summer..

[Sled-Works 1]

Decided to go the route of mounting the spoiler servo inboard of the spoilers and use a pushrod to actuate the spoilers. Here are the servo boxes that will be mounted between wing ribs. They are made of light balsa sandwiched between a layer of ply and a layer of hard balsa. Pretty tough. The servos are Hitec 225mg.

[Sled-Works 1]

Good suggestions and comments guys. Thank you and please keep them coming.
Tom - Good question...I failed to call out

a second hatch that would run the length of the spoiler box

on the underside of the wing. This, when used in conjunction with the servo hatch, would allow swapping out the servo. I will do this with whatever solution I end up implementing so as to gain access to the entire spoiler box.
Dave - I agree with you...if not done well, this may very well be a weak point in the spar.
Arup - Larry suggested the same idea a few days ago...that is using a rotary drive fitting on the servo. Great minds...
Gene - I typically use a hatch with the servo attached directly to it...somewhat similar to your servo box. Will see how this shakes out.

This evening I was looking at another design that incorporates an in-line pushrod that would meet the actuator rod (connecting all four of the spoilers) from the fuse side of the spoilers. I think this a valid option and will explore this a little more. - Sled On

[ARUP]

You could put a Rotary Drive fitting on your servo! https://www.robotshop.com/en/actobot...oupler-14.html Just remove a set screw to allow servo the be removed if needed. The shaft which attaches to spoiler array penetrates a small opening in the shear webbing.

[Gene C]

Sled-Works 1,
You might build a box to insert the servo from the back something like was done on my 1/3 scale Cherokee II. The servo fit is tight but removable. This would require the removal of the servo mounts, but the servo will not be going any where.
Gene

[Dave Smith]

And maybe a weak point in the spar due to non-continuous shear webs? Unless everything fits tight as a drum, in which case, as Tom says, you're going to destroy things to swap out the servo.

(but I love your drawing!!)

Dave Smith

[Tom]

Took another shot at the spoiler servo mount. Seems to work.

How do you change out the servo when it goes bad?