Elevator control chain.

 Acroduster  Comments Off on Elevator control chain.
Nov 032019
 

Need to get from the (future) servo under the seat to the back-end in an orderly fashion. I’m using the full size method as guide. Main part is the reversing bar behind the seat. It has to be zero play. No play, whatsoever. After the usual fiddling around for a while, I got it sorted. It’s a once you install it, you can never change it construction. Failure here is no option. The bolt at the bottom prevents the assembly sliding out of the bushings. It does not support anything. The 2 little square supports were reamed out to provide a zero play bushing.

Next will have to be the construction of the stick assy, and the mechanical interface to the servo. Lot’s of fun ahead!

pushrod is for illustration only.
and something for the pilot to hang on to.

I am only installing the main stick, front seat is ”occupied”. Not sure yet if I am going to use a separate servo(s) to drive it. Separate seems safer, since there is a reasonable mass in this contraption. Might build a pilot with power arms 😉

full down..
full up, looks like it’s enough..

The stick has to be fixed with AN4-22 bolt, 4 washers, AN310-4 nut and a AN380 1-2 cotter pin. Yup, M3 bolt and nut will do fine! (for the curious: AN4 is 1/4 ” = 6 mm. So 2 mm would be scale. Since those 2 mm bolts are usally quite soft, I won’t waste my time installing one, they will rattle loose in no time at all. The nut is a castle nut so you can put a cotter pin through the bolts hole to stop it going awol. I know you wanted to know all this.

..more tail-bits..

 Acroduster  Comments Off on ..more tail-bits..
Oct 282019
 

..many times you have to make parts before the other parts that need to go on before the parts that you need to fit to get the job done. This was one of them. Needed to make more hinges. Not difficult, just fiddly, and a bit dodgy, since I try to cut them on the lathe, with a dodgy china cutting wheel going full speed. However, hats of to the china-folk, I have not had a single one fail on me. So far I have used approx 20 odd discs on this project.

cutting some hinge-parts.

After checking the tail, I noticed the main spar was bend. This appears to be almost inevitable when you heat bits. I decided to simply cut the middle, and add a sleeve. Problem sorted. My metal working skills don’t go so far that I can predict how much distortion I will get. Of course I could make very expensive, very heavy jigs. yup, I could..

fudge, I had to cut the front, because the rear was not straight after brazing..

A bit of a showoff.. Starting to look like it wants to fly!

1569 gram, still smiling

Just one more weighing session. 1569 grams as seen here. Good stuff!

enough done for today!

And I am calling it a day. All in all it does not seem much, but I am happy with it! The section above weighs 300 gram. As a comparison: the ”light” elevator from my 2.5 meter Extra weighs also 600 grams. Ok, there’s 2 servo’s included in that figure, but still..

Finished the rest of the elevators today, another milestone reached! Also bolted the motor back on to get a feel for the CG. At the moment I am still slightly nose-heavy, so things are good! I don’t expect to have to add any of the grey gravity stuff.

yes, that’s 288 grams!
That’s the elevator horn-thingy sticking out there. Added a bit of wrap around as well.

The rear stabilizer mount consists of a single bolt, as per original, the front is made up of a few gussets. I probably simplify that part. Not sure how, but simpler as original. (too many small bits that fall apart when you heat things up, is the main reason)

Lets make some tail bits.

 Acroduster  Comments Off on Lets make some tail bits.
Oct 262019
 

The plans call for square tube at a few locations. I don’t think it will be a problem to use round tubing. As usual, use what you got! I also don’t think I have enough space for the 2 central bearings, another fudge expected there.

remember: full size!
..bend some tubes..

My template has a more rounded outline at the outer elevator. Might have to redo it, since the big one has a smaller radius.

test fit, looking good.
..and preparing for the next fun parts