Flite Fest 2017: Bugatti 100P

[rockyboy]

Two of those maiden attempts - the EVA Sport & Arrow - actually flew and landed well! It was only the other three that had issues... :black_eyed:

And thanks for doing the tree walk looking for the Baby Bugatti with me - I picked up two dog ticks and one deer tick once the day was over.

 

[willsonman]

Yeah, I had a couple loosely on my leg and noticed them at the charging station. I did a thorough check when I got home and found nothing. I was glad I did not bring anything home!

 

[willsonman]

So, some of the "know-it-alls" (you know who you are) have been debating this a little offline and seem to think that rather than trying to sync the motors, I should be trying to use different props. So here is the run down on the prop situation...

With the motors I have selected I'm pretty much limited to 8" diameter. I currently have one backup 8x8R and a couple 8x8. The front prop currently is the 8x8 with the rear being the 8x8R. After the landing it seems like the front props are more likely to break with my tendency to nose-in. Just a part of life on this airplane. The issue then becomes, do I sacrifice speed and try to find a lower pitch prop for the front? All the research points to having a higher pitch on the rear prop. So lets check our options.

One option here would be cutting down a 9x7.5 or 10x7 to 8x7.5 or 8x7. Based on my static RPM test, the 7.5 pitch puts me at 96MPH and 7 pitch puts me at 89MPH. for reference the 8" is 102MPH.

Another option is to put the 8x8R on the front and cut down a 9x9 to 8x9 for the rear. 8x9 at 13.5KRPM equates to 115MPH. So we are splitting hairs a bit here. Given that the motors are rated for higher power I'm not concerned with the increase in pitch to 9.

Any input or thoughts on this would be insightful. In the name of saving battery flight time, my inclination is to cut down a 9x7.5.

 

[FAI-F1D]

After the landing it seems like the front props are more likely to break with my tendency to nose-in. Just a part of life on this airplane. The issue then becomes, do I sacrifice speed and try to find a lower pitch prop for the front? All the research points to having a higher pitch on the rear prop.

You need to decide for yourself what is more important: speed or ground handling. I've spent enough time with pylon racing gurus to know that they consider props expendable and keep a big supply of them around. Props are broken on as many landings as they're not. Something tells me you'll break a lot fewer props than they will given that you at least have landing gear to provide an additional point of contact (impact?).

It's important to note that changing props isn't going to do a blessed thing for your landing behavior. If it breaks props on landing now, it will continue to do so with a lower pitch prop because you're going to be idled at landing. Lower pitch would, however, make the takeoff more civilized, but you've already demonstrated a greater than 1:1 static thrust from your maiden flight by literally hanging the thing on the props on takeoff.

Another option is to put the 8x8R on the front and cut down a 9x9 to 8x9 for the rear. 8x9 at 13.5KRPM equates to 115MPH. So we are splitting hairs a bit here. Given that the motors are rated for higher power I'm not concerned with the increase in pitch to 9.

Any input or thoughts on this would be insightful. In the name of saving battery flight time, my inclination is to cut down a 9x7.5.

Why not think about this another way: why does the front prop have to go the usual way 'round? APC sells an 8x10 (http://www.apcprop.com/product_p/lp08010(1).htm), and you've got that 8x8R, so you're all set, in theory.

I think the optimal setup would be to have the 8x10 in back (8x11 would be even more optimal, but I don't know where you'd get one) and have the rear motor be a slightly higher kv via a custom wind. This might not be super difficult if you can easily disconnect the rear armature and change it out. Perhaps a hair tedious, but it seems like a viable option since your rear armature is pretty much stock anyway.

 

[PsyBorg]

From what I heard on the maiden I do not think a prop change will solve your problems. It may help at a specific RPM range though.

You could hear the mismatch change as throttle was added or removed and it varied across the range. I take it you didn't get far with the Taranis RPM mod for automated mathing? I wonder if you could put the "Trim" (or some other control feature I have yet to learn with the open TX) for the rear esc on one of the sliders and manually "tune" as you fly. You would at least be able to get it close to where you want for steady speed laps which is what you are striving for in a race anyways.

 

[HilldaFlyer]

Ticks...

I woke up this morning and after a shower, saw that I had two ticks on me. Check yourself boys... this is going to be a rough tick season.

Ticks are nasty little guys.

I found one on me from my Saturday's excellent fly day.

I have a anti-tick-tip if you all want to look like more of a nerd... I learned this from boy scouting and it really works. Tuck your pants into your socks and your shirt into your pants. Ticks always climb up, so they will keep climbing on the outside. Wearing lighter colors also helps spot them while they're still on the outside. But, when it gets hot, tucking shorts into your socks really looks goofy!

 

[agentkbl]

you gotta have a really long shirt to tuck in to those shorts.

 

[willsonman]

All worthwhile considerations... except that tucking shorts thing. That's just weird.

So I got the bottom sanded down and then started applying the WBPU and BP mix. Just eyeballed it. Left it fairly thin.


Still drying


and more drying


Then I flipped her over and did the bottom... more later on what I did in between the top and bottom.


I forgot that I still had to fill the segment between the tail cone and the fuselage so I did that quickly. I'll sand this back and do another skim layer.

 

[willsonman]

So tagging behind the previous post I thought I would show something that I've been wanting to show on this forum for years.

Using the servo hatches here. Previously you saw them primed. I coated them lightly with metallic spray paint. This takes FOREVER to dry so give it at least a few days to fully cure out. See how the rivet marks are more dull than previous?


So we start the process by simply painting the parts. I'm using Behr premium indoor latex paint here. The same can be done with acrylic paints. Using another spray paint over top of the initial spray paint... Its not really going to work because of how the molecular bonds work in spray paint. Stick to latex or acrylic.


Next we take some steel wool and drag it across the surface where you would expect the air to flow. So the leading edge of the panels and of course along the rivets. The rivets are flush but they will still see turbulent air. The wool will create tiny scratches in the top paint and reveal the metallic finish beneath making a very nice weathering effect. This can take a HUGE amount of practice to do right so be sure to practice. You can easily over do this. Airplanes never flew looking like they just came out of 50 years in barn storage. There is a little wear and tear but never at apocalyptic proportions.


From there, I sanded with 3000 grit to smooth out any blue overspray and dull the wool work a bit. It seemed a bit too harsh but I was happy with the amount of metal exposed.


And the flap hatches done as well. Notice how well the rivets are now blended in with the paint? They are present enough for you to take notice at a fair distance but not so prominent that they distract up close. It is a happy balance.


I love this technique and I would do it all over this airplane if I could keep the weight of two layers of paint. Perhaps a little could be applied on the front of the exhaust fairings. Just be careful as it is very easy to overdo. It looks cool, its easy to do,... WHY NOT DO IT?!

 

[CrossedUpChris]

If I fly my planes long enough they always look pretty weathered. The whether being a tornado after the inevitable crash.

 

[agentkbl]

that weathering does look really good.

 

[willsonman]

Given that this kind of airplane would only really have seen a runway on a good day I've opted not to do any washes to weather and dirty things up. That technique will be saved for another time. I think that this more used look has weight and merit to it and my hope is to strategically apply it elsewhere.

 

[willsonman]

Tail cone blending is done. I hit a couple of rough spots with the 120 grit and applied more BP and WBPU. Sanded back the battery hatch a little and applied another coat there. Since that will be the most "handled" part of the airplane I wanted to be sure it was well-finished and robust.

I had some other things to do in the shop but I also got the printer fired up and got a print done for some other goodies on this project...

Now what could I need 64 of that is 3.2mm in diameter?

 

[PsyBorg]

Side covering for the motor part of Rockyboys Caudron. I planned to use a painted piece of plastic sheeting or a game time card similar to a credit card to make it.

Well that or bullet holes depending on perception of that print .. have to see the finished product to take a real guess.

 

[willsonman]

Not even close. To drop another hint I've included the picture below of a completed test print. You can just make out the hex pattern where I colored in sharpie. To get this detail I had to slow the print speed to 20mm/second. For the final print I went to 15mm/second. More detail always means slower speed, especially with the smaller stuff. With 64 of them, I took time yesterday to sand the bottoms to remove the bed adhesion material. Left with tiny pieces that were only safe when stuck down to tape. I painted them silver.


Moving on, I had time to draw up a fun accessory. This is the first of 4 pieces to make wheel chocks. There is a hole in the side to run a bit of string through. I'll clean them up and prime, then paint yellow, with some black string. Should look quite the part when all is said and done.

 

[Joker 53150]

On one of the 3D printing sites I found a set of wheel chocks complete with a "rope" between them. I'm not sure what scale they were designed at, but could be scaled as needed. I haven't printed them yet, but plan to do so to see how well they'd work.

For your tiny prints, I'm assuming they have something to do with creating a rivet pattern for the plane.

 

[willsonman]

I saw that one, Jeff. Sized for 4.5" tires. These are similar in design but I did not want a printed rope.

You are MUCH closer on the tiny print but keep fishing.

 

[F106DeltaDart]

I saw that one, Jeff. Sized for 4.5" tires. These are similar in design but I did not want a printed rope.

You are MUCH closer on the tiny print but keep fishing.

Are they the fuel fill caps?

 

[PsyBorg]

Now that I know we are only looking at the tiny black parts and not the whole I would say they are knobs and switches for the cock pit consoles and gear. The blue area almost looks like it could be some sort of radar or mapping

 

[willsonman]

Nope and Nope.