Can I install a Flyware 650-F5 inrunner with an OD of Ø40mm (Ø1.58") on the E-Chrysalis?
From : Don Stackhouse
I'm not familiar with that particular motor, so from an electrical standpoint I can't comment. The motors we've been using make the plane fly really well (near vertical climbs or better) on about 180 watts from the battery, going into anywhere from an 11-7 to a 14-9.5 prop.
Dimensionally that motor will almost fit. It's within a few thousandths of the dimensions inside the nose at the front end, close enough that you could sand the insides enough to make it fit. You might need to hollow out the underside of the nose cover and the hatch to allow for the top of the aft end of the motor, because of the down thrust. You will probably also have to make a new F1 (the ply nose bulkhead) unless by some miracle the mounting bolt and cooling hole patterns are the same as a Speed 600. Not a big project, but a little bit of a nuisance item.
I have some runs I've done in Motocalc, but I'm not happy with the way it tries to estimate aircraft performance. I can say that if you put enough watts in anything, it will fly well. In the case of a 2-M Chrysalis, it flies adequately well for sport flying on a stock Speed 600 with an 8-4 prop, and bores very large, exciting holes in the sky (about 20 seconds to winch-launch heights) on a brushless setup that pulls about 180 watts or more from the battery.
I read your advice on which covering to use, but visiting some on-line vendors has my head spinning. Which cover do you recommend that is currently available?
Oracover's German website lists Horizon Hobbies as the distributor, but they only sell Ultracote, Worldtex, and Solarfilm. Which one is OK for the Chrysalis?
Ultracote and Oracover are exactly the same thing. I've even bought roll of it that had the label for one on the package, but the other name ink-stamped along the edge of the covering inside.
Since the Chrysalis 2-M does rely on the covering to help provide enough torsional stiffness to the wing to avoid flutter, you should stick with coverings that have good stiffness, and that hold their tension well. I'm not sure about Worldtex. It's been a while since I used Solarfilm, but in my experience it was pretty soft, tore fairly easily, and the adhesive didn't hold well when exposed to heat.
Regular-weight Ultracote is quite strong and stiff, and very tough as well. It adheres well if you follow the instructions and apply it with more heat and pressure than you would other coverings. It uses a high-temp adhesive, and some folks try to apply it at normal settings on their iron, then blame the covering when it doesn't stick well. Properly applied it holds very well, and also (in part due to the high-temp adhesive) it doesn't sag or blister in hot weather as much as the other coverings.
Hobby-Lobby sells Low-Temp Ploycover, which they consider a replacement for Low-Temp Oracover. Are they the same?
Not sure, but you don't need low-temp covering for this airplane anyway. Low-temp coverings are for applying over foam, so you won't melt the foam. There is no foam in the Chrysalis, the structure is all wood.
Coverite is heavy, and surprisingly not very stiff. I'd avoid it.
Transparent Monokote is actually stiffer and lighter than regular-weight Ultracoat, so it's better in terms of torsional stiffness. However, it's more brittle, and prone to splitting from sudden shocks (such as a hard landing) in very cold weather. It also has more tendency to develop blisters, and to sag in hot weather, so you should figure on ironing the edges back down and re-shrinking it occasionally (typically maybe once a season or so). It also is a little harder to apply around complex curves, so it's a bit tougher to avoid tiny wrinkles around places like the wingtips.
Of the two, I prefer Ultracote, with Monokote as my second choice.
Note, the covering that is critical is on the inboard panels of the wing. You could probably get away with lightweight Ultracote for the outer panels of the wing and for the fuselage and tail. It would save a small amount of weight, although probably not enough to be worth the trouble. The plane has lots of wing area and isn't especially critical on weight. Don't go hog-wild with glue, etc., there is no merit in unnecessarily adding weight, but it doesn't require fanatical attention to every last gram (a desirable characteristic in an airplane that will be popular with beginners).
One more question (for today ...): Do you recommend any covering adhesive for the Chrysalis? I have seen planes where the Monokote peels right off the wood, and detaches from the ribs. Would an adhesive help?
I've never had a problem with that myself. In cases I have seen, it's been because they used some ancient, dried-out covering with deteriorated adhesive, they were trying to apply it to a dusty, dirty and/or oily surface, they didn't use the right heat and pressure from the iron (either not enough heat, or way too much, test on some scrap wood first if you're not sure), or else (and I'm not joking about this) they forgot to take the plastic backing off before trying to iron it in place!
Adhesives like Balsarite can help the bond, although if you use too much it can actually get in the way. However, in my experience they normally aren't necessary, and just add unnecessary cost and weight in most cases.
Don Stackhouse
DJ Aerotech
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February 9, 2012
