Hi. I'm currently building a Kyosho Trainer ARF kit. Much of the construction has been fairly straightforward so far. However, I'm having great difficulty in aligning the stabiliser to the wings so that the distance between the wing tips and stabiliser tips is equal on both sides of the aircraft (I'm sure you know the one, A = A", B = B", etc). Any hints on an efficient method for doing this? I'm currently using a piece of string to measure the distance on both sides but just can't seem to get it right. How much tolerance is there in these measurements anyway? Does it have to be spot on or is it ok to be out by a few millimetres.

Thanks
Xactibu

G'day Mate,
It is no good using string, stretches too much, but anything that is solid will do, I use a straight edge rule, but a long piece of dowel or wood will do, just mark it, & then move to the other side & adjust to suit. the horizontal stabilizer can be a bit out, but the fin has to be as straight as you can make it. It is also important to make sure the tail & the wing are aligned, Parallel to each other, so look from the tail towards the wing hold the tail up so you can look straight down the centre line of the fuselage & make sure they are lined up, if they are out a bit adjust to suit.

Good Flyin Mate,
Allan.

A few Millimeters max. I like to keep it within 1/16" (1.5mm)

The best way to do it, is to measure the length of the stab and draw a line down the center from the Leading edge to the trailing edge. Place it on the Stab Saddle so it is centered and push a pin through the centerline near the center of the stab (Front to back)

Don't use a string to measure - string will stretch, get anything that's long and (relatively) straight - You can glue a few long balsa scraps together or tape a stick to a ruler etc.

Make your measurements from a stable point - For example, put one end of the stick in the grove between the end of that aileron and the wingtip to keep it from slipping off

Now do your measuring. Once you can get it right, remove the Stab and smear on the 30-minute Epoxy. Replace the stab, line it up again (making sure that it is also horizontal in relation to the wing - Shim if necessary) and then let it cure, rechecking it every few minutes until the epoxy has completely set

Try using a couple of seamtress tape measures. They are flat, flexible, and inexpensive. You can get them at the "dollar store". You can "pin" one to the same point of each wing tip, then measure to the respective tips on the horizontal stab and adjust until you're "right-on".

Vagent has the right idea. I've used his method for years. The fabric tapes measures don't stretch like string and most have graduations in inches on one side and centimeters on the other to make it easy.

I use a laser to set my alignments. I have one that can set to point straight ahead like a regular laser, but can also be angled both left and right at 1/8" or 1/4" increments (not quite sure which, I don't have it in front of me at this moment, but I believe it is 1/8" ).

I just place the laser on top of the fuselage behind the wing saddle, adjust the straightness so that it sights right down the middle of the stabilizer, then keep adjusting the measurements left and right until the laser beam points to the same exact spot on either side of the stab until perfect. Mark it, then epoxy. Always perfect.

This is good advice. I went back and checked my horizontal stab and then my fin when gluing in place with epoxy every few minutes. Has a tendacy to move slowly if not pinned securely in place until it cures.

somegeek

AVG,

Vagent has more than the right idea, that is an awesome idea.
Since my wife doesn't sew I need to go out and buy a tape,
and at the same time buy one of their self healing cutting boards for when covering.

KW_Counter

Buy two tapes. The beauty of this technique is that you're not constantly moving from one side to the other with the same "measuring stick" and "guessing" at the amount of adjustment. You have measurements on both sides (main wing tip to horiz stab tip) at the same time. You can fasten the tapes to the tips of the main wing, hold the ends of the tape in your hands and adjust the position of the horiz stab with ease.

Hi,

The Kyosho ARF was the trainer I used to get back into RC after a 20 year hiatus about five years ago. I wanted an ARF (little emotional involvement) to learn on whilst I built a PT-19 kit from Dynaflight.

The advice given is all correct but assumes the wings are aligned. I would strongly suggest you use the rubber band option rather than the bolts.

I would also suggest the following sequence to assemble and align your wings and tail surfaces: From a fixed point at the tail, (usually a pin) align the wings using the methods described. Once wings are perfect then from a fixed point at the nose align the tail plane and check with the wings.

Good luck, you will find this trainer is as easy to fly as any. Make sure you use enough rubber bands to hold the wing firmly and always replace with new bands for each day's flying.
I used old bands and the wing parted company at the bottom of a loop. I still have the wing Don't ask about the fuse.

Colin

I've used a metal yardstick for years, but vagent's idea is the best. too bad RCM is still not around, that might have won a prize!

Get a compact 2m retracting rule from your local Bunnings. Cheap as, and you'll use it for a myriad of things over your years in R/C.

No, alignment it doesn't have to be exact to the mm. It's desirable it is +/-2mm, but for sport flying, a difference of up to 1cm wouldn't even be noticed by most people. In a trainer, in terms of handiling characteristics once the model has been trimmed, pragmatically it'll have no adverse effect. Truth is, even a 2cm difference can be trimmed out so as not to be noticed or have undue adverse effect upon handling upon normal ops conducted with a trainer. You're not flying pattern, so +/-5mm will be close enough although with a retracting rule and moment's patience, +/-2mm is quickly and easily achievable

2m
2mm
+/-2mm
2cm

Sounds like that crappy european measuring stuff to me. I still like good ol' American inches/feet/miles. Hey, it's what I'm used to even if your way might be better.

It could be worse Bruce, you could have grown up in Canada during the conversion to metric and learned half and half.
I generally think in miles/feet/inches regarding distance, and mph for speed, but thinking of them in metric as well is second nature. Temperatures in Farenheit confuse me, I have to mentally convert to a close temp in Celcius, except for certain ranges of temperatures that are common. Weight is pounds, and I have to convert kilos to pounds for them to make sense. About the only thing I have down: I was an electronics technician in the Navy so 12/24hr time is thoughtless for me. [sm=lol.gif]

I do have to say though, in general, metric measurements make more sense, and are pretty much universally factors of 10, which makes them easier to work with.

Cheers,
Graham

ghtracey,
I lived in Italy for 3 years, and after driving on the Autostrada over there I got to the point that I could almost instantly convert between Miles Per Hour and Kilometers Per Hour. I had to, I had an american car with the speedometer in MPH and all of the speeds over there are listed as KPH!!!!

Ken

I learned about grams and Kilos many years ago when I lived in California.

Hmmm, care to elaborate on that a little more Mike????? [8D]


Ken