View Full Version : Building a 2M Spirit
01-22-2007, 03:20 PM
I've just started building my 2M Spirit and I'm looking for any suggestions or "improvements" to the construction. My plan is to build it with the spoilers, the one-piece wing, and I'm toying with the idea of powering it. This will be my third flying kit..the first 2 were a Gentle Lady and a Herr J-3 Cub parkflyer.
So, any suggestions for areas that need strengthing or ideas that will make life easier later?
01-27-2007, 06:02 PM
I like to keep my Spirit with a 2 piece wing. Makes it much easier to store and transport. After I assemble it, I run one layer of clear packing tape around the seam. Makes it very strong. End of the day I remove the tape, or cut it, pull the wing apart and it goes in a box for transport and storage.
I have never had the wing separate on hi-start or winch launch and the joint has survivied many crashes that broke other parts of the wing.
I have servos in each spoiler bay, but you can also do the center servo with strings. both work. I have seen people even mount teh servo in he wing rather than the fuselage.
I sheeted the front of the outer wing panels. Said to reduce tip stalling.
If you go for a pure glider, move the electronics as far forward as possible to minimize the needed weight. HS 81s or GWS mini servos would work well. Standards will fit but it is harder to move them forward.
If you want to put a motor on it, you will be creating a Spectra, which is the motorized version of the Spirit.
I would suggest a brushless outrunner of 150 to 250 watts. If you can power it with Lithium packs, say 2100s, you will be much lighter than NiMH packs. Be sure you use a folding prop and a speed control with a break.
When I built my Spirit I did the one piece wing BUT the rib inboard of the dihedral break I made of 3/8" balsa with brass tubes extending one bay either side of it. When the wing was finished and covered I ran it through the bandsaw down the center of the thick rib, tubes and all. This left me with 3 panels with 1/8" end ribs (having last about 1/8" to the saw cut).
The advantage I found in having a three piece wing is that the joins do not occur at a dihedral break point and most time I can leave the center panel in place and it still fits in the car easily. I used 2 nylon bolts to hold the center section to the fuselage.
I also made the stab removable using two set screws into blind nuts attached to ply epoxied into the tail section (if you do this, don't put the forward one too close to the rudder hinge or you won't be able to get the screw out, ask me how I know)
These mods mean that you can break the model down to 5 pieces which will pack away in a minimal space.
01-28-2007, 01:29 PM
What an interesting idea. never heard of anyone doing something like that. Have to file that for future use somewhere. ;)
Here are a couple of shots of the mods I used to enable me to have flat components for storage/transport on my Spirit (now looking very well used!)
I would recommend capping the inboard ends of the tubes to stop the wires migrating. I also tape my wing joints on fitting the tips.
The front stab bolt needs to be about 1/4" to 3/8" further back so that you can get a driver on the screw after you unhook the rudder push rod clevis and move the rudder to one side.
If you are fitting spoilers be warned that it is a good idea not to initialy use them at too low an altititude as it pitches nose down when they are deployed. Have enough recovery space the first couple of times you try them to see what happens.
02-01-2007, 01:32 AM
Can I correct the pitch issue by mixing some "up" elevator with the spoiler deployment? Or is this unnecessary?
That would be the way I will go if I ever decide to get my spoilers working again (their servo is now in another model) but the point was to stress to you not to make the first time you use them the time you are striving to make the "spot" on landing, thats what I did (yeah I know!) and repairs became necessary. Just make sure you are high enough the first couple of times to recover so you can see what happens.
I've enjoyed my Spirit very much and some time with it and the bungee is always good fun.
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