What all do I need to build and fly an FMA Razor? - RC Groups
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Sep 19, 2001, 12:11 PM
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Steve Fehr's Avatar

What all do I need to build and fly an FMA Razor?

I've got 4 hours logged on my Firebird XL, and I'm getting itchy for my next plane. It's a toss-up between the Zagi 400X and FMA Razor 400, and both have their proponents, so for the price difference, I'll go with the Razor for now and just take extra care on the trimming If it doesn't work out, I can always transfer the guts to a Zagi wing or a Wally.

At any rate, one thing I'm not sure of is what all I need by way of glue, foam, adaptors, spares, etc. I'm planning on picking up a Razor 400 "RTF1" pack with motor, battery & ESC packaged. I'm also planning on getting a Hitec Flash-5 radio w/HS-81 servos, and a high-quality charger TBD.

What glue should I get? Do I need to buy reciever foam or rubber bands or anything? Also, I suppose I'd be best off with some extra battery packs... any recommendations?
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Sep 19, 2001, 10:17 PM
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poobs's Avatar
I used Shoe Goop to assemble my Razor. It worked great.

Use the self stick tape that comes with it to reinforce the wing bottom but do so near the trailing end.

The FMA razor will rip the wing trailing edge if it hits nose first at full speed.

If you buy the full spar version forget the above.

Make sure the motor wires are reversed, the motor is spining backwards and the prop lettering faces TOWARD THE MOTOR.

This is a fun plane - enjoy
Sep 19, 2001, 10:43 PM
Space Coast USA
hoppy's Avatar
Be sure to put some strapping tape across the trailing edge 6" on each side of the body like poops says. Those wings WILL shear off. You'll also want to paint either the top or bottom sides of the wings for orientation purposes. I'd recommend some other ESC then the FMA one. Past models have had only 1/2 throttle range control. It works, but I like to have the throttle control over the full range of the stick. So while you are at it, you might as well buy some sanyo 1600 mah NiMH cells at $2 each and make a long duration pack instead of the one they sell. The great planes ESC's have worked well for me. Speed 400 motors, well, everyone has them for under $10.
Sep 20, 2001, 12:57 PM
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rlt55's Avatar

FMA Razor winglets

If you get the Razor, don't saw the winglets off too short. Let them hang aft enough to protect the control surfaces when landing.
If you do go with short winglets, make sure you get metal gear servos.

After 3 sets of plastic gears, I went to metal. Also cut off my winglets and used the leftover plywood (from the winglet cut-out) to make new longer winglets. Checked it out last night (5 packs) and it still flys the same(very well).

Also, use 30 min epoxy on the CF spar and 5 min epoxy on the wing halfs. Makes it easier to get good wing alinement.

I'm using light weight 8 cell 600 mAh packs (and the stock 7 cell) and it soars great on light lift .
Only problem is, it floats down the whole runway when you want to land short

Sep 21, 2001, 11:10 PM
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Steve Fehr's Avatar
Well, I bit the bullet and bought it today! Got it mostly assembled; I'll let you know how it goes It has the full spar, so hopefully that much will be OK; I bought some red strapping tape- gonna do lateral orientation stripes along the top, which should add strength, plus it comes with that plexiglass tape now.

Hoppy, who has sanyo 1600 mah MiMH for $2 ea?? Everywhere I've seen is way more than that! I'd love to pick a few of those up tho
Sep 21, 2001, 11:24 PM
Space Coast USA
hoppy's Avatar
HR-AAU $2 Don't let them charge you $7 for shipping!
Sep 22, 2001, 12:04 PM
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Steve Fehr's Avatar

Razor ain't a trainer!

Well, I've learned the hard way that this plane is no trainer! At least it's indestructible, heh. If I hadn't spent so much money yesterday I might set it aside and try a high-wing aileron trainer first... oh well, if it can take the punishment I just dished out with just minor repairs (nosed-in about 2 dozen times during trimming and another 4 during brief "flights", the last time from about 20' at full throttle inverted into the ground & broke the canopy from the wings along about half the epoxy). The last flight, I managed to fly about 200 yards in a J with very little semblance of control before crashing. Does it get easier with practice, or could I still have a trim problem?

When I glide test, the plane goes smoothly down, with the wings horizontal the whole way, slipping just a little left due to, I think, an almost imperceptible crosswind.

In the field, it goes straight at full throttle with no elevator but is very very sensitive and immediately goes covorting out of control... Due to my not really being capable of flying it yet, lol... When might I look forward to some semblance of a controlled flight? My total experience thus far in RC has been 4 hours on a Firebird XL and a few upstart flights on a Gentle Lady sailplane.
Sep 22, 2001, 12:42 PM
Registered User
What a tough bird that Razor!

I would guess that your servo throws need to be reduced. Another suggestion would be to find an instructor near you and let him do the setup on the Razor and get you to altitude before handing you the sticks. Beginners seem to fly way to low and wonder why they hit the ground. I've been flying RC over 30 years and still climb to 100 feet plus before playing around just so I have time to recover if I screw up.

Get that instructor and good luck
Sep 22, 2001, 01:40 PM
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Steve Fehr's Avatar
Yeah, that's for sure! I wanted to go 3-mistakes high, but I didn't have enough control and was lucky just to keep it airborne at all- The controls are set for exponential but I'm probably still giving it too much stick. I'll reduce the throw before going out again, thanx Maybe I'll convince my one buddy to come over and help me trim & learn to fly it... if that fails, I'll shelf the bird for a while & transfer the electrics to the freebie glider sitting in the back bedroom!
Sep 22, 2001, 01:41 PM
Space Coast USA
hoppy's Avatar
Steve, like most elevon/aileron planes, it goes where it was last pointed. Sounds like you are way behind the plane as far as control inputs are concerned and overcontrolling on top of it.
Solution.....reduce throws to half of what they are and get it up high before you make any attempts to manuver. After a manuver, get it back up high again. Altitute is your friend!

The other solution is to buy a T-52 and spend some time flying it...then convert it to an aileron trainer and spend some more time learning. After that, the Razor should be a snap.

PS I've been there, done that, with a razor. I'm afraid that the razor will not survive the learning curve...

Sep 22, 2001, 02:18 PM
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rlt55's Avatar
There are 4 holes in the control horns, use the 2nd hole from the top.
If you have the Flash 5, set your Expo rate on channels 1&2 to -50%. (Don't make the mistake I made, using +50%, I was over-controlling like crazy). I've got a lot of flights on mine, so now I've backed down the Expo to -35%.

Double check your Radio setup to make sure everything is set right. (Like when you turn it on, it says ACRO 1 ELEVON).

To get used to launch handling, I did many glide test flights. At first just going straight and later, adding in some slow turns. (I had a nice little hill to glide down).
I did have someone fly it up (I tossed it) for the first 3 powered flights, they set the trim and told me what I was doing wrong (over-controlling with my bogus +50% Expo settings)..
Zagi pilots landed it for me the first 3 times, but after that, they said, "your'e ready, go for it".

Try not to use so much throttle close to the ground, don't over control, move the stick slowly and wait a little to see how the plane responds. With -50% Expo set, mine flies like it was on rails. After you get the feel of it, then you can Yank&Bank..

Try to do large slow turns, instead of sharp U-turns. A real sharp turn low to the ground will sometimes spin you out into the weeds.. After a while, you'll be able to turn as tight as you want. You'll learn to come out of the turn, pushing your high wing down firmly and watching your nose to make sure it stays level. Don't let the nose pitch up or down, If your too slow, push it down a little to get your speed back. (If you're so low and you can't push it down without crashing, just cut the power and save your prop). What I'm saying is, learn tight turns up high

If you get too low in a turn, your throttle can't do much for you if you are already flying slow and have the nose too high. Try to stay level as you add power, then pull up only after you have more air speed.

If you can't "Get that instructor" as already suggested, you might want to fly the Tzagi sim plane until you feel confident flying and landing it.. (Do a search on Tzagi to find out about the file edits etc). I used it and it helped me a lot!

This is just one guy's opinion (and a newbee pilot at that), the Razor is a good trainer. I will grant you, it's not super easy to fly, but it's not real hard either.. I'm positive that a lot of people will tell you the same thing. I'm no where near being a hot dog pilot, but I've got tons of hours on my Razor and have not had to add any glue to it yet. (Did add some anti-weed tape to the LEs).

I just came back from the field after flying down 5 packs. The wind was 5 to 8 MPH (I measured it) and I had a blast (It was loop city and lot's of inverted). All five landings were on the LZ and most of them looked really good (all being rightside up )..
The only problem I had was being a bit too high on a couple of approaches, had to add power, turn around and do it again, only lower.. This thing wants to glide forever!!

Last edited by rlt55; Sep 22, 2001 at 02:20 PM.
Sep 22, 2001, 02:41 PM
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rlt55's Avatar

Servos & CG

Be sure to check your Servos for damge.. My HS-81s all have metal gears now. My Razor flew like it had a mind of it's own when a servo stripped

Make sure your CG is good. I have the 555 radio in the back of the battery compartment, so I have to add a 1/2 foam spacer in front of the stock 7 cell pack, to get a good CG.
Sep 22, 2001, 03:08 PM
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Steve Fehr's Avatar
Rich, I have a Hitec Flash 5- I set exp to -50 on channels 1 & 2, and EPA to 30% on channels 1 & 2, but it's screwy.. When I test it, left aileron goes 30% on both servers but right aileron goes full on both servos. For elevator, when I push down, right servo moves 30% but left moves 100%. When I push up, right moves 100% and left moves 30%. Is there a elevon glitch here, or did I adjust something wrong?


CG feels good, balances about 1/8"-1/4" aft of the proper point, but if I move it, it doesn't glide well. I'm using HS-81 servos, which are larger than apparently designed for; had to shift the bat back about 2" to fit, and I move it every flight. (There's a mark). I built a light balsa & ply spacer, but that got crushed just during glide tests, heh.
Last edited by Steve Fehr; Sep 22, 2001 at 03:10 PM.
Sep 22, 2001, 03:34 PM
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Steve Fehr's Avatar
Wierd, it's something with EPA. Anyhow, I set up D/R as 30% instead and that's it's better
Sep 22, 2001, 04:52 PM
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rlt55's Avatar
I think I have my EPA set for 70%
When I did my setup, I just wanted them not to bind up on the wing. (Not go past the usable travel)..

I don't understand what D/R is all that well, so I just left it at 100% and leave all the toggle switches in the UP posistion..

I do notice a really big difference when I change the percentage of Expo..
I wonder if you can see any photos at this site?