New Spectra, Tips and Mods??

[megotroulette]

Hey everyone,

i am going to be getting a spectra.. and was wondering what mods and tips are there for going over a second hand heli or building a new gasser...

i see on previous threads in here about the spark plug boot cap and cord, and how the protective stuff over it if you have it too close to the boot cap it will cause glitching arking etc...

what are some tips for a Gasser NEWBIE :mrgreen:

Thank in advance,
matty o'connell

[ClayK]

I had that RF shield over the ignition cable, the spark was actually grounding out to it and not making a spark. I couldn't figure it out for like a week what was causing it. Another well known gasser resource had me remove it and it fired right up.

Go through all the screws/fasteners. I was surprised how much stuff will back out after flying. I've had stuff that was threadlocked on, back out after a couple tanks. My suggestion, after you double check all the screws, take paint or nail polish and draw a stripe across the screw to the frame. This should help you visually inspect when a screw is backing out. More PM is necessary with my Spectra than is necessary for the rest of my birds combined. Just keep on top of it and you should be fine.

Probably the biggest mod/addition, get the aluminum insulator block to go between carb and engine. I was running real lean and my tuning was all jacked up because the stock block was heat warped.

Raja recommended to me to capture the servo linkages. He had an inflight failure of a servo linkage to a ball. I haven't flown mine nearly as much as he, so I can confirm. However, it might be a good idea to be safe rather than sorry.

[paulw1283]

Go through all the screws/fasteners. I was surprised how much stuff will back out after flying. I've had stuff that was threadlocked on, back out after a couple tanks. My suggestion, after you double check all the screws, take paint or nail polish and draw a stripe across the screw to the frame. This should help you visually inspect when a screw is backing out. More PM is necessary with my Spectra than is necessary for the rest of my birds combined. Just keep on top of it and you should be fine.



So basically you are saying the vibration is so intense it shakes everything apart every few flights, even with Loctite?

[rbort]

Not in any particular order, just a brain dump:

1. Use JR rubber dampners for the landing gear. They raise the machine (sits low) and reduce damage in the future in case of a crash.

2. Put a plastic washer under the pivot screw of the stock choke if you are using it, prevents choke from closing in flight later down the road. The happened to me on the 1005 gasser, I do it on the Spectra as a precaution.

3. Capture the ball links as Clay said for added security. This is only for the fat rods. Don't worry about the thin ones. I had one pop off but at the time I was using a vibrant g26 and that could have been the cause.

4. Speaking of G26's, if you plan to use one make sure Hanson balanced it. I use that now and its great, alot more power than a stock g231.

5. Do not use the carb spacer plate (carbon fiber), not needed.

6. Do not use the spark plug wire braid. Instead use a PCM receiver with a revolution whip up front and you will have no RF issues.

7. Put a 16oz Dubro tank up front inverted on the radio tray. This is the largest tank that will fit and it will give you guaranteed 15 minutes doing 3D with leftover reserve. You cannot see the fuel tank in flight as its under the canopy so this works well. Also, do NOT use the one way valve for the vent. I can be too restrictive and cause a lean run. Instead put a double loop in the vent line.

8. Install an on-board generator as this will solve the low battery issues and you can fly worry free all day. I make those for the Spectra with the mounts so they are an easy upgrade to install! :-) They run with a standard 4 cell AA pack like a JR 1100mah, 1400mah or similar.

9. Install a Century v2/v3 when available. Works well and stays on.

10. Do not use MAH tail blades. They are not balanced well and they will shake and tear the tail rotor apart. SAB blades will work just fine (I've been using those and Minair warned me about MAH tail blades).

11. Do not use a throttle servo with metal gears. Metal gears tend to strip from vibrations over time. Plastic works well.

I have never had a screw back out on me. They all stay put. Must be something in Clay's setup/machine there my guess.

Any questions I'm becoming the Spectra-g experienced guy quick. I got 112 flights logged on mine since last fall now.

-=>Raja.

[CustomPC]

Hi Matt,

Bigrcr (John Garst) has an excellent Spectra build Video on these forums.

Also, download the Spectra Manuals and users guide from MA's site. The user guide has a lot of good tips.

As someone who has just gone through this process i can tell you that you'll find a wealth of information here.

[megotroulette]

Awesome information guys...

keep it coming!!..

Thanks
matty

[Red Sky]

Tip:
If you want to properly align the tail boom, you have to take the heli to a specialist. Perfect alignment is guaranteed.

[brunobl]

Tip:
If you want to properly align the tail boom, you have to take the heli to a specialist. Perfect alignment is guaranteed.
He definetely seems to be doing some very serious alligning! The attitude does count a lot, doesn't it? :D


Lucian, I have not yet started to build the Spectra (now waiting for the kit) but have downloaded the manual/drawings and started reading. I see you chose "position 2" (near the engine) for the fuel tank (as opposed to under the radio tray). The manual says this position will call for additional canopy trimming, so I assume there should be a trade-off advantage for using this tank position. May I ask you why you chose it? Perhaps for the smaller CG excursion (tank is nearer the CG in pos 2) as fuel is consumed?

I am inclined to believe that the Spectra tank is smaller than comparable gasser helis' tanks (do you know the tank capacity?), and it seems to me that this tank position allows for the installation of a larger tank in the future. Is this so?

[CustomPC]

I have my tank in Position 2 as well.

I chose that position because i found with the tank in position 1 my CofG was too far forward and like you say, in pos 2 there is less CofG excursion as the tank empties.

The other reason i chose pos 2 is that most of the tank is visible so i can easily see the fuel level in flight.

The stock tank is nothing more than a HDPE plastic bottle made by Nalgene. It is labeled as 250ml but mine takes 300ml when filled to capacity.

During break-in i got about 8 mins flight time with the stock tank. As the motor broke-in and properly tuned i get around 12-15 minutes now.

[brunobl]

I have my tank in Position 2 as well.

Thanks for chiming in.


The other reason i chose pos 2 is that most of the tank is visible so i can easily see the fuel level in flight.
That's excellent news! I was expecting the tank would only be visible in position 3, but since I would really rather not have the ignition lead too close to the receiver (as would be the case with a fwd facing motor), I was settling for clocked flight times. Being able to see the tank will be a great bonus for position 2.

The stock tank is nothing more than a HDPE plastic bottle made by Nalgene. It is labeled as 250ml but mine takes 300ml when filled to capacity.

During break-in i got about 8 mins flight time with the stock tank. As the motor broke-in and properly tuned i get around 12-15 minutes now.

That's just like my Raptor 50 Hyper flight times: 8 minutes during break-in and 12-15 after. I expected a bit more endurance from gasser helis. This is not something that worries me now. However, some time in the future I might want to try and expand flight time a bit. From what you see in your heli, does it look like a larger tank would fit in the Spectra (without massive surgery to the canopy)?

[CustomPC]

Well, you certainly get better economy from gassers. You get the same flight time with 300ml of gas that you do off 480ml nitro on a .50.

Increasing the tank size to 500ml or 600ml will extend the flight time considerably.

I've searched far and wide for a larger tank that is a neat fit in position 2. The throttle servo plate is the limiting thing.

A Dubro or Sullivan 12oz tank will fit in a sqeeze but the small gain in capacity is hardly worth it.

I think the ideal size for position 2 would be a 400ml square bottle or tank. I did find a graupner tank with the right measurements but it's only available in Germany.

I know a lot of people mount a 16oz Dubro tank inverted into position 1 which gives long flight times.

I saw pictures of one guy here in Australia who uses 2 stock tanks in positions 1 & 2 with the tank in pos 1 feeding the tank in pos 2. He says it works well.

[carlos]

G'day Mick Yes it does work well.
I have a 12oz dubro up front.
Fill through the primer bulb return line.
Normal dubro clunk in front tank and the Stens (MA) clunk in the rear tank
My Spectra Plumbing

[rbort]

I've already given my tips above about the tank and such, see my pictures here for my setup:

www.massheli.com/gallery/raja

I prefer a single tank setup and I am fitting a 16oz dubro which will give you 15 minutes of 3D flight with some reserve. You cannot see the tank in flight but no need as it never runs out (in 15 minutes) being that size.

This way no extra plumbing for two tanks and no canopy cutting to make the tank in front of the engine fit.

-=>Raja.

[Red Sky]

...smaller CG excursion (tank is nearer the CG in pos 2) as fuel is consumed...

...The other reason i chose pos 2 is that most of the tank is visible so i can easily see the fuel level in flight...


Those were the reasons why I chose pos 2.

I think 10-12 minutes is more than enough for a flight time.
On my other gasser (Comeback, not a 3D) I fly ~40 minutes with a 550cc tank. Waaaay too long...

You can see in the pics I attached that the tank is (almost) fully visible in flight.

I do need an advice regarding the C of G. Now, it is exactly under the main shaft (axle...). Is this ok? With some fuel, it will be a little forward, I think. Anyone who fly this machine can tell me where the CG is on his?

Mine is ready to fly. I'm just waiting for a good receiver. Hope to maiden it in this weekend.
Any tips before first flight?
It's my first heli that I built it. Until now, just flying them.

PS
I'm glad you enjoyed my first photo :) I couldn't resist to post it.

[CustomPC]

Sounds like your CofG is spot on and much the same as mine which is only slightly nose heavy when unloaded with not too much change when full.

For fast forward flight, you want it to be just slightly nose heavy and for 3D most like it to be neutral under the mainshaft.

[Red Sky]

I just remembered.
Anyone had problems with the space for the gyro sensor?
I mounted mine exactly where the manual said. The canopy were too close to it. I used two foams and the metal plate under the sensor. And the space between them was under 1mm.
I had to lower the front canopy mount holes. Now it's ok.

[CustomPC]

What gyro?

I have a CSM SL720 which is taller than the typical Futaba gyro and it clears the canopy ok.

[Peter]

Red Sky . I'd suggest you throw away the one way valve on the fuel breather line ... They are grossly unreliable .. .. Most of use a couple of loops of fuel line in the breather line as a trap .......

[carlos]

Red Sky.
Yer I had gyro mounting dramas as well.
As Pete said . Left shoulder that one way valve. the Valve is a POS.

[Red Sky]

What gyro?
611
I'd suggest you throw away the one way valve on the fuel breather line
Left shoulder that one way valve.
I was thinking about this because I really don't like that valve. You guys convinced me. Thanks.

[brunobl]

There is really a lot of very good info going on here.
I hadn't thought of the possibility of using 2 tanks.

I prefer a single tank setup
I do see that 2 tanks would imply more complex plumbing (and probably a more involved fuelling procedure, too) and lots of space taken up with fuel lines, making it harder to get a tidy setup (although Carlos managed to get a very clean installation with 2 tanks). To boot, that many extra fuel fittings offer greater chance of air being sucked into the system. Oh well, seems that a 2 tank setup dosn't comply with the "Keep it Simple" guideline. I wouldn't rule it out for future use, though.

and I am fitting a 16oz dubro which will give you 15 minutes of 3D flight with some reserve.
Raja, I assume you are running the more powerful 26 cu.in engine? Would the stock, unmodified 231 be a lot (if at all) more economical than yours?

[rbort]

Hey Bruno:

Yes I am running the G26 but I have also run the G231 in the same machine and of course the G231 is a little more economical but not by alot. We are talking 3cc difference, not a whole lot but maybe that translates to a couple of minutes more at best.

When you can't see the tank and you fly 3D its nice to have that little extra reserve. With the G26 I would say the 16oz tank is a definate need as I've come back after my 15 minute flight and looked at the tank and there is like a third of on inch on the bottom of it left over. That is not much at all expecially when you are flipping and flopping around. Also the higher rpms you run the faster you burn. Most of the time I run 1650 and never ran a whole tank at 1750. I have to try it some time but I'm afraid it probably could run out at 1750 doing hard 3d.

If you are hovering around and such you can probably get away with a smaller tank and 10 to 12 minutes might be OK for you. If you want to 3D then you need to think about the last 1/4 tank being "not usable fuel" like in an aircraft as you need to be able to slosh back and forth and still pickup fuel. For me generally speak I would say I like to land with a 1/4 tank of fuel due to this. The last 1/4 tank I'm not entirely comfortable flying 3D with but when I'm alone at the field and I want to fly until I run out I have no problem spending the last 1/4 tank flying level circuits around the runway nice and easy (no aerobatics). In my case I think I can get a 20 minute flight before its deadstick with the 16oz tank.

-=>Raja.

[brunobl]

Thanks Raja,

Well I guess I'll try and get a 16oz tank that fits in the canopy then. I won't really be doing any hard aerobatics (in the foreseeable future) anyway. I just do some loops & stall turns with the Raptor, will likely do less than that to start with with the gasser.

From the above, It is unlikely that I'll use a very high headspeed, perhaps buying me a bit more flight time. Anyway, if flight time does turn out to be an issue, I now know there are some options.
Thanks again.

[rbort]

Dubro 16oz is the only one I found that fits. Needs to be installed inverted so that the hump of the tank can follow the contour of the canopy and clear the chin. See a picture of mine at www.massheli.com/gallery/raja if I haven't already given this website address.

-=>Raja.

[brunobl]

See a picture of mine at www.massheli.com/gallery/raja

Thanks Raja, There are some very nice photos there! Great Spectra detail, especially good for those like me who are about to start building.

I am thinking of fully documnting the build with pictures as it progresses.