Building Spectra

[ClayK]

I know this has been discussed before, but most of the threads are older.

Ok, I'm going to purchase a Spectra G and I have some questions.

1. How come they cost more from MA and less from Ricks or Heliproz?
2. Engine recommendations? I've been looking at the TRM Z231 from MA, but the bird is $300 more from them.... However, I've also heard BME is producing some interesting prototypes.
3. 9255's are my choice right now for servos, sound good? 9252 are a fallback if costs estimates are exceeded.
4. Throwing around the idea of a Futaba 611 w/9256, but it's damn expensive and I'd like to know what benefit I'll see from that over say a 401... (I have 3 401's on my birds)
5. Governor? GV-1 needed? I don't have a governor on any of my other 3, so why would I need one? How will having a constant headspeed help things?
6. Blade recommendations? Main and tail.
7. Fuel and oil recommendations...
8. Misc words of advice.

Ok, basically this will be the cadillac of my fleet for pod and boom. My scale project is not going to start for some time, so this will be the bird I'll fly the most (XCell 60 is being put up for now, Raptor will fly until the new 50 comes out from MA and then that will be traded in for that). I know I'm going to dump some loot on this project. I'm going to span the project out over a length of time.

This may sound weird, but I'm going to write this up with a build schedule, lifecycle planning including logistical support and operating costs (spares, PMCS, corrective maintenance, etc), electronic logbook and supply system, engine hours, flight hours, etc etc and more. Don't ask why.... Hopefully, I can fine tune it by the time I get to my scale project.

Lessons learned, advice and recommendations are welcomed.

[Laurens]

1. MA needs retailers. Its easy to get retailers if they can sell it at a cheaper price from them.

2. Dunno.

3. Both will work.

4. Depends on your style of flying.

5. Dunno.

6. Personal choice I think.

7. Dunno.

8. If it will be your flagship get all the best stuff for it.

[bigrcr]

1. MA offers sales to the public only at retail to discourage sales that would compete with the hobby shops/distributors.

2.The TRM G-231 is recommended as well as the stock G-231. Either of these along with the model can be purchased through the distributors/hobby shops.

3. Ditto...Both will work.

4. Some get good results from the GY-401 however , the GY-401 does not have the ooomph to control the torque of the gas models (at least using the older 9253 servo) as well.

5. A governor is not required at all. I use a governor on the Spectra-G mostly because it is easier to estimate RPM and head speed during testing. I use no governor on my other gas model nor do I do always use the governor on my S-G.

6. Use 700-720 mm main blades on the Extreme head and 690-710 mm on the Tempest head (as it adds to the overall length of the disc due to blade bolt/bolt length). Tail blades- use 105 mm blades. Some have/use 110mm tail blades and this is discouraged as the blade mass/weight tends to be higher.

7. use either a good quality gasoline (regular is best) or coleman fuel. For oil use a good quality 2 cycle oil designed for air cooled use. Amsoil, Penzoil, Yamalube, Stihl, Poulan and others are all good choices mixed at 50:1 in most cases. You can use a good quality non-synthetic (petroleum based) oil for break-in mixed at a slightly lower ratio (32:1-40:1) with good results. Learn to read the plug to zero in on the oil content.

8. Check the gasser and other gas related forums as much has been posted on these very subjects.

Good luck and most of all have fun!

Later,

[carey shurley]

2. Engine recommendations? I've been looking at the TRM Z231 from MA, but the bird is $300 more from them.... However, I've also heard BME is producing some interesting prototypes.

3. 9255's are my choice right now for servos, sound good? 9252 are a fallback if costs estimates are exceeded.

4. Throwing around the idea of a Futaba 611 w/9256, but it's damn expensive and I'd like to know what benefit I'll see from that over say a 401... (I have 3 401's on my birds)
5. Governor? GV-1 needed? I don't have a governor on any of my other 3, so why would I need one? How will having a constant headspeed help things?

8. Misc words of advice.


I wouldn't hold my breath on the glow motor retrofits. The engines were designed to run glow fuel, which mean they get a large part of their cooling from the fuel/oil that pass through them. They don't have enough surface area to keep cool when it gets hot and the motor is loaded. These may work in some limited way, under specific circumstances but you're better off using something guaranteed to work, like a Zenoah motor. You should be able to get both the motor and model from a hobby dealer (like Ricks) for quite a bit less than retail

I'm actually using 9151's, but both 9255 & 9252 are fine.

Gyro - tough to beat the holding power of a 611. You won't be happy trying to use the 401 on this model

Governor - I wouldn't fly without one, however opinions differ. If you use a Stator Gator sensor, its about the easiest addition you can make.

Download the "operators guide" for the spectra off of Miniature's web site. Its geared towards new gasoline operators

Get a copy of the March issue of Rotory Modeler, theres a build article there with several ideas

Go find the building video that John Garst and Will put together, they go through the whole build.

[ClayK]

Sweet. Going to read that Op Guide today and hopefully watch that video (it's in the video forum right?). I'll try and order a back issue of that issue. I'm terribly excited about this as it will be my first gasser. Hopefully I can keep it under wraps from the wife for a while.....

Thanks for the information guys! I searched the forums, most of the stuff I found was older and I wasn't sure if it applied.

[Tom Fiddler]

I have that issue Clay, I'll let you read it when you come up.
The Spectra is a good flier and MA quality speaks for itself.

[ClayK]

Sweet, thanks Tom. :)

[ClayK]

Now it's just a matter of where I order from. I'm sure I'll get loads of information this weekend, so I'm going to hold off ordering until at least Monday (if I can...). I know what I am looking for as far as kit, powerplant, servos and gyro are concerned. Just need to hammer down muffler, blades and some other minor things.

Calling Ricks to figure out pricing now as I have already gotten a quote from Heliproz. Just waiting on Nathan to call me back....

Looking forward to joining you gassers :)

[ClayK]

Ok, I'm not building, but I will be joining the Spectra family soon.

[ClayK]

Ok, page 30 of 68 Tempest manual says to install the M4 Hex Nut (0017-5) onto the crankshaft if I'm using the pull start. Drawing 5-A, that corresponds with this assembly action, says not to use 0017-5 (M4 Hex Nut) if using pull start. Which is it?

The instructions make sense, but the drawing does not. (This is of course assuming that the 100A is correct and the 100B is wrong)

[carey shurley]

If you're going to use the pull starter, remove the start cog as indicated, and then slip a #0848-3 spacer (which should have been included with the kit) over the threads and then replace and tighten the cog. The purpose of this is to space the starter cog out slightly in relation to the pull start mechanism, because of the thickness of the bottom plate

Originally, the hex nut was used instead of the spacer, however it was found that it reduced the number of threads that the cog could thread onto by too many and made it easier to strip the threads out of the starter cog while pull starting the motor. Using the spacer solved this.

[ClayK]

Happy day!

Most of the electronics are in, the rest are due in Friday. Frame is complete. I'm thinking of flying a little first with the stock carb and air filter. I have a 644, but require gaskets which are on order. I also have the MA filter, but I'm waiting till my new muffler comes in (Century V2) sometime later this month.

I required a couple more parts from MA (.3" rubber spacers and tapered socket head screws) unless someone has any suggestions?

[bigrcr]

Sounds great! Unless the carb is a WT 677. If it is DON"T USE IT.

Later,

[ClayK]

It's a 644.

[ClayK]

She's 90% complete. Only need to add receiver and governer (should be in sometime soon). She's now dressed and ready for pictures :) I'll get some on here after I clean her up a bit.