Another Whiplash gasser build.

[jharkin]

Ok so a little background. Long time plank pilot here, including 6+ years flying GS gas planks, but relatively new to heli's... however... I just so happen to fly at the same club field that Raja flies at so...

... of course I got talked into building a Whip-G.

... or did I talk myself into it?


... Anyway, my kit should be here next week, but most all the other parts I have now. Plan I discussed with Raja is to aim for a January 1 maiden at our Frozen Finger Fun Fly. I thought it would be fun to document my build here.I wont cover every step, as we don't need a replacement to the excellent build already document by Carey and others - more of a way to share the experiences of a gasser heli beginner in case it helps other newcomers and show issues I had questions on, etc. I might do things a little different based on my plane experience, so feel free to give me pointers if I try something that wont work.

Configuration:

• Whiplash Gas
  • MA tuff struts
  • Stomp Canopy
• Hanson 270 3DMax
  • Century V2 pipe
  • MA air filter
• Radix 710 V2 & Radix 105 tails
• Electronics
  • BD3SX
  • Futaba R7008SB
  • Futaba BLS451 cyclic
  • Futaba BLS256HV tail
  • Futaba 3072HV throttle
  • GV-1
  • Stator Gator
  • Futaba telemetry for rx voltage and headspeed (y- harness off SG)
• RadicalRC custom A123 6.6v 2300mAh LiFePO4 RX battery, unregulated
• EC3 arming switch wire to dual 20G servo leads for power (no switch)

Along the way I'm getting a lot of local help and coaching from Raja on the set up (THANK YOU SIR!).

So here we go....

[jharkin]

So off we go. Since Ive got everything I started off by prepping the motor.

The Century V2 is a really nice pipe. Out of the box there is some manufacturing debris so I gave it a good cleaning with alcohol and just for the heck of it a nice rub down with Blue Magic compound to really bring out the shine.




They supply an exhaust reducer tip to quiet it down which I am going to run, and also an extra setscrew to close the baffle hole you can see here, I beleive for even more backpressure and sound reduction. I am giong to run the reducer but leave the extra screw out for now (?). I'll crank this tight with red RTV and since I see reports of it coming loose anyway I might drill and tap for a setscrew.

The setscrews they provide to lock the mounting bolts are interesting as well. There were no instructions but reading the forums I gather the procedure is to fly is to torque the main screws, fly it, re-torque and then lock the setscrews? I'll be using the DDM reinforced gaskets with red RTV.

[jharkin]

Next up, the pull start.

Raja explained how he did his removable pull start, so i set one up. It was actually quite simple so here are some photos.

What we do is remove the stock mounting screws, and in their place install 4mm studs and wrap those in fuel tubing. Then the pull start mounting holes are drilled out to fit.

For the studs, you can cut the heads off the stock screws if you want. I dediced to keep those instead so to make up some studs I went down to my local True Value hardware and bought four 4mm machine screws for $0.80. Then you screw them in just till they bottom out, and cut off the heads so they just taller than the pull start housing. You can use a dremel cutoff wheel, hack saw or even the bolt cutter on a combination wire stripping tool to do this. I rough cut them with a bolt cutter then used the dremel to get the exact height I wanted and round the heads.

Once set, take them out and liberally drench the threads with blue loctite, screw in and let dry overnight. It will set up nice and tight, but I still might put a dab of JB inside the housing to make sure they cant ever back out into the fan.

Now put a piece of fuel tubing on - leave it a bit long so you with will help the start center as you push it on. I have a big reel of Aerotrend from my nitro days so I used that.




Next step is to drill out the holes in the pullstart to fit over the tubing. Using Aerotrend standard silicone tubing, a 1/4 inch drill was a perfect fit. No filing was needed, but you will need to use a boty ream or Xacto to clean up the holes.

To finish up I make some pull loops with tie wraps and used more silicone tubing on it to make it easy on the fingers (a trick we used for strapping things down on airplanes)

[jharkin]

[Edit - I see this is all in the install sticky oh well ]

Next up I installed the MA air filter. Who doesn't like the look of a little K&N action
I had to tweak a couple things, read on...

First up, the mounting bolts. I took of the stock filter and installed the MA filter back plate and extra spacer, but when I threaded in the stock screws they bottomed out. Here we can see why - they are too long!



My guess is that the spacer thickness might have been figured for the stock or TRM carb stack and the Hanson is shorter. No problem, we just need to change the screws (stock = M5x60mm).

You could cut them, but I decided to look around. Looking in my parts bin I had some spare Desert Aircraft carb screws (red ones below). These are M5x55 long aluminum cap screws. They might work but are still a bit too long. Then I had an idea - the stock muffler screw is a M5x50 and I wont need it with the V2 pipe. Turns out those fit perfect without the extra spacer. Just added some M5 lock and flat washers from the hardware store for $0.40 and we are done.

I much prefer the SHCS over the Phillips head anyway, its easier to make sure I torque them both evenly (we had a lot of issues on DA carbs with leaks if the two screws where not torqued equal, it would deform the reed cage).

Another thought here - I'm not going to bother but for the guy who was trying to make his gasser ultra light, you can change out all the M5 screws other than the muffler for aluminum. DA uses them to hold all their engines together and seems to work fine.

[jharkin]

Now I mounted the filter and ran into another issue. When I screws on the cover, the filter element was a bit loose and could flop around. Again I doubt its MA's machining - probably just a loose tolerance on the filter element.

At first I thought of securing it with some RTV, but that would be a pain to service, so instead I just lightly filed down the studs till I got a nice tight fit. Use the cover plate to check that you are filing them flat. Also make sure to stuff a rag in the carb and clean up well!




All done and fits tight!

[jharkin]

Alright, test fit the muffler and clutch , install the heat deflector and we are already to mount it in the heli.

Nothing is loctighted yet, as I will take this all off and reinstall after its in the airframe.

[fastflyer20]

Looks like a clone of Raja's

I found the gray air deflectors don't stay in position well. You can drill two holes (opposite the screw but closer to the mouth) in the gray deflector and the black engine shroud and use a small zip tie to hold it together.

[jharkin]

Originally Posted by fastflyer20

Looks like a clone of Raja's

I wonder how that happened.... Now if only I could clone the thumbs driving the TX....

[rbort]

To answer some of your questions:

1) No, do not use the screw to plug in the center hole in the muffler, you will lose too much power - in fact I occasionally stick a hex driver in that hole to clear it and check that no carbon has formed in it as if it did and I just cleared it I can see an immediate power increase.

2) Tom and Jeremy, on the hostile deflector, as I told Jeremy, a bead of goop all the way around the edge of it will seal it to the engine shroud and seal up any leaks. No need for additional screws, just weight it down until the goop dries and it will be good to go.

3) on the muffler, install it with the gasket and red rtv on both sides. Just snug it until the rtv starts to squeeze out and leave to dry for an hour. Then come back and tighten up the muffler bolds then tighten up the side set screws (I use M3x6 bolts instead of setscrews) against the muffler screws and you're done. No need to retighten after heating up, I find that too much tightening or retightening squeezes the gasket to almost nothing and eventually it won't hold and leak.

4) on the pull start, put some CA on the threads of the studs and put the fuel tubing over them. I would use stronger tubing than the blue stuff, it probably won't hold up long to putting the starting on and off. Anyway you can try this blue stuff for now and see how it holds up. The CA keeps it there as otherwise it can slip off the threaded studs.

Looking good so far, and will be cool to see you maiden it in less than 6 weeks!

-=>Raja.

[jharkin]

... I was going to do the goop trick you suggested.

I tried the blue tubing since I have more of it than I will ever use. I can switch it for tygon if it doesn't hold up.

Thanks for the tips on the muffler. I like the idea of using an M3x6 cap screw, be easier to snug. Also thanks for clarifications on that reducer. If you never use it maybe just drill out the threads there so there isn't a rough surface for carbon to grab and you wont have to worry?

Question for you whenever - is this the glove Pete bought? I might have to get one since you are dragging me out in the cold he he.

[rbort]

Only thought I have is that it may have too much space in it or too much square footage to warm up and you'll need a more powerful heater to warm it up.

See how Pete does with it and/or get one if you think it will be OK.

Yeah drilling out the threads might not be a bad idea, some people do that to get some more power also but expect slightly more noise too.

-=>Raja.

[jharkin]

... I'll try out Pete's when I see you guys next week. then decide.


Counting the days till the kit arrives....

....

...

[jharkin]

Kit is here! So time to get started.

Im folowing the manual order. First up I cleaned all the bolts and hardware in alcolhol and started building the head.

I did run into a little trouble here in that the grips where VERY tight once I had it together, even greasing the feathering shaft and dampers. I talked to Raja and he suggested flipping the grips.. No joy.. So I sanded down the carbon spacers lightly till I got a nice perfect fit. I worked carefully, sanding both sides a little at a time equally and retest till the fit was perfect, took about 3 tries. I was careful to clean up the carbon dust, clean all the parts and re-lube with grease - dont want any carbon dust anywhere near the finished assembly!!

Now the fit is absolutely perfect they spin easily but not loose and zero slop.

I know current MA owners this already, but for a first time builder I'm amazed at the quality and tolerances on everything - nice job MA




Also built the links... My ball link tool doesnt fit so I ended up giving myself a blister cranking them on by hand but got it done.

[jharkin]

... go with that gorgeous custom stomp canopy, and got a custom pilot logo from B&E, same as I have on my gasser airplane.

Anyone needs a spare green canopy it will be up in the helifreak classifieds soon.

[jharkin]

... I got the tail built.

Things still moving smoothly. I thought I might get it balanced perfect just putting the heavier blade on the light side, but it did need one small piece of tape.




All set...

[jharkin]

Since it only adds ~ $15 to the build I figured why not add the carbon tail pushrod that Carey documented in his build. I use Central Hobbies carbon/TI push rods on the large planes and love them so it was a no brainer..

Parts you need from MA are the 0868-0 universal carbon tail rod kit and a pack of 0868-5 carbon tail rod guides. The kit doesn't include everything that Carey pictured, you need some small screws to mount the guides to the stock guides - I used some 2-56 cap screws and nylocks from my airplane parts bin. You also need the small reinforcement tube - K&S 7/32 brass works and I happened to have a piece of that in my bin as well.

Cut to length (Dremel works fine, OR wrap the tube in masking tape and work slow with a fine blade razor saw) and glue in the ends with JB weld. Learning from experience with the CH rods I tape down the ends and pin them to the board so nothing shifts while the JB cures overnight....




Meanwhile got the TT installed and test fit the tail gearbox.





Today its pouring rain, the kids are watching movies on Sprout and my wife has started the Turkey day baking marathon...

So its a build marathon for me . See how much we get done by dinner!

[jharkin]

Got the tank plumbed, frames built, and skids installed.




Since the Mrs has been baking pies all day Im on for dinner. Time to quick and cook up some homemade pizzas.

[jharkin]

Got the tank done. I did things just slightly different, used a fitting with a dip tube for the return so I can fuel and defuel from the same Tee (I do this on my gasser airplane with a 3 line tank, works perfect)... I can just see Raja now thinking "Hey your not going to be ale to run the last 1/4 ounce in that corner of the tank!"

he he just kidding ya Raja

Vent will just be the looped tubing.
I did have to ream out the big hole slightly to get the clunk to fit.
To seal the fittings I used red RTV... Thinking about it now I probably should have used ultra black - oh well if it leaks I will redo it.



Up on the skids with everything in. One other small issue I ran into, maybe this is known. When I was assembling the clutch bell, I thought the two set screw holes on the start adapter where the same, so I lined one up with the flat and it ended up so tight that trying to turn the pinion it was digging into the brass collar. I took it off and lined up the other setscrew with the flat and its a little less tight... but still tight. I guess it just has to break in?

[jharkin]

Ive been warned by Raja and others to be careful not to snap the crank bolt installing the clutch. I was thinking at first "why the heck did they use a soft grade 4.8 bolt, why not an 8.8 or 10.9?" But it occurs to me that Zenoah likely meant this to be a shear bolt and break off saving the crank in the event something seizes the drivetrain.

So I left it alone, but to make sure I wouldn't break it I went out to the garage to get the 1/4 drive torque wrench from my auto tool chest. I torqued it down to the manual spec which is around 40 in-lb. And since I had the wrench out I torqued the other motor mount bolts in a criss cross to make sure everything is perfectly even.




And here I ran into the only real hiccup in the build so far. My kit appears to be missing the one way bearing bracket. I'll just give MA a call on Friday, shouldn't be a big deal.

[jharkin]

... Ive seen them fly at the field many times, but I still get impressed at the size of this bird!