E=MC3

[Jeff Hughes]

That sounds like a lot of work! Glad it flies good. Is Dick still 
selling pattern kits?


> Hi Jeff,
> 
> The E=MC3 is an E=MC2 with a bunch of modifications that I decided 
to 
> implement to try to improve the baseline design.  I flew a used 
E=MC2 
> for several years that I had purchased from Kirk Sutherland in 
> Tennessee.  It exhibited a number of good-to-excellent flying 
> qualities, but like most airplanes there was still room for 
> improvement.  Also, I was wanting an airplane that was reminiscent 
of 
> the classic Pylon Racer designs such as the Cosmic Wind as I think 
> it's distinctive and presents well, both on the ground, and in the 
> air.  Here's the construction mod's:
> 
> 1)  Raise the wing 2".  No, that's NOT a typo.  2".  During 
> construction I also had the wing moved forward 3/4" (bad idea), but 
> it came out nose heavy so I had it moved back 1-1/8" from there to 
> get it to balance properly.  My recommendation is if you're using a 
> 4-stroke, don't move the wing either fore or aft from stock.  If 
> you're running a 2-stroke motor like I am (especially if you tend to 
> build a bit heavy) you may want to consider moving the wing aft 1/2" 
> from the location shown on the plans.  The wing dihedral was left at 
> the stock amount.  The next one I build will have the geometric 
> dihedral reduced by 1/3 to attempt to eliminate the small amount of 
> residual proverse roll coupling.
> 
> 2)  3-1/2 degrees right thrust, 1/2 degree down thrust (I believe 
the 
> stock E=MC2 design is 0-0).
> 
> 3)  Replacement of the stock pipe channel with a custom one 
> fabricated from carbon fiber that allows the ES pipe to be 
completely 
> flush mounted.  The channel is extremely long, extending aft ~42" 
> from the glow plug, allowing for unobstructed experimentation of 
> tuned pipe system(s) set to almost any length.  I've given some 
> thought to offering the pipe channel for sale in limited quantities 
> as it can likely be used on a number of planes other than the 
E=MC2/3 
> (for those that are interested, please send me an eMail and let me 
> know.  If these is enough interest shown I may go ahead and have 
some 
> fabricated).
> 
> 4)  Small cheek cowlings that while functional, are largely cosmetic 
in nature.
> 
> 5)  I had the ailerons and elevator halves fabricated so that they 
> didn't fully extend out to the wing/stab tips.  While counter to the 
> current trend, I like being able to visually check whether a warp 
has 
> crept into a flight control surface.
> 
> 6)  Since the wing was raised and the pipe tunnel deepened, I was 
> able to use a one-piece Chris Dalby carbon fiber landing gear 
> (available from RC Model Enterprises, 
> http://home.att.net/~rc-enterprises/rcme_017.htm) mounted external 
to 
> the main fuselage.  It's much thinner and lighter than the two piece 
> carbon fiber gear, and also has a torsion effect in that it "gives" 
> in the fore and aft direction similar to the way wing-mounted wire 
> landing gear relieve under loading.
> 
> Did the mods work?  I think so based on my own observations and also 
> the comments I've gotten from those who have flown it:
> 
> Tony Frackowiak - "easily the best pattern airplane I've ever flown"
> Greg Frohreich - "you've fixed everything that was wrong with the 
> E=MC2 design and made it a competitive airplane again", "it flies 
> just like my Smaragd"
> Troy Newman - "this is by far the best E=MC I've ever flown"
> Frank Kelley - "this flies exactly like my HydeOut/Away
> 
> There's a link to some photo's of the E=MC3 on my website:
> 
> http://www.buddengineering.com/Merchant2/merchant.mvc?
Screen=CTGY&Category_Code=E
> 
> 
> Thx, Jerry
> 
> 
> >Jerry,
> >I've seen a couple of references now to the emc3. I assume its a 
variation
> >of Dick Hansons' emc2? What is the difference?
> >Jeff
> >
> >
> >
> >----- Original Message -----
> >From: Jerry Budd <>
> >To: <discussion at nsrca.org>; <pattern at rcmailinglists.com>
> >Sent: Sunday, March 30, 2003 2:17 PM
> >Subject: Re: [Pattern] 3M-140 For Sale
> >
> >
> >>  >Hey Jerry,
> >>  >    which engine do you prefer: the OS1.40RX or the Webra 1.45? 
Why?
> >>  >    Thanks,
> >>  >      Will B.
> >>
> >>  Hi Will,
> >>
> >>  I like the Webra a bit better than the OS but they both have 
their
> >>  merits.  I'm running them interchangeably in the same airplane
> >  > (E=MC3) on Magnum #1, OS-F or YS plug, ES-2C140L90 pipe set at
> >>  23-1/4" baffle to plug, stock Mac's 2-1/4" rise header, and an 
APC
> >>  17x12 prop.  Here's the differences:
> >>
> >>  Webra:  8200-8300 rpm with the Webra MC (mixture control) carb 
gives
> >>  a dead linear throttle response with NO jump onto the pipe.  
Setup
> >>  this way the motor performs and throttles exactly the same as a 
DZ.
> >>  With the stock ProMix carb it throttles a lot like the OS (see
> >>  below).  This is with a relatively new, low time motor (~20 
flights).
> >>
> >>  OS: 8300-8400 rpm with the stock OS carb, slight burble at mid-
range
> >>  transition, moderate jump onto the pipe around half throttle.  
The
> >>  motor goes slightly lean momentarily during inverted pushes 
during
> >>  the second half of the 20 oz tank.  My first OS in the same 
airplane
> >>  exhibited the same characteristic.  This is a motor with around 
30
> >>  flights on it.
> >>
> >>  The OS carb has a somewhat bigger throat than the Webra carb 
which
> >>  probably explains the power difference, but may also cause the
> >>  throttle linearity/burble/momentary lean discrepancy.  The OS 
also
> >>  seems to have significantly more bearing problems, although that
> >>  seems to be corrosion related and managed by switching to 
stainless
> >>  steel bearings.
> >>
> >>  I think the 3M-140 motor is comparable to an average OS in 
power, but
> >>  it throttles much better in the mid-range.  It would make an
> >>  excellent motor for a 9.75-10.5 lb mid-body airplace such as a 
Focus,
> >>  Temptation, HydeAway, Angel's Shadow, etc.
> >>
> >>  Thx, Jerry
> >>  --
> >>  ___________
> >>  Jerry Budd
> >>  mailto:jbudd at qnet.com
> >>  =====================================
> >>  # To be removed from this list, send a message to
> >  > # discussion-request at nsrca.org
> >>  # and put leave discussion on the first line of the body.
> >>  #
> >>
> >>
> 
> 
> -- 
> ___________
> Jerry Budd
> mailto:jbudd at qnet.com
> =====================================
> # To be removed from this list, send a message to 
> # discussion-request at nsrca.org
> # and put leave discussion on the first line of the body.
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> 
> 

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