Exian's composite planes

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Jsample40

Active Member
Joined
Jan 18, 2020
Messages
44
Location
Western North Carolina
Look into the Twin Power series of Lithium Iron Phosphate light weight batterys.... I went from standard motorcycle batterys (lead acid) to Absorbent Glass Matt (AGM) to the Twin Power version of Lipo batterys after repeated battery failures in short lifespan issues.
Very pleased in the reserve power, starting power, ability to hold charge, and rapid charge.
 

Jsample40

Active Member
Joined
Jan 18, 2020
Messages
44
Location
Western North Carolina
None of the above .... sorry... nor do I have any of these specialized low weight/ high power batteries for sale... Just another fellow passing on some of my actual empirical / experience based knowledge learned the hard way (ie: trial & error...LOL).
JWS
 

howardyin

Member
Joined
May 23, 2020
Messages
18
I will talk about my composite planes in this dedicated thread.

First project : EXIA, completed and flying well for almost 2 years (70h)
- single seat, under french UL regulation
- wing span 8,2 m
- lenght 5,15 m
- empty weight 130 kg
- MTOW 210 kg
- engine AIXRO XF 40, wankel type, 35hp, consumption 9l/h at 70% power
- tanks in the wings 36l total (wet wings)
- glass sandwich skins with some carbon parts (spars), made in typical composite molds
- special equipements : ballistic parachute (GRS)

Current performance (to be improved with adapted prop that I built but cannot test due to flight bans with COVID19 in France...) :
- Stall speed 65km/h (tested)
- Cruise 180 km/h (real, tested in long cross country flights)
- Top speed 205 km/h

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👍👍fatanstic
 

wanttobuild

Well-Known Member
Joined
Jun 13, 2015
Messages
744
Location
kuttawa, ky
Thanks for the very helpful information, Exian.

Regarding:

For their three VW derived engines, they give the following specs (all at 8:1 compression ratio)
1600cc: 60 hp (continuous) at 3200 rpm
1914cc: 75 hp (continuous) at 3100 rpm
2275cc: 90 hp (continuous) at 3000 rpm

With or without fuel injection, these power outputs for a VW engine (2 valve pushrod) of the displacements shown are "incredible" (literally-- not credible). They are at least 10% higher than people actually get with these engines, especially at those (relatively low) RPMs. If they used the same "helpful" dyno to get the advertised power output for their V-2 engines, well, there could be some disappointment.
Just my opinion.
Maybe you should read on the same website about how that power is attained. The CAMSHAFT. The info is there, just read it.
 

Vigilant1

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Joined
Jan 24, 2011
Messages
5,861
Location
US
Maybe you should read on the same website about how that power is attained. The CAMSHAFT. The info is there, just read it.
Maybe you can be a little less snarky, or maybe you can tell me how the camshaft cools those heads. I missed that part.
It is no trick to make the HP they claim for a short time. Street racers do it with RPM, CR, tailoring the camshaft, etc. It is another thing to make that HP continuously (as they claim) and have the engine provide reliable service in an aircraft. In the case of the VW Type 1, the limits are already well understood, and no magic cam will change them.
Looking forward to the flight reports.
 
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wanttobuild

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Joined
Jun 13, 2015
Messages
744
Location
kuttawa, ky
Cooling VW heads has long ago be solved. If your little Sonex gets hot, thats on you. Your continual rejection of the various solutions, well that speaks volumes, so continue to fly with a hot engine, I would suggest keeping the airport close by.
I have a notion that this cam might be of interest to some of the 1/2 VW guys.
 

Vigilant1

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Joined
Jan 24, 2011
Messages
5,861
Location
US
Cooling VW heads has long ago be solved.
Absolutely correct, we agree. Solved long ago. Proper baffling (according to conditions) and a respect for the limitations of the VW Type 1 head's ability to reject heat are the biggest factors that we've found to be critical.
If there is an example of anyone actually flying a Type 1 and getting 90 HP continuous (as Vaxell claims theirs can do) for more than a couple of hundred hours between overhauls, the whole world would be interested. Decades of experience with direct drive and PSRU Type 1 engines indicate otherwise. I'm not talking about sales literature or a "helpful" dynamometer report, but real-world flying.
Their "incredible"claims and inconsistent graph-vs-text specs for the VW-based engines casts doubt on their claims for their V-twins (why it was mentioned in this thread). Let's see them actually fly and produce those numbers.
 
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kubark42

Well-Known Member
Joined
Oct 19, 2020
Messages
90
(@Exian, pinging you here because I believe you have turned off your DMs.) Several of us here and from all around (RAS, Grasshopper, French DuckHawk e-conversion, etc...) have a Slack group for real-time discussion of eGliders. We're all moving in the same direction and it's been very helpful to swap experience and knowledge, esp. vis-a-vis vendors and other COTS parts. If you'd like to join, DM me I will send you an invite.
 

TLAR

Well-Known Member
Joined
Sep 29, 2020
Messages
218
I glue a piece of rounded Aluminium at the end of the carbon tube
Then I do manual winding of carbon roving around it : longitudinaly, and circularly to compact and hold together the firts layers.
The part with the pikes it a tooling that enables me to attach the longitudinal roving.
Of course I lay a thin layer of glass over the aluminium before doing the winding.

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Building notes, in french with horrible wrinting...
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Of course this takes longer than making the classic riveted end with a lathe, but I don't like the idea of the concentrated load of the rivets in the carbon tube.

Here the rovings transfer the load to the tube in shear on a broad area.
Exian
The push pull tubes are beautiful, well executed.
 
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