Hokusei Ultima EPP BX * * The most feral 3D EPP plane in its class * * NEW VIDEOS! - Page 4 - RC Groups
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Jan 29, 2010, 04:10 AM
Bush Flying Down Under
Aussie_Toyman's Avatar
I was going with the HTX900 Servo's, Turnigy 2213 1050kV Outrunner and a Rhino 1050mA 3S. Thats what I run on my EPP Extra and it pulls very well.

I have a few lighter Outrunners to try if this ends up a bit heavy.
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Jan 29, 2010, 04:49 AM
How many planes is too many?
groovejet's Avatar
That gear will be great. This plane is OK with some extra weight if that weight gives it more power . I've got a 62g motor in mine on 1050 lipos.

BTW since you're using the same servos as me, I'll list my recommended settings for a DX7 radio. It'll help to give you an idea of the deflections to go for if you want the highly dynamic nature you saw in the video.

Use the longest HXT900 servo arms, the ones that are non-symmetrical cross-shaped and have an extra hole on one of the 2 longer sides. Use the outer-most servo arm hole on all 4 servo arms. I always do this with these servos on any plane. I even cut the cross-shape servo arm with good scissors so that only the longest bit is left. That's just a cosmetic thing.

For the control horns, use the INNER hole on the ELEVATOR to maximise throw, use the OUTER hole on the RUDDER since you'll get full deflection anyway and I feel that tthe outer hole gives better geometry to help push the rudder to extremem angles. Use the INNER holes for the AILERONS.

Basically, use the inner (lower) hole on all control horns except the rudder.

These are the DX7 servo travel settings I use to get really great deflection of all control surfaces.

L: 120%
R: 120%

L: 125%
R: 135%

L: 110%
R: 140%

FLAP (i.e. my 2nd aileron servo):
L: 120%
R: 120%

Adjust as necessary, but as you can see I'm using more than 100% on every control surface. You could program something extreme like those settings and then use rates to tone it down while you get used to it. Hope that helps.
Jan 29, 2010, 07:33 AM
Registered User
Originally Posted by groovejet
4Dim, which planes have you bought after watching my videos? I suppose you could send your bills to me .
Got the Extra after I saw the movies. I cant imagine flying mine indoors. Send paypal payments to

Setting max travel (150%) on the radio is generally a good thing, especially with cheap servos. You can tune the actual travel on the control horns. I normally do that. Start with 150%, set the correct travel on the horns.
The HXT servos are quick, so the extra servo travel does not create significant delay. On the other hand, they have very poor precision, and this improves it a little bit (comparing to 100% on the radio and getting the same travel using the horns). The HXT500 are pretty weak, so this setup makes them work a lot better. 900 are much stronger, less of an issue there.
Jan 30, 2010, 06:07 AM
Bush Flying Down Under
Aussie_Toyman's Avatar
My Ultima arrived this afternoon (Saturday), I was more than a little surprised when the Aust. Post van stopped out the front.

It's about 50% complete as I stopped to go for a fly after dinner instead of building.

Thanks to Groovejet and NAC for all the helpful hints.
Jan 30, 2010, 06:50 AM
How many planes is too many?
groovejet's Avatar
Hey AT,

A very important tip if you're using a prop saver is to fibre tape the nose back at least an inch on the side of the fuselage. Check our recent photos or videos to see what nac and I have done. If you don't fibre tape it and you crash, the prop will chop up the nose and eventually you'll get tired or gluing it back together, so if you tape it now you'll save on glue weight.

Trust us; this plane encourages you to go feral and the nose will suffer .

Not sure which tips you've seen so far. The other mods I reported earlier on this thread that I did are worthwhile too. BTW the landing gear legs are very flimsy, even if you cross-brace them as I have done. Nac and I just hand launch and harrier land or hover catch.

Oh, and don't try to put the velcro directly onto the EPP. Use Scotch 6225n or UHU to give the velcro something to adhere to since the EPP isn't tacky enough on its own.
Jan 30, 2010, 07:19 AM
How many planes is too many?
groovejet's Avatar

New Video: Full Flight With No Edits

OK guys,

I've decided to be brave (actually I'm being lazy) and post the footage from the 2nd flight on Australia Day as a complete and uncut video. What you see here is the complete video file from start to end, as recorded by nac.

The good news is that you get to see the plane in action without any of the usual cuts that show just highlights. The bad news is that it's more than 5 minutes long and you may wish it only contained highlights .

There are no crashes here; just 5 minutes of intense flying of my favourite plane in ideal conditions (weather and pilot). I hope you guys enjoy it, don't hate the music too much, and that at least one of you makes it through the whole video without skipping ahead (or quitting) .

nac; I'm not sure why the takeoff wasn't captured; were you taking a nap?

As before, click on the vimeo dot com link to see the file at a higher resolution, with the option to watch it full screen as well.

Jan 30, 2010, 05:52 PM
Registered User
Great video. Now I understand what you mean by feral.
Feb 01, 2010, 01:52 AM
Look outside the Square
Boxhead's Avatar
Yipppeeeeee... mine arrived today . Seems us poor cousins up here on the Central Coast dont have an in like Aussie Toyman with Aust Post getting his Ultima personally delivered on a Saturday . Lucky Bugger AT. Must be a different Union up here. Have just ordered some motors like Nac is using, so it may be a week before mine is up in the air. really looking forward to it.

Feb 01, 2010, 03:55 AM
Registered User
nac's Avatar
Good news.

If you have any questions during the build don't hesitate asking

Hopefully we have posted enough info to make the build an easy one.
Feb 01, 2010, 05:46 AM
Bush Flying Down Under
Aussie_Toyman's Avatar
Still building mine . I've been a bit busy and not had much chance to work on it.

Wings and Tail installed, all the control surfaces hinged, just adding the Servo's now.

I had to Dremel the wood brackets to fit the HTX900's which was a bit of a pain.
Feb 01, 2010, 06:27 AM
Registered User
nac's Avatar
I didn't use the wood bits on my last build instead I used pieces of old plastic cards.

Might be worth looking at the build posts for the Primus BX as the build process is the same. You may pick up a few ideas.
Feb 02, 2010, 05:18 AM
Bush Flying Down Under
Aussie_Toyman's Avatar
One step forward, one step back..... I drilled holes for the Servo mounting screws and when I screwed in the screws the wood split.

I've carefully cut all the wood off and now going for the 'nac patented' plastic mounts .

Thanks nac.
Feb 02, 2010, 06:11 AM
How many planes is too many?
groovejet's Avatar
Bummer AT . I've had that happen but I usually just CA the broken bits together and it holds up fine.

I think that the wood has split when I've drilled a 1mm hole instead of a 1.5mm hole. I'm pretty sure that a 1.5mm hole is the ideal size for HXT900 servo screws. What size did you drill?

BTW I'm currently building my Primus BX and will soon be resizing my wood servo frames to fit HXT900 servos. The way I usually do it is to sit the servo frame flat on a hard surface and use a hobby city xacto style knife to split the wood down the grain so it's close to the right size, then I use the blade like a wood plane and slice really thin bits off until the servo fits in. This is a rather quick way to adjust their size, but I wish it wasn't required at all. I still prefer building Hokusei kits to any other foamy brand though because of well-thought out design features like a fully assembled main wing with embedded carbon fibre (I hate having to slice the wing on other brands to add CF rods myself), the hinges being in the middle of the control surfaces which give fantastic deflection on standard servo arms (on some other brands I need custom longer servo arms and still can't get the same deflection as on a typical Hokusei kit) and the pushrods are great, pre z-bent at both ends and easy to adjust to length without needing ez connectors or having to bend them myself. I also like the control horns that Hokusei use; very easy to install and really durable. I've never had one pull out; unlike on other brands.
Last edited by groovejet; Feb 02, 2010 at 06:20 AM.
Feb 02, 2010, 06:15 AM
Bush Flying Down Under
Aussie_Toyman's Avatar
I'm pretty sure it was 1mm, but it doesn't matter now, plastic brackets manufactured .
Feb 02, 2010, 06:25 AM
How many planes is too many?
groovejet's Avatar
I figured it'd be the "1mm trap" . I fell for it on my first kit and then at one point when I hadn't built a Hokusei kit for a few months I fell for it again.

Hopefully this info will help someone at some later stage:

If using HXT900 servos, drill a 1.5mm hole for the servo attachment screws and optionally put a drop of thin CA into each hole to strengthen the wood and better yet, thread the screw in, remove it and then put the CA in the hole to strengthen the thread. Don't be too concerned about this, as I've fixed a stripped thread by filling the hole with medium CA and screwing into that. One one occasion when that didn't work I just put a blob of hot glue over the end of the servo that was a little loose.

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