Magnus Build thread - TJIRC

[Konrad]

X20s I assume it is running Ethos. If so I strongly recommend you look at the glider temples By Mike Shellim at RC-Soar @RC-Soar Mike has done all the hard programing and given us a lot of features.

I strongly recommed going with switchless crow.

…

I know most use throttle/sliders etc. but I fly others and need the throttle and don't want this to mess me up.. Who fly's with their aileron controls reversed anyhow? (Raises hand) lol




Thanks everyone for all the help

~ Steve

You lost me here. “but I fly others and need the throttle and don't want this to mess me up.”

This leads me to think you don’t yet understand crow. Crow works just like a throttle (thrust device). In crow you are controlling the drag side of the lift equation directly. With your glider when you want to land or slow down one lowers the “throttle stick”, just like flat land powered planes. Now if landing short you move the “throttle stick” up to extend the glide path, again just like flat land powered planes. So from a muscle memory perspective crow is just like a throttle. Per the lift equation diagram this is easy to see, as thrust and drag are the opposite forces.

 

[Pricemo]

X20s I assume it is running Ethos. If so I strongly recommend you look at the glider temples By Mike Shellim at RC-Soar @RC-Soar Mike has done all the hard programing and given us a lot of features.

I strongly recommed going with switchless crow.

You lost me here. “but I fly others and need the throttle and don't want this to mess me up.”

This leads me to think you don’t yet understand crow. Crow works just like a throttle (thrust device). In crow you are controlling the drag side of the lift equation directly. With your glider when you want to land or slow down one lowers the “throttle stick”, just like flat land powered planes. Now if landing short you move the “throttle stick” up to extend the glide path, again just like flat land powered planes. So from a muscle memory perspective crow is just like a throttle. Per the lift equation diagram this is easy to see, as thrust and drag are the opposite forces.

Wow!!

Thank you Konrad, that's a perfect perspective I needed to see/read.. Makes perfect sense.. Honestly I would rather not to use a switch..

Also, thank you for the link for the templates, I'll have to check them out..

Ill get it set up tomorrow and like this new perspective!

 

[2MUCH2DO]

Got myself an 8mm x 20mm brass rod and made a ballast set. Now that I have it, I'll never want it, but that's probably better than the other way around. Can add 8.6oz, only moves the cg forward a max of 0.6mm, thats a pretty well placed ballast tube in that wing! Wish all designers could figure that one out.

 

[Konrad]

Source for the brass bars?

 

[2MUCH2DO]

this was the best deal I found easily, and way cheaper than mcmaster with the shipping ;-)

1pcs Brass Metal Flat Bar 8mm x 20mm x 500mm #EE-Ai GY | eBay

Find many great new & used options and get the best deals for 1pcs Brass Metal Flat Bar 8mm x 20mm x 500mm #EE-Ai GY at the best online prices at eBay! Free shipping for many products!

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Sadly these bars were about 0.1mm big in dimensions, and the tubes may have been similarly small, so I used a mill to take 0.5mm off width and height. sanding would have done it as well, but mill made it easy.

 

[Wayne]

When it rains it pours.. New speed records that is. Well done Steve!

Do I dare say that this is the fastest 60" with a 2 piece wing? I'm honestly amazed it can go this fast.

Makes me wonder what the Tracer might be able to handle. What do you think, should we get a Tracer over to Bruce to find out?

 

[Diceman]

I knew the Magnus was a solid frame.

 

[JJ Colorado]

Just comp;leted my Magnus. 1050g (37oz) with the CG set at 80mm. With the test flight nose weights removed the CG is at 89mm so I've got reasonable range to work with. HS08s for flaps, A08s ailerons, 6100 for elevator. Now just need a windy day from a good direction for a test flight. BTW flaps operate to 70-80 degrees so it should slow down nicely when needed.

Will wait for a better weather day to take an outside pic. And there are plenty of Magnus pics out there already. I did decide to upgrade hardware to the Tomas Liu links. A bit larger, but I like the 1.8mm pin connections and the stainless 3mm rods.

 

[Wayne]

No photo - must no exist.

Congrats!!

 

[JJ Colorado]

OK. Magnus keeping warm in front of the fireplace.
Five to ten inches of snow predicted for this weekend.
It's 23 degrees and snowing outside now.

 

[Wayne]

It looks warm and comfy. Linkages look like nice little jewels.

 

[TyFlies]

Hey JJ. I’ve started a Magnus build too. Bought it a few months ago. Most of my builds are done on a card table in the living room that my wife tolerates. A couple of hours in the evenings. Most of the dremmel grinding or dirty work is done in the garage.
Pic from a few days ago. Wing servos are in and linkages are in place.
They’re gonna fly great.

 

[JJ Colorado]

Yellow!!! How we gonna tell them apart in the air over Wilson?

Hmmm. Lets coordinate before doing anything to help differentiate them. Otherwise it could be interesting for the callers at the far pole.

But they should be a lot of fun.

 

[JJ Colorado]

Ty, Not sure if you installed your elevator servo yet but I found that an MKS 6100 is shorter than KSTs. By using a 6100 for elevator with a Z bend the pushrod runs free and clear to the elevator control horn without rubbing on the wing joiner.

Looking forward to some strong winds at Wilson next year.

Might fly the Forza for Open class racing, but I think the Magnus might navigate the turns a little better. Hmmm.

 

[bubbasks]

Hey JJ. I’ve started a Magnus build too. Bought it a few months ago. Most of my builds are done on a card table in the living room that my wife tolerates. A couple of hours in the evenings. Most of the dremmel grinding or dirty work is done in the garage.
Pic from a few days ago. Wing servos are in and linkages are in place.
They’re gonna fly great.

Thats an upgrade from what I built mine on! Trusty CA stained ottoman in the living room. Everything from EF to Skymaster and BVM built on it. You're gonna love it when it's done.

 

[TyFlies]

i went this route with the servo push-rod to lower it and clear the wing joiner... JB Welded a piece of 2-56 threaded rod inside the carbon pushrod, then stepped another threaded rod down about a quarter of an inch. The two threaded rods are well secured to each other. More JB Weld. Seems plenty solid. The white is heat shrink tubing to try and pretty it up a bit.

Yeah, JJ you probably have something bigger and faster to fly in the open race. Or I by chance we both fly a Magnus in a man on man heat, you’ll just need to race inverted so it’s clear who’s who : )

 

[bubbasks]

The kst ms320 put the rod right into the joiner as well, i inverted my servo and made mounting rails for the plate for service.

 

[bubbasks]

Balance method worked out well too. #8 shot with epoxy

 

[JJ Colorado]

i went this route with the servo push-rod to lower it and clear the wing joiner... JB Welded a piece of 2-56 threaded rod inside the carbon pushrod, then stepped another threaded rod down about a quarter of an inch. The two threaded rods are well secured to each other. More JB Weld. Seems plenty solid. The white is heat shrink tubing to try and pretty it up a bit.

Yeah, JJ you probably have something bigger and faster to fly in the open race. Or I by chance we both fly a Magnus in a man on man heat, you’ll just need to race inverted so it’s clear who’s who : )

That pushrod configuration should work well.

I might be flying the Forza in Open, but this year I noticed a lot of "intimidation" style flying in some heats. In those cases it is better to fly a smaller, more nimble plane so the Magnus could have a tactical advantage.

Perhaps I should set up an inverted flight mode, just in case.

 

[Wayne]

I have had to do inverted elevator servos on a number of planes. Seems odd, but works just fine.