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Tony Nijhuis' new Vulcan


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The 2S setup is very tempting, as it looks like I can get more total mAh, and I've got more latitude for adjusting the c.of g., but I think I'll stick with 4S. In this picture the 2S mock-up is hard against the leading edge, but there's plenty of scope to move it backwards. I'm going to keep my motors paired as inners and outers.

20200509_143505.jpg

Here's a 4S 2900mAh hard up against the front spars. Obviously it's too thick to go between the spars like the 2S pack does, and it's too thick to move any further backwards because the wing thickness diminishes towards the trailing edge.

20200509_143524.jpg

Hopefully with a bit more web browsing I'll be able to find a 4S pack which makes a bit more use of the available space.

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  • 1 month later...

Plodding along. I've gone for your electrical layout Martin, as it seems to reduce the wiring a little. And I've now got a couple of Overlander 4S 3350mAh packs that fit comfortably in the battery bays. I'm at the final shaping/filling/sanding stage at the moment prior to glassing, and I'm pleased that it's at around 3lb 8oz at the moment without vertical stabiliser or wing servos fitted, but with motors, ESCs, cabling for all servos, and retracts.

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Just had a peek at mine and those would fit maybe, but £48! they also do a 3s at 17mm deep for £37. Probably not too different to the Zippy 3300`s I have already and may think about getting some FMS or PowerFun fans, but there again my Concorde may not work out on its maiden so I would have those bits to hand.

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Yes, they're a bit pricey. But all the HK ones I looked at were, energy for energy, thicker than the Overlander ones. They also do a 3700mAh pack which will just squeeze between the front spars -- in fact it's £1 cheaper, but lower C rating. I'm also making a fibreglass replacement for TN's plastic belly pan, which will (a) be wide enough to reach the sides of the motor bay, (b) align better with the thrust tubes at the rear of the bay, and (c) hopefully save a couple of grammes.

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  • 3 months later...

Things have been on hold for a while as I've been sorting out a heli for which I'd updated the receiver's firmware and the flight controller's firmware at the same time -- not to be recommended!

Anyway, the Vulcan is almost ready for paint topcoat, and today I've been installing the elevons. I haven't yet applied cyano to the hinges, and they seem to work fine at the moment, but I'm a little bit concerned that the pin-and-socket joining them will cause them to bind when I eliminate the play in the hinges by gluing them, because of the different centres of rotation of the two parts. Tony Nijhuis in his notes says this is not a problem in practice, but it seems to me it shouldn't work unless the socket is made into a slot.

I remember reading in this thread that some builders installed two separate servos for the elevon halves, but has anyone who did it with single servos as per plan have any problems with binding? I'm at 4lbs 6oz at the moment, so I don't really want to add the weight of two extra servos.

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Hello Alan,

funny enough I was just talking about the pin arrangement with a club mate when I had mine out the other week.

i went the single servo route as per plan with the pin.

your right, it looks like it shouldn’t work, but it does. I think because Elevens don’t need yards of movement you can get away with it.

on mine I did use some interference fit carbon tube within the control surface (before I closed it off with sheeting) to act as a Bush to prevent the pin eventually wearing a hole if just Inserted through the rib.

im not sure if that’s necessary /Over engineered but I felt happier for it.

Craig

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I don’t have any pictures of the pin installation. But if you look at the covered control surfaces in this pic I have them hinged “dry” including the pin.

That is how mine looked with the surfaces in the max down position (but you want need that much movement when you set your servo up)

they still worked equally as fine once I’d finished covering the whole model and glued them in properly.

image.jpeg


image.jpeg

 

 

Edited By Craig Carr on 04/10/2020 22:23:52

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Hello Allan,

yes absolutely, “no slop”. It’s a while since I looked at the plans but if I recall correctly He shows one side glued into some snake outer and the other side just pushed through the rib of the next control surface?

so the bit that was just pushed through the rib I added some “slop free” tube glued to the floor of the control surface. But I didn’t glue the pin inside the tube/Bush (just glued it into the snake outer side)

craig

Edited By Craig Carr on 05/10/2020 09:35:16

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Tony did the same thing on his Concorde wing. This is an extract from the Concorde plan.

The bit I’ve circled in red is where I added some tube to hold the pin and stop it wearing a hole in the rib. But like I say I didn’t glue the pin into this tube.  I thought it best to still allow it to be able to rotate nice and freely.

198f9ddd-5b44-4c7c-a2d1-f96232c6070d.jpeg

Edited By Craig Carr on 05/10/2020 09:43:31

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Hi Allan

I’ve built 3 Vulcans and on the first two I did the same as you have done, although I glued both the pin in the elevon and a slightly flattened piece of brass tube in the slave surface without any problem of restricted movement and the system worked well.

As for the third that’s another story. I’ve used servos on each surface to operate independently, the inners as elevators and the outers as ailerons. The gear is removed and replaced by the packs, 2 x 3300 3S Zippy compacts in parallel. The motors have been upgraded and I have fitted a launching hook to the centre spine for bungee launching as I can only fly off grass now. Control authority is better although it does need rudder used with ailerons. Although un Vulcan like it also allows me to use crow braking for landing as otherwise it does float for a long way.

Hope you enjoy the flying with yours.

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Thanks for all the replies. Your comment about flattened brass tube is interesting for that's an easy way to allow the pin to slide as the two elevon parts move, and would achieve what I think is necessary for correct geometry. Even though many have confirmed that the designed system works okay, I think I'll see if I can find a suitable piece of over-sized tubing which I can flatten to form a slot. If nothing else, it's got to reduce the pressure on the servos.

I originally looked at snake tubing, but its outer diameter was greater than the thickness of the trailing edge of the elevon, which is why I went for brass.

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This afternoon I found a piece of 3mm i.d. aluminium tube which, when flattened carefully, gave me a slot 4mm long. Gluing it into the inboard elevon in place of the snug-fit tube has made a world of difference. Whereas yesterday, it was obvious there was some stiffness in the system, even with the hinges unglued, today with the hinges now glued the complete elevon is completely free to move, and it can be seen that the pin is moving at least 2mm back and forth in the slot.

In my opinion it's a mod that's well worth doing.

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  • 4 months later...

I dont have a youtube account but just thought id try out the functionality of the new forum to post videos direct. I think ive done this correctly.  Here is my Vulcan from last year.  Apologies footage not great just from my mates phone.

Edited by Chris Bott - Moderator
change video to mp4 version
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Hello Allan,

it’s a 3s set up but I used the 50mm dr mad thrust fans from hobby king (no longer available) but  upped the blade count to 12 (or 11 can’t recall) blades.   If I were to make the model again I reckon 4s is a better option.

GG, I tried embedding the video as an experiment of the new forum functionality, sounds like it worked ok for Allan.  I’m not sure why you should get that ?  
 

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5 hours ago, Allan Bennett said:

Looks good Craig.  I haven't got round to flying mine yet due to restrictions.  Just out of interest, what power and thrust did you record?

Allan, just a thought, the FMS units Tony recommends for his concorde would be a perfect match for this model

See here

Edited by Craig Carr
edit for typo
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On 2/12/2021 at 2:51 AM, Allan Bennett said:

Looks good Craig.  I haven't got round to flying mine yet due to restrictions.  Just out of interest, what power and thrust did you record?

Hi Allan,  I had a hunt around and found this picture of my watt meter on a ground run.  This was the reading from just a pair of fans though, so double up say a 1000 watt

1B5473AF-3BE8-4FEA-AA6B-985E7B963408.thumb.jpeg.bfa983fa7fcb5248b7f11cef4f0fed5f.jpeg

 

Edited by Craig Carr
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  • 2 years later...
On 13/02/2020 at 10:53, Murray Hackney 1 said:

Can I refer you way back to my post of 12.06.15. We have an extremely bumpy grass strip, and my Vulcan still flies well to this day off my lightweight trolley. Maybe I was lucky, but I have not changed anything since my original modified specification. Hope this helps!

 

I'm finishing off a repair (rebuild!) after my attempt to fly off our grass strip, and wonder if you could give some details of your lightweight trolley please, Murray.

 

Also, I'm sure I read of someone installing cheat-holes to increase the thrust, but I can't find the thread.  Can anyone point me to details please?

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