By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Tony Nijhuis Hawk - Build Log

All Topics | Latest Posts

Search for:  in Thread Title in  
Geoff Gardiner09/04/2020 14:31:29
avatar
534 forum posts
912 photos

I am just starting my build of Tony's 50 inch Hawk.

I have been collecting parts since the plan was featured in the magazine.

Thanks to Mark Elen, for selling me some of his unwanted bits, I have a choice of an 8s power setup or a 10s version. We will see how the weight goes before deciding.

First job is to trace all the parts from the plan in Inkscape and then begin cutting with the dremel for the ply bits and laser for the balsa bits.

img_0861.jpg

img_0862.jpg

img_0866.jpg

More later...

Mark Elen10/04/2020 11:55:54
522 forum posts
1021 photos

Hi Geoff,

I’m looking forward to watching this progress.

Cheers

Mark

Martin McIntosh10/04/2020 19:08:08
avatar
3332 forum posts
1178 photos

Get rid of as much ply as you possibly can at this stage. Many parts can have lightening holes made or dispensed with altogether and substituted with something lighter. I speak from experience! Good luck with it.

Geoff Gardiner11/04/2020 00:00:20
avatar
534 forum posts
912 photos

Martin, Drat..... Just spent the day gluing on the ply doublers to the fuselage sides.

img_0869.jpg

img_0870.jpg

img_0871.jpg

img_0874.jpg

img_0878.jpg

More later...

Geoff Gardiner11/04/2020 19:45:44
avatar
534 forum posts
912 photos

It's lovely weather for building out in the garden at the moment.

Bit more done today.

I have made the aperture in F3 a bit wider so as to fit two 5s Graphene batteries in, if I go down that route.

This means the battery tray is a bit wider but I have added some holes to take out a bit of weight.

img_0882.jpg

img_0883.jpg

img_0884.jpg

More later...

Craig Horsley13/04/2020 19:43:45
1 forum posts

I just subscribed to this website just for the purposes of following this thread, been considering this build myself but heard mixed reviews about the flying characteristics so looking forward to hearing your results.

Geoff Gardiner14/04/2020 10:55:41
avatar
534 forum posts
912 photos

Hi Craig,

Welcome aboard.

I fly off a grass strip and may have problems with the small scale wheels - but couldn't resist building one!

Ray Wood 414/04/2020 15:10:57
avatar
207 forum posts
44 photos

Hi Geoff,

I'm also watching with interest, I have all the bits for Tony's smaller version of the Hawk 😀

Regards Ray

Piers Bowlan15/04/2020 10:54:33
avatar
2123 forum posts
53 photos

I was sorely tempted to build one of these when the plan was published in the 2017 Autumn Special. I have a 90mm Lander fan for 6s so I thought by eliminating all the liteply/ply, adding lots of holes and doing away with the landing gear it might actually fly (after launching it with a catapult). I think weight is the No.1 enemy with this model as Tony's prototype on 8s had a wing loading of 43oz/squ/in. which, for a dyed in the wool gilder guilder like me is scary territory! Something I did consider was using a semi-symmetrical aerofoil section which might provide more lift at a slower speed. Another deviation from the plan I thought of, was enlarging the intake area and belly cheater hole to help the fan to 'breathe'.

I might well build one at some stage in the future as it is an impressive model but in the meantime I will be following this thread with interest - and taking notes!

Martin McIntosh15/04/2020 11:16:01
avatar
3332 forum posts
1178 photos

Hi Piers,

You have probably seen my blog on my 54" version which I built not knowing that TN was in the process of doing a 50" one. Even with a 12 blade 10s fan there was very little thrust but I had omitted the cheat hole, now done at 3x4" but when testing, a connector got sucked into the fan and blew it up. Awaiting a replacement impeller which I hope will fit.

As advised above, shed as much ply and other weighty parts as possible.

My YEP 120A esc and Rx etc are unavoidably blocking the airflow quite a bit but since it is the same as TN does it is obviously OK.

Piers Bowlan18/04/2020 08:03:07
avatar
2123 forum posts
53 photos

Yes, your blog on the 54in version is very interesting Martin. Probably a silly question but I assume you calibrated your ESC to ensure it was giving you 100% power? I am sure that once you get your new impeller the new cheater hole will make a huge difference to the thrust you are getting with your 10s setup. The 7.5% increase in model size will help with the wing loading too hopefully.

Just a suggestion but as the model has flaps you, (Geoff and Martin) could try 5 or 10 degrees flap (max) for take off and also droop the ailerons as well for that matter (if your Tx will do that). The added camber and extra low speed lift can only help, with a minimal drag penalty.

just my 2p worth!

Edited By Piers Bowlan on 18/04/2020 08:05:02

Martin McIntosh18/04/2020 10:14:41
avatar
3332 forum posts
1178 photos

Hi Piers, glad you enjoyed the build blog. I certainly am getting 100% power because the esc is programmed for an EDF and the Wattmeter confirms this. I think that the main question will be the small wheels on grass rather than lack of lift. Unless previously tested in the air there is really no way of knowing if flaps make a pitch change.

I just hope that the fan I have ordered fits OK since it is supposedly a different make but looks the same in the HK pics. I would buy a new unit but cannot get 10s so my 2x 5800 5s packs would be of no use.

Piers Bowlan18/04/2020 12:03:52
avatar
2123 forum posts
53 photos

I agree Martin small wheels on grass produce a lot of drag unfortunately but my thinking here with the flaps is that the wing will produce lift while it is accelerating. This will unload some weight which may help the model further accelerate to rotation speed (which will be lower due to the flaps). It works with full sized aircraft but it is only a theory as far as models are concerned! I am only talking about five/ten degrees of flap, so there shouldn't be any significant trim change. It will be an experimental model on the maiden flight anyway kulou wink 2

My apologies to Geoff for taking over his blog. I am suffering from CNC cutter envy!

Edited By Piers Bowlan on 18/04/2020 13:01:52

Geoff Gardiner18/04/2020 12:09:09
avatar
534 forum posts
912 photos

No problem Piers, it's all interesting stuff yes

Geoff Gardiner18/04/2020 19:03:16
avatar
534 forum posts
912 photos

I wanted to sort out the elevator servo mountings before gluing the fuselage sides together as I don't like servos on show. A little work with CAD and my 3d printer and I have come up with this:

img_0885.jpg

img_0886.jpg

img_0887.jpg

img_0892.jpg

img_0891.jpg

More later...

Geoff Gardiner19/04/2020 20:24:18
avatar
534 forum posts
912 photos

Fuselage sides going together today.

img_0897.jpg

img_0898.jpg

More later...

Geoff Gardiner20/04/2020 22:14:14
avatar
534 forum posts
912 photos

I am just cutting the beech fan supports and the build instructions suggest pre drilling the mounting holes before gluing them in.

What is the collective wisdom on the type of fixings - screws or nut and bolt? If using bolts, access to the underside will be tricky.

Mark Elen20/04/2020 22:24:30
522 forum posts
1021 photos

Hi Geoff,

I had planned to use the no4 cap head wood screws from Modelfixings. Although, I did also consider using 3mm cap screws and T nuts - not sure if they would work in beech. You could make up a tin plate with nuts soldered on and screw it to the underside. The cap heads would be easier.

Cheers

Mark

Martin McIntosh20/04/2020 22:29:08
avatar
3332 forum posts
1178 photos

T nuts and socket cap screws is the way I did it. Good job now that I have had to remove the fan.

Beech is a bit OTT, ply or spruce is fine.

Edited By Martin McIntosh on 20/04/2020 22:31:08

Geoff Gardiner21/04/2020 14:03:14
avatar
534 forum posts
912 photos

Thanks chaps, something to ponder!

Bit more done on the fuselage:

In an effort to help with weight I made some holes in the motor former

img_0900.jpg

img_0906.jpg

Glued in the battery tray

img_0904.jpg

Glued in the front and back formers

img_0908.jpg

img_0907.jpg

More later...

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
Sussex Model Centre
Slec
electricwingman 2017
Sarik
Advertise With Us
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!