Comp ARF BAE Hawk build thread
#2176
Thread Starter
I started this project a long time ago, well its finally finished. In the end I farmed some of the work to our ace Hawk builder Roger M, who did the cockpit for me and installed the air valves, plus Rx stuff so I could finish other models I had on at the time. The need for this EDF Hawk came from our local grass club where turbines can't be flown Mon-Fri. The owner has a turbine version with a P-140Rxi in it that matches (Also we are just finishing a SG Hawk for the same customer) all three are 2010 scheme. This one has a Schubeler DS94HST running 14s 10,000 Mah Thunderpower 70c cells. There are four 7s 5000 packs running parallel/series. One of the delays has been battery mounting, i expected the cells to sit in the rear of the cockpit, but it came out really nose heavy, so they have to sit on top of the wing. I eventually came up with a sliding tray. I'll do more detailed pictures when I have more time. Test flights soon!
#2178
Thread Starter
Need to weight it, but the packs weigh 3932g (8.65lb!) So a little more than a tank of kero...but this does not get lighter as the flight continues. I think even with the scale gear we used on this one, the OA weight will be less than a fueled turbine version.
#2181
Thread Starter
Ran the whole set up wing on and 10,000mAh today for the first time, thrust feels OK (should be around 24lb) did a 2 minute take-off, cruise, landing run on the power and ground temps are much lower than I expected.
#2188
Thread Starter
Did the very last job on the EDF Hawk today, had the stop the batteries sliding forward on the tray and wanted no tools. So a spare 5.5mm bullet plugs in through a hole in the plate. The black pull cord is a section of 8swg wire with a red 'visual' cap on the end.
Sadly winter is well and truly back in the UK this weekend so no test flight :-(
Sadly winter is well and truly back in the UK this weekend so no test flight :-(
#2189
My Feedback: (30)
Hey Dave,
REALLY nice EDF setup !!
Mine came in at 28lbs AUW with a RAMTEC 11 blade ran it on 12s 10,000 mah packs single packs (6.6lbs) and it still was a floater on landings even when nose heavy...had to play with CG to get better landings.
QUESTION: What's your peak amps with everything buttoned up?
Thx in advance for any input
REALLY nice EDF setup !!
Mine came in at 28lbs AUW with a RAMTEC 11 blade ran it on 12s 10,000 mah packs single packs (6.6lbs) and it still was a floater on landings even when nose heavy...had to play with CG to get better landings.
QUESTION: What's your peak amps with everything buttoned up?
Thx in advance for any input
#2190
Thread Starter
Nice and light, this has all the scale bits, but I'm a firm believer in energy verses drag and I think this will work well at 33lb
I'm 180.5A and 50.1V (14s) after 30s static. The small inlets won't help either, but once its rolling it will be fine.
Dave
I'm 180.5A and 50.1V (14s) after 30s static. The small inlets won't help either, but once its rolling it will be fine.
Dave
#2191
Thread Starter
OK, had three flights with it today, this is the second flight, still working up on the packs, it looks like we are going to end up around 7 minutes, but its early days.
https://youtu.be/2hxKdwCMC2g
Landing at 33lb is not causing an issue, it was fairly calm, cool and a bit misty today, not ideal for EDF! Packs were not as warm as I'd like before we start...but summer is coming :-) I slowed it up a little more on the third flight and it was still showing no sign of a wing breaking away.
https://youtu.be/2hxKdwCMC2g
Landing at 33lb is not causing an issue, it was fairly calm, cool and a bit misty today, not ideal for EDF! Packs were not as warm as I'd like before we start...but summer is coming :-) I slowed it up a little more on the third flight and it was still showing no sign of a wing breaking away.
#2194
Thread Starter
Yes, its now rotating at about 70m, I increased the flap after the first flight, it used all 90m of the main strip.
Once we get the cells bedded we can see what we really have.
Think back not that long and a Hawk with small unducted inlets would not have been possible.
I'll do a thread on some of the mods required
Dave
Once we get the cells bedded we can see what we really have.
Think back not that long and a Hawk with small unducted inlets would not have been possible.
I'll do a thread on some of the mods required
Dave
#2195
Senior Member
Awesome take-off with the maingear still on the ground during rotate on the electric Dave!
I am about to fly the fly my new Hawk with the "sports gear" very soon.
I already read in this thread about the soft springs on mains but didn't read about the o-rings brakes.
It looks to me there is not much breaking power, even with 9 bar (130 PSI) of pressure. It is not hard to turn the wheels with brakes on.
Anyone has any suggestions or normal system behavior?
Thanks!
I am about to fly the fly my new Hawk with the "sports gear" very soon.
I already read in this thread about the soft springs on mains but didn't read about the o-rings brakes.
It looks to me there is not much breaking power, even with 9 bar (130 PSI) of pressure. It is not hard to turn the wheels with brakes on.
Anyone has any suggestions or normal system behavior?
Thanks!
#2197
Senior Member
I think it is not a kinked line, as brake reacts instantly.
So it is NOT normal system behavior, hmmm. What do you suggest? Clean the brakes including the o-ring?
I don't have any experience with o-ring brakes as I always used Jet-1A.
Thanks!
#2199
Not braking with 9bar sounds strange. Last summer I used 3bar with pulsating valve and still managed to get small flats on the tires. Is the o-ring hard as glass? Actually this wouldn't be bad at all if controllable and symmetrical
btw. My new Hawk is ready for maiden. AUW 11,7kg with just CAT fuelled. Full lights and smoke system on board. Didn't even try to make it light weight... This is to be trainer for the another one and it is heavier with scale gear and all the details. Some 70g of lead on the nose...
/Jyri
btw. My new Hawk is ready for maiden. AUW 11,7kg with just CAT fuelled. Full lights and smoke system on board. Didn't even try to make it light weight... This is to be trainer for the another one and it is heavier with scale gear and all the details. Some 70g of lead on the nose...
/Jyri
#2200
Senior Member
I'm happy I asked, so it is not normal behavior. I will check the o-rings and clean them. I guess no lub is required. ;-)
Thanks