mjbennett9

Greg,

Looks like your battery pack wires are 10awg, or maybe 12awg? What is your serial connector for the two packs? i.e. 10awg? And what about your wires from ESC to motor? I see 4mm bullets on this forum, but nothing about wires.

mark_d

Just an update on the ducts - I can't sell them any more due to the return of my allergy to epoxy. [:'(]I looks like I'm going to have to avoid the stuff all together untill I can make a fume box and then it'll have to be for limited use. Anyone interested in the molds I'm selling them for $200.

Greg Covey

Mark,

Sorry to hear about your allergy to epoxy. I would imagine that working with fiberglass isn't all that healthy either. Take care.

MJ,

You are correct. I used #10 Castle Creations silver wire but #12 would work fine in this application as well. The ESC wires were also #10 gauge.

You can use 4mm bullet connectors because they are rated to 120 amps. I used the stock 4mm connectors on the ESC to motor connections and 6mm bullets (rated to 200 amps) on my Y-harness to connect the two packs in series. Again, you can safely use 4mm bullets here too.

Good luck!

mjbennett9

Has anyone thought about lowering the elevevators to a normal 90 degree position and adding a rudder (even if a nonfunctional rudder)? Bet it would fly/handle a LOT better. It would take very little work to lower angle of elevators (drill or dremel would do it), and adding a rudder wouldn't be much more work than that either. I'd be willing to try if anyone knows where I can buy/find a rudder to throw on top

Almost like the starfire - it has same tail shape to some extent. Actually, I'm wondering if the starfire rudder would be pretty scale if I put it on the predator? Should be close as it looks oversized for the starfire. I'm not sure where to order a rudder only but I bet that would work :-)

mjbennett9

I used castle 6mm on ESC and then used Deans ultra 12AWG wire with 4mm to motor. Should be good enough for 8S (will use 10awg to make serial Y for two packs).

mjbennett9

I wasn't sure if my 8lb 2oz 8S system was too heavy or not, but after seeing your 8.5lb plane, I feel better. I'm thinking of going from 2 3700mah packs to 2 4900mah packs.

Greg Covey

MJ,

Your new weight should be fine. Just remember to maintain the same CG.

Good luck!

mjbennett9

Videos

http://www.youtube.com/watch?v=Jua3rOOHBM0

http://www.youtube.com/watch?v=Z3kn0-yYiUQ

http://www.youtube.com/watch?v=Q1vXQTqiTqE

http://www.youtube.com/watch?v=jYuRMK1Gpe4

http://www.youtube.com/watch?v=MofJyknd7f8

Greg Covey

Nice flights. The afterburner lights are way cool! Do you have that documented? What LEDs did you use?

The Predator UCAV is a stable flier and seems to handle higher speeds well. The tricky part is to have the proper CG and land it fast enough so that the tail doesn't drop on you. It looks like you have those areas covered well.

mjbennett9

ugh. I typed a HUGE reply and the site timed out and lost all my typing. :-( I'll retype later.

Mikev

My Feedback: (1)

anyone know where I can purchase some inlet ducting. Maybe from one of the other jets out there someplace???????
Does this plane fly ok without them. Also noticed the former is missing the top half on the iinlet (no seal on top of the fan inlet on this one. I guess Ill have to make one. Does it need one??????
MIKEV

mark_d

I have molds for inlet ducts and use to sell them until I became allergic to the epoxy. If you are interested in a set I know someone that might be interested in using them to make more for sale. let me know if you are interested and I contact him.

Mikev

My Feedback: (1)

Mark. Yes Im interested. Got the plane today and have it half done. Hard to figure where to put the lipos and '''bec.
Mikev

mark_d

These have a tendency to come out tail heavy so keep that in mind.

mark_d

I should be able to give you more information about the ducts by the end of the week.

Mikev

My Feedback: (1)

OK Mark. Took mine out today and couldnt fly it as I left the connector to connect my two batts together in series. Just taxi tested it on 6 cells 5000mah . Not enough power. Its going to take 12 cells to fly this plane. It came out at 9lbs with the 6 cell batt in it. I have the cameo one. I have the Easy Tiger upgrated fan and scorpion motor and esc.
Have to get some other lipos like you have or use 3 4cell packs.
MikeV

Greg Covey

I was asked to post the control throws on my Predator setup many times so they were posted in the comment section of my AMP'D column called, [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=1153]Higher Power EDFs[/link] but I will also post them here since not everyone is finding them.
[ul][*] Tail Elevator: High Rate: +- ½� with 75% expo, Low Rate: +- 3/8� with 65% expo[*] Ailerons: High Rate: +- ¾� with 40% expo, Low Rate: +- ½� with 30% expo
[/ul]

mark_d

Is that with the HK4036- 800 and the carbon impellor? It sounds like you need the ducts to get the most of that set up.

rcboys

Mikev, What scorpion motor and EDF do you havein your predator? I purchased the 101 mm EDF and Scorpion 1900 from easytiger, where they told me it would be fine on 6 cells (22.2 v). I haven't started construciton yet, so I was thinking I may need more joice. Someone flew theirs on an 8 cell, so I was just wondering why you thought you needed 12?

Thanks for any help.

Mikev

My Feedback: (1)

ANYONE KNOW WHERE i CAN PURCHASE SOME INTAKE RINGS FOR DIFFERENT SIZE FAN UNITS. nEED A FEW FOR THE 101" FANS. Even the larger one 104" The only ones I can find are for the 90 size one.
MikeV

ATVAlliance

I know this is an old topic, but rather than start a new thread on the same plane...I figured I'd just revive this one.  Hopefully people are still flying this plane.

I bought this plane last year and only unboxed it to make sure nothing was damaged and then put it away until now.  Id like to try and get this thing going by the spring so I thought I may as well start collecting the electronics now.

What I would like to know is if anyone has a recommendation for a good EDF/motor/ESC combo in 90-100mm that would work good for this airframe for taking off from grass.  I prefer it to be 8s so I can use 2x4s packs in series to hopefully be able to use the batteries in single form for my Bobcat 25 I plan on finishing and flying this spring as well.

This is my first venture in EDF and do not need a 120+MPH plane.  Just want to make sure I can take off from grass and fly it.  Id be happy with 80-100MPH with it.  My biggest thing is to keep the costs down so Id like to have no more than about 250-300 bucks for the EDF/Motor/ESC.

Also, Id rather have a combo (if one exists) that already comes assembled (just because of balancing the EDF unit).  Like I said...I have no EDF experience and only bought this last year because it was a nice price and really have no liking of foamies (other than my Stryker...I really like that bird!).  I figured this could be a way to get into EDF and have something substantial to look at on the flight line at the field.

So to sum up...I'd like to have info on a combo of EDF/motor/ESC that will work good off grass (our field is roughly 250-300' long and isnt "golf course", but is nice and flat).  A battery size in 4s (mAH and C rating) that will work good in a 2x config to get 8s.  And quite possibly what servos people are using that works well.  Again, I dont plan on doing super fast flying with extreme control surface deflections.

As far as finishing the ARF...Ive built several planes and feel quite comfortable in putting this thing together and getting the CG right (note...read that this planes CG is an inch over per the manual...so that would put it somewhere in the 7.25 area).

Any and all replies are welcome!

Thanks

Greg Covey

The main issue here is that you have conflicting goals and your desired power system is not yet mainstream.[ul][*] Grass take-offs[*] Pre-assembled 90mm - 100mm unit[*] $250-$300 budget[*] 8s LiPo supply[*] 300' long field[/ul]While you can satisfy some of your goals (like this pre-assembled [link=http://www.ejf.com/index.php?main_page=product_info&cPath=77_163_180&products_id=834]RC Lander 90mm EDF[/link]), you will probably not be able to satisfy them all. At only 65amps on an 8s LiPo, you may not be able to take off grass using this power system. Other motor selections can provide around 2400 watts on 8s which should work fine on the Predator UCAV.

The good news is that you should be able to fly the Predator UCAV off grass using an 8s 90mm EDF system and can probably meet your budget. Ducted fans like the Wemotec Midi Pro do not need to be balanced but they will need the appropriate motor installed and an ESC wired up.

Hopefully, this will point you in the right direction.

Good luck!

ATVAlliance

Greg,

Thanks for your quick reply.  I wasnt sure if anyone would even reply to this since so much time had passed.  So again, thank you.

I had seen the Lander fans on a couple sites, however they are always out of stock and also the ones I seen were all setup for 6s.  The link in your post did not go anywhere but to a reply box here on RCU...so I just started looking for the lander edf units on ebay and found this one that is claimed to be setup for 8s supply.

http://cgi.ebay.com/RC-JET-Airplane-...item2eb1ea25bb

As I said previously, this will be my 1st venture into EDF jets and I really dont want to spend a few hundred dollars on hardware that wont make it in the air.  I dont plan on having any other EDF's for a while and the money could do good with other projects I have that are waiting for my attention.

I may have been asking for something that isnt possible.  Maybe this plane isnt for me afterall...so perhaps I should reconsider building it and possibly just putting it up for sale.  But really, I love the look of it and would absolutely love to fly it, but not at the expense of having to guess as to what I need to buy to get it in the air.

Also, even though I said I would like to have these certain requirements met...I am surely flexible on them.  If I cant get it done for 250-300, then I possibly could go a bit more.  I just dont want to waste my money with my guesswork and little knowledge of electrics.  All of my planes are glow or gas except for a couple (the Stryker...a micro Cub...a min Ultra Stick).

Is there any way you can get me in the ballpark with battery size...motor size and type and fan unit (unless the one in the ebay link will do...I'll just order that one).

Also, I dont mind wiring it all up...I do have a couple 450 helis that I have built and have worked battery packs, connectors, ESC's before.  Just really need to know what I need to buy so Im not throwing my money down the drain.

ATVAlliance

How about the Wemotec Midi PRO 90mm EDF unit and an ARC 36-75-1 or 1.5 on 8s and a Turnigy K-Force 120A HV ESC.

I think I can put all of that together for about 350 bux (minus s&h) so that is still close to my original budget goal for the power system.  Of course that is not counting batteries.

What 4s packs in mah and C rating would be best for this combo?  As stated already...I dont plan on flying around WOT all of the time.  Saying that, would be nice to get at least 5 min flights from the batts.

Greg Covey

Sorry about the broken link. I fixed it above and it is the same product in your eBay link but sold at the Electric Jet Factory.

Your ARC setup will be a good choice and work great! I would use a 30C LiPo cell around 4AH.

Good luck!