Hobbyking parkjet...need for speed!!!!!!!!!!!!!

[stuart]

well,i gave in for a pusher jet...,hobby king has this little kit for $14 and $17 shipping,with my point $5 off ...it's already shipped.

now i know the motor I've chosen is meant for a 2cell and 20ampesc,but the many who used this motor are using 3cell 1300mah 30c and finding it to provide adequate speed to thrill and old folk like me.

when it arrives,I'll revive this thread with pictures and I'll be putting carbon fiber rods installed on the wing and the trailing edges of the ailerons.[elervons?].the motor mount needs reinforcing ,and the canopy will have cooling holes drilled in the front and back.then some shocking bright orange paint for the top and a equally shocking darker color for the bottom.

I'll be tossing out a few questions on the correct mixing of the comp TX settings for the best control. hope to break the 100mph finaly.....a hk picture of the park jet.





HobbyKing ParkJet (KIT)

[stuart]

picture of the motor ......using a 30 amp esc.





Brushless Motor 3000kv

[savall21]

Post some video of your setup when its done!

[stuart]

I'll go ya one better....assembly pictures with all the mod's recommended on other threads/forums,and hopefully a video to boot.

I'll have to find out how Doppler works to rate it's speed. i wouldn't mind having a radar gun ,but then thats a luxury i don't need..lol.

[NJSwede]

I've been eying that one for a while. You have to tell me how it works out!

And, while we're at it, we have to do some flying together before the season is over! I'm only a 45 minute drive away from you, so it's a shame we haven't been able to get a "date" yet! I'd invite you to my club, but the field is pretty ugly after the floods...

[stuart]

hello njs,absolutely we should head up to my field,unfortunately I'm only a weekend flyer.yesterday and today after church.

i head up to the field around 9:30 and fly till 2pm or so. the best thing would be to drive up at your on timing and I'll stay as long as ya want. it's a good group of pilots there,and hanging out talking while others are flying is half the fun[OK,much less than half...lol]

i have a wedding to attend in belmar NJ next Saturday so maybe the weekend after that.let me know.........i could sneak the airfoils yak in the trunk and step out of the wedding to fly your flooded field...lol....i don't think my darling wife would be to happy with that idea.

as far as the park jet goes,it should be arriving any day,only i made the motor a second order on the same day. the parkjet was registered mail and the motor was standard mail. i would have ordered another motor from headsuprc that is 2700kv,but its out of stock.

pm/email me if your going to be in the neighbor hood during the week for business,and if it's early enough we'll shoot up to the club field and fly a few of my planes.i'll fly the airfoil yak at any ball field,they really are great for small areas.

[stuart]

parkjet arrive and glued together very easily. the foam is great and the motor mount was garbage,so i reinforced it and installed the turnigy motor. soldered the wires so it would run as a pusher and installed the 30amp esc and 2.4 rx.

plugged in the 3cell 1300mah 20c lipo only to have the motor run in a short burst...than nothing. throttle down and up again only to get a short burst. this repeated sevaral more times, so i tried to work the throttle back and forth and the motor ran steady but rough,like something is wrong with it. i don't even have to ask for help on this one....does the word "cheap" sound right...the windings look like crap on this little motor and the time spent mounting it was a waste of time.i got what i paid for and now must order another motor.i may upgrade to a 40+amp esc and a motor meant for a 3cell that has a high kv rating for speed.

so here is the big question to all the 100mph club members....what motor should i get to propel this little bird to 100+mph and not burn it up after a few flights?

heres a few pictures promised of the simple build,but i hope to provide a video thats a blur of the parkjet screaming by...

[flydiver]

That motor is notorious for shorts, which it sounds like you have.
Realistically it's a 20A motor. Trying to push it a lot higher than that in stock form mostly will produce heat, not a lot more in speed. Just because a lot of folks do it doesn't make it a productive idea.
As speed increases the requirement for power goes up significantly. Pretty sure you can't top 100mph with a motor of that caliber.

Maybe you've already seen this:
Flite Test: EPO ParkJet - REVIEW
They provide a serious option to upgrade for speed (big inrunner, at least big for a plane that size).

Another option would be to check out some of DonsRC options-he specializes in small jets.

Just a note-a plane that size going 100mph gets pretty tiny, awfully fast.

[stuart]

thanks flydiver,i saw all the vids on the parkjet. i just don't want to wait on another turnigy motor to ship from china. i did check out donsrcshop and ordered a small motor from him. after placing the order i revisited the the motor section and the motor i ordered is now out of stock....i hope thats because i got the last one since it was in stock when i placed the order...... $16 shipped, its the wicked jr brushless 3200kv uses a 3cell1300mah with a 4.5x4.1 prop. hope shipping is quick as the parkjet will be when its flying.

i'll still take other suggestions as i enjoy trying new motors and esc'combos all the time and having stocked items in the shop is always a plus when building stuff...lol..... can never have to much stuff.

[stuart]

it's been awhile to get time to build,so I'll post recent progress. new motor installed and it's a really smooth running motor,with the prop on ..its loud at wot. i know this will sound conceited,but i really hope this lil jet gets up to speed and gets noticed...lol.

i mounted the esc outside the canopy right in front of the motor for optimum cooling and the Rx goes way up front away from the power plant. the battery is very close in location for proper cg,although this is yet to be determined. now to find the perfect florescent paint to spray on the top and only a little on the bottom ,perhaps bright orange on the top and lime green stripes on the under side for pattern. I'll post pictures of the finished product and hope to maiden next weekend. i have the elervon programed into the TX and added expo ,not to impressed with the control surface throws,but i here deltas can handle pretty squirrelly at first. just hoping to get airborne and landed for the first few flights and only plane on 2 to 3 minute flight anyway with burst of wot on flybys only.

lastly,i plan to set my video camera in the middle of the field to hopefully get a Doppler reading on the speed....no 100mph but i do hope its quick!. i have a need for speed in the flock of birds sitting in the hanger.

[stuart]

ran the final bench test and fine tune the control settings. wattup meter say 205watts,pulling 19amps off a 1300mah 20c 3cell zippy. i still have to do the flight time math,but the first flight will be short so to trim it in the air and check battery power draw. then i'll adjust flight times with strafing flybys at wot.

gotta say,it make me more nervous than other maidens as thi is the smallest,fastest bird sitting on the table.

[stuart]

good evening my friends here at wattflyer,

every weekend i load up the SUV with 2 or 3 planes and spend several hours hanging out and flying with out so much as a second thought to "oooohhhhh,i might crash!".....it's calm, relaxing and truly exhilarating to fly aerobatics with kits I've owned a long time with many flights on them,some are the second or third kit of some planes and crashed before and rebuilt. by golly,I'm on my 3rd uproar with a replacement kit on the shelf...lol....[i do love taking chances]i do hate the dumb thumb days.


but Saturday is supposed to be perfect flying weather. 5 mph winds and blue sky all around...it's the big day for the parkjet!!!!!! in the morning its going to be tossed to the sky,and after reading the launch tendencies on this bird ,i will bring my foam safe ca with activator....lol...,cause i have butterflies in the gut waiting for the morning to arrive and see this jet scream across the field....serious butterflies that it only flies 20'ft before a death roll thats been haunting others who fly the hk pj.

anyway,I'll post the after maiden flights if it survives,i want to put the video camera in the runway and video wot runs....we'll see....yes sir ee,we will see.stu

dooooohhh ,my stomach.....dang butterfies.

[NJSwede]

Hmmmm... If only there was a way to get out of the honey-dos tomorrow, I'd drive up to witness this... This I want to see!

[stuart]

njs,you would have given our field an "a" rating[or at least a "B+"..lol. no wind at all!!!! and a warm,cloudless day.

maiden went great and made a separate thread reviewing it. hope you got the honey do list done cause Sundays another day after church and I'll be roaring,and parkjeting again. but i won't be spending 4 hrs at the field like today....that would be a "honey don't"thing when i got back home.... gotta keep the priorities straight...lol.

[dahawk]

Stuart,

Been flying my F-22 scratchbuilt where I might have invested $60.00 including the Grayson V-3 combo kit but this baby looks like alot of fun. How well do you think it would stack up in combat? High alpha? I can see gluing some cocktail spears to the ends of the wings for a lttle added effect. LOL I like your idea of painting loud flourescent colors as all of these small, fast birds can get away from you quickly. I've walked through the woods amongst thorn bushes looking for my F-22 and it's no fun with shorts on. Time to log on to HK again. Hopefully, the US Warehouse will have something. I did finally find a lightweight futaba 2.4 fasst knock-off R8FA Corona that will work great in the foamies.

Cheers,

Hawk

[stuart]

hey hawk,not having any experience in combat i really couldn't say. but this parkjet is a bit twitchy at high speed and i would think it would do a # in contact with the opponents plane. it wouldn't bee as much fun as flying a simple delta design that you scratch build for a couple a bucks.

I've only flown the parkjet 6 times[to windy lately] and have almost lost orientation 3 of those flights as it does get squirrelly and cover a lot of ground quickly. the only thing that made the saves possible was the bright colors.. i had it doing out of control ground loops far down the field before regaining altitude to fly it back...lol..green/orange/green/orange/orange/green,then i got the thing climbing out and everyone was cheering. what a blast to fly fast. with a few more flights under the belt ,I'll be much more capable of burning up the sky!!

here's how to use up the extra florescent paint....,its an airfoils yak replacing the one i destroyed over many test flights. that is testing my ability to expand my aerobatic skills[she sure does take a beating].

[dahawk]

Well, I checked with HK and they are backordered. Dang. I now have one on my wish list alert. One thing I learned about HK is never order anything that is backordered as it will literally be a "slow boat from China". I'm conditioned to a two week turnaround on things from them and it's usually worth the wait due to great prices. Just received some 9g servos and my knock off futaba rx today. 2 week deal but that's okay.

Love the paint scheme idea. Did that with my F-22, orange and blue for my Gators, and that helps alot even though it didn't prevent me from ground looping. It does help with the search and rescue missions. Think I'll do a Susan G Komen Pink color for the bottom an use some left over dark blue for the top. Do you have a recommendation on a vid cam? I could circle the battlefield with the HK Parkjet to film 4-5 other guys trying knock each other out of the sky.

Best,

Hawk

[stuart]

learned something really great this Sunday. don't hand launch with power,and don't hold up elevator for hand launching the parkjet.

a fellow pilot who's a 3d pilot was listening to my description of how hard a launch is with the torque roll ,he described the way to hand toss it level to glide and throttle up slowly.

this lil bird weighs a lot and with power off hand launches and up elevator ,she would swoop the ground before gaining flight.

i asked Ben to show me by flying it and I'd toss,i took 2 steps and threw it level and the glide without elevator was perfect!!!!slow throttle up and away it went[beautiful!]. Ben landed after a few passes and then tossed it up for me,and wow!!!talk about smooth launch....this parkjet flys great!!! got 3 flights on it,2 on the yak,2 on the pig. what a great day to be with friends at the field.

seems like this new way to launch may just improve alot of delta flights[new to me anyway..lol..]

[gramps2161]

Stu glad to hear your having a ball with this, and learned a better way to launch it. Sounds like you have to be on top of this one to keep orientation, and keep it close. Might have to try out one of these for next summers flying season been wanting to try a fast plane.

[stuart]

gramps,you'll love it!!! one thing ya got to remember is these parkjet glide so nice and slow with the power off,down right relaxing .....but the Adrenalin flows with the wot fly bys and the roll rate on high throws is uncountable...lol...

with out a doubt ,the bright orange top,and bright green bottom even at a distance can be seen so orientation really isn't the issue...now with 8 flight under my belt it's the control of this flighty lil bird that's getting easier with each flight....she really snaps with input from the sticks like no other plane in the hanger....ilove the way this plane flys so much ,I'm trying to decide what funjet/stryker type bird to get next.

a guy at the field flys a pushercat,another flys the stryker,but the fastest clocking over 130mph is a multiplex funjet on 6cells!!!! the batteries come out after a flight very hot,thats how I'd describe watching this plane scream through the air....compared to it my parkjet is slow.flying all 4 together sounds great. i still have to charge[find the cable first]the video camera i bought and try to get a Doppler reading from someone here at the wf.

all i can say ,this pkjet from hk for $14[plus shipping]i built is fun,fast and cheap,a great combination! Stu

[dahawk]

Hey Stuart,

I broke down and bought the HK Radjet 800. Wife doesn't know it yet but she's getting used to boxes appearing at the door with a Chinese mailing address. Could not resist the price and figure worse case? If I crash and burn ?, it's not the end of the world ! Looks like fun as it's a knock off of the Multiplex FunJet and I have a bunch of 3cell 1300mah lipos.

Can still fly my scratchbuilt dollar tree foamie F-22 in Combat until there's nothing left of it or until I run out of packing tape and Ca. I've found that these pusher park jets really do improve one's flying skills because you must" fly the plane" Getting hooked on them where I am starting to feel "the need for speed." Know my own limitiations and am not ready for EDF's yet. Still Fly with LOFT(Lack Of F***ing Talent) But who knows? another year under my belt?

Now the wait for the slow boat from China

-Hawk

[stuart]

hawk, do let me know what you find in the radjet's perfoamance, i also am thinking of having the mystery box show up to suprise my wife...lol....

i'm curiouse if the radjet is as nice to fly as the parkjet is. it sure looks cool ,and the price for the arf is great...$39,$31 to ship it. i get the feeling you'll want to boost the motors size to get radical speed. but i'll wait to hear from your experience first. thanks for posting ,stu

[stuart]

I've been getting some great flights on the park jet,learned that if someone tosses it hard and level ,it'll glide sweetly to add power slowly . been successful and really got the feel for handling the speed and twitchy controls by setting the throws on low rates....still would do blurring rolls.

today i flew it in the morning but no one was there capable of giving it a second toss. so i went back this evening with the intent to video it to hopefully get a Doppler readiing.

took off like a rocket and planned to do flybys at the camera i had sitting in the center of the runway.....it banked hard and i flew the tightest circle and went to pull out of it only to plow...no...lawndart it straight in at wot.

I've been concerned how dangerous a speedy lil parkjet can be,so i wish I'd paid closer attention to the TX settings then the Doppler camera. i felt rushed to get my flight done so the other pilot could fly his glow plane which might drown out the sound of the parkjet. what happened is a mistake all to often done with these programmable radios.......high rate switch should have been set to low. could have been prevented if i wasn't in such a rush........."speed kills"a saying from the 60's



man!!!did that lil bird snap in and the nose pushed in compression style. should be easy to repair if i can figure out how to un-compress the nose...lol. all good fun and this hk/pjet will scream through the skies again. i am amazed at the strength of the foam,it should have been vaporized but really is tuff stuff.

[dahawk]

Stuart, one thing I've tried successfully with foam is to place a very damp towel( not dripping wet) over the affected area and wave an iron over it , back and forth. It's amazing how much rebound there is. Did this on my T-28 earlier this past summer and was amazed.

Still waiting for the King to deliver the Radjet. Should be interesting. Keeping my expectations low for now.

Best,
Hawk

[stuart]

thanks hawk,gramps also said to use steam so i boiled up a small pot of water and covered with tin foil..then cut a slit in the foil to have control over heating the damaged areas[didn't have a tea pot..]. wow! it really did take shape nicely,i already lightly sanded the repairs and resprayed with florescent orange. except for the faint outline where long decals had been ,you might not know i smashed the nose.

if the canopy glue sets up right over night,I'm back in business,made a new motor mount and might touch up the bottom with the florescent green in the morning.[repair overkill]

it's at times like this the RC hobby is so rewarding...repairs done same day...almost like the dumb thumbs never happened.