Here is a helpful file so you can make the right choice.

Dynam Replacment Motors Chart

ParkJet Props

That is done by the ESC / speed controller and or swapping any 2 of the 3 wires from the ESC to the Motor.  If that is confusing, all our Brushless Speed Controller Manuals explain that a bit better.

Remember, the prop lettering ALWAYS faces the direction of flight.  Even of the motor is in the very rear of the airplane, the letter faces the direction of flight.  If the ParkJet motor is in the middle, the letter faces the direction of flight.

The GraysonHobby ParkJets are very powerful and will fly most airplanes with the prop on backwards.   So if you parkjeft feels sluggish, try reversing the direction of the prop, I bet that fixes it.

Happy Flying

Basil

And to top it all off, to make things just as bad as they can get, it took an ENTIRE DAY for the order to get here. It arrived here on May the 11th!!! The day after I made the order. Have you NO conscience? When OTHER vendors WAIT for 2 to 6 days before they actually ship and THEN it takes 8-12 days in transit.

What are you guys trying to do? Make the rest of the world look BAD??? I swear … if ya’ll can’t do business like the rest of the world, charging OUTRAGEOUS shipping rates and upi continue to NOT use shippers that take WEEKS to ship objects, then I just can’t imagine how you are going to stay in business. Get a CLUE guys!!!

———————

All seriousness aside … graysonhobby.com has always charged me less than what other vendors charge … and I appreciate your honesty. And my orders have always arrived in a timely fashion … I just cannot, not with any degree of verisimilitude, tell you how greatly I appreciate doing business with you. Thanks a lot. Thank you!

For most speed junkies, we want the timing as high as possible so the motor is spinning as fast as possible. The one problem with Super High timing, is that the pulse signal is sent too soon which actually will put the motor in “reverse”. The most common side effect is that awful screeching you hear. THIS IS BAD

So the most scientific way to set your timing is to keep advancing until it starts to screech, then decrease by one setting.

Do you need to advance the timing…in most cases NO.
Could you achieve a ‘faster’ motor while increasing the timing..Possible
Is it best to leave it in auto. Beginners YES, guys with experience and play around with this setting

FYI. This works with all motors not just parkjets, and actually, the larger 40 size motors, we have to decrease the timing since the larger motors spin much slower then then the parkJets

Hope this helps

Thanks

I have heard ESC and BEC called all different things, from Escapes, to BICS. I suppose the Escape key on the key board is how they came up with that one.

Any how, its called an E-S-C (the letters as you see them) or Speed Controller (shorten from Electronic Speed Controller)

BEC is how most often call the B-E-C (the letters as you see the) but occasionally I call them U-BEC (the letter U followed by BECK)

Boy did I digress on the topic…

What is a BEC you ask? BEC really stands for Battery Eliminating Circuit. But that makes no sense since you are using a battery to power your motor…right?

Sort of, the battery the BEC is referring to is the flight pack battery, the pack that powers the servos only, not the motor. Most smaller ESC have a built in BEC. Without getting into too much detail, the larger ESC do not have internal BEC due to heat. I am in the middle of a Vblog about the ESC / BEC which I will post in a few days.

But crazy as it sounds, the higher the throttle the ‘less work’ the ESC is doing. Hard to believe right?  Just stay tuned

Size / Thickness
The most commonly used thickness for scratch building RC airplanes is 6mm depron. The length and width is only determined by your project

Flying characteristics
A well built Depron airplane flies very precise, like its is on rails.

Depron is very rigid and only requires carbon reinforcements on the high stress points such as a wing spar and elevator spar and in some extreme circumstances and fuselage spar.

Depron foam most times snaps or cracks when it reaches it maximum stress point. Stress failures are easily combated by adding a carbon fiber tube on high stress areas on the RC airplane. Be sure to use epoxy, very sparingly, to glue in spars.

GLUES
Depron requires the need of special foam specific glues such as the foam safe glue and foam safe accelerator carried at graysonhobby.com

You can use epoxy and hot glue to build with depron, but this adds a tremendous amounts of weight to your build. Weight is not your friend when building airplanes of any size. Epoxy is a great for structural crash repairs, but I try to limit the amount of Epoxy.

CAUTION. The use of regular CA will burn and ruin your depron, so its very important you use the foam safe glue with accelerator. The accelerator is not mandatory by the manufacture, but I sure feel it its.

Another great glue for depron is the Foam Tac glue which according to the manufacture is specifically designed for depron.

PAINT.
GraysonHobby sells foam safe paint. This paint will not eat your depron foam and this is the paint that I use on all of my airplanes. Paints you purchase at anly local hardware or big box store most often will eat the depron. So be sure to test your paint on scraps. (if you do not have any scraps, then you are not flying hard enough ☺

Durabilty
With typical flying and moderately use, aka no crashing, you can figure for every 10 flights on a depron plane, you will spend about 10 minutes for repairing. If you crash your airplane hard, forget the repair and start the rebuild.

Now for EPP

Size / Thickness
The comparable size of 6mm depron is 9mm EPP. Graysonhobby.com sells factory cut sizes at 24 inches x 36 inches.

Flying characteristics
EPP foam is much much more flexible than depron, so EPP airplanes do not fly as precise as depron. Now you can tape your EPP from front to back and it really strengthen up the EPP, but adds a TON of weight

EPP airplanes require carbon spars. How much depons on the type of airplanes, but it will require carbon.

EPP tears when it reaches its stress point, but is easily repaired.

GLUES
For EPP I personally use Foam Tac and hot glue to build and repair. Yes I know this goes against what I said about depron, but lets face it, depron is for crash and bashing so I build EPP planes for crashing.

EPP is considered crash resistant but that all depends on your airplane and you definition of broke. I personally have flown a parkjet into the ground with a super mega jet going over 100mph with zero damage. The plane bounced nearly 10 feet high and the battery was effect, but the plane and literally no damage.

EPP it’s heavier than Depron but EPP is better for beginners.

A good tip for building EPP 3D type airplanes is to use a KF airfoil strip on the wing. It will make the plane fly better and makes the wing much stronger with not as much bracing, the theory being ,with less solid material to break

High speed EPP planes will need a considerable amount of bracing when using the KF air foil unlike depron airplanes.

So now that you are really confused, here is a quick summary.

Epp is more flexible than depron and usually needs some carbon reinforcing, especially in the wing although so does Depron. 1 square inch of 9mm, 1.3 lb/ cubic ft Epp weighs in at .12 grams. 1 square inch of 6mm Depron weighs in at .14 grams. I’ve built and flown planes made out of both and the EPP will take far more punishment if you are a beginning flyer/builder. Depron is slicker looking but breaks up much more quickly in an accident.

Good Luck

Basil

Dynam Servoless Retract

Unlike the much higher priced e-flight retracts, the Dynam retracts sold by us at Grayson Hobby don’t use an actual position individual micro controller to locate the sleds position, rather it has a time encoder and end point switches. The Dynam retracts don’t know if they are up or down until the circuit times and one of the switches is tripped, then it knows where the sled is. That position can be interrupted by changing it direction (flipping the switch mid way through a cycle) and now it waits for the opposite switch to trip. If it cannot make it from switch to switch within a set parameter then the cycle fails and the motor stops. For this reason, when you first power the system, it can take upwards of 30 seconds, uninterrupted, switch flipping seconds to find the sled and sync.  So Please allow ample time for the retracts to sync and this should solve your problem.

On landing we check out the motor and springily the motor was cool to the touch.  It looks like this is a real economical winner.  The Grasyon Hobby 2820-04 with a 7×6 gave us the best flying results.  Not the fastest times, but the most torque with the most flying time.

Great Motor for the Multiplex Dogfighter. The Grayson Hobby GH2820-04 can put your dogfighter at speeds near 90mph!

Similar to an E-Flite Power 15

Motor Stats:
Li-Po Battery: 2 / 3 cells
RPM per volt: 1500
Max Current: 60A / 60 sec
Dimension: 35 x 36mm
Shaft 4mm
Weight: 132g / 4.6oz
Max Watts: 600W
Continuous Watts: 500W
Recommend ESC: Grayson Hobby 60Amp
Recommend Prop Range: 10 x 5 / 9 x 6
Recommended Model Weight: 35oz – 88oz / (2.18lbs – 5.5lbs)

Multiplex Dogfighter Upgraded Speed Combo2820-04-Reverse