The Thrust Guage used throughout testing.

The Propellers Used in this test.

	Standard Gunther: 5 x 4 Small and quiet, provides adequate thrust for a Pico-Jet or Combat. Also used successfully on a Speed 400 powered Zagi. Must be mounted with the writing on the white section facing backwards. Rubber Band model Bow Tie : 5 x ? Same diameter and from the tests, seems to have the same pitch as the Gunther but it is not printed anywhere (for 27p what do you expect) and it worked. I kept this on for weeks as a result enjoying many long flights with my newly aquired 9.6 1300 cells.
	Graupner CAM Speed: 5.5 x 4.3 A high perormance propeller I was loaned to try. It makes quite a lot of noise and was in the middle group of props for performance in tests. I have not flown with this prop but Choddys Twin-Jet did and it makes an improvement over Gunther types supplied. Windsor: 6 x 3.5 (similar to Master Airscrew) This prop falls into the highest rated pair, coming second only to the FK. Good thrust and reasonable noise. If I had found this prop before the FK I would probably still be using it.
	Kavan ~ FK: 6 x 4 The Yellow bendy prop, favoured by learners as it is almost impossible to break. Noisier than a Gunther but not by much. Great performance in the air. Very long flights with good climb, also make a great sound when held in a shallow dive. This prop gave the highest readings of all and is still in use now. Choddys Twin-Jet also flies a pair of these to very good effect. However it does protrude past the bottom of the Pico-Jets fuselage so touch-&-go's can be tricky. Thimble Drome: 5 x 3 This is a cut down 6 x 3 prop and fits the middle catagory for performance. A bargain from some 3 for a pound box at a show. Not sure if the COX .049 it was attached to will ever run again tho! Origianlly fitted to the Zagi 400 with limited success. This is the noisiest propeller of the whole lot and would probably annoy the hell out of the natives.

The Battery Packs used in this test.

	Sanyo Cadnica 7 cell NiCad: 8.4v 500mAh The lightest pack at just 155g, this pack provides 3-4 minutes of reasonable flight. It is however the wrong shape to get far enough forward to correctly balance the Pico-Jet. Originally for a Zagi this battery is taken along only as a last flight pack.
	Ripmax 7 cell NiCad: 8.4v 500mAh This pack was used extensively in my Topic 400 prior to being conscripted into the Pico-Jet. Flight times of 6 minutes flat out and 8-10 with a little over half throttle (can we say throttle on an electric?) The pack is a little tall and has to be fitted laid at an angle inside the fuselage and goes just far enough forward to balance nicely. I still use one of these packs along with the Overlander packs.
	Sanyo Cadnica 8 cell NiCad: 9.6v 500mAh This battery gives lots of power for a very short time, and due to the low weight the climb is almost ballistic. It will sustain greater then 45deg climbs in the right conditions. Flight times are 2-3 minutes at full stick with 4-5 mins flying sensibly (if you can do such a thing with a Pico-Jet) Balance is ok as it is a slim pack and can fit quite far forward. Beware getting it wrong with this pack, very hard to keep the nose down if too far back.
	Overlander 8 cell Ni-mh: 9.6v 1300mAh The battery pack for Pico-Jets/Combats & similar. Although the voltage is the same as the Sanyo, the NiCad provides greater power for thrust but at a greatly reduced endurance. With the 1300 pack flights of over 10 minutes are not unusual and on a blowy day and some delicate elevon usage twenty minutes plus has been achieved with minimal power used every once in a while. I would recommend this pack to anyone who has a Pico-Jet or Combat, duration being my main selling point.

The Thrust Chart.

Comment by Bob Drinkall on 00000000000000. Rating 2

Would have been more useful if the amp's drawn per prop were recorded. In my test's I found the standard white prop's hard to beat for overall efficiency.Other prop's can give a little more thrust, but use more amp's. Remember you get nothing for nothing! For my test's I use a over head beam frame work, with the motor on test mounted at one end with the other end pushing a rod down onto a pair of digital scales. Thrust,amps & volts were recorded with a range of moters up to 600 size. If you would like to publish the results send me your site e-mail address.

Comment by Peter Gascoine on 00000000000000. Rating none

Thanks for the work. From a flying perspective I have found optimum Picojet performance with a Permax480, 8 cell 800AR, and Ripmax 5X5 black carbon

Comment by Ian Webster on 00000000000000. Rating none

Great article - great website. I'm an ex-pat living in the USA - any idea where/how I can get the yellow bendy prop?

Comment by Bill Gough on 00000000000000. Rating 4

Great article to spark interest in the topic. Easily comprehended, not overly technical. All the hi tech stuff will come to those whose interest is ignited by introductory articles like this one.

Comment by Peter Angus on 00000000000000. Rating none

Static thrust is only half of the story. You should also measure efflux velocity (with a wind meter).

Comment by Dave Fritzke on 00000000000000. Rating 4

KavaN "Bendy props" availabe from Hobby Lobby in the US. (hobby-lobby.com, note the hyphen) I'm ordering some before thay are all gone due to this article! Dave

Comment by Tony Leigh on 00000000000000. Rating 3

Good article, From my own flight testing with a ME163 and Microjet, I have found that a permax 480 7.2 volt motor 8 x 500 AR's and cam 5.5 x 4.3 works best. I have now gone brushless and have found that the Mega 16/15/5 with a 6 x 6 cam prop give excellent performance on 8 cells with reasonable duration (3 mins on 500 ARs 5 mins on Kan 950)

Comment by Engineman on 00000000000000. Rating none

No complaint. Just a different method. I hang a 3ft piece of 2X1 timber from a nail in my garage roof so that it swings. Ihave a 6X6 platform on its bottom and a quadrant of card at the top fixed to a rafter. Strap a plane on the platform and apply full power so that the whole plane flies forward and up until the motor power balances the angle. Mark the position of the pole. Change the prop and try again. A good way of determining the best prop for static thrust.

Comment by ian raw on 00000000000000. Rating none

has anybody fitted a fun 400 brushless into a picojet?i belive these motors are 6 times more powerfull than a standard 480 motor i am thinking of doing so and could do with some tips

Comment by KA on 20040803103333. Rating 3

Good article. I fly a Twinjet with standard 400 motors 7 cell 3000 Mah NiMh have replaced Gunthers with APC (LP 05545) 5.5x4.5 propellors. There is a significant improvement in peformance

Comment by Paul Davison on 20040929205717. Rating 5

Great article but I found the Kavan FK yellow bendy props extremely difficult to come by anywhere on the Internet, then found The Model Shop in Belfast had them in stock, as well as the Graupner domed adaptor

Comment by Flan5ter on 20060307173400. Rating 5

Nice report and really cool way to test the thrust.

VIEW / ADD Your Comments This is where you can leave your comments about the article itself or about the subject of the article. For example maybe its a review and you would like to tell people about the experience you have with this particular model. Name: Email Address (optional): Rating: 1 2 3 4 5 Excellent = 5 Comments: