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c/f's blog
Posted by c/f | Aug 25, 2012 @ 11:16 AM | 2,170 Views
Fwiw
Posted by c/f | Sep 18, 2011 @ 08:11 AM | 2,725 Views
JETCAT Turbines and BVM composite Jet building.....

http://www.rcgroups.com/forums/showp...15&postcount=7
Posted by c/f | Sep 18, 2011 @ 07:53 AM | 2,951 Views
"I had a vey good view of the whole incedent. The guy in all black in this photo is me"

http://news.yahoo.com/reno-crash-kil...212230699.html
Posted by c/f | Mar 14, 2011 @ 10:50 PM | 4,544 Views
Buddy on Lake Hodges
Posted by c/f | Feb 03, 2011 @ 11:41 PM | 5,648 Views
WOW, This was uncovered in the MIHIA findings after SEFF 2009 with a new DX7 sent in for evaluation.

http://www.rcgroups.com/forums/showp...&postcount=195

Now two years later:
DSMX (10 min 6 sec)



I'd like to see the 100 transmitter test be executed one at a time out of range of the TEST model where the collision avoidance feature of the 100 upon activation is void of the TEST model TX, Then they be brought onsite of TEST model. The turning on of the 100 in such close proximity of the TEST model where the Collison avoidance feature is active, is not indicative of what happens at large venues and multiple flightlines across large expanses and proves nothing.

It is long understood that 2.4G transmitter protocol of Collision avoidance prior to transmission of ALL brand TX, was the ONLY interferrence protection Spektrum has had since its inception. The MIHIA test proved 2 years ago there was no guidded active protection. The receiver just shuts down and returns on as if nothing happened and not part of the lost frame data aquisition or LED flashing.

Time for a DX8 MIHIA test......
Posted by c/f | Feb 03, 2011 @ 10:18 AM | 3,176 Views
Fwiw.

Nemesis
Posted by c/f | Feb 01, 2011 @ 11:20 PM | 3,322 Views


XH RHINO, BUFFALO, FLIGHTMAX,TURNIGY,NANO

always looking for a more complete chart help
Posted by c/f | Feb 01, 2011 @ 10:50 PM | 3,187 Views
To me this all dovetails into my theory the battery is the HP, the prop is the load, and the motor is nothing more than a gearbox between the two to convert battery electrons to rotory motion required by the air screw.

Very tough to do with liquid fuel as your "gearbox" selection is so limited by design.




http://www.rcgroups.com/forums/showp...8&postcount=30

More of the same:
http://www.rcgroups.com/forums/showthread.php?t=1536290
http://www.rcgroups.com/forums/showthread.php?t=1550460


Some EDF stuff.
http://www.rcgroups.com/forums/showp...65&postcount=4
Posted by c/f | Dec 25, 2010 @ 09:08 AM | 3,495 Views
Heres some more theory of mine a bit unconventional but gets you the best thrust to weight ratio and litest wing loading.

My formulas are "in air" proven versus moto calc effiency winners, I use the battery as the weakest link as its the easiest to upsize or swap out for longer flight times. IT also is the only item that is evolving rapidly each year and improves your models performance futher given this info.

Consider that "THE BATTERY " isthe power NOT THE MOTOR.
Consider that it takes 10grams of battery weight to net 25 watts usable power.

Consider that a motor is a means to an end to get the energy/Horsepower out the of the battery into a a usable format ie spinning a propeller, thus is nothing more than an empty gearbox in which you input these " gears" A;watts capable in grams of motor weight, B;prop size needed for desired flight application, C;desired cell count/kv to keep rpms/watts/amps in check with goal.

Consider that watts capable is gram weight of motor.
www.gobrushless.com will get you up to 400w on 33 gram motors.

www.hyperion-eu.com will get you to 2000 watts on sub 200gram motors.

www.sneumotors.com with gearboxes will get you near 4000W with sub 700gram motors.

Using cell count and KV you will find the right motor combo to hit your target of wanting to put X number of watts into X prop @ X speed of model.

So target a prop and the watts you want to put into it. and go reverse engineer shopping from there. Once finding a motor, this is where the calcs come into play to show thrust and amps to check out if battery is capable.

Keep in mind my formula 10g of battery nets 25Watts usable power, this makes cell count kv irrelavant. you interchange the cell count and KV to get targeted watts into the prop of choice.




3D Huck'N 60"rs......

http://www.rcgroups.com/forums/showp...&postcount=477
Posted by c/f | Oct 17, 2010 @ 10:25 PM | 3,678 Views
Intresting Castle design info from Patrick himself:

Hmmm, so you are just showing that you have no idea what you are talking about at all. The chip we use is Silicon Labs C8051 core chip, which have ideal peripherals for motor control. I worked with Cygnal, the company that designed the chip, to ensure that they had all the correct peripherals on the chip for motor control early when they first started the company.

To compare to other CPUs being used:

Jeti and most other brands use the Atmel Mega 8, which is a 16 MIPS processor. The C8051F367 (used on the ICE controllers) is 50 MIPS, over three times faster.

The C8051F367 has superior analog on-chip, (better A/Ds, better comparator offset voltage, better flexible PWM generation, better analog multiplexers, lower analog noise in the analog sections.... etc...) lower interrupt latency, lower power consumption per MIP, etc.

Also, you talk about quality of components - - WE USE ONLY THE BEST COMPONENTS AVAILABLE. PERIOD. The processors are by Silicon Laboratories, FETs on the ICE series are made by Infineon or On Semiconductor, the drivers by Intersil or International Rectifier, capacitors by Panasonic or Rubycon, etc.etc. etc. All the parts we use are made by American, Japanese, or German companies, and are the finest quality parts available. We are also THE ONLY ESC manufacturer that uses 1% and .5% resistors throughout the design -- you spout off about our "tolerances" being poor - -when in FACT our...Continue Reading
Posted by c/f | Apr 14, 2008 @ 10:40 PM | 5,896 Views
quote:

The amusing part in all this is the fact that people who have now proven that most, if not all, of the claims made by XPS are either false or misleading are still being branded as "hating" XPS.

None of this is a surprise. I, and many others, called XPS out on their fantastic claims from the day he appeared on the Net...
Dead right.

I have no "vendetta" against XPS or JD (Jim Drew) but I do get really annoyed when I see someone with only a passing understanding of the (RF) technology they''re using trying to bamboozle and deceive people.

I was one of the original critics of JD''s claims in respect to XPS and *all* of my criticisms and predictions as to the limitations of the system (despite denials by JD) have ultimately turned out to be true.

In my case, once it became obvious that he couldn''t argue the facts (since they weren''t on his side), JD resorted to character assassination but that didn''t worry me, I''ve been called worse by others whose silly claims I''ve challenged before. Sticks and stones etc.

However, here''s the score to date:

1. "experts" say the tiny 1/4-wave stub antenna on the transmitter module is inadquate JD says that''s BS and he''s extensively tested the system to prove that it''s all you''ll ever need. However, at the system''s very first large public demonstration a dipole is hastily fitted to the transmitter being used and now dipoles are standard equipment. "experts" 1,...Continue Reading
Posted by c/f | Jan 14, 2007 @ 03:06 PM | 7,343 Views
More useless info.

Weights are rounded off.

Wing area does not include control surfaces or appendages, just the space between the sponsons.

... type.......................weight...wing....square inch/ foot...wing loading

Original Hydro foam.... = 10oz's, 12x15.5 = 186 si / 1.29 sf = 7.75 oz psf

Proto storm Launcher. = 6oz's, 8.25x10 =82 si / .57 sf = 10.5 oz psf

production SL...........= 9 oz's, 10x10 = 100 si / .69 sf = 13.4 oz psf

proto Mini SL........... = 1 oz ,6x5.5 = 33 si / .22 sf = 4.5 oz psf

Production Mini SL.... = 2 oz , 6x 5.5 = 33 si / ,22 sf = 9 oz psf


I realize that you are trying to make yours as light as possible, Where, in my case , I have been mainly going for power to weight ratio.

Because, as you have stated before, this is really a thrust vectoring machine. The dual motor has the advantage of better thrust vectoring then a single motor model and the prop blast go's directly over the control surface.

However as you have also stated , you do lose the power of one motor in full yaw maneuvers. and you also gain the weight of one more complete motor and speed control, when you can actually get the same thrust with one motor and a bigger prop. But we know the issues that can cause also.

My Brushless setup, each motor pulls about 8.5 oz's thrust, for a total of 17 oz's thrust. But two of them together pull a least 16 amps at full throttle. So I have to use 3S 910 mah battery's to handle the current.This puts me at a full...Continue Reading
Posted by c/f | Jan 12, 2007 @ 09:07 AM | 7,348 Views
............
Posted by c/f | Dec 19, 2006 @ 07:01 PM | 7,706 Views
General comments on thread

--------------------------------------------------------------------------------

This thread has grown and grown, and gotten off topic more times than any of us care to count.

I'd like to make a couple of statements that I know to be correct and may help some of the discussion that has recently taken place. Most of you know I don't typically reply to questions posted in threads. So, if you want to ask a question of me the best thing to do is to e-mail (not PM) me.

DSS systems operating in the ISM band of 2.4 GHz (like XPS and Spektrum) are required by band rules to avoid collisions with other systems. This virtually eliminates the possibility of a system causing a problem with another system. It does not matter if the system hops or sits on one or two frequencies, a hoping system (following the rules) will not hop to the frequency of a system already operating. A Direct Sequence system will not turn on on a frequency already in use.

Video camera systems are a problem. It is NOT the RC system causing the problem, it is the video system. Many of these video systems being imported are far from legal. They often operate on too wide a band width and most operate at illegal power output. If you want to operate a video system, get one that operates legally and properly.

DSSS/FHS will be long debated and different manufacturers will do it one way or the other. Some find advantages to one way or the other. In general there is no clear-...Continue Reading
Posted by c/f | May 01, 2006 @ 08:05 AM | 8,940 Views
Kokam America

Joon Kim, Ph. D.

Kokam America Inc.

5555 N. Campbell Ave.

Tucson, AZ 85718

1-520-529-1305 (office)

1-520-529-5534 (fax)

1-520-271-2422 (mobile)

joon_kim@kokamamerica.com

www.kokamamerica.com



Kokam Korea

Harris Kim
Director / Sales & Marketing,Customer service

Kokam Co., Ltd.
1261-3,Jeongwang-Dong,Siheung-Si,
Gyeonggi-Do,Korea, 429-849,
(Siwha Industrial Complex 2Na 304)
Tel. :+82-31-3620-141
Fax.:+82-31-3620-160
Cell :+82-11-9725-4503
www.kokam.com
hjkim@kokam.com