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Old Mar 01, 2010, 09:43 PM
The Kid
Thekid3418's Avatar
Detroit, MI
Joined Dec 2007
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Quote:
Originally Posted by murdnunoc View Post
APC Sport props are great! They pull less power and put out less thrust, more RPM than a same size APE Electric prop.

How bout 7x7, 7x8, 7x9?

Prices are right on and shipping is fair and quick.

They also have the 6.5" diameter Pylon props in 5, 5.5, 6, and 6.5 pitches if the higher pitch 7" props are too much for the power system.
Don't forget the 7x10" APC. Tower doesn't carry it, but my LHS had a bag full. I like the strength afforded by the Sport props, but that takes it toll on your motor shaft and mount. Its a trade off in strength its safe to say.

Kid
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Old Mar 01, 2010, 09:43 PM
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United States, CA, SF
Joined Mar 2008
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murdnunoc,

Did you get that data from ESC's logging?

The RPM is in the range I expected but your Watts are way way way too low compared to what I was expecting.

You know I have data for same prop from 16/40 on 4S.
Mopar sent me calibrated meters to measure volts and AMPs.....my numbers were within the accuracy range of the meters which Mopar sent me....so I know I'm good on accuracy of my numbers.

I was expecting nearly double the watts (little less????)


***Can you verify numbers from ESC's logging against Eagle tree's logging?


Gryphon
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Old Mar 01, 2010, 09:53 PM
Argue for your limitations
ajbaker's Avatar
Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by GryphonRCU View Post
ajbaker,

Return the pushrod/clevis package.
***Do not run stock pushrod or stock Clevis....under any circumstances.
Golly, Why? I looked pretty closely at them and they appear ok to me. What is the problem with them? What did I miss? Has anyone else had problems with them?
AJ
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Old Mar 01, 2010, 10:06 PM
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United States, CA, SF
Joined Mar 2008
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ajbaker

The stock rod is flimsy and flexes in flight and have been known to break occasionally (at the 90 degree bends).
The 2-56 sized rods are the perfect solution.

But way way way worse is the clevis, the damn 1 cent parts fails and you can just watch your Stryker Spiral out of control and get destroyed when it hits the ground.
The part which fails on the clevis is the plastic nipple which goes through the control horn...it breaks off, you lose control and down you go.


All of the above can be fixed for $5 and a bit of work from you.


If you are not experienced in making a rod to correct length then post and maybe others will help.
I'm going to skip on that write up...sorry.

You can search for that , or others can give you a link or do that detailed write up.
***If you have ever done an ARF build up, then you know exactly what to do.


Gryphon
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Old Mar 01, 2010, 10:22 PM
Argue for your limitations
ajbaker's Avatar
Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by GryphonRCU View Post

If you are not experienced in making a rod to correct length then post and maybe others will help.

Gryphon
I have made hundreds of push rods (for more scratch built models than I can count) over the years and I have 2 different "Z" bend pliars. So, I am sure I can work it out. I don't use the clevis method anyhow.
I just looked at the clevis and sure as rain, the little piece in the middle is plastic. That is just pure crazy IMO - A failure waiting to happen.
AJ
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Old Mar 01, 2010, 10:26 PM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
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Quote:
Originally Posted by GryphonRCU View Post
murdnunoc,

Did you get that data from ESC's logging?

The RPM is in the range I expected but your Watts are way way way too low compared to what I was expecting.

You know I have data for same prop from 16/40 on 4S.
Mopar sent me calibrated meters to measure volts and AMPs.....my numbers were within the accuracy range of the meters which Mopar sent me....so I know I'm good on accuracy of my numbers.

I was expecting nearly double the watts (little less????)


***Can you verify numbers from ESC's logging against Eagle tree's logging?


Gryphon
Uh-oh.
Yes, those were pulled off the Eagletree. I tried pulling up the Castle logging for the session but couldn't find my 8x8 prop tests in the data.

This sounds like it's either very good or very bad for my motor.

Gryphon, I can send you the Eagletree file to look at if you like.
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Old Mar 01, 2010, 10:30 PM
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United States, CA, SF
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No need my friend,...I trust you.


This site in link below always gives fairly low efficiency numbers in my mind...I mean too low.

But in this case it shows 135% LOL....your data is convicted, killed and the nails have been put on the coffin.

You are my good buddy and I am playing and teasing you a bit...I know you'll laugh.


Maybe Eagle tree had a hiccup.....Hey when it happens, you'll know....such as 50,000 RPM if you are expecting 30,000....or voltage is zero then jumps to right amount, etc....don't worry it is rare.

Just try it again tomorrow.


http://www.badcock.net/cgi-bin/power...+++0&Temp=20.0


Note: select prop and also enter Volt, and AMP

***********Do not enter Watts, it gets calculated.


For many of the props listed, you will not see thrust constant....in this case it does not affect us, because we don’t need that number, we are looking for efficiency.

Other props maybe mislabeled but the experienced PRO’s know that the APC E 6.5X6.5 is really APC Pylon series.....


I'm not saying this site is all that.

p.s. I know your motor is capable of more RPM at higher voltage, 5S is likely way too much....and 4S not maxed....Wish there was 4 1/2 Lipoly so you could see your motor's max RPM for 8X8 Sport.
I told you this is just a little side distraction.
But your Watt numbers caught me off guard.

***My guess is that only your AMP reading was off.......I'm sure you have logger set on 10 poles and have correct RPM right/close to where I had assumed without any calculations based on our previous offline discussions on other props and voltages.

p.s. I better go finish helping my relative for next 1/2 hour to 1 hour.....I'll be back.


Gryphon
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Old Mar 01, 2010, 10:39 PM
You down with EPP?
johnnyrocco123's Avatar
Houston, Tx
Joined May 2009
6,833 Posts
Quote:
Originally Posted by murdnunoc View Post
I ordered 2/13 and it was delivered on 2/27. Didn't leave the warehouse till the 23rd.

They're running, but it's slow.

I don't know what's up with the live support, either. Tried calling them re: my order and no answer. My guess is that while the warehouse is open, their call center is still closed.

The online chat was up when I tried it last week.
I ordered on Feb 21st and it has been idle ever since. Problem is one out of 20 items on a multiple person order is backordered. They will keep it until it comes in, there is no way I know of of contacting them to tell them to drop the item and ship the huge order. No email, chat, phone....

Status still reads closed, national holiday
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Old Mar 01, 2010, 11:16 PM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
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Gryphon,

Gots to get some sleep now. Dang new heli has different plans than rest for my schedule.

I'll run the test again tomorrow and see if it comes out different. I'll also make sure to have the ESC's logger going to get some degree of redundancy. If anything, the ESC should read 20% high or so.

135%... Now THAT'S some power! I'm writing an email to NASA right now.
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Old Mar 01, 2010, 11:36 PM
Argue for your limitations
ajbaker's Avatar
Lincoln, CA
Joined Oct 2006
8,422 Posts
Choose my motor

Attached is a list of my motors and ESC's. It is simpler for me to just give you the converted spreadsheet and sort it by Watts. Let me know what you think.
AJ
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Old Mar 01, 2010, 11:37 PM
Argue for your limitations
ajbaker's Avatar
Lincoln, CA
Joined Oct 2006
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Quote:
Originally Posted by johnnyrocco123 View Post
I ordered on Feb 21st and it has been idle ever since. Problem is one out of 20 items on a multiple person order is backordered. They will keep it until it comes in, there is no way I know of of contacting them to tell them to drop the item and ship the huge order. No email, chat, phone....

Status still reads closed, national holiday
If you are a platinum member, you should be able to edit your order. I have done it several times because of the same situation you have.
AJ
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Old Mar 02, 2010, 02:19 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
4,997 Posts
Quote:
Originally Posted by Thekid3418 View Post
I like the strength afforded by the Sport props, but that takes it toll on your motor shaft and mount. Its a trade off in strength its safe to say.

Kid
This is where the Custom RC Parts motor mount comes in, along with a 5mm shaft for a "bulletproof" motor/mount/prop setup.

I was running an 8x4 E prop from APC, came in for a landing, touched down, and nailed the throttle. (I needed to check the strength of the mount) The prop broke @ the hub/blade interface and there wasnt any damage to the shaft or to the motor mount from Gary.

If you havent had the chance to try a mount from Gary, when you stop by this way, we can bolt one up to your speedster and see how you like it.

I absolutely HATED fluids, just about unpredictable till you wrap yourself in it 150%, then you can start getting it. At least thats how it was for me, any distractions and I had to start over.
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Old Mar 02, 2010, 02:47 AM
Why the dirt on the wings?
moparmyway's Avatar
New York
Joined Jan 2009
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Quote:
Originally Posted by murdnunoc View Post
Your wish is my command, Sir!

Scorpion HK3026-1400 APC 8x8 Sport
14.83V 64.91A 19,672RPM
14.68V 63.80A 19,607RPM
14.50V 61.63A 18,404RPM
14.05V 56.50A 18,237RPM

I'll wait to see what KV my modified Medusa 1400 comes out at. If it's around the same as the Scorpion, that'll make it worth the plunge to run 6S on both motors.
Murd Dude..............
Thats like 95% RPM efficiency @ close to 150 mph pitch speed ?????????

Are you sure the pole count is correct ??


Your box is going out TODAY.
I mailed out a package last night, but (am embarrassed to admit) I didnt have enough cash on me to send yours, will PM ya on the "overnight" package later when I get home from work tonight. Sorry again for another delay, Mr. Murphy has been staying real close lately, probably a good thing we still got about 6-8 inches of snow, at least I aint having any flights with him !!!!!
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Old Mar 02, 2010, 08:41 AM
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
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Quote:
Originally Posted by moparmyway View Post
Murd Dude..............
Thats like 95% RPM efficiency @ close to 150 mph pitch speed ?????????

Are you sure the pole count is correct ??
Yep. Pole count is on 10 poles. I'll be running this test again this evening to get a second batch of results. Hopefully the Amps were a glitch and something that makes more sense will come out this time.

The true KV of my motor is 1470KV, so that brings the RPM efficiency down to 90%.

i HAVE been getting RPM efficiencies in the 90-83% range at 2400-3300W with this motor. This baffles me, as it seems that it ought to be drug down some by this much power. Data analysis and graphing with Mr. Gryphon's help does suggest that the motor is starting to drop its efficiency at this power range, though.

One thing I do need to do is run a second KV test now that the motor has had some workouts.

I'll post the second results tonight.
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Old Mar 02, 2010, 08:10 PM
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murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
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Okay, all bet are off on this Scorpion's performance till I get some bugs worked out/figured out.

My Eagletree 150A logger is now reporting the same amps as my last test (65A) while the ESC reports 113A from the same data point. Given the Ice having read 20% high before, I can assume that my true amps are 94A for the 8x8 prop on 4S, which is also much closer to the estimates TheKid and Gryphon came up with.

So it appears something's screwy with my Eagletree logger.

Also, my KV for the Scorpion 1400 motor has jumped from 1470 to 1690. Bad, I think?

Surely I couldn't have hurt those 200c magnets when the motor windings have never come down above 100F.
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