SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Nov 13, 2012, 05:33 AM
Closed Account
Joined Jun 2002
921 Posts
?

Your post says that the balancer shows the location of where to put the weight and the amount. Do you take in consideration the areas where is virtually impossible ( the blades, other than at the tips) to add any weight? Can you program the hub diameter, which is probably the area any weight can be added. Balancing an EDF assemblied has its plus's and minuses. It takes into consideration the complete rotational assembly. But if you remove the rotor from the motor and replace it back, re-balancing is probably going to be required.

Larry E.
LJE4357 is offline Find More Posts by LJE4357
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 13, 2012, 07:37 AM
Gorilla Glue Expert
PikeStaff's Avatar
United States, PA, Doylestown
Joined Sep 2010
2,707 Posts
DH, question regarding the cradle you used; the springs under the transverse bar appear to have some kind of guide bar / filler inside the springs. Please advise what you used there, as it would seem something reasonably stiff would be necessary to enable stability to the springs.

Thanks much!
PikeStaff is offline Find More Posts by PikeStaff
Reply With Quote
Old Nov 13, 2012, 10:45 AM
Registered User
Joined Feb 2010
285 Posts
my 2c, if you add the test weight to the spinner hub only when doing a 4 point balance method(my fav), then you have the access to any radial location to put the solution weight since it would also go on the hub. I tend to avoid adding to blades for several reasons, aerodynamics, limited locations etc..
db_sonic is offline Find More Posts by db_sonic
Reply With Quote
Old Nov 13, 2012, 02:51 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Quote:
Originally Posted by Underthetire View Post
Ohhhh another toy. Looked at all the vids, I really like it. My 8k dollar unit for precision spindles is just too big to work for the small model stuff. I might just have to order one. About how much in US$ and shipping to US?
Hi, please visit our webstore and you should be able to see cost + shipping in USD.

Thanks

DH
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 13, 2012, 02:59 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Quote:
Originally Posted by LJE4357 View Post
Your post says that the balancer shows the location of where to put the weight and the amount. Do you take in consideration the areas where is virtually impossible ( the blades, other than at the tips) to add any weight? Can you program the hub diameter, which is probably the area any weight can be added. Balancing an EDF assemblied has its plus's and minuses. It takes into consideration the complete rotational assembly. But if you remove the rotor from the motor and replace it back, re-balancing is probably going to be required.

Larry E.
Hi Larry,

The balancing software only considers the location at the hub at this stage (rather than the blades). You can program the radial position and the software will adjust the weight to suit.

Yes balancing the entire assembly can be complex, especially if there are coupled effects. Most balance solutions are single plane, however if the motor is unbalanced then you will get coupled effects. This can drive modellers crazy.

I have a link which discusses coupled effects (http://commtest.com/support/category...erhung-rotors/).

If you have difficulty in balancing, then I recommend performing a vibration spectral analysis to understand where the vibration is coming from. This site has some great info http://www.vibronurse.com/.

regards

DH
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 13, 2012, 03:03 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Quote:
Originally Posted by PikeStaff View Post
DH, question regarding the cradle you used; the springs under the transverse bar appear to have some kind of guide bar / filler inside the springs. Please advise what you used there, as it would seem something reasonably stiff would be necessary to enable stability to the springs.

Thanks much!
Hi,

I just used soft foam rubber similar to what we used to wrap our RX. The rubber should be soft enough to allow the spring to work but only applies enough damping to stop the spring from over oscillating. You could get away without it I guess, but seemed to work for me.

The trick with the cradle is to use soft springs (or soft mount). Hard mounts can be more difficult to use.

Good luck.

DH
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 13, 2012, 04:06 PM
Closed Account
Joined Jun 2002
921 Posts
My balancer

Here is a pic of the balancer I'm working on. It's primarily made to do turbine's and compressors for the auto superchager market. It will balance an EDF rotor, but not a complete EDF assembly. As you can see, most of the mechanial is done. The power supply, RPM, Radial, and Amplitude, displays, Acelometers, Radial Encorders, are complete. I'm presently working on the Micro Processor to do all the math and filtering. I'm doing the software on each function individually. I plan to have 2 versions, single plane for $1000 and dual plane for $2000. The balancer will do the same job, units that cost more than $10,000 will do.

Larry E.
SouthEast Model Products Inc.
Orlando, Fl.
LJE4357 is offline Find More Posts by LJE4357
Reply With Quote
Old Nov 13, 2012, 04:50 PM
Gorilla Glue Expert
PikeStaff's Avatar
United States, PA, Doylestown
Joined Sep 2010
2,707 Posts
Going to be an excellent option for commercial uses, Larry. Not reasonable for the everyday, average modeler, tho.
PikeStaff is offline Find More Posts by PikeStaff
Reply With Quote
Old Nov 14, 2012, 01:24 PM
Closed Account
Joined Jun 2002
921 Posts
Base

If there is enough interest, I will make the base & cradle to mount the EDF's on. Not sure of the price yet, gona depend on how many I make at one run. The more there are, the lower the cost.

Larry E.
SouthEast Model Products Inc.
Orlando, Fl.
LJE4357 is offline Find More Posts by LJE4357
Reply With Quote
Old Nov 15, 2012, 07:15 AM
Gorilla Glue Expert
PikeStaff's Avatar
United States, PA, Doylestown
Joined Sep 2010
2,707 Posts
Help

DH, having considerable trouble getting software to run; single plane loads up alright, but neither of the 4 pointers will. Constantly get messages that Flash content won't upload on web app, and the .xls says it has errors that prevent upload.

What am I doing wrong here?
PikeStaff is offline Find More Posts by PikeStaff
Reply With Quote
Old Nov 15, 2012, 02:50 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Quote:
Originally Posted by PikeStaff View Post
DH, having considerable trouble getting software to run; single plane loads up alright, but neither of the 4 pointers will. Constantly get messages that Flash content won't upload on web app, and the .xls says it has errors that prevent upload.

What am I doing wrong here?
Hi,

Check out the tip for using flash on our website,

http://www.dynexhobby.com/tip.html

Basically, you need to add the website as a trusted location. The other thing is to ensure you have the latest version of flash installed.

As for the xls, what version of Excel are you using?

cheers

DH
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 15, 2012, 02:59 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Re: Your balancer

Hi guys,

I have attached a spreadsheet for the 4 Point method for early versions of Excel. When opening, you need to enable macros.

cheers

DH.
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 15, 2012, 04:06 PM
Registered User
Joined Oct 2012
129 Posts
where are you located?
matchpoint is offline Find More Posts by matchpoint
Reply With Quote
Old Nov 15, 2012, 04:47 PM
Good vibrations.
dynexhobby's Avatar
Joined Nov 2012
233 Posts
Quote:
Originally Posted by matchpoint View Post
where are you located?
DynexHobby is based in Australia.
dynexhobby is offline Find More Posts by dynexhobby
Reply With Quote
Old Nov 16, 2012, 02:42 AM
Registered User
Joined Jul 2011
231 Posts
I remember ,some years ago, Jesus Artes (KJ66) had made a similar stuff to balance his turbines via a double trace oscilloscope.
michel49 is offline Find More Posts by michel49
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question EDF Impeller Balance old_dude Electric Ducted Fan Jet Talk 8 Nov 16, 2012 04:24 AM
For Sale Optical EDF Balancer for sale yakhakker Aircraft - Electric - Jets (FS/W) 2 Jul 29, 2012 12:16 PM
Sold Pair of balanced Wicked 4800 motor and matching ESC for twin EDF setup The Don Aircraft - Electric - Jets (FS/W) 4 Jun 25, 2012 07:34 PM
Discussion EDF fan balancing Mike873 Electric Ducted Fan Jet Talk 7 Apr 24, 2012 07:29 PM
Sold Exceed-RC stock 70mm EDF/Motor (balanced!!).......30 shipped RC_Bob Aircraft - Electric - Jets (FS/W) 2 Mar 26, 2012 11:46 AM