efflux RC...Viper jet / Skyworld 70mm EDF installation - RC Groups
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Feb 22, 2010, 09:35 PM
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efflux RC...Viper jet / Skyworld 70mm EDF installation

Hi guys,
I'm doing this Semi-build as a company project, as we are installing a few of our products in the jet. This project will be our entry in the "SAPAC Viper speed contest"
The main topic will be the installation of a Skyworld 70mm EDF in the Viper composite jet. This would most likey be similar for the T-45, and the L-39 composite jets. (Although I have not seen the inside of them yet, so don't hold me to it.)
Here's a few pics to get started with.
We're starting of with the red/white version, as this one will be the easiest to apply our custom Scheme to. The finished model will be clearly identifiable as our SAPAC product when completed.

Should be fun build with the absence of foam dust.
Latest blog entry: Updated blog - Oct 2017
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Feb 22, 2010, 10:27 PM
1ONkar, Satnaam
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Looking very nice

Feb 23, 2010, 12:25 AM
Registered User
If the fan support is the same as the SAPAC L-39 (held in place by tie wraps), you will need to do a modification to the 4 support plates that the fan sits on due to the center ring on the outside of the fan body. Once you have lowered these plates the fan will perfectly and snugs right up to the inlet duct and the rear fan support.
Feb 23, 2010, 12:41 AM
efflux RC's Avatar
Thanks Dennis.
Your getting ahead of me. The crossmembers between the two fan formers have been slotted. I want to get some work done so I don't spend all my time posting. Pics coming. There are a number of things that will be unique to the installation of the Skyworld EDF. The fan will not be secured with tie wraps, as the power levels will be very high, and I don't want to risk the fan unit rotating in the formers. No glue either.
Latest blog entry: Updated blog - Oct 2017
Feb 23, 2010, 03:01 AM
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The first pic shows the component brands being used for this project.
Next is the Skyworld JP-700-101-T, 70mm EDF kit. The included 8 bladed (70% nylon, 30% glass) rotor has been tested by us to 1284 watts. We will be far exceeding this, and will be using a Schubie rotor time. (a less expensive alternative would be a HET or WeMoTec rotor, which we hope to have available soon)
The skyworld EDF has some differences worth noting, an will cause some differences in the build procedure.
The unit is ALL aluminum (minus the rotor) Therefore is quite rigid, and not easily subject to deformation. It will transfer very high loads.
The unit is very effective as a heat sink to draw heat away from the motor (especially in high KV applications)
The unit has a non removable intake lip.
The Heat sink cone also draws heat from the motor, and smoothes the airflow behind the motor. We will be cutting a 5/8 Dia hole in the end of it to aid "flow thru ventilation" for the motor. Pics later
There is aft section (Thrust cone) which has a feed thru for the motor wires. (so they don't penetrate the plastic thrust tube, which often deforms it when assembled)
The Thrust cone maintains 100% FSA until the efflux is past the motor/motor fairing. Then it necks down at the aft end. This is important to proper efflux as can be found in the posts of Clausxpf. The Plastic (or Mylar) thrust tube extension, to the end of the jet is attached to the aft end of the alum Thrust Cone. Pics on this later.
Latest blog entry: Updated blog - Oct 2017
Feb 23, 2010, 03:29 AM
efflux RC's Avatar
The SAPAC Viper instructions are very well written and photograhed.
Due to the design of the Skyworld EDF and the purpose that it is intended for me in this build, I will be deviating from the SAPAC manual.
this build is to be used a a guide only for similar installations. Other means of the installation may be better for your project.
I have decided not to remove the inlet lip from the EDF housing. Being alum, the O.D of the housing is far thinner than the plastic ones. This would leave about a .10 diametrical gap (per side) between the EDF housing and the enlarged end of the intake duct. It fits better with the lip in place. (I really don't think this will degrade the perfomance noticably)

The EDF housing has a double ridge in the middle area. The the braces for the EDF formers need to be notched slightly in this area. I will epoxy a small CF or ply plate under the braces later. The new notches are visible in the photo.

In the photo with the EDF next to the intake duct, note that the mating angles of the EDF mount, and the duct are slightly different. Leaving a(his would not be a problem with a slip in fit (as with the stock SAPAC fan). But I will be butting the inlet lip radius to the duct end. I don't want to trust this big of a gap to tape. So I fabbed a small CF strip from .25mm plate. At sizes 1mm thick and less, it's easy to score and snap. I heat formed it a bit to resist "spring back" aa bit. This piece will not be installed (taped in place) until the fan assy is complete.
Last edited by efflux RC; Feb 23, 2010 at 03:43 AM.
Feb 23, 2010, 03:40 AM
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The Plastic Thrust tube will be installed different from the SAPAC dirs. I will be fabbing a new Thrust Tube from .015 Acetate (Mylar). The Mylar Thrust Tube will be attached to the alum Thrust Cone, and installed from the Power Hatch. Then, after the edf is installed, the Thrust Cone can be slipped onto the EDF, and taped in place with alum tape.
Latest blog entry: Updated blog - Oct 2017
Feb 23, 2010, 09:58 AM
1ONkar, Satnaam
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[QUOTE=efflux RC;14423224]

The Thrust cone maintains 100% FSA until the efflux is past the motor/motor fairing.

Gary, what is the reason for thie above statement. Does it improve any thing?
Man, you do good work. love seeing you build this bird.
Last edited by 1satnaam; Feb 23, 2010 at 10:00 AM. Reason: add more comments
Feb 23, 2010, 01:51 PM
efflux RC's Avatar
Thanks Fredie.
I'll leave it up to you to make your own determination.
Here's some discussion and diagrams regarding EDF duct design by clausxpf:
Last edited by efflux RC; Feb 23, 2010 at 01:58 PM. Reason: spelling
Feb 23, 2010, 11:05 PM
efflux RC's Avatar
We've decided that a build thread for this project would not be in our best interest. and are discontinuing it.
If you would like assistance installing Skyworld EDFs in any jet, please contact us.
Latest blog entry: Updated blog - Oct 2017

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