Fully Protected Propellers by SFC - Quad/Tri/Hexa - RC Groups
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Jul 16, 2012, 11:54 AM
sfc's Avatar
New Product

Fully Protected Propellers by SFC - Quad/Tri/Hexa

########## UPDATE 11/14/2013 ############
This frame pictured below did not go into production -- please refer to the new thread or http://safeflightcopters.com for current production quad airframe

As a long-time lurker on these rcgroups multi-rotor forums, I'd like to introduce myself: My name is Erik and I represent Safeflight Copters, a new venture that aims to promote multicopter/multirotor safety as its #1 goal.

Some background: After injuring myself on numerous occasions over the years while testing and flying my tri's/quads/hexas, I started trying to re-think propeller protection on these machines. I wanted something that fully protected the propellers from the outside world while still being lightweight, nimble, and having little reduction in flight time (as compared to a machine with bumpers). My only goal - which became an obsession - was to create a propeller guard template for almost any multi-rotor configuration that one can fly anywhere (especially in close quarters) without fear of risk of injury to oneself or others. That goal has been met. My only fear is that the propeller manufacturers will disown me because I never have to replace and balance propellers with these machines, even after crashing.

Some technical info:

For simplicity and ease of assembly, our Quadcopter kit is based around the rcexplorer.se tricopter electronics and motors. Props are 10x4.7

Current specs (approximate and subject to change):

All Up Weight with battery: 1050g (37oz)
Frame weight empty (no electronics, motors, or battery): 400g (14oz)

Flight time with 3s 2200mah lipo: 8 minutes

We are currently taking pre-orders and - based on interest - will aim to launch a limited production run of 1000 QuadCopter kits Sept 1st, 2012.

Please don't hesitate to comment and ask questions or submit questions through the site. http://safeflightcopters.com
Last edited by sfc; Nov 18, 2013 at 02:09 PM. Reason: added update
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Jul 16, 2012, 12:28 PM
Registered User
is this modular ? would be interested to see it fit into some common frame.
Jul 16, 2012, 12:38 PM
Registered User
As a long time lurker myself, and after reading about and seeing the results of multi-rotors gone wild, safety has always been a major concern for me. I really like this design. I watched the videos, and now I want to build one. Well done.
Safeflight Copters Quadcopter Summer Fun Flying (1 min 3 sec)
Safeflight Copters Prototype Montage (1 min 35 sec)
Jul 16, 2012, 12:42 PM
G-unit's Avatar
I like it, I would like to try that...
very cool..
Jul 16, 2012, 12:44 PM
Ape-pilot Extraordinaire
TS00's Avatar
I would be interested in seeing a few crash tests. The frame doesn't look very strong to me. I'd also be interested in seeing some gyro vibration data. A less stiff frame will transmit lower frequencies much better, leading to more gyro noise.

Jul 16, 2012, 01:04 PM
Registered User
Really like the idea and the design. Looking forward to see the tricopter. For me it makes more sense to make versions for smaller props, because they are more likely to be flown in limited space and closer to people.
Jul 16, 2012, 01:13 PM
manual flying apologist
Adidas4275's Avatar
Looks good.

I would buy a set of the prop guards to out on my gear if you ever sold them separate and for other sized props

Looks like a good idea
Jul 16, 2012, 01:15 PM
sfc's Avatar
Glad you guys are liking it!

@newmanhyde: I originally designed this to be modular where folks can order the prop guard and screen kits and mount them directly to their own scratch-built machines. Stay tuned on this as it's on the roadmap!

@bh flyer: Thanks for posting the vids!

@ts00: The rings are designed to "break free" at their mounts upon a modest crash. They snap back on. The ring's thrust angles are also adjustable for yaw authority. The frame has isolator bushings in which the battery, receiver and flight controller are mounted together one unit isolated from the rest of the frame. I don't currently have a data logger to log vibrations. However, when I mount a GoPro to the isolated section via a standoff mount the quality is great without visible vibrations. Sorry no pics of this because we're still finishing up the gopro fuselage housing, which is elongated to offset gopro and battery weights. We will include that housing and hardware in the kit.
Jul 16, 2012, 01:19 PM
Registered User
Pre ordered! Sep. 1 seems like a long way off.
Jul 16, 2012, 01:42 PM
Registered User
Definitely interested in the professional design for AP work.
Jul 16, 2012, 02:59 PM
Nice mission You've got to like any project that makes multicopter's a bit safer.

Your recommended list for motors only mentions the DT750. Will your design fit Pulso, Tiger, RCTimer ~2830 , ~50g sized motors as well?
Will you be making replacement parts available?
How does one gain access the FCB for setup?
Where are the ESCs mounted?
Quadrocopter and Tricopter Info Mega Link Index
Last edited by jesolins; Jul 16, 2012 at 03:08 PM.
Jul 16, 2012, 03:20 PM
Registered User
ripmax's Avatar
Looks great, very interested in buying if it will retro fit to my existing quad electronics, naza fc, esc's etc.
Jul 16, 2012, 03:23 PM
James not bond
jy0933's Avatar
what is the efficiency loss due to the top/bottom cover?

also the prop upgradability? ( when you want more payload.. you will need to change motor/prop.. the frame might limit the max possible payload.. how do you solve it? (also you didnt specify the size)

also for the material.. is there any way to reduce? 400g seems a bit heavier for mini size quad.. any plan for cf?
Jul 16, 2012, 03:59 PM
sfc's Avatar
@jesolins: Jim, thanks for your questions and positive response. I like your headline about focusing on safety in 2012! To keep prototyping costs low, the motor mounts are currently designed around the DT750, however, production models will feature universal mounts that allow the height of the motor to be adjusted, featuring a simple clamping system to accept most popular motor mounts. I am currently in the prototyping process of these universal mounts and once finished testing I will provide a list of motors that are confirmed mount-able. The limitation is the area where the motor passes through the bottom screen mount, but can be trimmed based on motor diameter. Replacement parts will be available as soon as we release. The FCB is accessible for tuning, etc through a slip-on hatch cover in the top of the fuse, and the mounting area available for the FCB on the airframe is large enough for the KK-based controller board which allows the others to fit. (I fly with the KK and the DJI Naza controllers). The larger FPV fuselage (under development) has plenty of room for more gear. The ESCs are mounted along the sides of the airframe body, with cooling coming through slits in the body. I hope that covers your questions, and please don't hesitate to ask more. The website is a work in progress and we'll be updating it with more pertinent info as questions come in.

@ripmax: See above!

@jy0933: The efficiency losses were measured at 10% average loss in thrust with the 10x4.7...Any more than that I would have scrapped the project As you pointed out, the limitation to protecting the props, of course, is that it limits what props you can run. The 10x4.7 APC's do great with the non-FPV weight or the addition of the GoPro and 900mhz 500w transmitter. Our design is easily scalable and we plan to release smaller kits down for 8" props up to 12"-15" props, based on demand. While I can't promise anything, our final target weight for the empty 10" prop quad airframe is more in the 300 gram range as we are experimenting with lighter plastics and injection molded screen material. I'm well aware of the trade-offs with this design vs. open props but I believe they are worth it!

edit: Forgot to mention that there are no plans for CF at this time due to high costs
Last edited by sfc; Jul 16, 2012 at 04:05 PM.
Jul 16, 2012, 04:32 PM
James not bond
jy0933's Avatar
how about replaceable cage.. so it wil be easier to replace with different size props? (according to duct fan, if the cage is close fit with prop, you might reduce the tip loss.. so the over efficiency loss can be minimized)

radial upper/bottom cover might reduce the efficiency lose.

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