***This article was posted in the New Jersey Airsoft Association's November Premier Player Report. Reposted courtesy of AirsoftNJ.com***
Review of Siegetek Concepts Dual Sector Gear
The Quest for 60 RPS
Disclaimer: This review is for people who have a general understanding of the mechanics of a gearbox. If you're not too well versed in how a gearbox works Mechbox.com has a great diagram you should take a look at: http://www.mechbox.com/data/how-the-mechbox-works
Do I really think I can get my AEG to shoot 60 Rounds-Per-Second at an acceptable FPS? I have no clue, but I'm going to try, even if I destroy my gearbox in the process. I'm proud to introduce a new product by Siegetek Concepts, the Cyclone Dual Sector Gear. It is developed and produced by RiotSC, the Administrator of AirsoftMechanics.com. It retails for $55.
How it works: instead of having the sector gear pull back the piston and release it once every 360 degree revolution, this pulls back the piston twice in one revolution. The downside is it only pulls the piston back half way so your power output is decreased by about half. I'm thinking that it my original setup gives me 30 RPS, this might give me 60.
Cyclone Dual Sector gear (left), and Prometheus standard sector gear (right)
Compared to a Prometheus sector gear, this gear looks just as good. Perfect CNC work, no burrs, no rough edges. It's made out of chromium molybdenum steel. Chromium molybdenum steel is used in things such as AK-47 receivers, clutch and flywheel components, gears, crankshafts, and structural tubing. Furthermore, the steel is case hardened. This significantly hardens the outside of the metal which reduces the wear and tear on the part.
The gear is compatible with all flat standard ratio and high-speed gearsets. It is only recommended to be used on guns with M4 length (363mm) and shorter barrels due to the decreased volume of air in the cylinder.
note the double notches for the semi-auto cut-off lever; this makes semi-auto shots still possible with this gear
I'm using my high speed Noveske M4 for this project; it currently shoots 30 RPS at 320 FPS with .25's
. Parts installed that we have to worry about
: PDI 170% spring, piston short stroked 2 teeth, TM EG1000 motor, 10.8v 4200mah Intellect Ni-Mh battery (and other electrical tweaks like 16 gauge wiring, deans connectors, etc.).
Installing this gear is like any other; shim it properly and you're all set. The tappet plate has to be shortened so it doesn't interfere with the 2nd nub that pulls back the tappet plate for the second shot. Like all high speed setups, at least the 2nd to last tooth of the piston should be removed to negate any timing issues. If using a high powered spring a piston with all metal teeth is advised.
Since the gear only has 8 teeth pulling the piston back (versus a regular sector gear which has 16 teeth), you will loose FPS. I installed the highest spring I had on hand which was a PDI 190% (which normally gives me about 450 FPS with .2's).
INITIAL ROF/FPS READINGS
With this setup I was hitting 41 RPS at 300 FPS with .2's!
That is 11 RPS higher than I've ever been able to obtain before. Also keep in mind this test was with a stock TM EG1000 motor, which although it's the benchmark for all motors out there and an absolutely great motor, isn't the highest performing motor out there. The FPS of 300 with .2's isn't ideal, but better than a stock TM. Note that my TM hi-caps would not feed at this RPS for prolonged periods of time. I didn't get a chance to test my MAG midcaps or TM standards.
NEXT EVOLUTION - RAISING THE FPS
Now that I've proven the gear works as advertised, it was time to raise the FPS to what I'm used to. As long as I could get the same FPS the Noveske was originally getting (at a higher ROF of course), I would be happy. The parts I was missing to accomplish this was a monster spring (remember your FPS is reduced by about half), and a new motor to pull back that spring.
I decided on getting the strongest AEG spring on the market, a Guarder SP170. I had previously used the SP160 before and was getting 580 FPS with .2's, so I can only imagine the FPS this stronger spring would get. For the motor, although the EG1000 would pull back the spring, I needed something with more torque. I decided on the G&P M160 Charger motor which reviews cite as having comparable performance to a Systema Magnum for a little over half the cost (and none of the QC issues, bad pinion gears, or shorting problems like the Magnum).
I installed these parts into my gearbox without any issues (besides literally spraining my wrist wrestling the spring into the gearbox) and went for the first test: 345 FPS with .25's at 34 RPS
. Perfect. A little under 400 FPS with .2's for the fields that require that, yet still enough FPS to reach out to 200 feet with a burst of full-auto. 34 RPS also wasn't too shabby for my second try. Unfortunately, the SP170 spring was too much for my 7mm Kanzen bearings and I blew one of them. Reinstalled another to replace it, and another one blew.
Stay tuned for my future tests when the 7mm bushings and a Systema Magnum motor arrives.
By the time those parts finally arrived RiotSC had already sent me the spacer to use with the Cyclone Dual Sector Gear. This spacer precompresses the spring to produce higher energy output.
Photo borrowed from RiotSC of AirsoftMechanics.com (I forgot to take one of my own)
I installed the spacer, MODIFY 7mm bushings, and tested the gun with the same G&P M160 motor but with the original PDI 190% spring. 38 RPS at 320 FPS with .25's
I still had the Systema Magnum motor to try, but I ended my testing at this stage since my hi-caps still feed at this RPS, so I decided not to push the bounds and install the Systema Magnum motor which would almost undoubtable raise the ROF higher than my mags could feed.