Need help with motors and gearboxs...

[Anythingoes]

Hoping to get the attention of a few of you tech savvy guys, shop technician or experienced builders. Let's talk gearboxes an motors for a few mins...

Project - Umarex Hk416 cqb (aeg) Circa 2009.
Completely stock.
V2 gearbox.
Current fps - dunno.
Site limits - 350fps.

Okay so basically I have a lil project I was starting an I need some advice on a few things. The end game will be lightning trigger response and great accuracy over range, robust and sturdy. Consistency is key with the fps too.

I have a few points I want help with...

1. What is the best order to begin. Basically where do I start?
I was thinking - Prowin/G&G hop > PDI barrel > Guarder M100; or larger (more robust) spring trimmed down? Then from there, moving onto the motor an gearbox. Am I heading in the right direction?

2. I am considering getting a Lonex M170 high torque balanced motor, the one with the neodymium magnets. It's probably overkill, but I'm future proofing the lower incase I fancy sticking a larger upper on one day an cranking up the spring to DMR spec.

So, what kind of modifications to the gearbox you recommend to stop the motor stripping everything apart? The only thing I know really is maybe 1:13 ratio high speed gears, to up the ROF, along with the high torque motor will that be okay?

3. R-Hop... What is this voodoo and is it all its cracked up to be? Read a lot of people saying it is the best, but the hardest to do. What difference does it actually make? Is it expensive?

I realise it's a bit long winded, so thanks for sticking with me.




There she is... Ignore the cable tie. She was in an accident I believe an needs new plugs.

Sent from my LG-H850 using Tapatalk

[sj_asc]

Re: Need help with motors and gearboxs...

What I can suggest is;

#1 - Ditch the prowin idea, particularly if you have question number 3 in mind. You are simply paying for eye candy and a slightly nicer dial, the actual hop arm angle is inferior to the stock design when it comes to flat hopping, some people have made attempts at custom arms but in reality they still don't work as well as an OEM arm for this. Furthermore, the other internal dimensions are off spec, so in some builds it can take a bit of work to get them to find the right balance between feeding and sealing.
In addition to this, the internal chamber bore is also offspec, so even when you get the feed/seal balance right, you are still likely to end up with sealing inconsistencies that will be caused by magazine feed rate/tension and it's relation to the nozzles position whilst returning to battery.

#2 The motor is a monster for power output (both rpm and torque), the only downside is power consumption will rocket. The main thing you want to be looking at here is current draw both and stall and nominal. Stall current is starting current, and that's what is required each time you pull the trigger, the closer to this figure that the motor can get the faster it will start up and the higher the starting torque figure will be and thus the quicker it will reach peak rpm.
Firstly, for optimal results, I would ensure that your battery pack can SUSTAIN the stall current draw, this way you will have a faster startup as the voltage sag under load is likely to be significantly lower than with a conventional "airsoft" battery pack.
Secondly, but just as if not more importantly, ensure that the wiring loom is within capacity, this means completely through - no bottlenecks (tamiyas, spade connectors, etc..)
Make use of a high amperage FET to ensure that the wiring loom rating is carried through whilst switching and obviously to prevent arcing at the trigger switch contacts.
For wire with this motor, I would go for at least 16awg.
For battery pack, I would suggest avoiding airsoft specific packs as the majority of them are over priced and very poor performers - go for an RC market LiPO pack if possible.

13:1 gears will work, however in conjunction with the said motor and wiring config you will see some very high rates of fire even with a 2 cell Lipo, it depends on what your main performance goals are.

Others;
Piston - Correct angle of engagement for prolonged lifespan of the initial pickup teeth.
Avoid anything made from polycarbonate as it is sub par for dynamic loading applications. Something that is made from GR Nylon or POM and with side reinforcements to the initial pickup tooth area will serve you well. At UK power level, there is no need to be using a Full metal rack piston unless going for insane rates of fire or dual sector configurations. It's safer to use a piston with a part plastic rack in the pickup area where possible. Something like a Laylax Prometheus Hard piston, supercore or even Lonex red (might need a diet though!)

#3 - R-hop, yes worth doing, but the biggest advantages will be seen if you are using heavier weight BBs since that's where the more efficient application of hop and related energy efficiency gains shine through. Expensive? not really, even if you opt for the genuine parts from Hunterseeker5, they are relatively cheap. Tutorials out there will allow you to figure out how to do the mod correctly and for free. The expense of paying someone else to do it can be high since it can be time consuming, but also with many "recommended tech professionals/related businesses" being so busy you end up with a higher chance of a rush job (something which has become more common in recent times) and a large amount of money wasted. If you take a look at the tutorials and decide it's not something you could do, then maybe it's worth the gamble, but otherwise it's worth the extra level of quality and time that you can put into it to get it just right.

[Sprint]

Re: Need help with motors and gearboxs...

]Hoping to get the attention of a few of you tech savvy guys, shop technician or experienced builders. Let's talk gearboxes an motors for a few mins...

Project - Umarex Hk416 cqb (aeg) Circa 2009.
Completely stock.
V2 gearbox.
Current fps - dunno.
Site limits - 350fps.

Okay so basically I have a lil project I was starting an I need some advice on a few things. The end game will be lightning trigger response and great accuracy over range, robust and sturdy. Consistency is key with the fps too.

[/QUOTE]

Hi! For your goals I would do the following for max user enjoyment and least amount of time messing about.

GEARBOX
* Strip and thoroughly clean all parts, check the grooves that the piston guides run in are nice and smooth, the same goes for the groove the tappet plate runs in.
* I would keep standard gears, ROF will be high enough if your packing a high C rated discharge Lipo, super high ROF doesn't really go hand in hand with shot to shot consistency and reliability.
* With the gbox now clean and dry, shim the gears, starting with the gear nearest the piston and then work your way down the box.
* You should already have a Type D ~ 3/4 cylinder in there, cool.
* Get a piston as recommended above, sorbothane the cylinder head, correct AOE.
* PTFE tape the outside of the cylinder head so that when you insert it into the cylinder you have no doubt its air tight.
* I do not know if the Umarex has a ballraced spring guide, if it hasn't and the new piston hasn't you'll need one.
* For the money the ICS turbo motor is excellent, I you're feeling flush then go for the Lonex motor.
* Nozzle - a dab of silicone grease so it moves nicely, dry build the gbox with the tappet plate/nozzle in the full forward position, check either by measuring or witness marking the hop bucking lips that the nozzle penetrates into the bucking a good 0.5mm, this is essential for air seal and hence consistent FPS.
If it doesn't go in far enough either use a longer nozzle or sand the front of the tappet plate to allow more forward motion.
* SP100 spring should do you 340fps with perfect air seal.
* Build up the gbox with high quality silicone grease on the piston head / cylinder, grease the rest of the box with extreme pressure grease, I personally use moly.
* Blue Loctite / thread lock the gbox case screws.

HOP UNIT
* Keep it stock, just make sure there is no play / wobble in hop arm.
* To begin with id run a straight Prometheus soft blue bucking and flat hop tensioner, this will yield pretty damn good results, if you feel like it later on you can get the parts together for R hop, but as said previously it is time consuming and unless its done perfectly will hinder rather than improve, don't get me wrong, done right they are the ultimate.
* Use a quality barrel thats between 6.03 and 6.05, i have better results with the latter.

ELECTRICS
* 25 C or higher discharge Lipo, stay with 7.4V, you may have semi auto overcycling issues on 11.1
* A decent charger, Turnigy Accucel for example.
* High amp smart Fet that you can wire in trigger sense (MERF 3.2 for example), this removes the trigger contacts carrying the load and increasing resistance.
* Deans or XT60 connectors
* 16 or 14 AWG wire
* you can also ditch the little blade terminals on the motor and screw the wires on with mini ring terminals for a more solid / high amp / low resistance connection if there's room.

SUMMARY
* Shim set, Sorbothane, piston, spring, ball raced guide, SP100, ICS Turbo motor, check nozzle to bucking.
* Prommy straight soft blue, Prommy flat nub, 6.03-6.05 barrel.
* 7.4 Lipo, Fet, wiring.
* 0.25 - 0.28 bb's

All well you'll have no issues accurately semi'ing 180-200ft, farther if R hop'd, and it'll have a pleasing ROF, and i nice quiet / deep note to it in light of proper air seal and sorbothane / POM piston.

I like the venerable AEG, always ready for abuse!

[Anythingoes]

Re: Need help with motors and gearboxs...

Wow. Some really thorough and detailed instructions and guidance there guys. I'm very grateful! You really know your stuff. By far and away the two best answers I have had. With all this knowledge I'll surely get the edge over my friends next time.

I'll heed the advice, and I'll hold off on the R for now give myself time to get used to the flat so I can notice the difference. And that range of around 180-200 will be a HUGE improvement on what I get now. Very excited to get started!

Thanks again guys, true gents.

Sent from my LG-H850 using Tapatalk