29. 11. 2024
Based on our customer's feedback we've decided to dedicate today to thorough testing of our PandoRA gears and pistons. The feedback consisted of complaints regarding our 20:1 and 10:1 gears and pistons breaking just after a couple of shots on M120 Springs.
So we've built a replica from our parts, including a pre-production version of the new receiver, standard V2 gearbox, and prototype versions of the outer barrel and handguard.
Used parts:
- New Receiver AR15 (7144)
- Gearbox V2 with prototype horizontal adjustment (6392)
- Nozzle 21,3mm (6731), Silent piston head (7549), Cylinder head A (7026)
- CNC stainless steel cylinder C (7165)
- Tappet plate (7210)
- Standard piston with 16 teeth piston rack (6696)
- AOE Piston Head Pad 2,5mm (7600)
- QSC Spring guide (6712)
- INOX Shims - Ø3mm (7217)
- POM delay chip 3mm (6683)
- Selector plate V2 (AR15) (6473)
- AEG SiCr progressive Spring M130 (8815)
- CNC ANTIROT bushings 3mm (6868)
- CNC adjustable trigger AR15 - J modrá (2240)
- CNC trigger safety V2 2025 (9304)
- CNC antireverse latch COMPRING (7207)
- Motor Guarder Infinite Torque-Up
- Perun V2 hybrid
First we would like to address the issue with white POM pistons. Yes, they were bad, so we stopped manufacturing them approximately 8 years ago.
To resolve the complaint with current piston cracking - it is possible that a piston with a manufacturing fault slipped through. Please bear in mind that for you, as a customer, it can be 'the one' piston or one out of 10, but for us it is one out of thousands that got returned to us. So... we are pretty happy with the success rate of our pistons.
Now to the tricky part. The remaining complaints consisted of cracked teeth on our gears. That is rather unfortunate and alarming, so we wanted to test them... again. Pre-production tests consisted of torture with fast motors (usually Warhead Ronin 45k), freezed gears, and springs with ratings around M170 (M150 without any problem, M190 an up is doable but risky).
(https://www.facebook.com/watch/?v=387493124205191&ref=sharing)
Today's tests represented a standard build on an M130 spring with randomly picked parts from our stock that were ready to be sent to you, customers.
In the first stage we assembled the gearbox as it should be (shimming, motor height, lubing... standard stuff). Here we wanted to test just the reliability of the assembly. After approximately 6k shots we got bored and started to deliberately create faults to make any of the components fail. So we started to shoot without BBs, with BBs stuck in the barrel etc. Faults were there, but nothing broke, not even after another couple of thousands of shots.
In the final stage we disassembled the gearbox and assembled it wrongly - bad shimming, wrong motor height, no lube on gears. Again without a failure. This was done on 4 different gearsets with the same result - everything was alright.
You may have seen the video on our FB or IG page, where you can see and hear a magdump with wrongly assembled gearbox. (https://www.facebook.com/reel/1117387536675281).
Those are the photos AFTER all the tests.
So far it seems that the components fail either instantly, or never. So the only meaningful results from today's tests are that the products may have been faulty and slipped through QC. If something breaks, write a complaint and we will resolve it.
To mitigate the probability of something breaking in your gun, please:
- Always quadruple check polarity on your motor when reconnecting
- Check if the piston sits in the rails after the GB assembly. It is possible that it can get misaligned and stuck.
- Our older version (2017 and older) GBs didn't have a cutout near ARL for Spur gear - check if your Spur gear cannot get into contact with your GB at this area
- Check piston travel - when using stronger springs (M140 and higher) and/or spring pre-load washers it is possible that the spring won't be able to compress enough for the piston to move fully back.
- ALWAYS Shim Bevel-to-pinion. Shimming Spur lowest is an ancient technique that should be illegal. Shimmed like that not only there is a bad shimming between Bevel and Pinion gear, but Spur gear can scratch the gearbox, or its teeth can catch an edge of one of the neighbor bushings, that's not good
- Always secure the QSC spring guide. It is NOT meant to sit inside the GB secured only by the tension of the spring. When the spring compress, it tends to twist and bend, misaligning the spring guide and causing a jam.
What truly happened to those customers we can't exactly know and from information consisting of 'the piston broke like a match' cannot be determined more. We need more information mainly about the circumstances of the fault. Build setup is a must, but also what conditions were you shooting in? What was the fire rate? Was it making funny noises before failure? What spring manufacturer did you go with? Etc. Nevertheless if anything breaks in your replica, please contact us at info@retroarms.com, we won't only resolve your complaint, but we can also improve our products thanks to your feedback.
Thank you for your trust and cooperation.
RetroArms
