Try one of these...
http://www.amainhobbies.com/product_..._id/23951..the wire gets pinched in between the cap and base...just put a small "o" ring between them to protect the wire as you tighten the screws down. Good luck!
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S