RC Plane Launcher

This 'Thing' is not complete at the time of publishing. Hopefully will be completed soon.
https://www.youtube.com/watch?v=f0HsWktBPlk

Project:
RC Plane Launcher
I find it hard sometimes trying to hold the radio and hand launch a plane at the same time.
I have seen bungee cord launchers that are basic but required a very long bungee cord to work. While searching for more Ideas I saw a launcher that didn't require a long cord but used pulleys to help get the force needed to get the plane in the air. So I took both Ideas and made this up.

Build of Materials:
1 2020 aluminum extrusion 1 meter long.
2 2020 aluminum extrusion 450mm long.
2 2020 aluminum extrusion 90mm long.
2 m8 x 75mm bolts.
2 m8 lock-nuts.
4 m8 6mm spacers.
4 50mm diameter pulleys with 608zz bearings and u grove for 10mm rope: https://www.amazon.com/gp/product/B01HD4QJFK/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
Shock Cord- 1/8" x 25' (more than enough): https://www.amazon.com/gp/product/B078NFB25P/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
1 V-slot gantry plate 20-80mm: https://openbuildspartstore.com/v-slot-gantry-plate-universal/
1 Compression spring,7-8mm dia. x 20mm length. here: https://www.amazon.com/WINGONEER%C2%AE-accessory-Compression-Ultimaker-Makerbot/dp/B077X9RSSB/ref=sr_1_7?s=industrial&ie=UTF8&qid=1528970778&sr=1-7&keywords=3d+printer+spring
4 V-Wheel kits: https://openbuildspartstore.com/delrin-v-wheel-kit/
2 6mm eccentric spacers: https://openbuildspartstore.com/eccentric-spacer/
2 M5 9mm Spacers: https://openbuildspartstore.com/aluminum-spacers-10-pack/
2 M5 3mm Spacers: https://openbuildspartstore.com/aluminum-spacers-10-pack/
4 M5 x 25mm bolts.
4 M5 Lock-nuts
4 M5 flat washers (optional)
1 4mm x 100mm rod
1 M3 x 35mm bolt
12 M3 flat washers
7 M3 lock-nuts
5 M3 x 30mm bolts
2 2.5mm x 12mm Slotted Spring pins