Hi guys, thought I would do a detailed overview of my latest project, a fully machined rainbow pistol!I've always wanted to make a really solid rainbow pistol, because I love the form factor and simplicity of the design, but have snapped the PVC plunger tube of the one I built back in 2018 (probably shouldn't have been trying to do John Wick-esque flips with it) - I have since repaired it. Additionally the pvc flexes a bit when I prime powerful springs, which doesn't fill me with confidence. So I collected everything I would need, and set to work, lockdown providing the perfect oppurtunity for this sort of manual labour.Internals:This blaster has a set of turned internals, with an omni-directional rainbow catch at the heart. Mine is made of acetal plates with a printed spacer inbetween, which provides enough space for the catch plate to slide without friction. The bore through the catch was reamed in situ in the plunger tube, so that it is concentric with the walls, thus guiding the plunger rod and head to improve the seal.Attached to the catch is a printed aeromech style spring guide, so that when compressed, the spring doesn't buckle like on most homemades. This prevents the spring getting caught in the catch groove, as well as ensuring the force of the spring is exerted directly forwards on the plunger at the beginning of the stroke (it is also interchangeable for different sized springs, and I can adjust precompression by editing the files).The plunger rod is a hybrid, consisting mainly of aluminium, but with an acetal insert as the catching surface, so that wear is minimised on the plate. In this way I can easily flip or exchange the insert if it ever wears down, like I found happened in my previous rainbow homemeades (they use a full aluminium plunger rod and an acrylic catch plate, which was quite brittle and wore down). The insert is sandwiched between the two sides of the rod, with the whole joint held together by m4 threaded rod. The T handle has some slight aesthetic contouring, and the entire assembly has been polished to minimise friction with the catch.The plunger head is acetal, and like usual uses the floating o ring design. It also has a spring guide on it and an airbrake attachment, which seals into the coupler to form an air cushion when the plunger is at the end of it's stroke, replacing any plunger padding (this principal was taken from the Lynx, but was probably done somewhere else before that). I quite like how it has turned out, although the seal might be too good, as it takes a while for the spring to fully decompress!The coupler is machined from 38mm aluminium, and has a tight o ring seal into the plunger tube, which prevents any air escaping (the fixing screws are behind the o ring, and thread into non - through holes, so no teflon tape is needed on the screws, unlike my previous homemades. It can take any UK spec 1/2" PVC attachments via a press fit, lightly tapered bore, so I can use any of my absolvers or PVC shrouded barrels. However I plan on mainly using the brass breach attachment I made for this, which is threaded for JET style barrels, and which has a 17/32 core with a 9/16 rotating piece. This allows for a sort of two stage barrel, where the start is tight, allowing for pressure to build, and then it gets looser in whatever threaded barrel you use.Externals:For maximum durability, I used 3mm wall aluminium for the plunger tube, which is thick enough to thread into (PVC would always be about 1.5mm thick and just lose the threads). I gave it a nice polish and a big chamfer on the front end, as well an angled back to match the grip. The grip and front trigger support are both cut from 50x20mm aluminium bar, and were shaped with a hacksaw, files and too much time to a very comfortable profile! In the same way, the tops of the pieces were made concave to sit flush with the plunger tube. I've sanded the grip and trigger to 800 grit, but need to buy a bench polisher/grinder to finish polishing them.The side plates are made from acrylic, which were scrap laser cut parts (made at school) from my last rainbow pistol, and these were also given radiused edges so that they don't scratch my hand. They provide the mounting for the trigger (also aluminium) via two steel rods - one as a pivot, with turned aluminium spacers, and the other as a stop for the trigger spring to push the trigger against. The catch spring is working fine at the moment, but if I find that I need to replace it with a different size, that will be fine, as on the trigger I have a grub screw which can be used to adjust the length of trigger pull, or to allow for a different sized catch spring.For the scar I am using one I machined, with 6 strings, reamed bore, adjustable twist rate and tension, and grub screw mounting onto 15.8/16mm barrels.Future upgrades:I would quite like to get my old rscb working, or maybe a hopper, and maybe use a bobololo style pump grip (Just a slide that fits around the plunger tube and which pushes back the T grip). More feasibly, I would like to get an aluminium picatinny rail on it to mount a scope, and I have made provisions for a stock attachment (threaded holes in the bottom of the grip and the back of the catch).Performance:I'll update this post with some numbers once I get a chance to tune and test it, but it has an LS sized plunger tube, and with the 16kg spring, a 45cm loose alu barrel and the scar in my chimera, I was getting 270 fps, so hopefully I will be able to get comparable numbers.Overall I'm super happy with how this turned out - I spent 7 days of solid work making it, but overall costs were under £20 including the 16kg spring! My parents say this is the prettiest blaster I have made yet, and in a way I agree with them, although I can also see all the flaws. However in terms of design, I can't see anything I would change about it - perhaps there is too much 'feature creep' as Martin from Wintergaten would put it!