Even when first starting my replica chainsaws, I at least had an original real Homelite chainsaw body before I started, and just worked from there. The Mechanical Arm would need to be made entirely from scratch with raw materials. As it turned out the only part I could buy off the shelf ready-made was the chainmail glove, and even that needed some modification.
I suggested the customer get in contact with Mike at Blind Squirrel and ask him to make one, although he already had and was told that since Mike didn't mould any of his parts, it would basically mean starting the whole project from scratch again and he didn't want to do that. So anyway over the next few weeks I hawked the project around to some of the local modelmaking companies to see if anyone else would be willing to do it (I work within Shepperton Film Studios). I was only too happy to completely pass the project onto someone else. Unfortunately I couldn't find anyone who could do it for a resonable price, so I put it on the back burner until the end of May 2014 when I had more free time. I downloaded & printed off Mike's plans and started working on the rough designs. As I went I found that with regards to the broad measurements & shaping, Mike was spot on, but many of the finer details on his plans were incorrect, misplaced or missing altogether.
So over the next 10 weeks I worked away, from making the parts out of heat-formed plastic sheets to make mouldable forms, which I then made silicone moulds of so I could replicate them in plastic resin. As the continuity on the screen original varies from shot to shot (especially as it's being constructed), the overall design is somewhat an amalgamation pulling together various details seen over the film, rather than an exact match to one particular version. It goes without saying that the finished version is a non-working prop, in-so-much that it can be worn over someone's arm, but it's not mechanised on it's own. It can only be worn right-handed, and I won't be making a left-handed version.
The hand cover section is made in a rigid plastic, comes in one size (roughly medium to small) and is not adjustable. The hand cover is held shut using two little loose-pin hinges; one above, and one below the thumb along the seam. When the hand cover is shut, the hinges on both sides align with each-other and a veneer pin can be inserted into each one firmly holding the hand cover shut. Doing this is not all that easy with one hand, so if wearing it you might need to get someone else to do that bit for you.
The brass/leather arm frame is attached to the inside of the vambrace by Velcro pads. It can be re-positioned either further forward or back (moving the elbow pivot point forward for people with shorter arms, or back for people longer arms) or rotated to change the orientation of the vambrace while worn. It's shown in a number of orientations in the film, so it's really down to you how it's positioned. The bolts at the elbow point of the frame are loose so the frame will move freely with your elbow, but they can can be tightened to hold the brass frame at a particular angle for display. The leather straps can be adjusted a few inches either way to accommodate thicker or thinner arms, but again if your arm is too thick for the straps, then you may not be able to wear it.
The vambrace handle can be cranked as shown in the film. It's held shut via a magnet underneath which will hold it closed at any angle, but once this is disengaged, it moves freely, with a stopping point at around 45-degrees. While a sprung mechanism may have been preferable, it would have had to have been quite strong to firmly hold the handle tightly in place, and if someone was to let go of the handle while at it's full flex, it would snap back and might cause damage.
It's supplied with two black under-gloves; one for use with your own hand, and the other is padded to use when displaying. The padded glove has articulated fingers which can be positioned. While wearing it, taking the chain-mail glove on and off repeatedly over time will shred the black wool glove underneath, so this will need to be replaced periodically. You can find them sites like Ebay for around £1 a pair, sold as 'magic', 'stretch', or 'one size fits all' gloves.
The chain-mail glove is actually a high quality Zeva Brand chain-mail protective glove which closely matches the screen version. The original wrist closing band has been modified. This is because most gloves are made to be worn left-handed (as the knife from which it's giving protection would be in the users right hand). Wearing it right-handed places the band adjusting buckle on the inside of the wrist, rather than the outside, which does not match the screen version. This is corrected and the glove is held shut via a red Velcro band
The Mechanical Arm comes as standard with a weathered & aged metal finish, but this could be scaled back making it look newer, or even increased with blood splatters & additional dirt. The metal effect armour pieces are made from a black impact resistant heavy duty polyurethane plastic resin, spray painted with primer, then silver paint, then aged using water based paints & sprays. Wherever there is friction between two pieces the paint will wear over time, and there is really nothing that can be done about that regardless of how hard-wearing the paint is. If needed, the finish can be touched up using black water based enamel paint stippled on using a little sponge. Do not use spirit based paints, as this can effect the silver & primer coats underneath.
The overall length with the brass/leather arm frame out straight is 660mm or 26", and the total weight is just 1.5kg or 3.5lb