November Release - SSR2 Alpha (part 1)

Guys, I've been quite unwell for the last week and I've not made the progress I'd hoped. So here's the plan: as promised I'm going to release today the STLs as they are, which includes the finished receiver and top frame.

I will follow up with the chassis and electronics enclosure soon, as well as a wiring diagram and the firmware. In the meantime I'm going to attach some notes so that you can get started putting this together. I'm also going to set up a livestream for Monday in which I will go through assembling the parts I am releasing here.

Assembly notes:

I have used M3x5.7mm inserts for most holes on this design. The M4 VESA mounting holes use M4x8.1mm inserts.

Get yourself on the discord server if you aren't already. #maker-chat is the best place to ask for help and feel free to @me there. You can also check out last month's livestream if you need any hints.

Receiver:

I recommend that, if you can, you print the receiver parts in a high layer resolution (say, 0.1mm) and that you randomise the seam locations.

The bevel pulley and the bevel pulley flange both sit on a 21mm length of 3mm brass rod. The flange should be placed onto the rod so that the flat part is against the belt pulley end. A 7x3x3mm bearing goes on each end of the 3mm shaft that protrudes from the bevel pulley. You may need to file down the 3mm rod and/or use a 3mm drill bit on the bevel pulley parts to get this assembly to fit together.

The bevel pulley on its shaft with the bearings fits into the fixed receiver where it is held in place by the fixed receiver pulley cover. The end of the belt is looped around the pulley with the teeth facing inward. This is screwed into place using 4x M3x8mm countersunk bolts.

You will need to cut out five sections of 1mm-thick PTFE for the receiver. These are 3x rectangles 36x18mm, and two  “washers” one with an outer diameter of 88mm and an inner diameter of 71mm, and one with an outer diameter of 108mm and an inner diameter of 91mm. The larger washer sits on top of the twist receiver and the smaller washer sits underneath the twist receiver retainer. The thee rectangles sit in the the slots in the fixed receiver.

With the PTFE rectangles and the larger washer in place insert the twist receiver into the base of the receiver. This should sit smoothly and snugly against the PTFE washer and rotate freely. Now drop the smaller PTFE washer onto the protruding end of the twist receiver and screw the twist receiver retainer down into place. Once the retainer is in place unscrew it slightly so that the twist receiver spins freely. The twist receiver is locked using an M2x8mm bolt, which stops it rotating. When you have the retainer in the desired position use a small drill bit to make a small hole in the twist receiver beyond the hole in the retainer. Then expand the hole in the twist receiver to take the end of the 2mm bolt.

Chassis:

I have included the prototype chassis for those of you who want to have a go at putting the whole mechanism together. I aim to replace this part in the next week or so, so only print it if you don’t mind throwing away about 300g of filament.

The 4x idler pulleys are mounted using 4x M3x16mm bolts. The drive pulleys are attached to the motors using 4x M2.5x5mm bolts each, and the motors are screwed down using the M2.5x10mm bolts the motors are supplied with.

The drylin bearings are slipped into their slots and held in place using M3x8 bolts, though don’t fully tighten these until the receiver, top frame and rails are fully installed.

Top frame:

The rails should be 200mm long. The 3x rails are located first into the slots on the top frame and clamped in place using 6x M3x16 countersunk screws crewed into 6x M3 nuts. The rails are next inserted through the drylin bearings and into the fixed receiver. There is additional depth to these holes to allow the length of the rails to be adjusted.

The belt tensioner uses 3x M3x16 bolts. The two tensioning bolts use M3 washers.

(The files are protected with the november password because of an ongoing Patreon security flaw. Check your email. Check your Spam Folder. As a $8 or $16 patron you should have received the passwords in your welcome email, but feel free to contact me if you have any trouble finding them. The files are also available on my discord server.)