What with all the milling going on lately, I decided to replace the crusty bellows on the Sherline mill. The previous design worked reasonably well, but I’ve had a few tweaks in mind for a while.
Herewith, a PDF file with some Sherline Bellows – Improved:
- Color coded lines so you know which way to fold them!
- Unlined side up for a neat look
- Fits on Letter and A4 sheets
- Taping cuts and hints
The PDF page size is about 8×10 inches; call it 204×280 mm. Print it without scaling and it should just barely squeak onto the sheet. If you don’t have a full-bleed printer, the tips of the sides may get cropped off, but you can extrapolate easily enough.
Some assembly required:
- Cut it out
- Fold the central valleys (red) first, flatten it out again
- Fold the central ridges (blue) next
- Pleat the whole thing into a half-inch tall stack
- Squash it into a neat package to harden the folds
- Fold the tips along one side
- Fold the tips along the other side
- Squash the folds again
- Make the saddle cuts & fold the tabs
- Apply double-stick tape as noted (some on back)
- Install on your cleaned-up mill
- Admire!
The tip folding is the trickiest part. Basically, flip the first tip from a ridge to a valley, then chase the little transition folds into place. Repeat for each tip along that side, then do the other side.
It gets easier after you fumble around for a while.
My nimble-fingered daughter has offered to fold ’em for you. Stick a few bucks in an envelope and mail it to me; we’ll mail back two folded sets (two each, front and rear bellows) for your amusement. Kid’s gotta earn her college money somehow…
Address? Go to the QRZ.com database and search for my amateur radio callsign: KE4ZNU. Cut, paste, that was easy.
For the do-it-yourselfers, start with the PDF file in the link above. That’s the easiest way to get the correct scaling. The tabs on the ends should be 4.0 inches across on the printed page.
Here are some 300 dpi PNG files, but you’re on your own for scaling.
If you want the original Inkscape SVG files, drop me a note.
The Smell of Molten Projects in the Morning 
>The tip folding is the trickiest part.
No kidding… Your shop assistant’s college fund is looking like an increasingly attractive investment.
My fat-fingered technique: bend the entire length of the corrugated sheet along the corner-to-be the way it’s supposed to become, then coerce the first pleat into being. That holds the bend in place and I can generally chase the rest of the pleats into line.
I’ll admit it takes more concentration than, uh, I’d like to admit…
I rarely feel as if I have fingers the size of cucumbers, but this project makes me feel so clumsy. I think I got the hang of it on the second side of the first attempt (but we’ll see once I try the front-side bellows.) Then, platen, and starting to figure out limit switches and depth microswitch. maybe also a side-plot involving something based on the sherline chip guard, only fully encircling the head, with a shopvac attached to it. So much to do!
Note to anyone else who made a set of these way covers: brush chips off them. Do not attempt to vacuum chips off them with your big monster shopvac, because it will ingest them in their entirety, and then you have to fold another set.
Aside from that, they sure do work great.
Obviously, I need a bigger shopvac!
Usually I sneak up on the chips by putting the vac’s nozzle to the side of the bellows. Then I rattle the pleats with a fingertip, which surprises the swarf into jumping off the bellows, whereupon the wind whisks it into the nozzle.
Dirty trick, I admit, but sometimes a man’s gotta do what a man’s gotta do…