This is my first instructable. Let's see if I am any good at this. The project is basicly a fairly simple machine intended to be used in cutting glass bottles to make :drinking glasses, rings, ashtrays and stuff i have not thought of yet.
Step 1: Materials and Tools
1 beat up old bike with a single piece crank
1 old tire
5 bolts, carriage bolts or similar. These should be approxamatly as long as the radius of your crank
5 wingnuts sized and threaded to fit your bolts
10 washers sized to fit your bolts
5 compression springs large enough to fit around your bolts and as close to the bolt length as you can get them.
grease ( I like white lithium but your mileage may vary)
pvc cement or rubber cement
wrenches and or rib joint pliers
vise (a pipe vise is also helpful)
utility knife or box cutter
Step 2: Strip the Bike Down
Step 3: Remove the Crank Assembly
then remoce the nut with rib joint pliers (or a really big wrench if you have it). now you will need to loosen the bearing cone with a screwdriver until it can be turned by hand. Now thread the cone off of the crank arm by hand. The bearings from this side of the crank assembly should slide off fairly easily at this point. Next remove the whole assembly, being careful to keep the other bearings.
If the bearin gs look like they were attacked by a martian rust monster, you will want to replace them. Finaly remove the other pedal.
Step 4: Cutting the Frame Down
Now we are marking the frame to cut it with the angle grinder. Leave the bottom bracket housing and the rear section of the frame intact. cut the seat tube so that it is even with the top of the rear trialngle. anything else can go.
most bikes will not need it but for this one I needed to use the dremel to remove the surface rust from the bearing cups. This will make it rotate much more smoothly.
Step 5: Cutting on the Crank Assembly
This particular bike has some plastic attached to the assembly. it has to go as well.
Once the crank arm and any plastic nonsense has been cut away, take the angle grinder with the wire wheel attachment and remove any paint, corosion or other gunk coaring the sproket.
Step 6: Cleaning the Bearings and Such
If the cone and washer look like this you will want to take the dremel and a grinding bit to them and gently clean the rust away.
Step 7: Building the Base
If you are not so lucky you will need to cut a rectangle from a sheet (or some scrap) of plywood. This should be at least as long as the remaining portion of bike frame and as wide as you would like. (wider is going to be heavier and more stable but it is not terribly important)
Measure the distance betewwe the dropouts in the bike frame. cut a piece of 2x4 to this length. It is actualy better to cut this piece too big by 1/8 inch. The frame will flex a little and this makes for a tighter fit. Make sure this piece fits.
Measure the width of your base, cut three pieces of 2x4 to this length.
Center the bike frame on the plywood cut for the base. Mark the distance from both ends.
Mark a hole where the flat metal piece has a hole . mark this spot.
Predrill holes on the lines you drew.
screw the base together.
Step 8: Preparing Pieces for the Claw
Using the angle grinder, cut your steel to length.
Measure your steel and mark them each with a line where you intend to bend them.
Place the flat steel in a vise one at a time, and bend them to 90 degrees on the lines you drew. For best results heat the pieces with a torch before bending. you will need to beat on them a bit to make this work.
check the angle of the pieces with a speed square.
If you need to adjust a bend, place the piece back in the vice. hammer to bend farther. If you bent the steel too far use your rib joint pliers to bend it back
mark each piece where you will drill holes for the bolts.
place pieces one by one back in vice and drill holes.
Step 9: More Pieces for the Claw
You will want to remove the metal bead from where the tire contacts the rim. This process is the same as the method for removing the sidewall from the tread.
Stab through the sidewall with your knife.
Cut the sidewall off the tire
Cut a strip off of the sidewall with your razor.
Cut this strip in half along the short axis. the razor is the best tool for this.
You will have noticed by now that the sidewall is tapered, drill a hole in the thicker of the twi pieces of tire you have just cut.
Repeat this until you have 5 sets of tire pieces
Put a washer on each of your bolts.
Slide the thick piece of tire onto the bolt.
Repeat this for the other 4 bolts.
use pvc or rubber cement to glue the thin rubber pieces over the bolt heads onto the thicker pieces.
Clamp and let these sit for 8-10 hours.
Step 10: The Welding Bit
If you do not have acess to a welder you could use a few bolts in each piece to hold them to the gear.
Step 11: Attaching the Frame to the Base
The frame i used has a flat piece of steel near the point where the top bars connect to the seat tube. If your bike does not have this feature you can ues brackets or u bolts to connect the frame to the plywood.
your frame is now connected to the base.
Step 12: Put the Bottom (now Top) Bracket Back Together
It is also important to tighted the assembly enough that is does not wobble but not so much that it becomes hard to turn.
Reattach the pedal to the remaining crank arm. Remember that this is reverse threaded.
Step 13: Extending the Claw Into the Realm of the Useful
Repeat this for the other 4 fingers.