o-ring grooves/make your o-rings fit
Posted: Thu Oct 08, 2009 7:24 am
So, You don't have a lathe, and you don't have a table saw. You need a groove that fits your o-ring and seals perfectly, probably both directions.
You may also have an o-ring that is just too small to seal a chamber.
You can make perfect seals with as little as some good tape for a female groove, and a drill for a male groove. (Male groove being a groove on the moving piston, female groove being a groove in the chamber the piston slides in).
So, It's very simple, firstly,
male grooves:
<img>
You will need:
Your o-ring
A drill bit the same size as the thickness of the o-ring
Super glue
A caliper
optional:
A vice
lube (recommended)
Steps:
1. Using a permanent marker or other, draw onto your piston/ whatever it is a line around the cylinder exactly where you want the groove to be.
2. Take out your trusty drill, with a drill bit the same diameter as your o-ring's thickness, or cross section. It would be good at this point to put either your piston or the drill in a vice for steading I did however make do without a vice.
3. With the side of the drill bit, bore into the cylinder WITH THE SIDE of the drill bit, perfectly along the line you drew. I guess you see where this is going. Don't worry about making it perfectly even for now, just concentrate on a small section at a time.
4. Every now and then take out your caliper. and measure the diameter of the groove, all the way around. If your o-ring is a good fit, you should be aiming to get the grove the same diameter all around as the inside diamter of the o-ring.
5. If your o-ring is a little too small for the chamber, make the diameter of the groove a little larger than the inside diameter of your o-ring (As in make the groove less deep).
6. Now, I wouldn't expect you to get it perfectly even all round. If you did, wohoo. But, if you find that your ring doesn't seal properly, or you've dug in too deep, don't fret. This is where the glue comes in. Simply squirt a little super glue into parts of the groove that are too deep and wait for it to set (PLEASE wait for it to set?)
7. If you find it hard to take the o-ring out of the groove when readjusting, use tweezers, just be careful not to dig in to the o-ring itself but rather lever it out with the tweezers.
Female grooves
<img>
These are the type of grooves that dont move up and down: the piston or whatever you are using will slide through the groove.
You will need:
Tape (not soft tape- hard tape)
Super glue
thin wrapping plastic/tissue paper
Cylinder that fits into your chamber, but is too big to fit your o-ring around. I.E. If using PVC, use a pipe one size down.
Remember: The o-ring's inside diameter must be smaller than this pipe's outer diameter, but the pipe obviously needs to fit in your chamber.
Steps:
1. Get your thin plastic/ wrapping paper, and wrap around the pipe two times. The wrapping is there so that we can remove the tape later. It needs to be as smooth as possible, no wrinkles.
2. Start wrapping your tape around the wrapping. Try to wrap it perfectly onto itself, so that it starts making a thick wall. Wrap it until it makes the pipe fit perfectly into the chamber.
3. When there is enough tape on, put super glue all on the surface of the tape, and shove it down your chamber to where you want your groove to be. Please note that the groove will not be in the middle of the tape: The o-ring will be sitting in between two rolls of tape in your chamber.
4. Once it's dry, pull out the tube, and you should have just a nice roll of tape on the inside of your chamber. Now, shove your o-ring down there until it rests against the side of the tape roll. We're now going to make an identical roll of tape, glue it, and shove it down the chamber again so that the o-ring is sandwiched between two rolls of tape.
Ok, if some of that, or maybe most of that, doesn't make sense to you, just let me know and I'll elaborate.
PS my images didn't work for some reason the post just deleted the mI'll try get it to work tomorrow.
You may also have an o-ring that is just too small to seal a chamber.
You can make perfect seals with as little as some good tape for a female groove, and a drill for a male groove. (Male groove being a groove on the moving piston, female groove being a groove in the chamber the piston slides in).
So, It's very simple, firstly,
male grooves:
<img>
You will need:
Your o-ring
A drill bit the same size as the thickness of the o-ring
Super glue
A caliper
optional:
A vice
lube (recommended)
Steps:
1. Using a permanent marker or other, draw onto your piston/ whatever it is a line around the cylinder exactly where you want the groove to be.
2. Take out your trusty drill, with a drill bit the same diameter as your o-ring's thickness, or cross section. It would be good at this point to put either your piston or the drill in a vice for steading I did however make do without a vice.
3. With the side of the drill bit, bore into the cylinder WITH THE SIDE of the drill bit, perfectly along the line you drew. I guess you see where this is going. Don't worry about making it perfectly even for now, just concentrate on a small section at a time.
4. Every now and then take out your caliper. and measure the diameter of the groove, all the way around. If your o-ring is a good fit, you should be aiming to get the grove the same diameter all around as the inside diamter of the o-ring.
5. If your o-ring is a little too small for the chamber, make the diameter of the groove a little larger than the inside diameter of your o-ring (As in make the groove less deep).
6. Now, I wouldn't expect you to get it perfectly even all round. If you did, wohoo. But, if you find that your ring doesn't seal properly, or you've dug in too deep, don't fret. This is where the glue comes in. Simply squirt a little super glue into parts of the groove that are too deep and wait for it to set (PLEASE wait for it to set?)
7. If you find it hard to take the o-ring out of the groove when readjusting, use tweezers, just be careful not to dig in to the o-ring itself but rather lever it out with the tweezers.
Female grooves
<img>
These are the type of grooves that dont move up and down: the piston or whatever you are using will slide through the groove.
You will need:
Tape (not soft tape- hard tape)
Super glue
thin wrapping plastic/tissue paper
Cylinder that fits into your chamber, but is too big to fit your o-ring around. I.E. If using PVC, use a pipe one size down.
Remember: The o-ring's inside diameter must be smaller than this pipe's outer diameter, but the pipe obviously needs to fit in your chamber.
Steps:
1. Get your thin plastic/ wrapping paper, and wrap around the pipe two times. The wrapping is there so that we can remove the tape later. It needs to be as smooth as possible, no wrinkles.
2. Start wrapping your tape around the wrapping. Try to wrap it perfectly onto itself, so that it starts making a thick wall. Wrap it until it makes the pipe fit perfectly into the chamber.
3. When there is enough tape on, put super glue all on the surface of the tape, and shove it down your chamber to where you want your groove to be. Please note that the groove will not be in the middle of the tape: The o-ring will be sitting in between two rolls of tape in your chamber.
4. Once it's dry, pull out the tube, and you should have just a nice roll of tape on the inside of your chamber. Now, shove your o-ring down there until it rests against the side of the tape roll. We're now going to make an identical roll of tape, glue it, and shove it down the chamber again so that the o-ring is sandwiched between two rolls of tape.
Ok, if some of that, or maybe most of that, doesn't make sense to you, just let me know and I'll elaborate.
PS my images didn't work for some reason the post just deleted the mI'll try get it to work tomorrow.