Need tips on squaring 6" Acrylic tube

[anthonyg]

anyone have any tips on squaring 6" acylic tube. i am trying to make a kalk reactor.

[NanoReefWanabe]

use an 8 inch tall fence on your table saw...i am not sure if the guys like to spin the tube on rollers while holding it against the fence or just put it through with the blade all the way up and then rotate the tube and pass it through again...pretty sure they spin it on rollers while riding the tall fence, which keeps the blade only 1/2" above the table instead of 4". and the wonky end of the tube will be the high point and always riding the fence....just be sure your rolling is completely perpendicular to the blade...i suppose you could also clamp a guide board perpendicular to the blade on the table and just spin the tube against it...but you still need the fence tall enough to cover the height of the tube...

[troylee]

compound miter saw... how bad is off?? sometimes you can stick some sandpaper on the table "flat surface" and take the pipe and sand it flat....

[Plankt0s]

I took mine to a machine shop and he put it on his miter bandsaw. I tried doing it on my table saw and my chop saw but couldn't get it perfect.

[BeanAnimal]

use an 8 inch tall fence on your table saw...i am not sure if the guys like to spin the tube on rollers while holding it against the fence or just put it through with the blade all the way up and then rotate the tube and pass it through again...pretty sure they spin it on rollers while riding the tall fence, which keeps the blade only 1/2" above the table instead of 4". and the wonky end of the tube will be the high point and always riding the fence....just be sure your rolling is completely perpendicular to the blade...i suppose you could also clamp a guide board perpendicular to the blade on the table and just spin the tube against it...but you still need the fence tall enough to cover the height of the tube...

The end you are cutting off is not the end that rides the fence, you lose the "reference" point once the tube is almost fully cut through and the cut-off side is allowed to flex due to the saw kerf. The end that rides the fence needs to be the end farthest away from the side you are trying to true. In MOST cases, that is greater than the distance that the fence can be moved from the blade. That means building custom jig/fence that can clamp to the saw top :)

[mr.maroonsalty]

Never done it, but have done a lot of things with table and mitre saws; I'd put a stop block on the mitre saw or cross-cut sled big enough so the long point on the acrylic always hits (assuming the end is out of square) make my first cuts, readjust my stop block, and cut the other end.

[stugray]

I just made my Kalk reactor square.

Easier and a LOT cheaper.


However, I have used the method that troylee suggested.
I just taped down some large pieces of sandpaper to my countertop & sat there and sanded away while watching TV ;-)

Stu

[2_zoa]

Depending on how bad off it is. I would build a jig that consisted of two saddles (like a gun rack) with an end that is nice and flat. Cut a hole in the end just big enough for the tube to stick through. Place said tube in the saddles with just the end sticking out, then using a large block that will span the whole face of the end panel. Block sand the end down.

I hope I explained that ok. It makes sense in my head.

If you use the table saw idea.....do use caution. Spinning a tube on a saw is just dangerous without a proper jig. The slightest bit off angle when you spin the tube, it will kick out at you. Plus you have to start over.

[NanoReefWanabe]

i dont see how holding the tube and rubbing it on a table would ensure it is square, i just cant see how anyone even with a dozen levels taped to teh sides of tube could sand something level freehanded..

and yeah bean...the tube would obviously have to go between the fence and the blade, i could see how anything over 20 or so inches would be a problem though since most tables arent that wide...

i still think a couple simple rollers mounted to a wooden jig clamped square on the table perpendicular to the blade would be the best though, then it wouldnt matter how long the tube was....could be a little bit dangerous depending on how high up the blade had to be though to compensate for the thickness of the rollers and the wooden jig though...i would sit the rollers slightly below centre of the tube...

[Engloid]

All you have to do is use the fence to keep your length, and then clamp a piece of something perpendicular to it that is a little shorter than your pipe. Imagine a corner, so that on your left is the fence, and a 90 degree piece jutting out from it so that it keeps your pipe perpendicular to the blade and fence.

[Acrylics]

use an 8 inch tall fence on your table saw...i am not sure if the guys like to spin the tube on rollers while holding it against the fence or just put it through with the blade all the way up and then rotate the tube and pass it through again...pretty sure they spin it on rollers while riding the tall fence, which keeps the blade only 1/2" above the table instead of 4". and the wonky end of the tube will be the high point and always riding the fence....just be sure your rolling is completely perpendicular to the blade...i suppose you could also clamp a guide board perpendicular to the blade on the table and just spin the tube against it...but you still need the fence tall enough to cover the height of the tube...Unless I'm routing the tube, this is essentially what I do... (this is where a table saw sled comes in handy.)

then
stick some sandpaper on the table "flat surface" and take the pipe and sand it flat....^^this

Use the table saw you square it up if you can, then tape 220 dow to a flat table and sand until smooth and flat, then 320 if desired. Sanding alone won't square anything, but will make for a nicer gluing surface than a saw-cut.

Also, only sand in one direction and rotate 90 degrees every few strokes. It's most people's nature to press the work down at a slight angle; when this is done in a back and forth motion, the tendency is to rock the piece a little - ending up in a piece that's slightly rounded.

Of course a big miter box also works :)

HTH,
James

[mr.maroonsalty]

i still think a couple simple rollers mounted to a wooden jig clamped square on the table perpendicular to the blade would be the best though, then it wouldnt matter how long the tube was....could be a little bit dangerous depending on how high up the blade had to be though to compensate for the thickness of the rollers and the wooden jig though...i would sit the rollers slightly below centre of the tube...

that is essentially what I built when I had about 120 10' resin columns to cut: a set of rollers, an adjustable stop to keep the tops level, and a circular saw screwed down so the blade could be lifted and lock up and out of the way, then dropped down to make the cut while turning the column.

There is nothing like a crosscut sled or a miter saw bench with a stop; using a fence cutting something shorter than the exposed blade is dangerous.

[anthonyg]

Thanks everyone i think i am going to try using a sled on my table saw

[anthonyg]

I'll let everyone know how it turns out

[Engloid]

Thanks everyone i think i am going to try using a sled on my table saw

Use the fence also, to hold the length of it. Otherwise, as you spin it, you may slide it side to side a little bit.

[mr.maroonsalty]

Use the fence also, to hold the length of it. Otherwise, as you spin it, you may slide it side to side a little bit.

the problem with holding it captive on one or both ends comes in when you don't clear the cut. A fixed crosscut fence would work well on a table saw, if you have the skills to hold the piece stable with one hand while raising and lowering the blade with the other.

[Acrylics]

the problem with holding it captive on one or both ends comes in when you don't clear the cut. A fixed crosscut fence would work well on a table saw, if you have the skills to hold the piece stable with one hand while raising and lowering the blade with the other.no need on a sled, just double face tape a piece onto the fence - big enough to cover the end of the tube. Hold the tube against the fence and sled and push the work into the blade, then rotate the tube. When the cut is complete, pull the sled back, should take all of about 10 seconds.
BTW, wrap some tape around the tube so you don't scratch it while turning it.

James

[mr.maroonsalty]

no need on a sled, just double face tape a piece onto the fence - big enough to cover the end of the tube. Hold the tube against the fence and sled and push the work into the blade, then rotate the tube. When the cut is complete, pull the sled back, should take all of about 10 seconds.
BTW, wrap some tape around the tube so you don't scratch it while turning it.

James

Agreed, thats how I first said to do it, though I would recommend using a stop block, and not mix a rip fence with a cross cut sled; a lot of people seemed like they wanted to turn the thing, but if you do that you still have to clear the cut by either lowering the blade, pushing the stock through or carefully backing out. I would use my slide saw, marking the piece and cutting it, only using a stop if I had to produce multiples of the exact same length.

[sabalough]

Most of these posts are not good ways to cut tubing but are good ways to loose fingers!!!!!!!!!

Never use a fence and a miter guide together. The fence can be used with a guide block to position your work on the miter guide but it must completely clear the guide before it contacts the blade. (if allowed to bind your work pice will become a projectile or a bomb)

Never use a fence if the work piece contacting the fence is 1 1/2 times the blade length. (same reason as above....)

!!!Rotating the work piece is insane. It can catch and would likely bind then explode the work piece at you.!!! I am sure a nice jig could be made to do this safely but it would be a bigger project then the reactor.

A sled with a stop block is the best way to go make a pass, stop the saw, reset the sled, rotate the tube, and repeat until done.

I have done it with a band saw(work pice) clamped to a miter sled with a thick blade and the blade guide rollers set as close to the tube diam as possible.

[Acrylics]

meh

[REEFROOKEE]

use a peace if 3 inch masking tape around the tube. make sure it lines up all the way around. cut with weapon of choice! then sand tp perfection! remove tape! vola!

[NanoReefWanabe]

the only problem with the stop block is the ends of the tube are neither square to the axis of the tube nor are they coplanar with it...

the best way to do this is with a 14" chop saw...but not everyone has one in their garage...

a fence large enough for the height of the tube plus some and something to hold it square is one of the only options for most DIY'ers...clearly it is not the safest thing in the world to do, but you have to do what you have to do...you have to be sure to spin the tube into the blade and not with the blade( ie spin the front/ leading edge of the tube upward), you have to go slow, and your blade must be set high enough to clear the inside diameter of the tube by no more then 1/8" and you should be fine...the sharpest newest of blades is also a no brainer, less force and stress to cut...

[Engloid]

the problem with holding it captive on one or both ends comes in when you don't clear the cut. A fixed crosscut fence would work well on a table saw, if you have the skills to hold the piece stable with one hand while raising and lowering the blade with the other.

I may not be clear on what I'm saying, as I'm 100% sure it will work. I'll try again:

If you want an 8" piece of tube, you first need to realize that neither end is likely to be square to begin with.

1) Therefore, first set your fence at about 8.25-8.5" from the near side of the blade. If your fence is not as tall as the diameter of your tube, clamp a piece of wood on it that is. What this does, is as you spin your tube, the longest point of the tube will always be in contact with the fence, as long as you keep it perpendicular to the blade.

2) You can use one of these below to hold the tube perpendicular to the blade, as you spin it. Be careful that it stays in contact with the fence and the slide. This will give you a good square cut on the first end.

3) Then set your fence to 8" from the edge of the blade, and cut the other side in the same way.

I may not be explaining it very well, but this method WILL work, and give squared cuts on each end of the tube each and every time.

[Engloid]

Forgot to attach the pic:

[mr.maroonsalty]

thats just the mitre attachment; by itself its not often used. A sled, usually looks like a sleigh; its usually a cabinet grade piece of plywood with two runners (one runner sleds are built too) attached to the bottom that fit perfectly into the two dados on the table saw so the sled slides just like the way the mitre attachment works. On top a square crosscut back fence is attached. With a good eye and a steady hand, the reference line made by the saws cut through the sled should be all you need to accurately make the repeated cuts to make a nice square end. If multiple pieces are being cut that must be all the same (production) a stop is added that assures that, but you must clear the cut, backing out is dangerous because you are loosing the solid support of the crosscut fence. as is pointed out the fence is used in combination with the sled when a stop is fixed to that ends before the cut starts; its up to the worker to hold the material in place through the cut, if not that piece is between the spinning blade and the fence and it will fly.

[Amp2020]

Wouldn't it just be easier to use a band saw with a sled? All these suggestion about cutting with a table saw sound ridiculous and dangerous. I know how to use a table saw very well but I would never suggest turning a work piece while cutting to someone who obviously doesn't have experience in this. Otherwise they would have already done it and not bothered posting it here. Making a sled is easy but who is going to spend the time and money for just one cut. Better off making a miterbox and use a handsaw. Take three scrap pieces of wood. Nail or glue them to make a U-shaped box with all three boards lined up perfectly at one end. Then use this end to guide your blade. Sand the rough endges with some sand paper. Don't worry about having a perfectly flat edge. Just get some weldon16. To fill any gaps that are left from the Weldon4. Please be safe and don't take everyones suggestions as being perfectly safe things to do. Because they are not!

[noobtothereef]

wow, this is an old thread but dang, the best way and only way i would cut acrylic tube is make a v block and attatch it to the table saw and rotate the tube over the blade, anything else creates a ridiculously crappy cut.... Only other way would be a massive lathe which would be hard to find..... After i cut the tube on the table saw i attatch my router to the v block and route the ends making it perfect....

[Acrylics]

wow, this is an old thread but dang, the best way and only way i would cut acrylic tube is make a v block and attatch it to the table saw and rotate the tube over the blade, anything else creates a ridiculously crappy cut.... Duly noted :hmm4:
ugh..gotta get outta this place..