Pie cutting

[Gamble97]

Anyone have any good how to's on pie cutting pipe/tube?
Do you use a chop saw or do it by hand?

 

[GRAVEDIGGER]

A chop saw works the best, but you can use a cutoff wheel too. Here's how...
http://www.motokarts.com/resources/pie_cut_calculator.xls

 

[snowborder714]

I have a calculator coming very soon to help you do pie cuts. That's about all I can contribute at the time

Edit: ^It's actually that one that I turned into an online version.

 

[99gst_racer]

I've always use a chop saw. Though if I had one, I'd probably use a bandsaw instead.

I've always eyeballed it too, so I'm no help with how-to's.

 

[bryanwheat]

I only use pic cuts on really tight angles. For what you will spend on filler rods and gas you can buy some pre bent mandrel bends and spend about the same money but spend a tenth of the time. Buy yes, as others have stated a chop saw or a band saw are the way to do. You could also use a reciprocating saw or a cut off tool, but you won't end with nice flat surfaces to mate together.

 

[Gamble97]

I've always use a chop saw. Though if I had one, I'd probably use a bandsaw instead.

I've always eyeballed it too, so I'm no help with how-to's.

I tried eye balling it a few times and it ended up being larger than 1.5" diameter so I'm just assuming I cut it too much of an angle.

A chop saw works the best, but you can use a cutoff wheel too. Here's how...
http://www.motokarts.com/resources/pie_cut_calculator.xls

Is number 2 & 3 always going to be the same then? Sorry I am TERRIBLE with math and equations.

 

[99gst_racer]

I tried eye balling it a few times and it ended up being larger than 1.5" diameter so I'm just assuming I cut it too much of an angle.

I usually keep most cuts at no more than 15*. Any more than that and the opening begins to oval too much. 10* is probably best though.

 

[bastarddsm]

I use a band saw, and about 10* cuts.

 

[genegoesfast]

I've done them with a sawzall in a vice. Not the best way but worked well.

 

[doubleclutch99]

A chop saw will work the best for fast cuts, band saw for more precise cuts but is definetly slower. the best thing i found is the chop saw in combination with a belt sander to fine tune the angle.

 

[99gst_racer]

I've done them with a sawzall in a vice. Not the best way but worked well.

The first O2 housing I ever built (about 7 or 8 years ago), I did with a hacksaw in a vice. It worked, but Never Again! I'm so thankful to have real/better tools now.

 

[Gamble97]

I usually keep most cuts at no more than 15*. Any more than that and the opening begins to oval too much. 10* is probably best though.

Is that what you used on that upper radiator pipe you made?


So I'm guessing that 22.5 degree with make it a lot more oval then huh.

I use a band saw, and about 10* cuts.

If I don't blow up this F*****G band saw I will. It keeps kicking out blades on me, I hate this thing. I want an OLD vintage band saw where I can adjust the speed.

A chop saw will work the best for fast cuts, band saw for more precise cuts but is definetly slower. the best thing i found is the chop saw in combination with a belt sander to fine tune the angle.

My other thought is if you cut it on an angle then one side is fat and the other tends to be REALLY thin. Almost small enough to where with aluminum it will just melt and not take a weld.

 

[99gst_racer]

Is that what you used on that upper radiator pipe you made?

I actually didn't make that pipe. Alien Auto made it. I'm not sure what angle cuts they used either.

So I'm guessing that 22.5 degree with make it a lot more oval then huh.

Yeah, that's getting severe. Several of those together would equal too much cheating and could probably hinder flow by being too sharp of a directional change. Like angles will fit well no matter the degree of the angle, but heavy angles don't flow as well. The problem comes when you try to fit a heavy angle up to a straight cut pipe or a much lighter angle. That's when you get issues with fitting oval to round.

 

[doubleclutch99]

Just remember to do a true pie cut you'll almost always have two cuts 1 one each end of the pipe to make a symetrical vee. yes you have to take into concideration where your cut will end up that's why i make a little wider cut and then fine tune it with a belt sander. i also try to make it so the thin section that goes on the inside radius is no less than a 1/4 in. that way you'll usually have enough to not melt thru.

 

[bastarddsm]

If I don't blow up this F*****G band saw I will. It keeps kicking out blades on me, I hate this thing. I want an OLD vintage band saw where I can adjust the speed.

What kinda band saw are you using? What blades? All I have is a old delta 4x6 one that my dad bought at farm and fleet for like $300. I run 20 or 24 tpi blades when cutting pipe, at the slowest speed. It can be finicky, but overall its not to bad.

 

[Artago]

I believe this is what you are looking for...

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... sorry, couldn't resist

 

[PieEyedPiper]

Never have fights at the dinner table again! Everyone is served an equal piece!


What kinds of band saw are you guys using, are you using wood equipment and interchanging a metal cutting blade? I only have access to wood machines, and the blades with their large serrated edge and spacing is definitely made for wood.

 

[turboglenn]

I usually keep most cuts at no more than 15*. Any more than that and the opening begins to oval too much. 10* is probably best though.

15's work nice but if you've got patience and a willingness to do some more welding i prefer smaller angles

I use a harbor frieght 4 x 6" bandsaw, i've done the mods you can find anywhere on the net to increase it's cutting and consistancy. I use Morse brand blades that are usually 18TPI for both aluminum and stainless and just change blade speeds to compensate for different metals. Probably the most important thing to do when getting into metal fab is learning what are good and bad when it comes to blades, drill bits and the like. HF and sears brand blades would only last one cut on anything hard like a piece of SS pipe, but a good blade with a good cutting oil will make a blade easily last through a good 30-50 cuts.. I usually price out one blade replacement per job of SS when quoting some one.. (between 11 and 22 dollars) so when i add up the materials and am doing the labor i toss 2 bucks on top of that and strictly go right to buy new blades with it, and that way i'm sure that every cut on the down pipe, IC pipe or whatever will be nice and clean and the rest of the work from there reflects in the bead and else where from having that nice clean cut


Here;s what i do.. I set my bandsaw to roughly 7.5*, then i mark a pipe with straight lines 180* apart lengthwise (to position the pipe to get the cuts as consistant as possible, if you don't flip it 180* each time you start to make "curves") then i use something on the saw to line those marks up with and just start cutting pipe while working on other things, before i know it i have 20-30 pie cuts that i take to the beld sander and clean up the edges on them. Onc ei'm stocked up on pie-cuts then i can start taking them together and making my final piece

I have to say the 7.5* has been my favorite angle. I leave the inside of the cut (the thinnest/shortest side) about 1/2 inch long or less and although a little more work to weld up and keep from getting too hot on stainless it works out nice and gives me the closest results to a real mandrel bent piece of pipe that i could try and duplicate

cutting a ton of these little anlges hours or days before you'll need them really helps you form losing motivation when getting an idea because instead of hunting and cutting pipe to try and match a mental picture you have going on you cna just pick up a hand fulland start taping them together and seeing if it will work or not for what's going on in your head. I have probably 2 feet of 1.5" wastegate SSpipe and probably another 2 foot of 3" SS pipe cut into tiny little pie cuts under my welding table at about any time


I think the biggest issue of working with these typoes of pie cuts at elast when you're starting off a sinlge piece that isn't very larg, is dealing with the parts rolling around and coming off alignment befor eyou weld them up.. what i do is simple have a pair of locking pliers on the table that i can grab oneor both pieces with so they don't move on me.. sounds simple but they can be a headache towork with at times, especially for some one like myself who doens't like to use auto tinting shields

 

[Meshuggah]

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Love me some pie.. cuts

 

[richard33]

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Love me some pie.. cuts

Thats intense! A 1,000$ intake

 

[Imback]

That's what i'm talking about . I can't stand when people make pie cuts out of stright tubing and end up looking like this

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[Gamble97]

^What's wrong with that?

Glenn, what did you do to slow the speed down of the band saw? I need to do this to mine.

 

[Imback]

Look at all the straight sections. Looks like a spine with Scoliosis.

 

[99gst_racer]

^What's wrong with that?

Absolutely nothing, IMO. Looks just fine to me. Some people are just really picky.

There's nothing wrong with using straight pipe to pie cut. Overly picky people can simply use smaller angles and more sections when using straight pipe.

 

[viperlp01]

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Love me some pie.. cuts

That is beautiful. The amount of time to put that together would be ridiculous.