Mcmaster confusion??????

[crazyfreak0075]

Ok so my next pneumatic will be a piston so that i can better educate my self about high flow valve systems. I want to be able to enter a contest some day so i will have to learn how to do this.


So i was going to purchase my pvc rod from mcmaster along with some other items and i was looking at the pvc rods section and they list them by diameter.

Now this might be a stupid question but i dont wanna make a mistake, is this diameter the real true diameter or the size of the pipe it will fit in. E.g.(2" diameter pipe does this actually fit in 2" pipe or is it 2" in diameter). Thanks!!!

[imablackskater]

no they actually round it off it really is a little bigger.

there is a chart i saw it once but i dont remember where so just research it

[VH_man]

no. its not. heres a link to the actual ID's

Nevermind, the link doesnt work. go to the homepage, click on the "pipe" link. go to plastic pipe/fittings, and then click on the "pipe" section. where MCmaster asks you for the schedule parameter theres a little link at the top that says "schedule information". click that. its all you need! if oyu cant find it, PM me and ill give you the ID and OD of the pipe you are using.....

[crazyfreak0075]

Hey thanks, but i was going to buy solid pvc pipe. Here i'll tell u how i got there, i typed in pvc rods, then i clicked on the pvc rod link in the search box and then on the right a page came up saying bars, strips, cubes,...........i clicked on the one that said rods and discs.

Then it lists a bunch of diameters, e.g. .25", .75" ect. So im just to assume that these are the actual diameters of the solid rod, not the pipe they fit into right???

[frankrede]

2" sch 40 isn't exactly 2" so you need o rings.
I wonder how ABS rod would work in a piston valve

[c19o]

sgort (spud gun expert, just look at his mauler valve) told me that a 2" pvc rod would TIGHTLY fit in 2" pipe.

[WOW!!]

Here
http://www.harvel.com/pipepvc-sch40-80-dim.asp

[VH_man]

yeah, the rod OD is what is listed. if not, contact them and ask. they should tell you......

and sry, i thought you needed the ID of different kinds of pipe.

[crazyfreak0075]

No problem VH it was my way of putting the question. And the chart did help.

Hey thanks guys i'll probly order this weekend.

[boilingleadbath]

As they said, 2" rod is supposed to be 2" in diameter (although mcmaster's stock says it might be up to .06" bigger), whereas 2" sch 40 is 2.047" in diameter.

Now, I don't have any experience with that stock and how it fits in 2" sch 40, so I can't evaluate Sgort's claim of "tightly" - but I would'nt doubt it.

(personaly, I prefer to start with 2.25" stock and reduce it's diameter to ~2.037".)

If this is for a piston, I might note that large-diameter PVC stock is a bit heavy, so you may want to drill a large hole in one end with a forstner bit.

[crazyfreak0075]

I'm sorry boilingleadbath, why do i want to drill a hole. You have to excuse my ignorance im just kinda starting to learn about building piston valve systems.

[boilingleadbath]

Because holes are hollow.

Seriously.

That is, when you drill a hole, you remove material you don't need, so the piston weighs less.
This doesn't improve preformance much, but means that it's less likely to break something when it slams backwards.

[VH_man]

Weight Definetly improves preformance. the way i make my pistons work is that if i cant open it (unpressurized) by blowing down the barrel its too heavy........ it makes a huge difference. it goes from bam t BANG!!!!!!!!!!!