Drilling thousands of small holes in HDPE "poly pipe"

[huleo]

Figured it was worth a shot to see if you guys have ideas. We will be drilling around 3000 small holes in 1" poly pipe for drip irrigation purposes. This won't be a CNC operation, but looking for a way to make this go faster. But beyond speed right now, I am trying to select tooling that will do this and make a nice, clean hole. I am just not convinced a twist drill is the answer. The pipe is thin wall so drill pressure is an issue, but we are talking about a .125"-ish hole.

Basically a small barbed fitting goes in each hole and I am trying to minimize leaks, though I realize this won't be, or even need to be perfect. I ran testing on a sample, one hole drilled with a straight flute step bit, another was simply pierced. The drilled hole was leak free at 60psi, but the pierced hole had a small leak. Piercing was also problematic in that it deformed the pipe, even with support, just due to the force needed.

I also attempted to melt a hole in but I think that would take very precise heat control and did not make a nice hole regardless.

I know PE pipe will make some serious stringy chips, which is not really a problem, other than I would like to minimize burrs inside/outside the pipe.

 

[SIP6A]

I would build a drill jig that will hold the pipe round (and depending how close together the holes are drill several in one set up) and then use a two flute endmill.

 

[EmanuelGoldstein]

Figured it was worth a shot to see if you guys have ideas. We will be drilling around 3000 small holes in 1" poly pipe for drip irrigation purposes. This won't be a CNC operation, but looking for a way to make this go faster.

Seems like a natural for a laser ? And could be automated pretty easily ?

 

[memphisjed]

Brad point drill bit. Cheap and fast.

 

[EmanuelGoldstein]

I'm not sure you guys are real machinists ... Here's a good excuse to spend a thousand bucks on some new technology, fart around with it for two weeks, spend hours and hours reading up and trying stuff, but all you want to do is spend $5 on a drill bit

 

[memphisjed]

I'm not sure you guys are real machinists ... Here's a good excuse to spend a thousand bucks on some new technology, fart around with it for two weeks, spend hours and hours reading up and trying stuff, but all you want to do is spend $5 on a drill bit

Order a flexdrill with pipe option, build new shop space, drill pipe with a carbide brad point (9 real dollars).

Better?

 

[EmanuelGoldstein]

Order a flexdrill with pipe option, build new shop space, drill pipe with a carbide brad point (9 real dollars).

Better?

If you specify an 18" deep foundation, okay, we'll let it go this time

 

[swarfless]

Down in this neck o' the woods we just punch the holes with a 3.5mm diam punch, 45 degree included angle point. The dripline adapters go in with a satisfying click & seal every time. This as a manual DIY, home application, for 'production' I'd use a multiple point punch & maybe a close-fitting cradle to support the polypipe & an arbor press. Use a skip space punch if pipe tends to collapse despite cradle. I'd be surprised if you couldn't successfully punch 20+ holes per stroke with a one ton press. Small punch press self-feeding would be nice but feeding slippery poly might be tricky ..

 

[BT Fabrication]

drill jig, as bits like to walk and give oblong holes, which might be why its not 100% sealing. drill jig will guide it. its plastic pipe, just drill and go. Seconds a hole.

 

[DDoug]

Melt them in.....

 

[guythatbrews]

Use the punch with a sleeve to hold the pipe round while you punch. You'll get better holes that won't leak. Slide the sleeve along while you punch.

The punch is hard to beat and no swarf to clog things later. Also a stronger joint since the pipe is deformed in for more bearing surface on the barb.

Never tried spinning the punch in a drill while punching but bet it will help. Use a steel punch instead of the crummy plastic one.

 

[Scruffy887]

I would take a drill blank and hand grind the end in a shape sim to the Washington Monument. Then a quick experiment with high RPMs to make a swarf free friction melted hole. Bonus would be a melt ring making the hole seal better.

 

[dgfoster]

Use the punch with a sleeve to hold the pipe round while you punch. You'll get better holes that won't leak. Slide the sleeve along while you punch.

The punch is hard to beat and no swarf to clog things later. Also a stronger joint since the pipe is deformed in for more bearing surface on the barb.

Never tried spinning the punch in a drill while punching but bet it will help. Use a steel punch instead of the crummy plastic one.

Would someone mind posting a link to an image of these punches or posting a picture of one? I am unfamiliar with them and am curious about their design.

Denis

 

[boslab]

My feeling is the pipe should be as cold as possible before drilling, possibly connect the pipe both ends with a chiller recirculating cold water before the drilling, then drill on a standard drill with register index pin as fast as possible, fast flute carbide drill, 1000 holes isn’t a big job, girls on the drills in the Ali works where I worked ( the mrs!) would do that in a short day while talking incessantly.
Cooling makes the plastic brittleness increase
There are spot coolers that work but hardly worth it for such a small job
I’d guess you’d have to tinker with speed and feed, part of the fun, pipe with Color in tends to have a different MP too, white is loaded with Ti oxide, red is iron etc, slight change I suppose
Mark

 

[Bill D]

Is spacing consistent or varies? Why not buy the pipe with the built in emitters?
Bill D

 

[Strostkovy]

I've had good luck with stub length sharp point drills (90 degrees maybe?) back when I was drilling holes in thin PVC for a project.

 

[Bill D]

500' x 17mm PC Drip Line with .95 GPH Emitters Every 12" (DIG)

The Drip Store's Excel Pressure Compensating Drip Line from DIG is extruded drip tubing with self-contained, flow regulated inline emitters molded into the inside wall of the drip tubing in preset spacing.

www.dripirrigation.com

 

[ratbldr427]

I have used form drills on metal never on plastics but as Scruffy says no chips to worry about but would be a lot slower than punching. As for chilling just shoot a CO2 fire extinguisher in it.

 

[gbent]

The manufacturer has punches. Quit trying to roll your own. Don't drill the holes, the chips will plug the emitters. If you won't buy the really cheap factory punch, then melt them in.

As far as the line with molded drippers, I'm guessing the OP wants the push in drippers so he can put a line on the emitter discharge to go to a pot or similar.

 

[CarbideBob]

Seems like a natural for a laser ? And could be automated pretty easily ?

3000 holes. Not exactly production world.