Need advice on drilling PVC tube for E-11 build

[Rich330[TK]]

I'm attempting my first E-11 build from 40mm PVC tube and am having a torrid time with the drilling.

 

I have three types of drill bit with for my drill:

 

L to R: wood, metal, masonry

 

None of these is producing the right results.

Obviously I discarded the masonry bits immediately as they are totally useless for PVC tube.

I wasn't going to use the drill bits for wood either but I had no success with the drill bits for metal so had to give them a try. As expected they just tear a really unsatisfactory ragged hole in the plastic.

With the smaller drill bits for metal I can drill the pipe fine and get a nice clean hole. It seems to be the right type of drill bit. But as soon as I switch to the larger drill bit for the correct hole size it just breaks the tube.

 

Any advice would be very much appreciated.

Edited November 4, 2010 by Rick330

[pandatrooper[TK]]

Drill a smaller hole using the metal bit. Doing it in stages helps. Or drill a small one first, then enlarge the hole with a Unibit. It works great.

[NoGoodSkills[501st]]

drill a small whole like panda said then use the metal bit

 

i did that and it worked fine had a lil bit to sand up but it was nothing major

Edited November 4, 2010 by valder

[Rich330[TK]]

I've drilled in up to four stages, using a larger bit each time. Tried using the large bit immediately, tried drilling in two stages, threes stages ... no use.

I will look into the unibit idea. Sounds promising.

Edited November 4, 2010 by Rick330

[john danter]

It's going to fur up dude due to the heat generated by the friction

 

Centre tap the holes first, then a small bit then a larger one

 

Finish off with slow turns if your drill can do that?

That will clear most crud away for you......but it'll never be totally clean and will require some sanding

I recommend a semi circular file for the insides

 

John

[john danter]

These hand held hole tappers are great too

 

Sold in radio control car shops usually

 

http://www.google.co.uk/m/search?site=images&gl=uk&client=safari&source=mog&hl=en&aq=f&oq=&aqi=-k0d0t0&fkt=2791&fsdt=15808&q=hole+tapper+RC#i=10

Edited November 4, 2010 by john danter

[Rich330[TK]]

Thanks to all for the feedback.

 

I understand I'll need to do a bit of sanding, that's fine. It was the total splitting of the tube between holes that was the killer.

 

My drill is decent and can do slow. I'm going to try out different methods of drillign pilot holes and see what's best. Then just give it a go and try and do it slower and be more patient.

 

Cheers.

[Rich330[TK]]

Making progress, chaps! I was applying too much pressure from behind the drill and turning the drill too fast as well.

Thanks again!

At least I bought a good length of pipe!

[TK_LEPER]

Do you have a bonded template?

[john danter]

 

These little things are brilliant mind !!!!

 

Glad to see you're making progress, and a PVC blaster

[Rich330[TK]]

Do you have a bonded template?

 

I have a template and it's stuck to the outside of the tube if that's what you mean, Jess.

[Rich330[TK]]

Yay!

 

[matt black]

It looks like you could do with letting the bit free spin in those holes a bit to make them a little more circular

[dashrazor]

a conical rasp bit works wonders on getting the holes nice and round

[john danter]

Loving the state of that desk dude

 

Try either of the following to sort those holes out.

 

My tool suggested above (hand held reamer)

 

A circular file (large one,) spun around a few times inside the holes

 

Dash's advice is ace too!

 

Re drill and let it spin as suggested above

Edited November 4, 2010 by john danter

[TKRobert]

This is great advice guys as I will be starting on my PVC E-11 soon. Have prepped the resin bits and will be doing this drilling soon....of course, I'm in the US and don't have 40mm tube, I have the 1.5" which is slightly larger and thicker walled.

 

Loving the state of that desk dude

 

Try either of the following to sort those holes out.

 

My tool suggested above (hand held reamer)

 

A circular file (large one,) spun around a few times inside the holes

 

Re drill and let it spin as suggested above

[john danter]

Robert, actually your pipe is more accurate dude

 

My friend 3D laser scanned my real sterling and measured every piece. There's not one metric measurement on there

 

All imperial

[Rich330[TK]]

Thanks for the help, chaps.

I'll be in the DIY store tonight on the look out for another file/rasp/reamer type tool.

I think the walls are quite thin on this tube which is why it deformed so much with the heat of the drilling. Happy I got my rough holes drilled though.

[TKRobert]

Sweeeet.

 

Robert, actually your pipe is more accurate dude

 

My friend 3D laser scanned my real sterling and measured every piece. There's not one metric measurement on there

 

All imperial

[Shooter]

A little late to this party, but I found that if you drill a small hole first then use the cone shaped dremel grinding accessory (sorry don't remember the name, but it's a pretty standard piece) it's about the perfect size for the holes you need.

[Rich330[TK]]

I have new toys ...

 

 

... and some very clean-looking round holes! I'm amazed. Hardly any sanding to do!

 

[Rich330[TK]]

 

Glad to see you're making progress, and a PVC blaster

 

 

I love it when we get you onto your "chosen specialist subject", John!

[carbonitekid]

Just to arrive far to late to this party....

 

Best method for drilling in this type of situation is this:

 

Drill pilot hole with 3mm HSS drill bit.

Open up holes to required diameter using correct size drill bit ground up to be a pin drill with 3mm pin.

Same as this:

 

http://www.rutlands.co.uk/cgi-bin/psMultiImage.cgi?prod_code=DKT6ℑ=DKT6_b3.jpg

 

Then deburr .

 

I knew 16 years detail fitting for the aircraft /military Radar industry would come in handy one day.

[Tray[TK]]

When we did this to ours we used a drill press. It allowed the bit to stay stationary. Made for nice clean round holes.

 

We have since added a pipe inside so that we can cast the gun and make hard rubber ones.

 

[TK bondservnt[501st]]

I start with a pilot hole with a dremel,

 

then I move to the wood 7/16" bit

 

after that I use a dremel grinder to smooth it out.

 

also if you have the correct size T Tracks you should not see any holes below

them, as GINO's track completely covers them.

 

I drill out the front, and rear holes only, adds a bit of strength.

 

I only use 3 tools to do them.

 

the key, really is to mill slowly with plastics.

 

putting a lot of pressure, and speed is not the correct way, not like with drilling metals.

it's more like drilling wood.

 

that's why I use the 7/16" wood hole cutter bit.

 

something like this: