Author Topic: Making parts from pop bottles  (Read 9663 times)

Offline DICKEYBIRD

  • Full Member
  • ***
  • Posts: 215
  • Country: us
  • Collierville, TN ya'll
Making parts from pop bottles
« on: April 29, 2011, 11:32:57 AM »
I posted this over on the HSM site but thought it may be useful to you fellows as well.

I needed a fan duct for a treadmill motor cooling fan on my little CNC lathe cobble job.  I've used this trick on many r/c model airplane canopies and engine cowls back before the metal disease got me.  Soda bottles (and many other containers) are made from P.E.T. (polyethylene terephthalate) plastic and shrinks really well with a heat gun.  Around 25%, I think.

The pics show the sequence.  I made a plug blank from scrap soft maple, turned the round end to match the o.d. of the treadmill motor, machined the square end to match the 80mm fan from an old PC power supply and carved a transition between the 2.  I then glued on a couple blocks to clear the brushholder lumps on the motor, stuffed it into a 2 liter pop bottle and hit it with my heat gun (about 400F I think.)  You shrink down the open end 1st to capture the plug and then heat it until it won't shrink any more.  You trim off the excess and split it down one side to get it off & voila!  Free (well almost free) custom-molded fan duct!

Since these pics were made, I found that the wimpy 18 cfm fan didn't have enough airflow so I picked up an 80 cfm fan cheap from eBay.  It's still 80mm square but is thicker so I'm going to add-on to my plug and do another one this weekend.

 I hope this trick may help somebody here solve a gnarley problem! :wave:







Milton in Tennesee

"Accuracy is the sum total of your compensating mistakes."

Offline DICKEYBIRD

  • Full Member
  • ***
  • Posts: 215
  • Country: us
  • Collierville, TN ya'll
Re: Making parts from pop bottles
« Reply #1 on: April 29, 2011, 11:41:45 AM »
Oh yeah, almost forgot.  If you wet-sand and then wash it down with thinner, it takes paint very well.
Milton in Tennesee

"Accuracy is the sum total of your compensating mistakes."

Offline Divided he ad

  • WARNING: LIKES SHINEY THINGS
  • The Collective
  • Hero Member
  • *****
  • Posts: 1949
  • Country: gb
  • Between Chester, Wrexham, ruthin & Holywell :-)
Re: Making parts from pop bottles
« Reply #2 on: April 29, 2011, 11:45:45 AM »
Hi Milton  :wave:  Long time no see!


This is a great idea. :smart:

I never thought of doing such a thing. Definitely one for the memory banks  :clap:




Glad you decided to share it  :thumbup:






Ralph.
I know what I know and need to know more!!!

Offline crabsign69

  • Full Member
  • ***
  • Posts: 165
Re: Making parts from pop bottles
« Reply #3 on: April 29, 2011, 02:47:16 PM »
wow this never crossed my mind great idea. thanks for sharing  :beer:  :thumbup:

Offline spuddevans

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1590
  • Country: 00
  • Portadown, Northern Ireland
    • My Photo website
Re: Making parts from pop bottles
« Reply #4 on: April 29, 2011, 03:03:50 PM »
That is a really great idea, thank you :clap: :thumbup: Consider it filed for future use.


Tim
Measure with a micrometer, mark with chalk, cut with an axe  -  MI0TME

Offline Brass_Machine

  • Administrator
  • Hero Member
  • *****
  • Posts: 5258
  • Country: us
Re: Making parts from pop bottles
« Reply #5 on: April 29, 2011, 03:14:09 PM »
Now that is an awesome idea. I will be using something like that for my CNC mill...

I do wanna hear more about this though...
Quote
little CNC lathe cobble job

Eric
Science is fun.

We're all mad here. I'm mad. You're mad.

Offline DICKEYBIRD

  • Full Member
  • ***
  • Posts: 215
  • Country: us
  • Collierville, TN ya'll
Re: Making parts from pop bottles
« Reply #6 on: April 29, 2011, 05:00:02 PM »
Thanks all!  It's one of my favorite tricks since it's cheap & easy and one can brag about being "green" and a loyal recycler.

The lathe project started as a quick (hah, that's a joke!) experimental mod to the Denford CNC MicroMill I got off Craigslist last summer for $100.  It's a "training" mill with a tiny little Sherline mill in a VERY robust enclosure.  I worked over the mill and hacked the control (thanks to the Brits over on the Denford forum) to get it working via TurboCNC and the parallel port instead of serial FANUC control with a dongle & proprietary software.  That's why it was $100; no software, no dongle, etc.

After I got it working, I got this crazy idea to do lathe ops by mounting a treadmill motor (already had that) powered homemade ER32 spindle mounted to the left side of the enclosure floor, run the mill table almost all the way to the right and stick a toolholder on the left end of the table and use its X/Y movements to do small part CNC lathe ops.  I added 1.5" X 4" rectangular steel beams (from the scrapped treadmill) under the enclosure to tie the mill into it more rigidly.

I have it crudely working and it looks like it's going to be useful but I have a ways to go yet before I call it done.  I have a spindle encoder & wheel mounted and have to get that working.  If it all works OK, I plan to get a Homann DigiSpeed XL to let TCNC control the spindle speed via the KBIC-10 cheap eBay speed control...who knows, maybe even threading?  If it all works OK, I hope to build a bigger lathe to put all the good stuff on.  This one's work envelope is very small.

That's the synopsis but if you want more gory details & pics, I can start a new thread here later and post links to threads on HSM showing how it all came about.  There's a lot of stuff and it'd be easier to do that instead of typing it all over again.

Here's a couple more pics; cuts a mean taper, yay!



Milton in Tennesee

"Accuracy is the sum total of your compensating mistakes."

Offline sparky961

  • Hero Member
  • *****
  • Posts: 839
  • Country: ca
Re: Making parts from pop bottles
« Reply #7 on: April 30, 2011, 12:14:38 AM »
I'll add my own thanks for this tip as well!

I recently acquired a small dust collector and was trying to figure out a quick/easy/cheap way to hook up the 4" ducting to my 3" table saw outlet.  Can you guess what I'll be trying? :)

Now - where to find a pop bottle?  We don't drink the sugary syrup that comes in those containers..... :(

-Sparky

Offline jgroom

  • Jr. Member
  • **
  • Posts: 87
  • Country: us
  • Kansas USA
Re: Making parts from pop bottles
« Reply #8 on: April 30, 2011, 04:58:42 PM »
Hey Sparky, I know you can get mixers (tonic water, club soda, etc) in 1L bottles, and possibly 2L.  Might be time for a party...  :headbang:

Cheers

Jeff

Offline MikeA

  • Jr. Member
  • **
  • Posts: 76
Re: Making parts from pop bottles
« Reply #9 on: April 30, 2011, 05:50:34 PM »
Brilliant! I am right at this moment thinking of several applications where this is the answer to my problems!

Thanks a million for this,

Best,
Mike
'Better is the enemy of good enough!'

Offline Blade

  • Full Member
  • ***
  • Posts: 119
Re: Making parts from pop bottles
« Reply #10 on: May 01, 2011, 10:31:31 PM »
Great tip, thanks for sharing.