Kit Building If you're building a kit and have questions or want to discuss kit building post it here.

Making large holes in Lite Ply

Reply

Old 09-04-2017, 10:20 AM
  #1  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,520
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Making large holes in Lite Ply

Just starting a project and was going to use the hole cutter to make some lightening holes in a some lite ply fuselage sides. Even using the hole cutter, the lite ply will splinter and not leave a finished look. What methods are good for making 1 inch to 2 inch holes in light ply that leave a nice sharp edge with no splinters?
thailazer is offline  
Reply With Quote
Old 09-04-2017, 10:32 AM
  #2  
foodstick
 
foodstick's Avatar
 
Join Date: Mar 2005
Location: ankeny, IA
Posts: 5,547
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I think your best bet is to find a fine tooth holecutter.. or maybe they make one with more of a grit? than teeth... Also I have had the same kind of issues and often use a sanding drum to go in and clean up the edges after the hole saw.

I never mentioned also this is probably easier on a drill press, than a hand held. I hope you get it perfected and keep building !
foodstick is offline  
Reply With Quote
Old 09-04-2017, 10:38 AM
  #3  
3dorbust
Junior Member
 
Join Date: Sep 2017
Posts: 6
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Large holes

A router with a flush cut bit make a round template first that the router will run inside mount it with clamps or wood screws
3dorbust is offline  
Reply With Quote
Old 09-04-2017, 11:18 AM
  #4  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,584
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

A hole saw run part way through on both sides normally cuts a clean hole. Another option is to use a hole saw one size smaller and drum sand to finished size as Foodstick recommended. I've done both with good results though, when it comes to the sanding, I use this drum/horizontal belt sander to finish the holes:
Click image for larger version

Name:	6818470c-cf09-4143-829c-3cd7b30a2274_1000.jpg
Views:	14
Size:	92.7 KB
ID:	2230506
Hydro Junkie is online now  
Reply With Quote
Old 09-04-2017, 01:00 PM
  #5  
flyboy2610
My Feedback: (1)
 
flyboy2610's Avatar
 
Join Date: May 2004
Location: Lincoln, NE
Posts: 487
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Use a drill press, use a backer block for the lite ply, use a hole cutter, and when the teeth are a bout halfway through the ply, flip it over and finish the hole from the other side. It still may need a little sanding to clean up, but it will look a lot better.
flyboy2610 is offline  
Reply With Quote
Old 09-04-2017, 01:22 PM
  #6  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,520
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hey, Thanks all for the suggestions! I think I am going to grind down my hole cutter as it is indeed way to aggressive. Backing plate is a good idea too, and I do usually cut in from both sides. Appreciate the help.
thailazer is offline  
Reply With Quote
Old 09-04-2017, 06:37 PM
  #7  
All Day Dan
My Feedback: (5)
 
All Day Dan's Avatar
 
Join Date: Dec 2002
Location: MANHATTAN BEACH, CA
Posts: 4,605
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I uase a forstner bit. Dan.
All Day Dan is online now  
Reply With Quote
Old 09-04-2017, 08:55 PM
  #8  
rrembert
 
Join Date: Nov 2007
Location: West Palm Beach, FL
Posts: 51
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by All Day Dan View Post
I uase a forstner bit. Dan.
+1
rrembert is offline  
Reply With Quote
Old 09-05-2017, 07:25 AM
  #9  
Hemikiller
My Feedback: (125)
 
Join Date: Dec 2001
Location: Killingworth, CT
Posts: 694
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

A good sharp Forstner bit should give you a reasonable finish. The cylindrical hole saws have too low a tooth count.
Hemikiller is offline  
Reply With Quote
Old 09-05-2017, 08:54 AM
  #10  
FlyerInOKC
My Feedback: (6)
 
FlyerInOKC's Avatar
 
Join Date: Nov 2004
Location: Oklahoma City, OK
Posts: 9,550
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I wonder if one of these would work?

Hobbico Circle Cutter
FlyerInOKC is offline  
Reply With Quote
Old 10-02-2017, 04:26 AM
  #11  
thailazer
Thread Starter
 
thailazer's Avatar
 
Join Date: Mar 2008
Location: Liberty Lake, WA
Posts: 1,520
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by 3dorbust View Post
A router with a flush cut bit make a round template first that the router will run inside mount it with clamps or wood screws
I think you have hit on the best way to cut those holes! A bit more time and equipment involved but those router bits do indeed produce a clean cut. Do you have a source for 1/8 inch shank router bits with the ball bearing for use with a Dremel tool? Been looking and have not found one yet. That would be handier than a bulky router with the larger shank.

For now, I have found that my Milwaukee hole cutter does a decent job if I run the drill backwards. Thanks again for all the inputs.

Last edited by thailazer; 10-02-2017 at 04:34 AM.
thailazer is offline  
Reply With Quote
Old 10-06-2017, 01:27 PM
  #12  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,900
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Large Forstner bits will make perfect clean cut holes that look like they were cut with laser precision. The bits are a bit expensive but well worth it if you are cutting quite a few holes. I have bits from below 1/4" to over 1.5".

For relatively soft woods like Lite Ply or balsa, you can also make a hole cutter from a piece of thin wall SS tubing of the correct size. You sharpen one end of the tubing from the inside and afix the other end to some kind of handle. Rotate the tubing against the wood using light pressure and it will cut like a die. You can get very clean cut holes using this method. Brass tubing works well for smaller holes.
Truckracer is offline  
Reply With Quote
Old 10-07-2017, 02:57 PM
  #13  
acdii
 
Join Date: Jan 2011
Location: Capron, IL
Posts: 7,734
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Forstners here too. I found that cutting from both sides gives the cleanest cut, very little sanding needed.
acdii is offline  
Reply With Quote
Old 10-07-2017, 08:38 PM
  #14  
Truckracer
My Feedback: (19)
 
Join Date: Apr 2004
Location: Des Moines, IA
Posts: 4,900
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Yes I forgot about cutting the holes from both sides. Good call! Otherwise the bit may catch on the thin ply and tear it.
Truckracer is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service