Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Big holes

Matronics Email Lists Forum Index -> Zenith-List

View previous topic :: View next topic

Author Message

Jaybannist(at)cs.com
Guest

Posted: Sun Jul 23, 2006 9:12 am Post subject: Big holes

I've got another question for the learned group.  How do you get a 1 1/8" dia. hole in .090 aluminum?  This is for the torque tube bearings.  ZAC shows a "flat faced drill bit" but no suggestion as to where one might obtain one of these. I searched the internet to no avail.  I don't think a hole saw would make a smooth enough hole for a bearing.  I would be afraid to use a fly cutter.  Is it possible to get the desired results with a series of step drill bits (in a drill press)?

 

 Jay in Dallas, working on XL fuselage

ding(at)tbscc.com
Guest

Posted: Sun Jul 23, 2006 9:55 am Post subject: Big holes

Jay,

              My standard method is to drill undersize (1" in this case),  and open bigger with a sanding drum in a drill. I first mark the desired  perimeter and work out to the line. A hole saw can be used this way, but  otherwise is not precision enough.

                                                             Lynn

                                                             Corry PA

                                                             601XL    tails & wings done

tonyplane(at)bellsouth.ne
Guest

Posted: Sun Jul 23, 2006 11:13 am Post subject: Big Holes

 I        used the Uni-Bits (great tools) for holes in sheet metal from        about 5/16 inch (8mm)  up to I believe 1-1/4 inch dia.(30.5mm).         Any good hardware store has them.

       Tony Graziano

       601XL N493TG;  118 hrs and just finished        first Annual Conditional Inspection

        

        

         

        

        

        

     Big      holes        From:            Jaybannist(at)cs.com (Jaybannist(at)cs.com)        Date:              [b]Sun Jul 23 - 10:12        AM[/b]  	  Quote: 	
		   	  Quote: 	
		  I've got another question for the learned group.  How do you get a 1 1/8" 

dia. hole in .090 aluminum?  This is for the torque tube bearings.  ZAC shows a



"flat faced drill bit" but no suggestion as to where one might obtain one of 

these. I searched the internet to no avail.  I don't think a hole saw would make



a smooth enough hole for a bearing.  I would be afraid to use a fly cutter.  

Is it possible to get the desired results with a series of step drill bits (in



a drill press)?



Jay in Dallas, working on XL fuselage

rstone4(at)hot.rr.com
Guest

Posted: Sun Jul 23, 2006 11:13 am Post subject: Big holes

 Jay,   

       I had the  same problem and did it with a fly cutter but not with the regular tool steel  cutter.  I took an old file and ground it to look like a knife blade on one  end the other end to fit into the cutter slot on the fly cutter.  Draw it  down on the .090 sharp end first and apply pressure very slowly.  This will  make the most clean cut you ever saw.  When you think you have the cutter  adjusted to end up with a hole 1 & 1/8th, check by drawing the blade  down on a piece of wood and check the diameter.  Aluminum is soft and much  easier to work than any other metal I know of unless it has been alloyed with  harder metals

  

 Bob Stone, Harker Heights, Tx

Zodiac XL (Not too far along)

 [quote]   ---

admin(at)arachnidrobotics
Guest

Posted: Sun Jul 23, 2006 11:20 am Post subject: Big holes

    If you find that you still have problems making a clean hole, I have several extra Torque Tube Bearings for the XL.  I'd send you one if you wanted to pay shipping.  The 1.125 DIA hole on these was punched with a single punch of the correct size, so they look great.  Let me know off-list if you're interested.



Do Not Archive

Jaybannist(at)cs.com wrote: 	  Quote: 	
		   I've got another question for the learned group.  How do you get a 1 1/8" dia. hole in .090 aluminum?  This is for the torque tube bearings.  ZAC shows a "flat faced drill bit" but no suggestion as to where one might obtain one of these. I searched the internet to no avail.  I don't think a hole saw would make a smooth enough hole for a  bearing.  I would be afraid to use a fly cutter.  Is it possible to get the desired results with a series of step drill bits (in a drill press)?

 

 Jay in Dallas, working on XL fuselage

raymondj(at)frontiernet.n
Guest

Posted: Sun Jul 23, 2006 7:53 pm Post subject: Big holes

You  might try a Forsner bit. Used in woodworking.

  

 Raymond Julian

 Kettle  River, MN.

 Corvair core acquired.

 [quote]   --

pacificpainting(at)comcas
Guest

Posted: Sun Jul 23, 2006 8:24 pm Post subject: Big holes

Jay,

  

 I have a set of Rotabroach sheet metal cutters.  They are expensive but they work very well. They actually cut holes, not  saw or drill them. Look up Rotabroach on your browser. I looked them up. They do  come in the size you want, but I don't know how much they are.

  

  

 Dave in Salem

 801

  

  

 [quote]   ---

grs-pms(at)comcast.net
Guest

Posted: Tue Jul 25, 2006 10:15 am Post subject: Big holes

Jay:

  

 The "flat-faced drill bit" probably refers to  a flat wood boring bit, the kind with little spur projections on each  side.  You should be able to find one at almost any hardware store.   Locally, I find them at Lowe's and Ace Hardware.  They work well in a drill  press, or even with a handheld drill and they leave a clean hole.   Expect to pay about $3.00

  

 George

  

 [quote]   ---

Jaybannist(at)cs.com
Guest

Posted: Tue Jul 25, 2006 10:17 am Post subject: Big holes

Thanks to all of you for your input on drilling large holes in .090 aluminum.  I finally sprung for a 1 1/4" step drill bit.  I drilled the torque tube bearing and got a beautiful hole, 3/32" off center!  So I fabricated another bearing and carefully drilled it.  Worked out great.

 

 Thanks again - Jay in Dallas

 Do not archive

rstone4(at)hot.rr.com
Guest

Posted: Tue Jul 25, 2006 12:02 pm Post subject: Big holes

     The tool you guys  are talking about is called a "Spot Facer"  it is used to provide a flat  surface just a little larger than the bolt or screw head when the part being  fastened has a surface that is not at the same angle as the part it is being  fastened to.  I have attached a drawing to help show what I am talking  about.  If you are going to get one or a set of these remember the reason  for the spot facing around the hole is not only so the bolt head will fit flat  on the surface but so you can also get a socket on the bolt head when you are  trying to tighten a nut on the other end.

  

 Bob Stone, Harker Heights, Tx

Zodiac XL (Not too far along)

 [quote]   ---

Spot_face_example.BMP

Description:

Filesize:

1.01 MB

Viewed:

129 Time(s)

ggower_99(at)YAHOO.COM
Guest

Posted: Tue Jul 25, 2006 2:35 pm Post subject: Big holes

This are the type of bit I use for making holes up to 1 1/4" diam.  (The biggest one I have from a bit kit).   

Is better using a variable speed hand held drill,  just make low and even presure,  use a low speed where you feel confortable.  practice in a scrap piece.  put a piece of wood under the work.  Is easy and the results are great.  



For the first ones I used our Bridgeport,  that was overkill  



Saludos

Gary Gower

Do not archive.

George Swinford <grs-pms(at)comcast.net> wrote:[quote]       Jay:

  

 The "flat-faced drill bit" probably refers to  a flat wood boring bit, the kind with little spur projections on each  side.  You should be able to find one at almost any hardware store.   Locally, I find them at Lowe's and Ace Hardware.  They work well in a drill  press, or even with a handheld drill and they leave a clean hole.   Expect to pay about $3.00

  

 George

  

 [quote]   ---

Display posts from previous:

	Matronics Email Lists Forum Index -> Zenith-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum