 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
gareywittich2000(at)yahoo
Guest
|
 Posted: Sat Dec 29, 2012 8:59 am Post subject: Countersink Bit for 4-40 Screw |
 |
|
Happy Holidays:
Looking for Countersink Bit for 4-40 Screw that fits in a Microstop. The Pilot Bit (Guide Pin) has to be 0.089" Dia so the finished screw hole after countersinking can be TAPPED for the 4-40 screw threads !!!! Where can I buy a 4-40 Countersink Bit with a guide pin of 0.089" Dia or any suggestions as how to do this ?
I took a normal -3 Rivet Countersink Bit and had a friend turn the Guide Pin down from 0.098" Dia to 0.089" Dia. I tried this and it did NOT work as the cutting flutes of the Countersink Bit did NOT extend all the way to the reduced diameter Guide Pin which is now 0.089" Dia. Also tried a normal Debarring Tool Bit, but it "chattered" because of no Guide Pin to keep it centered on the 0.089" Dia hole - result very poor.
Appreciate any suggestions !!!!
MANY THANKS,
Garey Wittich RV-8A Builder
[quote][b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
 |
JLuckey(at)pacbell.net
Guest
|
| Posted: Sat Dec 29, 2012 11:49 am Post subject: Countersink Bit for 4-40 Screw |
|
|
Garey,
I’m working from memory here, but I think that the countersink geometry between a rivet and a standard flat-head screw is different. The countersinks that I have for my microstop have the rivet geometry, so even if your mod to the countersink worked, the screw head probably would not seat properly in that countersink hole. (I think the difference in geometry is about 15 degrees, so it may not matter in your application.)
You should be able to use a ‘standard’ non-aviation-geometry countersink. I regularly use one in a drill press to countersink thick aluminum. Cutter RPM is important to prevent chatter.
-Jeff
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Garey Wittich
Sent: Saturday, December 29, 2012 08:59
To: rv-list(at)matronics.com
Subject: Countersink Bit for 4-40 Screw
Happy Holidays:
Looking for Countersink Bit for 4-40 Screw that fits in a Microstop. The Pilot Bit (Guide Pin) has to be 0.089" Dia so the finished screw hole after countersinking can be TAPPED for the 4-40 screw threads !!!! Where can I buy a 4-40 Countersink Bit with a guide pin of 0.089" Dia or any suggestions as how to do this ?
I took a normal -3 Rivet Countersink Bit and had a friend turn the Guide Pin down from 0.098" Dia to 0.089" Dia. I tried this and it did NOT work as the cutting flutes of the Countersink Bit did NOT extend all the way to the reduced diameter Guide Pin which is now 0.089" Dia. Also tried a normal Debarring Tool Bit, but it "chattered" because of no Guide Pin to keep it centered on the 0.089" Dia hole - result very poor.
Appreciate any suggestions !!!!
MANY THANKS,
Garey Wittich RV-8A Builder
01234567890123456789
No virus found in this message.
Checked by AVG - www.avg.com
12/28/12 [quote][b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
vanremog(at)aol.com
Guest
|
| Posted: Sat Dec 29, 2012 12:09 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
Just to confuse things further, countersinks for AN solid rivets are 100deg, for pop rivets they are 120deg and for screws they can be 82deg, 90deg or 100deg depending on whether they are either of the two types of SAE or metric.
-GV
--
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
Larry Bowen
Joined: 09 Jan 2006
Posts: 802
Location: NC, USA
|
| Posted: Sat Dec 29, 2012 12:11 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
Maybe you can shorten the pilot on the #40 countersink so it's almost not there -- just enough to do the job. Then after countersinking drill additional depth at 0.089 and tap for the screw.
Or, use #6 screw instead. 4's aren't very durable.
--
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com
On Sat, Dec 29, 2012 at 11:59 AM, Garey Wittich <gareywittich2000(at)yahoo.com (gareywittich2000(at)yahoo.com)> wrote:
[quote] Happy Holidays:
Looking for Countersink Bit for 4-40 Screw that fits in a Microstop. The Pilot Bit (Guide Pin) has to be 0.089" Dia so the finished screw hole after countersinking can be TAPPED for the 4-40 screw threads !!!! Where can I buy a 4-40 Countersink Bit with a guide pin of 0.089" Dia or any suggestions as how to do this ?
I took a normal -3 Rivet Countersink Bit and had a friend turn the Guide Pin down from 0.098" Dia to 0.089" Dia. I tried this and it did NOT work as the cutting flutes of the Countersink Bit did NOT extend all the way to the reduced diameter Guide Pin which is now 0.089" Dia. Also tried a normal Debarring Tool Bit, but it "chattered" because of no Guide Pin to keep it centered on the 0.089" Dia hole - result very poor.
Appreciate any suggestions !!!!
MANY THANKS,
Garey Wittich RV-8A Builder
| Quote: |
_blank">www.aeroelectric.com
.com" target="_blank">www.buildersbooks.com
="_blank">www.homebuilthelp.com
_blank">http://www.matronics.com/contribution
t="_blank">http://www.matronics.com/Navigator?RV-List
tp://forums.matronics.com
|
[b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
_________________
Larry Bowen
RV-8 SOLD,
RV-7QB in progress... |
|
| Back to top |
|
|
JLuckey(at)pacbell.net
Guest
|
| Posted: Sat Dec 29, 2012 12:25 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
GV – thanks for filling-in the numbers…
-Jeff
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of vanremog(at)aol.com
Sent: Saturday, December 29, 2012 12:08
To: rv-list(at)matronics.com
Subject: Re: Countersink Bit for 4-40 Screw
Just to confuse things further, countersinks for AN solid rivets are 100deg, for pop rivets they are 120deg and for screws they can be 82deg, 90deg or 100deg depending on whether they are either of the two types of SAE or metric.
-GV
-----Original Message-----
From: Jeff Luckey <JLuckey(at)pacbell.net>
To: rv-list <rv-list(at)matronics.com>
Sent: Sat, Dec 29, 2012 11:49 am
Subject: RE: Countersink Bit for 4-40 Screw
Garey,
I’m working from memory here, but I think that the countersink geometry between a rivet and a standard flat-head screw is different. The countersinks that I have for my microstop have the rivet geometry, so even if your mod to the countersink worked, the screw head probably would not seat properly in that countersink hole. (I think the difference in geometry is about 15 degrees, so it may not matter in your application.)
You should be able to use a ‘standard’ non-aviation-geometry countersink. I regularly use one in a drill press to countersink thick aluminum. Cutter RPM is important to prevent chatter.
-Jeff
From: owner-rv-list-server(at)matronics.com (owner-rv-list-server(at)matronics.com) [mailto:owner-rv-list-server(at)matronics.com ([email]owner-rv-list-server(at)matronics.com?[/email])] On Behalf Of Garey Wittich
Sent: Saturday, December 29, 2012 08:59
To: rv-list(at)matronics.com (rv-list(at)matronics.com)
Subject: Countersink Bit for 4-40 Screw
Happy Holidays:
Looking for Countersink Bit for 4-40 Screw that fits in a Microstop. The Pilot Bit (Guide Pin) has to be 0.089" Dia so the finished screw hole after countersinking can be TAPPED for the 4-40 screw threads !!!! Where can I buy a 4-40 Countersink Bit with a guide pin of 0.089" Dia or any suggestions as how to do this ?
I took a normal -3 Rivet Countersink Bit and had a friend turn the Guide Pin down from 0.098" Dia to 0.089" Dia. I tried this and it did NOT work as the cutting flutes of the Countersink Bit did NOT extend all the way to the reduced diameter Guide Pin which is now 0.089" Dia. Also tried a normal Debarring Tool Bit, but it "chattered" because of no Guide Pin to keep it centered on the 0.089" Dia hole - result very poor.
Appreciate any suggestions !!!!
MANY THANKS,
Garey Wittich RV-8A Builder
No virus found in this message.
Checked by AVG - www.avg.com
12/28/12
01234567
890123456789012345678901234567
No virus found in this message.
Checked by AVG - www.avg.com
12/28/12 [quote][b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
n146wb(at)cfu.net
Guest
|
| Posted: Sat Dec 29, 2012 4:45 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
I ran into this a couple of times on my -6. I simply used a pilotless countersink with the correct angle. I used a hand hole deburring tool that accepts tools with the ¼-20 thread (same as microstops). I went slowly and carefully, checking the result often and making corrections as I went. I did not use any 4-40 screws on structural components. If you are using them on your wings tips, my method is probably too labor intensive to complete in a reasonable amount of time. I used 6-32’s on the tips.
Warren
[quote][b]
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
sheldonb(at)frontiernet.n
Guest
|
| Posted: Sat Dec 29, 2012 4:57 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
I used 4-40s' on the tips (the kit came with the countersink) but I forgot who supplied the kit... But it was for wingtip install... However, I agree, use 6-32's instead...
Sheldon
[quote] ---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
sheldonb(at)frontiernet.n
Guest
|
| Posted: Sat Dec 29, 2012 5:05 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
I used 4-40s' on the tips (the kit came with the countersink) but I forgot who supplied the kit... But it was for wingtip install... However, I agree, use 6-32's instead...
Sheldon
[quote] ---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
bsavage22(at)hotmail.com
Guest
|
| Posted: Sat Dec 29, 2012 5:33 pm Post subject: Countersink Bit for 4-40 Screw |
|
|
Here's a link to Cleveland Tool and their kit for wing tip attachment. I used this kit and their dimple die for the wing aluminum. I used a hand tool for countersinking the fiberglass. It is pricey though and time consuming but the result was very nice. I also used their #4 nutplate jig.
http://www.cleavelandtool.com/prodinfo.asp?number=WHS220#.UN-WVKywXTo
Bob
From: sheldonb(at)frontiernet.net
To: rv-list(at)matronics.com
Subject: Re: Countersink Bit for 4-40 Screw
Date: Sat, 29 Dec 2012 17:57:28 -0700
I used 4-40s' on the tips (the kit came with the countersink) but I forgot who supplied the kit... But it was for wingtip install... However, I agree, use 6-32's instead...
Sheldon
[quote] ---
| | - The Matronics RV-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV-List |
|
|
|
| Back to top |
|
|
|
|
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
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
