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Wing bolts - from slot to Robertson

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Old 12-31-2013, 08:08 PM
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grosbeak
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Default Wing bolts - from slot to Robertson

I really don't like slotted screw or bolt heads. It's difficult to keep a driver centred in the slot, especially when driving with power. The only 1/4-20 wing bolts I could find locally are slotted and working with them is a bit of a PITA, so I decided to try my hand at converting them with heat to a suitable new drive type. I decided on #3 Robertson. Here's my process.


I used:


- a drill press (doesn't need to be plugged in)
- a platform to hold the bolt
- clamps to fasten the platform to the drill press table
- a #3 Robertson driver bit chucked in the drill press
- a blowtorch and igniter
- A small hammer to tap the drill press table and / or platform into alignment
- A slotted screwdriver to insert the bolt into the platform
- A #3 Robertson screwdriver to remove the completed bolt from the platform
- A hobby knife to trim off the slag from the melting process


1. Create a mounting platform of some type. I had already tapped a small piece of ply for a strength test so I mounted that to a larger piece the size of my drill press table.





2. Insert a bolt in the platform.


3. Place the platform on the drill press table


4. Set the depth stop of the bit carefully - it should go into the bolt about 2/3 of the depth of the head. Too shallow and the driver may cam out of the bolt - too deep and the head is weakened. When the depth is correct, make an alignment mark on the column of the drill press.


5. Align the bolt to the bit as closely as possible. I eyeballed it and that was close enough in all cases. Note the position of the bit, indexed 45 to the slot.





6. Clamp the platform to the drill press table.


7. Check the alignment again. Use a small hammer to tap the platform or the drill press table into place.





8. When the alignment is correct, fire up the blowtorch.


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Old 12-31-2013, 08:15 PM
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9. Apply heat to the bit for 20 to 30 seconds.







10. Turn off the blowtorch and carefully set it aside.


11. Firmly plunge the heated bit into the head of the bolt to its full depth and retract it.





The result will be a Robertson head with some melted plastic around it.







12. Use a hobby knife to remove the plastic. In my experience it comes off quite cleanly - sometimes all at once.


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Old 12-31-2013, 08:29 PM
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If you've done everything right, the result will be a nice new #3 Robertson socket in the centre of the bolt head.







Once I had done it two or three times I found I could turn them out at a rate of about one every two or three minutes. These should prove to be a lot easier to install and remove than the slotted types.


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Old 12-31-2013, 09:09 PM
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Interesting idea, but with the plastic displaced at the center where the head meets the threaded portion, did the bolt get weakened at all?

Time will tell i guess!

I prefer hex head bolts, and keep a nut driver in my box for them. It doesn't slip off like a slotted and has served me well for many years.

Bill S.
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Old 01-01-2014, 05:43 AM
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Quote:
Originally Posted by Twin_Flyer View Post
Interesting idea, but with the plastic displaced at the center where the head meets the threaded portion, did the bolt get weakened at all?

Time will tell i guess!

I prefer hex head bolts, and keep a nut driver in my box for them. It doesn't slip off like a slotted and has served me well for many years.

Bill S.
Time will tell, indeed. And in any case I've found plenty of nylon SHCSs online so I may order up a set and convert to those!

Edit: I could have saved myself a lot of time and effort by picking these up at the LHS!

1/4" Nylon Wing Bolts - 2" (4)

Last edited by grosbeak; 01-01-2014 at 05:46 AM.
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Old 01-01-2014, 08:19 AM
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grosbeak,
Those are the ones I use....

Bill S.
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Old 01-01-2014, 06:40 PM
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Quote:
Originally Posted by Twin_Flyer View Post
grosbeak,
Those are the ones I use....

Bill S.
I got inspiration from some other replies I received. I thought of wire nuts and I found the perfect size in my bucket...




It'd be a matter of choosing a tab material of the right thickness, cutting a slot (note the marks) across the wire nut and gluing the tab at the ideal depth to (a) fully engage the bolt slot while (b) keeping the rim of the wire nut flush with the bottom of the bolt head.

I should note that I will be stopping at the LHS tomorrow for a few of those Du-Bro hex bolts, though!
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Old 01-01-2014, 09:45 PM
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Hey grosbeak. Or you could get one of these handy, dandy tools from G.P. http://www3.towerhobbies.com/cgi-bin...&I=LXK356&P=ML They work well. Great for adjusting a snug clevis also.
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Old 01-02-2014, 05:19 AM
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i use one of these: http://tinyurl.com/ll2kabv

At the time i had a Snap-On account so it was easy to get but any brand will do.

Bill S.
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Old 01-02-2014, 08:35 AM
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Quote:
Originally Posted by kwblake View Post
Hey grosbeak. Or you could get one of these handy, dandy tools from G.P. http://www3.towerhobbies.com/cgi-bin...&I=LXK356&P=ML They work well. Great for adjusting a snug clevis also.
I used the 'handy, dandy tool" too. I do find that sometimes they crack and I end up buying another one. They do make them in metal as well, but are just for clevis's.

Last edited by hookedonrc; 01-02-2014 at 08:43 AM.
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Old 01-02-2014, 06:16 PM
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Someone else showed me that handy dandy tool. The outside reminded me of a wire nut so I dug around in my parts bins and made my own. The JB weld is to secure the ears of the metal tab.






Of course, these are probably easier all around!











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