Anyone want to take a stab at my drilling problem?

[Mayor_of_BBQ]

I need to drill a hole thru this stud, the hole will be occupied by a clevis pin to hold my seat in place.



Problem is, I need the hole thru the tapered/cone section of the pin...  See the sharpie mark? about right there.  The stud doesnt protrude thru the fender enough to drill thru the straight portion of the shaft.

I am mounting a V7 cafe seat on my v65.. this is the last piece of my restore..  I have looked at attaching it multiple ways, I think this is my best bet.  I will of course grind down the tip of the stud's point once I get the hole drilled so it doesn't drag on the tire if I bottom out the rear suspension...  but even bottomed out, the tire will never hit the underside of the fender, so I should be good.

I have a drill press and a hand drill.. it doesn't seem like there is anyway to line it up with the drill press, too oddly shaped and too long to clear

Before you ask, no I can't take the stud out, drill it, and put it back in.

If I cant drill thru the tapered part, I am thinking cut off the point, then center drill the stud and screw a bolt into it (to get the length right) and then drill the bolt head or shaft??

where is that ear emoji??? Lemmie hear your suggestions

[Kiwi_Roy]

Cut a "V" notch in a piece of steel scrap to match the pin then drill thru the scrap and the pin at the same time.

Either that or make a new pin.

[rodekyll]

Acupuncture.

I'd file (dremel) a flat at the point of the sharpie mark and drill through with a small bit.  Then chase the small bit with the proper caliber weapon.

[normzone]

Hmmm...since your plans look to me like poor solutions to a bad problem, I'm going to throw out some worse suggestions.

If I had to drill that sharpie mark with a hand drill (and I've done WAYYYY dumber stuff than that, to quote Minmax the Unstoppable Warrior), I'd attempt to peen a tiny divot in that spot with a sharpened tool and a hammer. Then take a succession of tiny drills to it. Great way to break a bunch of drills and ruin the tapered profile of that surface, and maybe even your seat pan with heat and pressure.

Rather than center drill that stud and put a bolt into it, another train wreck waiting to happen, is there enough clearance in the hole this pin (hereafter referred to as Pinny) to allow you to enlarge Pinny's diameter ? Or if not, is it in a surface that you're willing to open up a little ?

I think if it was me, and my schemes to drill Pinny looked pretty sketchy, I'd open the hole that pin goes through enough to allow me to press a sleeve onto Pinny. You could keep that sleeve in place either by a slight interference fit, or by drilling through both the sleeve AND pinny in that conveniently flat relief Pinny has, and putting...ANOTHER pin through both Pinny and the sleeve.

Or epoxy, or whatever. Because what you would then have would be a longer version of Pinny. Before you sleeved him, you could grind his crown off, and just drill the sleeve tube that would now project over where Pinny's crown used to be  to your clevis pin size.

Or is all that worse than your original ideas ? Oh, and [rodekyll]'s idea is, of course, better than mine.

[oldbike54]

 Velcro , don't laugh , a couple of loops will hold a seat in place , no drilling , get back on the road .

  Dusty

[Mayor_of_BBQ]

Acupuncture.

I'd file (dremel) a flat at the point of the sharpie mark and drill through with a small bit.  Then chase the small bit with the proper caliber weapon.

Good thinking!



Except then the drill is too bulky to get a straight shot thru (from either end)



After i ground a flat spot with the dremel, I did use a small punch to make a divot in the flat face to start the first bit. Good point normzone!

It was only then I realized the drill wont hit it from the correct angle!




Cuttently I am weighing the sense of using the dremel to just make a groove all the way around the neck of the pin... Then instead of putting the clevis pin THROUGH the stud... it could just lock AROUND the stud.
it will still have to be grooved around the sloped/pointed part tho...

[normzone]

Well, that would work if you got a sufficiently aggressive overlap twixt groove and pin.

But I've always wanted to use explosive bolts on something. Is this that opportunity ?

[Mayor_of_BBQ]

Velcro , don't laugh , a couple of loops will hold a seat in place , no drilling , get back on the road .

  Dusty

This is approach #2
my first was using 3/4" nylon webbing with straps & buckles like you see on a backpack...  it's not secure enough.

I had already drilled the hole thru the fender and was just using the stub/hole to 'locate' the seat.. with the straps providing retention.

The hole thru fender with clevis pin was my goal all along.. I only switched to straps when I realized the pin was so short that only the 'cone' protruded thru the hole...  At that point I went with straps...  When the straps didnt work I got back here 

[Idontwantapickle]

I am all in for the Velcro Option.

[rodekyll]

There are 'airplane bits' that are much longer than standard (I have some over a foot in length), and there are bit extender shafts.  Either will get you the reach you need.

Riffing on your ideas -- if you cut the groove clear around it with the dremel, you could use a circlip.

You could also thread the entire stud and use a nut.

[Moto]

Good thinking!...
Except then the drill is too bulky to get a straight shot thru (from either end)....
It was only then I realized the drill wont hit it from the correct angle!

How about using a hand drill? You know, with a crank. That's my everyday drill, and it's able to get the angle you need. You'd be surprised how unnecessary that motor on yours is!

[kevdog3019]

Acupuncture.

I'd file (dremel) a flat at the point of the sharpie mark and drill through with a small bit.  Then chase the small bit with the proper caliber weapon.

This.
With a good eye and hand start small and go progressively bigger. Patience will reward you. Keep your other hand clear of slipping start-up. Be done with it. Not hard.

[canuguzzi]

Done something very similar before. Here is how I did it:

1. Into a piece of aluminum or even hard wood (or whatever you have) drill a hole the diameter of that pin.
2. Mark the height of the hole you want to drill
3. Drill the hole since you can put the piece you have just about anywhere and even hold it in a clamp or vise.

Now you have a jig to drill that hole. You slide the pice you made up over the stud and drill away. You don't have to worry about the bit slipping or moving around because you have yourself a nice little drilling jig.

Shouldn't take you but a few minutes to make up. A spare piece of scrap material is all  you need, something at tall or taller than the stud and large enough around to drill a hole end on so it slips over the stud.

You're welcome.

[Kiwi Dave]

How about using a hand drill? You know, with a crank. That's my everyday drill, and it's able to get the angle you need. You'd be surprised how unnecessary that motor on yours is!

Methinks you've been watching Ichiban Moto too much!  Have you noticed he always rotates the drill backwards?

[Moto]

Like this. A sharp bit, low speed and plenty of oil is what you need for drilling mild steel. The angle is his problem, which the hand drill solves, as the picture shows. You don't need a high speed motorized drill. Grinding a flat with a Dremel is the way to start.

Ichiban Moto's hand drilling technique leaves a lot to be desired!

Moto

[normzone]

Done something very similar before. Here is how I did it:

1. Into a piece of aluminum or even hard wood (or whatever you have) drill a hole the diameter of that pin.
2. Mark the height of the hole you want to drill
3. Drill the hole since you can put the piece you have just about anywhere and even hold it in a clamp or vise.

Now you have a jig to drill that hole. You slide the pice you made up over the stud and drill away. You don't have to worry about the bit slipping or moving around because you have yourself a nice little drilling jig.

Shouldn't take you but a few minutes to make up. A spare piece of scrap material is all  you need, something at tall or taller than the stud and large enough around to drill a hole end on so it slips over the stud.

[Norge Pilot]'s idea is good. A piece of 2/4 would serve as jig material. And if you get a little oversize on the hole diameter, it doesn't have to be straight.

Keep it wet while you're drilling it - heating Pinny probably won't improve his grip on the seat pan.

[drums4money]

My favorite hardware store has a variety of different brass & aluminum tubes with different ID's and wall thicknesses.

You could cut threads onto the spiked seat-keeper.  Then tap threads into an appropriate size tube that'd give you enough extension to protrude through the receiving hole in the fender.  Locate the correct spot & pre-drill for the clevis pin.  Finally- Screw the threaded tube onto the spiked seat-keeper, then glue/epoxy/solder/swage the extension tube on permanently.

You might have to slightly enlarge the locating hole in the fender to accommodate the slightly larger diameter of the extension shim/tube. 

[Chuck in Indiana]

Is it ok if I just do the  to all this? 
It's too late, now..

[pehayes]

You had me confused with the "clevis pin".  A clevis pin looks like this and requires a cotter pin or some other securing wire:


I think what you are trying to install is known as a "hitch pin clip" that looks like this:



Patrick Hayes
Fremont CA

[Mayor_of_BBQ]

Is it ok if I just do the  to all this? 
It's too late, now..

I would LOVE a better solution but yeah, I'm done for now!

You had me confused with the "clevis pin".  A clevis pin looks like this and requires a cotter pin or some other securing wire:


I think what you are trying to install is known as a "hitch pin clip" that looks like this:

Yessir you are quite right!

[atavar]

to answer the original question, the way to drill the hole would be to fid a piece of hard steel tube that is a tight fit over the pin, drill a small pilot hole at the right height, clamp it down hard and drill through the tube and the pin.
If you can't find a pin find a piece of square bar stock double the pin diameter, and cut a slot in it that will be a tight fit to the pin, drill a small pilot hole through the sides of the block that passes through the slot.  Clamp it in place and drill away.
Use a *SHARP* hard drill.  Spin it fast with lube.  Those pins are hard.  Breaking the surface of the pin at the entry point with a tiny diamond dremel may be a good idea.

Way easier would be to make a new pin.  Drill the hole before machining the taper.  Use AR steel.

[Mayor_of_BBQ]

so I cut off the pin with a 'cone' haircut.  Then I spun a nut on a M8 bolt, and cut that off as well.  I marked the pin and hit it with a punch to mark a drill hole




I drilled a hole thru the bolt head for the hitch pin clip.. started small and worked up to size



Then I drilled out the pin itself, about 4 bits working up to 1/4.




Then I tapped the hole to m8x1 and put the bolt in there. Once I have the bolt height dialed in, i will use some JB weld in the side where the threads are visible to fully seal it.



I left enough of a gap to put the pin around the bolt (with head retaining) or through the bolt. I will prob just get an assortment of pins and figure out what works best, the fit 'through' isn't perfect.




Thats it folks, thanks for the help!

Chuck you aren't off the hook, i am still looking for a better permanent solution!

[Mayor_of_BBQ]

My favorite hardware store has a variety of different brass & aluminum tubes with different ID's and wall thicknesses.

You could cut threads onto the spiked seat-keeper.  Then tap threads into an appropriate size tube that'd give you enough extension to protrude through the receiving hole in the fender.  Locate the correct spot & pre-drill for the clevis pin.  Finally- Screw the threaded tube onto the spiked seat-keeper, then glue/epoxy/solder/swage the extension tube on permanently.

You might have to slightly enlarge the locating hole in the fender to accommodate the slightly larger diameter of the extension shim/tube. 

If my solution doesnt work, I will prob go this route, I wont thread it tho.. I have no dies and only metric taps up to m10
Prob just cut to length and jb weld the sleeve over the pin. I will have to enlargern the hole thru the fender to do that tho :-(

[kevdog3019]

You actually don't NEED anything to pin it in.  Your seat aint going anywhere when you're sitting on it.  Maybe it's for when you're not.

[Mayor_of_BBQ]

You actually don't NEED anything to pin it in.  Your seat aint going anywhere when you're sitting on it.  Maybe it's for when you're not.

The seat is not a stock seat for the bike.. It needs more than my booty holding it in place! I took a test ride up 'Elk Mountain Scenic Highway' (that's a good one to Google Earth) to test the retention with just my strap setup... It NEEDS the pin! :beer

[Chuck in Indiana]

Chuck you aren't off the hook, i am still looking for a better permanent solution!

That looks like a good redneck repair to me.  Got er done.. 

[cleatusj]

If you decide to use the brass tube and JB, I would also peen in the brass into the flats of the original pin before the JB sets up.

[moltoguzzi]

Take a piece of round stock, minimum a 1/4 inch larger than the tapered pin and twice as long. Drill a hole on one end to just slide over the pin and on offset (the same amount as the tapered pin, measured from the center) hole on the other end the same size of the hole you need to drill and you have a drill jig.   

[mtiberio]

Also called an "R" clip because of the shape. Also called a "jesus" clip because if you do not use one on your small aircraft throttle linkage and it comes undone, you go to see Jesus (if you have been good according to a popular iron age mythology).

[Chuck in Indiana]

I'd never trust something like that in an airplane, even if it *is* an ultralight or something. A proper cotter pin won't vibrate loose.