drilling and counter sinking holes

I need to drill and counter sink a few holes ( 96 actually ) Anyone point me to a good bit for the old drill press for this job?

Look into a center drill. Because of their construction they're also good for creating pilot holes especially in angled or round surfaces. www.use-enco.com and do a search for "combined drill and countersink"

www.mscdirect.com is another good one... I buy most of my tooling from them.

2 things... Slow speed and cooling fluid / cutting oil at all times!!!

Joel, getting ready to drill some strips. I see.
The original screws were slotted flat head fine thread w/washer and nut. I used Philips head, course thread, 2-1/2 inch 5/16 dia SS screw with nylon insert nuts and split ring lock washers to follow the movement of the wood. Got them from Jamestowndistributors.com

The diameter of the screw head is 0.575 and it looks like about a 60 deg angle.

All strips are drilled the same, so you could stack them and drill several at a time (countersink separately then).

BFR, how'd you get the wood?

rmgill said:

BFR, how'd you get the wood?

Click to expand...

I do not have it yet, just working on the metal strips that go between the planks.

So this is for the black locust, not steel?

If you want to drill and countersink a 5/16" diameter machine-screw hole into wood in one operation, then these "Carbon-Steel Adjustable Countersinks" look like the right tool for that:

http://www.woodtechtooling.com/Fore...untersinks/CountersinksCounterbores2.html#125

They should cut more aggressively than the center drills and should be adjustable to whatever depth of hole you need to penetrate through to the bottom those locust planks. They seem to have the correct profile for a machine screw and are available with 5/16" bits.

Also, if the angle of the screw head does not match the angle of the countersink then maybe you would be building little rot traps under the screw heads. Perhaps check for a match before purchasing countersinks and screws.

the drill/countersink is for the steel strips that hold down the locust.

And these things can be handy:

http://www.amazon.com/gp/product/B0000E6TM6/102-0627756-4900914?v=glance&n=228013

(That particular model has received mediocre reviews though.)

the drill/countersink is for the steel strips that hold down the locust.

Click to expand...

Oh. Duh. Like in the photos.

jodka,
I do a lot of woodworking and the drill/ countersink method is th ebest way to go. Any good hardware store or woodworking store would have a good set for you. You can adjust the stop on your drill pres to get consistent depths.
I'm not familiar with the qualties of locust, but if it is a hard wood like maple or oak I would advise you to use bees wax in screwing in the screws, if you are using screws, just scrape the screw across the wax to lube the screw.

Guys, there is no drilling in the wood. The locust (which is one of the hardest woods in America, btw) is routed
and held in place by the metal strips. This allows for some movement of the wood.
The original M756 pipeline truck bed was made with red oak based on a surviving sample I have.
I'm very happy with my locust bed after one year of use and exposure.

BFR Wrote> the drill/countersink is for the steel strips that hold down the locust.

Click to expand...

Jodka Wrote> Oh. Duh. Like in the photos.

Click to expand...

Just to avoid any misunderstaning; I was not directing sarcasm at others, just expresing surprise at my own dumness for not having seen that its the steel strips, not screws, which hold the planks to the bed.

After receiving my combination drill/countersink it became clear that my drill press is not up to the task. I am probably going to use a decent size bridgeport to drill & counter sink the holes in the strips for my bed. I have very little experience with this type of machine. I will be drilling 5/16 holes w/counter sink into 3/16 mild steel. Any tips/thoughts?

A bridgeport styled milling machine will work fine for this project.

I'm a machinst by trade...and I can offer a couple of ways to do this.

The safe way:
1) lay out the strips using a centerpunch. If accuracy is open +-.030" use a fine tip marker.
2) Align a vice on the machine table and bolt it down.
3) Use ground parallels or a piece of aluminum to raise strip off of the bottom of the vice.
4) Slide in strip and clamp in vice when mark aligns with drill point.
5) Drill hole. After establishing proper depth, set quill stop so depth is repeatable.
assuming the strips are mild steel and the drill/countersink is HSS, using the high of low gear or the low of high gear will be fine. Use cutting oil as well.

The less safe way:

1) layout the holes with a centerpunch.
2) Clamp a couple of Milling machine table clamps to the table so that if the part smags the drill, it won't swing the part into you, cutting you in half.
3) slide the part under the spinning bit until it aligns with the centerpunch and drill.
4) Set the quill stop as described above to repeat the proper depth.

If your clever, as most of you are, you will align the clamps so the hole aligns over one of the T-slots so you don't drill into the table. This also eliminates the need to put down a sub-plate.

If you need a pic, let me know. I can make a mock up and post a pic.

BTW, anyone interested in trading precision/custom machining and plating for a deuce, or at least a good deal on a deuce should contact me . I'm still searching for my first MV.

Thanks !

just finished drilling/countersinking the strips . I made through all 96 holes without changing the tool, but I would have changed it before attempting another. now I need to round up some hardware

Don't know why I'm taking so long to finish this job. Anyway, Joel, your boards were planed today. Next, I'll rip them to required widths and finally the edges get routed for the metal strips.

I'm leaving the top rough sawed for a good walking surface. It's hard to find locust that's good to a full 7 or 8 inches, so any defect in the wood is placed face down (the side that was planed).

Now that's a planer!!!!

Love that locust wood. Such cool stuff. Wish I had a bunch for firewood.