Gang drilling 11 ga sheet metal?

[tominboise]

I have some 11ga sheet metal plates I need to drill 6 1/4" holes in. There are 8 plates total, 5"X8". I would like to stack these all and drill them all at once, on my 728VT Mill. Any reason not to stack them and drill them?

 

[Karl_T]

that works good. find a way to clamp them all together so they don't shift around on you. You could just put one bolt in after hole 1, then another after hole 2

 

[RJSakowski]

I often stack parts for drilling. Clamp securely and as Karl said, it is useful to run a bolt and nut through the first hole or two to maintain registration. One thing to look out for is drill wander. If the hole positions are critical, you may not want all the plates at once.

 

[extropic]

It depends on the locational tolerance required of the holes. In other words, the deeper the hole, the more likely and more severe will be the drift of the twist drill.

8ea x 11Ga is less than 1 inch total thickness. 1/4" drill drift shouldn't be very much, if you use a well sharpened twist drill.

 

[tominboise]

It depends on the locational tolerance required of the holes. In other words, the deeper the hole, the more likely and more severe will be the drift of the twist drill.

8ea x 11Ga is less than 1 inch total thickness. 1/4" drill drift shouldn't be very much, if you use a well sharpened twist drill.

Maybe I'll do them in sets of four. They are backer plates for wheel chocks going on a trailer, so tolerances are loose.

 

[tominboise]

My vise isn't big enough to hold the 5" width, so I ended up using my old Buffalo drill press from WWII. I laid out and drilled the first one, then used it to gang drill the remaining 7 in 2 groups - 3 in one and 4 in the other. It worked OK. It helped to bolt them together as I drilled them to maintain the pattern and also clamp them good and tight. I still have all my fingers and all the holes line up, so that part of the project is a win.

 

[extropic]

@tominboise
I think you previously wrote that the chocks were for a trailer. I interpreted that to mean you were going to use them to chock the tires of a trailer.
Now that I see what type of chocks they are (E track) I wonder if you're building, or modifying a trailer. Do tell (and show).

 

[tominboise]

@tominboise
I think you previously wrote that the chocks were for a trailer. I interpreted that to mean you were going to use them to chock the tires of a trailer.
Now that I see what type of chocks they are (E track) I wonder if you're building, or modifying a trailer. Do tell (and show).

I am indeed modifying an old home built 5'X10' utility trailer to haul my ATV. I did not build the trailer originally. I will take a few photos after I install the tracks.
I already built and installed a spare tire bracket (the PO had used a ratchet strap) and added some chain to the tail gate pins so they don't get lost. It has a 3500lb axle in it, which is way too much for this size trailer. It bounces all over the place when empty. I will probably remove one leaf from the spring pack when I get a chance.
Best not to look at the welds too closely, lol.

 

[tominboise]

Chocks installed. A tedious project drilling and installing 48 1/4" bolts but I don't think it will come loose.
Before:

During:






After:


The pile of ratchet straps this all replaced.