How do you mark blind holes for drilling

old · Jun 11, 2021

So I am making a couple doglegs for my 1947 Cub. The 2 bottom holes are blind hole and while the first one was close I'd like to get them right on. There 1/4 inch bolt hole in the casting.

Thanks

grandpa Love · Jun 11, 2021

Put a screw in the hole. Smear lip stick on screw head. Lol works every time

GordoSD · Jun 11, 2021

I am surprised that Smear lipstick on the screw head didn't get poofed. LOL

markct · Jun 11, 2021

Spotting punches, for threaded holes they make ones that look like a setscrew with a point, for non threaded they have a round pilot and shoulder and a point

550Doug · Jun 11, 2021

(quoted from post at 17:26:56 06/11/21) Put a screw in the hole. Smear lip stick on screw head. Lol works every time

I have a tube of toothpaste in my toolbox just for that job.

old · Jun 11, 2021

I sort of did that. I put a stove bolt in the hole and sprayed it with paint then put the dog leg in place and it marked it as I needed. If my stupid cell phone would work you would have a 3rd picture of the doglegs. I just finished up the 2nd one and the next project will be the grill. Still not sure how I cam going to make the curved bends on the sides for the grill. Don't think Thing for making bends would work since it is made to make a true 90 degree bend

Mike(NEOhio) · Jun 11, 2021

Transfer screws. As markct said. Grind a sharp point on a Gr 8 set screw. If you can't get to it from the other side of the hole file or saw flats so you can get it in and out with pliers. Gr 8s will be hard enough for a couple of uses. Leave the points about 1/16 above the surface and strike the part to mark locations.

steve_in_mo · Jun 11, 2021

Do you have a piece of PVC pipe about that size?

old · Jun 11, 2021

Not that I know of but I think I have some steel pipe about that size

caterpillar guy · Jun 11, 2021

I use paper or cardboard and tap the hole gently to make a hole in the paper/cardboard screw in a bolt then do the next usually going across from the first to get the most distance so it will not be Multiplying the err. And keep putting bolts in as I go. Then check for true then lay on piece you want the holes in punch and drill. Transfer punches work good for the marks to drillthe holes.

Stephen Newell · Jun 11, 2021

I would be inclined to set up stops on the drill press instead of marking them. When doing multiple parts its the best way to get them uniform.

grizz02 · Jun 11, 2021

Buy a set of transfer punches 40.00 on line

4520BW · Jun 11, 2021

I guess the metoo movement people are too busy worrying gender identity and who is on the syrup bottle to look at tractor website...for now

TimV · Jun 11, 2021

Under 10 bucks for a set of 6 1/4-20 transfer screws on Amazon. For a couple uses, just turning down the head of a bolt into a point works fine--I'm still using ones I made 20 years ago like that for the occasional time I need an oddball size that I don't have store-bought transfer screws for. You're just trying to make a mark, which you can then make deeper with an actual center punch if necessary.
transfer screws

rustred · Jun 11, 2021

yep, yep, thats the ticket. as old says... btdt ! lol.

chvet73 · Jun 11, 2021

My $9.00 Harbor Freight Transfer punches work just fine.

old · Jun 11, 2021

So what is a transfer punch??

rustred · Jun 12, 2021

look what markct said.

TimV · Jun 12, 2021

Old: link below hows a typical set of transfer punches. while they are very handy, they're not what you need for marking blind holes--they're meant, among other uses, for putting down through an existing hole and marking the center of a matching hole to be drilled on the piece below.
Transfer Punch Set

bc · Jun 12, 2021

Not sure of what you are trying to do but can you get some gray gasket material in there and make a template?

old · Jun 12, 2021

Either way I have the 2 doglegs done and one the Cub now to figure out how to make the grill and the 2 bends at the end. If they where straight 90 bends it would be easy but these are slow curved bends

Pete in MD · Jun 12, 2021

A transfer punch won't work in this situation. See Tim V's explanation below.

GarryinNC · Jun 14, 2021

My Dad made a pretty good looking grill for a cub years ago. He used 1/2 inch wide x 1/8 inch thick bar stock. Fairly easy to bend, especially with a little heat from torch. He bent two pieces of the bar stock into a framework that fit the shape of the front of the cub where the grill would go. The frame fit all the way to the bolt holes that hold the grill in. He used two pieces of the same metal to make vertical members that fastened (welded) on each side, near the doglegs, to the top and bottom curved pieces.
He then took some light weight expanded metal and formed it to fit the inside of the frame and welded it in with oxyacetylene.
I wish I had a picture of it. It was easier to make than to explain.

Garry

How do you mark blind holes for drilling

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