Woodworking help, please. Centering circles in corners....:confused;

[MichaelD]

Hi all,

I need your sage advice, please. I'm going to build one of these threaded-rod type AV racks.

I'm going to need to drill lots of 7/8" holes in the corners of the boards (see the last pic towards the bottom, right, on the link above).

I want to make sure I get the holes on my "template board) exactly in the corners of each board.

How do I "center a circle in each corner" of the board? Slightly to the left or right won't cut it. Thanks!

 

[FoBoT]

either create a jig or template and clamp it onto your drill press base

or are you talking about using a hand held drill? hmmmm....

they make drill guides also, but i don't know if they would be for a corner like that, i have one for centering holes in the edges , but not corners
hmmm...

 

[MichaelD]

"Centering holes on edges" ...you mean like a dowel jig? Yeah, I know what that is...but I do mean "in the corners."

BTW, I'd be drilling these with a big mutha Delta drill press with a 1" chuck. Woodshop is a beautiful thing. I have spade bits.

I do plan on making a template and clamping each new piece of wood (shelf) to the template.......OR if I could make some kind of "hole centering corner jig" I could do each shelf separately.

 

[olds]

Use my link in your last thread.

 

[MichaelD]

Originally posted by: oldsmoboat
Use my link in your last thread.

Thanks. *goes looking*

 

[olds]

I'll make it easy for you.

 

[MichaelD]

Thanks, Oldsmoboat.

 

[olds]

Originally posted by: MichaelD
Thanks, Oldsmoboat.

Sure, now put me in your sig.
"Freedom isn't free"
oldsmoboat

 

[bleckywelcky]

What kind of bit is being used? If it is a regular wood bit, just wide, then just plot your circles on the board and place the bit in the center. If it is a hole saw bit, then you would need to match up the outer rim to the plotted circle unless the hole saw bit also has a center guide bit (lots do), then just set that at the center point. Don't really see any problems there.

But, if you are asking for help with plotting circles, then just make a quick template. Get a square or rectangular piece of skinny wood to make it out of. Radius is 1/2 inch, so add that to whatever inset you want from the edge of the board to the edge of the circles, then make two points on each side of the board and connect both sets of dots with two different lines. Use a compass to trace out the circle. Cut out with bit.

-

 

[Harvey]

Assuming each shelf board is rectangular, mark off lines the proper distance in from each edge. They will cross at the center points of your holes. Then, drill a smaller hole as a guide hole for each larger hole.

 

[Electric Amish]

Originally posted by: Harvey
Assuming each shelf board is rectangular, mark off lines the proper distance in from each edge. They will cross at the center points of your holes. Then, drill a smaller hole as a guide hole for each larger hole.

Yup. That's what I was going to say.

Measure however far you want the hole in from the side.... say 1"

Draw a line 1" in from each side of the wood and they'll cross where you want the center of your hole.

amish

 

[MichaelD]

Thanks guys. I will probably go w/the "drawing lines" method....it's sounds foolproof enough that even an idiot like me can't mess it up. We shall see. Thanks again.

 

[Pliablemoose]

"Measure twice, cut (drill) once."

 

[olds]

If your going to do some projects make yourself that jig. It will really come in handy when you change your mind and use dowels instead of all thread. Also go down to Home Depot and get yourself a speed square. It will help you to make more accurate marks. Even the cheap $3.00 one will work for this project.
Homedepot Click on "Tools/Hand Tools/Squares"
Hopefully these links work and are not just tied to my session.

 

[RossGr]

Your best bet would be to set a jig on the drill press for a single hole then drill the same hole in all boards, reset the jig for the next hole, drill all boards, repeat. One key would be always set your jig against the same edge and end of the board, thus any errors in the lenght or width of the boards will not show up as errors in the location of the holes. That is what will happen if you measure from the nearest edge and end for each hole.

Edit;
Another good trick, make your holes over size, then you can have significant errors and still be ok, the washers and nuts supporting the shelfs will easily be able to hold the shelfs if the holes are 1/8" larger then the rod diameter. (This is the sloppy,... but it works, way, good for hand drills!)

 

[MichaelD]

Originally posted by: RossGr
Your best bet would be to set a jig on the drill press for a single hole then drill the same hole in all boards, reset the jig for the next hole, drill all boards, repeat. One key would be always set your jig against the same edge and end of the board, thus any errors in the lenght or width of the boards will not show up as errors in the location of the holes. That is what will happen if you measure from the nearest edge and end for each hole.

Damn. Not only have you obviously done this before...you have watched me working on my projects. B/C that's EXACTLY what seems to happen most times. Bah!

So, you're saying that if I follow your directions, basically any errors on "one hole" will be repeated at ALL the holes, in that same place, so it won't affect anything, right?

I wish I was rich and could afford top-notch equipment...and robots....

OLDSMOBOAT

I hate to admit this. I have that Speedsquare...um, I use it as a straightedge. How do I USE it to do this?

 

[olds]

Just use it as a straight edge. For example: measure 1" from each corner. Use square to draw lines. Where they intersect is where you drill.
As long as you start with square material, you'll have accurate marks. You can also use it to check a piece of material for squareness, but I am sure you know that.

 

[MichaelD]

Originally posted by: oldsmoboat
Just use it as a straight edge. For example: measure 1" from each corner. Use square to draw lines. Where they intersect is where you drill.
As long as you start with square material, you'll have accurate marks. You can also use it to check a piece of material for squareness, but I am sure you know that.

Excellent. That's what I do now. See? I knew I bought this way-cool triangular aluminum thingamabob for a reason! I don't know the proper names for things...I just kinda figure things out as I go. :Q I usually don't injure myself w/a power tool.

 

[RossGr]

Just use it as a straight edge. For example: measure 1" from each corner. Use square to draw lines. Where they intersect is where you drill.

This method and at least 1/8" oversize holes will work fine.

Think of the board as a huge coordinate system, set up one corner as your orgin do All measurements from that one corner, this will result in any errors in board length or width showing up on one side and one end but your support holes will (or should if your jig is good) be lined up form board to board. Of course if you use a good table saw to cut the shelfs this may not be much of a problem, but if you are in the same boat as me, and must use a skill saw to cut the boards measurements from each corner is hazaradous to the outcome of the project.

Good luck man,

PS 1/8" oversize holes are still a good idea!

 

[MichaelD]

Thanks for your help, RossGr.

I will be cutting the shelves on a big mutha table saw. I'm picky as all heck when it comes to woodworking stuff. 1/16" off is unacceptable to me. 1/32 I can live with. .

I rip to width, then cut all shelves concurrently, w/o moving the fence. Identical shelves. I have some neat ideas AFA finishing the wood goes. Need to buy the all-thread though. Will be painting it black. Thanks again.

 

[lowtech1]

I want to make sure I get the holes on my "template board) exactly in the corners of each board.

Measure what you need on a thick piece of paper if you are unsure, then apply it on the top board. Stack the boards & clamp them down tightly together with a supporting board at the bottom & drill once. The supporting bottom board is to stop the bits from splinter the last board.

You can free hand your center corner if you are careful with 2 pencils, or a pencil & nail (use the nail or the extra pencil as a rail/guide to scribe the lines). Another way is to use a doweling & 2 nails if you are unsure & need a scriber in a pinch.

Too bad AT doesn't alow image so I could load a quick drawing of what the tool should look like.

[edit] Oops! make sure you prime a small hole with a small drill bit first for centering purposes as suggested in the above post.

 

[lowtech1]

See this link for a simple scribe tool: Not the best job at making a scribe tool - 2 nails and a doweling make a much more accurate tool.

Ulmia Mortise Gauge: Over price fancy scriber with measuring scale - 2 nails and a doweling would do just as good a job.

 

[olds]

Originally posted by: lowtech
See this link for a simple scribe tool: Not the best job at making a scribe tool - 2 nails and a doweling make a much more accurate tool.

I am going to have to check that site out.

 

[MichaelD]

Good morning guys. Thanks very much for all your help. You rock.

 

[olds]

Let's see the finished product!