How do I drill a PERFECT 8mm hole through a 35mm Dia. Dowel ?

[M C]

Hi,

Novice woodworker here, please help!

I am making a freestanding hi-fi rack unit using 35mm (dia.) dowels as the vertical spacers between the 6 MDF shelves. I am using 8mm dowels (or metal stud) going through the full height of the unit on each corner so as to secure it all together.

I need each of the dowels to have perfect 8mm drilled holes through their complete lengths. I have a need to make 24 of these dowels. (4 corners x 6 shelves = 24 dowels).

I've already done a trial (by eye) and it did not work out very successfully. The hole was not perfectly straight as I would have liked it. I don't want my finished unit to be wonky!

I have a drill with bits and a basic bench vice. I don't have a drill stand, lathe or any other big woodworking tools available.

How can I best drill these perfect holes through the dowels ???

Any help would be much appreciated!

Thanks to all!

Marc

[Locutus]

How long are the dowels?

[RayV]

Why not just drill shallow 35mm holes in either side of the MDF shelves with a forstner bit then glue the dowels in place? I would think this would be sturdier than a metal rod threading all of the parts together.

[bent]

steel washers are sold by size. The size is the internal diameter x the external diameter. The sizes are common, like 1/2 x 1/4. 1x3/8", etc. Therefore, there aren't that many really. There are diff. types, and a few thicknesses, heavy duty thickness,etc. Its often not hard to match the ID to thedrill you are using. You could clamp a washer(s) to the end of the dowel and use it as a guide bushing, or buy a guide bushing, or cut a pipe of tube/pipe to do same. You could go from both ends. Then wriggle through with a long bit, maybe auger.

[David]

How about using tubing that will accommodate the rod diameter? Then all you have to do is cut the tubing to length and apply a suitable finish.

Dave

[bent]

anohter thing that comes about by knowing this is that you can take a 1/2 x

1/4" washer and use it as an offset to scribe a line along a straight edge, or profile to get an exact 1/8" offset line. Just put a pencil in the center and swirl away. The offset is limited only by the eqn: 1/2(OD- ID)

[Michael Houghton]

You have bit off a "hard" problem. Even with a drill press, getting the holes to be perfectly centered at both ends is going to be a chore. Be prepared to toss as many rejects as clean ones.

I don't see how you can get where you want to go with the tools you have.

One approach would be to take pieces of wood 35mm x 18mm. Use a router to scoop out an 8mm groove (semi-circular) down the middle. Glue two pieces of this together. You now have an 8mm hole straight and centered. Cut pieces to length, and run that 8mm drill down the hole to clean out glue squeeze-out and any irregularities. Now you need a lathe to make the outside cylindrical

No, I didn't say it would be simple.

yours, Michael

[alexy]

First a nit-pick. You will not get a perfect hole, no matter what equipment you have available. You can get a plenty-godd-enough hole for your purposes, but it will take more equipment or time (and expense for practice material and waste) than you'd want to spend.

I strongly second the suggestion made here for drilling just a little way into each end, then connecting the larger dowels that way. If you want the shelves to be able to be knocked down for moving, get some hanger bolts

threaded inserts Drill your shelves just a little larger than the hanger bolt, so it passes through, but without a lot of slop. In the top of each 35mm dowel, drill a pilot hole for the wood thread portion of the hanger bolt. In the bottom or each, drill a hole that will let the machine screw portion of the hanger bolt be inserted freely, then drill the proper sized pilot hole for a threaded insert.

The hardware is probably available at a local HW store or a borg--I'm just showing the lee valley and mcfeely's links since they are easy to find online, and you know they will have things like this.

[Guess who]

Gouge out with a router round-end, using table and guiding jig, the length of some squared wood. Cut in half and clamp/glue halves together [carefully, of course.] Cut/shape the finished product. I'd leave square.

[Dave Balderstone]

Short answer: You can't. Find another solution.

djb

[mac davis]

Perfect? A laser in the correct laboratory environment might be able to do it...

As others have said, your design seems to far exceed your tools... most of us use that as an excuse to buy more tools.. *g*

Are you working from a set of plans, or is this your own design? If you could provide some dimensions, such as the length of the dowels or the space between shelves, that would make helping you easier....

EXAMPLE: a 30 mm long dowel has much less complications and room for error that a 300mm long dowel..

Mac

[Morris Dovey]

| Novice woodworker here, please help! | | I am making a freestanding hi-fi rack unit using 35mm (dia.) dowels | as the vertical spacers between the 6 MDF shelves. I am using 8mm | dowels (or metal stud) going through the full height of the unit on | each corner so as to secure it all together. | | I need each of the dowels to have perfect 8mm drilled holes through | their complete lengths. I have a need to make 24 of these dowels. | (4 corners x 6 shelves = 24 dowels). | | I've already done a trial (by eye) and it did not work out very | successfully. The hole was not perfectly straight as I would have | liked it. I don't want my finished unit to be wonky! | | I have a drill with bits and a basic bench vice. I don't have a | drill stand, lathe or any other big woodworking tools available. | | How can I best drill these perfect holes through the dowels ???

Marc...

You'll need help from someone with a lathe big enough to turn your spindles (no huhu, we all need help from time to time.)

Drill your 8mm holes through round, square, or whatever spindle stock that's bigger than 35mm. Take these to the 'someone with a lathe' and have them turn 'em down to 35mm with your hole in the center.

Reward them appropriately (cash, beer, or something gee-whiz that you've made) to make you both feel good about the help given/received.

Take the spindles home and finish your project. Think about how neat it'd be to have your own lathe. :-)

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

[alexy]

Or, at least so close to perfect that you will not be able to prove with any woodworking measuring tools (or maybe any lab measuring tools) that it is imperfect.

[foggytown]

I think your design is questionable. Running a steel rod through the middle of the dowels probably won't add THAT much extra rigidity to the whole piece. You will still need to brace the unit (probably at the back) in some fashion. You would be better off using a 35 mm spade or forstner bit and drilling "through holes" in each corner of the shelves and then sliding one whole-length dowel through all the holes in each corner. Secure the dowels to each shelf with glue and one chunky screw entering the dowel from the front and one from the side with a countersink that you can plug or fill. Make sure the fit of the dowels through the shelves is snug.

FoggyTown

[M C]

Many thanks Alexy. That idea seems the most understandable and high quality solution I've read so far in this thread, that may be a winner but I'll read on.

Much appreciation to all who are helping with these ideas!

Marc (OP)

[M C]

The dowels will be cut down to something between 14 to 16cm in length, which will then obviously equal the spacing between a pair of shelves.

Marc

[M C]

Sorry, should have mentioned that. The dowels and therefore the spacing between the shelves will be approx 14 - 16cm each. Each set may vary so as to give greater shelf height but not significantly. The plan is my own design but part based on the Quadraspire unit that can be bought for a lot of money. The Quadraspire is modular and uses metal supports. Have a look at their website if you're interested. I thought dowels would be easier for me to fabricate as an alternative, larger seemed better to drill and more chunky so that's why I went for the 35mm dia.

Thanks again for all your help!

Marc

[Wilson]

Assuming you have a long bit, which is cheap at the Borg: Cut 2-3 1" pieces of dowel Mark centers and drill holes through Thread two of the sections on the bit Clamp the sections in line with a section of the dowel to use in the corner of your TS fence, or other straight right angle corner Drill the hole If the short guides are a few inches apart they will align the bit pretty well. Make the holes a bit oversize, to allow moving the dowel a bit if necessary. Think you have troubles? Imagine drilling a rifle barrel in the 1700s! Wilson

[Locutus]

This is what I would do.

Make a box that surrounds the dowel snugly. Make it out of ply, 1x's, whatever, but make sure to use the same material for all sides so the sides are of consistent thickness.

[O]

cut a piece of 3/4" ply and affix it to the top of the box. Make sure the edges meet up with the sides of your box. Drill a hole in the center of the top piece, this should also be the center of your dowel. the 3/4 top board will guide your hand held drill bit to keep it straight. After drilling as far as you can (you should use a fairly long bit), take the dowel out and turn it over, drill into the other side.

viola.

[justme]