need to drill a 2" hole 11" from edge - DONE with pictures

[junquecol]

Re: need to drill a 2" hole 11" from edge

Andy, I have a micro adjustable circle jig for my router.We could cut a guide that is correct size, attach to flywheel, and use flush trim bit to cut hole. Remove guide and repeat till we run out of depth on bit. Then drill through to remove most of the waste, and create through hole. Using a "bridge," which divorces router from second face, use a pattern trim bit and finish hole. It would be true to first face, but not necessarily to second. Sounds like second face isn't parallel to first anyway. We could probably use a forstener bit and make original guide. Bruce

 

[CarvedTones]

Re: need to drill a 2" hole 11" from edge

Thanks, Bruce but I am going to follow up with DaveD first. That base appears to be small enough to clamp onto the center board of the better face and stable enough to get it square if I go slow.

 

[James Davis]

Re: need to drill a 2" hole 11" from edge

Andy,

With this much mass moving when the lathe is in operation, would it not be prudent to take the flywheel to some one who has a wide belt sander and get the two sides parallel to each other?
Then you can use a router to get the hole perpendicular to both faces and true to each other. I know that this is not precision machining that you are trying to do, but you do not want the lathe walking all over the shop either.

James

 

[CarvedTones]

Re: need to drill a 2" hole 11" from edge

James,

Yeah, it would probably be prudent, but I hope it won't be necessary. It's made of three layers of boards of consistent thickness and it looks obvious that the side with the board in the middle was the bottom layer on a flat surface. The other surface has minor uneven spots, but the weight distribution seems good. I am planning to use the better side not just as a reference for alignment, but also the side to face the support.

 

[CarvedTones]

Re: need to drill a 2" hole 11" from edge

OK, I borrowed the drill, guide and bit from Saint (in my book) DaveD.

[STRIKE]If you catch this thread before I get back to it, you will see a bunch of photos below with no explanation. I am posting that way and will be back to edit in a bit[/STRIKE]...

First a little bit of Thale's theorem to find the center (though the circle isn't perfect, so the center is not either, but it is close enough to true it to). If you look close, you will see pencil marks left by whoever originally made this; they aligned and marked, then glued up slightly off. I filled the center is filled with a slurry of sawdust and epoxy and let it cure for a few days. It had recesses on both sides that were a little under 1.5" in diameter and about 1/4" deep and it had a 1/2" hole that had been wallowed larger all the way through.

I used a small bit just for alignment of the guide. I decided to scew it down to ensure consistent placement; I would rather have a couple of small screw holes than another misaligned hole. The "C" penciled in on the wood is to note that the Crafteman label was on that side of the guide, so I would align it the same after I took the base off to check alignment (still to come).

I started with a 1/2" bit so that I would be able to check the alignment. Plan B would be to use the borrowed bit and go borrow time on the radial drill press from another gracious offer (y'all are awesome! :icon_thum) if the alignment wasn't good enough.

Done! Not all the way through, but close enough to test.

I stuck the 1/2 rod in and clamped it down. I gave it a few test spins and declared it adequate (will need minor truing).

About to screw the guide on again. I put the bit in the hole, lined up the label with the C and tighten the screws back into the existing holes.

Time to pull the trigger!

I would only do a little at a time, stop and vacuum chips and dust and let the bit and drill cool. Total elapsed time was about a day because I would just go drill a little more every now and then when I had the chance.

Finally through!

Even stopping often, I still had a lot of burning.

I dug through my pile of spindle blanks and found one with a section of 2" diameter to use to check alignment. Same process as with the 1/2" rod - spin it and see if it is workable.

I sighted down the groove at a spot on the floor and then spun the wheel slowly.

It needs minor truing, but it would not throw a belt as is. so I am pretty satisfied that I got this done and can move on to making the hub. I will continue to document the build in the thread I started about the treadle lathe:
http://www.ncwoodworker.net/forums/f32/wip-gloat-thanks-mike-davis-31487/

 

[Mike Davis]

Re: need to drill a 2" hole 11" from edge

I would mount that up, put the treadle on it and turn that groove live. Maybe even do a little truing too.

 

[CarvedTones]

Re: need to drill a 2" hole 11" from edge

I would mount that up, put the treadle on it and turn that groove live. Maybe even do a little truing too.

Yup, that is the plan now. I added the promised commentary to the pictures above.

 

[DaveD]

FANTASTIC. Glad I was able to help. :icon_cheers:icon_cheers:icon_cheers

 

[CatButler]

So, 200 years ago, were they just really good at drilling perfect 90's or did they have some sort of adjustment built in to balance the wheel?

 

[Mike Davis]

You can drill a near perfect hole with a bit brace if you have help to visually line up to a square.

 

[CarvedTones]

So, 200 years ago, were they just really good at drilling perfect 90's or did they have some sort of adjustment built in to balance the wheel?

I am not that old, so I can't be sure, but I think they were that good.

I could have done the 1/2" at 90, but any larger than that I would have a problem. That's because I have a 1/2" chuck on a hand drill, so I could use a bit that had a shaft the size of the hole and make a guide hole in a scrap block or use a small square to keep the shaft straight. Once the size requires a Forstner or spade then a guide hole would not work nor would I be able to use a small square next to the shaft.

Purely a guess on my part, but I bet the person that made it used a spade bit to drill that hole with a 3/8" chuck on a consumer type hand drill. I base that on the saw marks on some of the pieces, which appear to have been made by a circular saw.