Question about table saw alignment

[keakap]

...This brings me back to my other question which seems to have been over looked. What kind of bits I should use to drill out the out-feed trunnion holes to match the 1/2" speck of the front trunnion holes? Or in other words are there special metal cutting bits that I need? ....

Well now I can't resist. I have used bits called "reamers". Briefly, they are tapered, so a hole can be enlarged while the bit is engaged at all times, for one, and the multiple cutting edges prevent (mostly) chatter-n-grab that is likely with twist bits. If I remember correctly (going back 40 or 50 years) the reamed hole is "cleaned up" by the upper part of the bit which is the ultimate hole size and non-tapered.

I haven't seen tapered reamers in years, many many years. Don't know if they still exist.

[keakap]

The replacement trunnion has been installed and with it installed the table aligned with no difficulty.

I did forget to use the dollar bill and had to do it all over so that the table would tilt without squealing.

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Btw, that bolt is one of three and the middle one at that. It is 'almost' redundant, and certainly not critical. I wouldn't lose too much sleep over its presence.

[JPG]

A straight reamer is used to create a round, smooth inner surface in a hole. The tapered reamers I have/encountered were hand operated. The step 'bit' has pretty much replaced the tapered ones. I remember 'dreamers' that had a twist drill on the end with a reamer further up the shaft. Drilled and reamed in a single operation.

Twist bits rarely create a round hole. Chatter causes a triangular shape often especially with hand held drills. A drill press with good workpiece clamping greatly improves that.

All that above relates to metal working, but the same stuff can happen with wood.

If you want a good round, smooth hole in wood, use a router bit and drill press(vertical or horizontal).

[reible]

Back in the late 1960's I worked in a machine shop and we did have bits that were designed to drill the hole and then go into a reamer portion of the bit. They were employed for certain operations on a gang drill press. Even then a second reamer was used, as was a bit that drilled a hole before the second bit with reamer.

Wonder how many holes I drilled that way. It sure kept you busy, you clamped the part in place, the part was about 6 feet long with three holes, one on each end and one in the middle. It had 3 drill heads so it was just a matter of location on one end and make sure it was held in place. You started with all three with pilot bits, turned on the coolant and started the first drill press (they automatically do the drilling of about a 2" thick hole. You then moved to the second drill and started it, then the third. About then the first hole was done so you swapped tools to the drill/ream (all collets so it went pretty fast) stared that one again, by then the second one need a bit change and by the time that happen the third one was ready and you started all over until the last drill finished the last hole. Reset and do it again. That was a boring job but a batch was done in just a couple of days, me working nights and the day guys doing there bit.

I'd say that was the second worse job, the first was milling cast iron fingers for a mail sorting machine. That dust would make your finger look like you hadn't washed them in a year!

My guess is that they still make those. Lot of good applications for them.

Ed

Well now I can't resist. I have used bits called "reamers". Briefly, they are tapered, so a hole can be enlarged while the bit is engaged at all times, for one, and the multiple cutting edges prevent (mostly) chatter-n-grab that is likely with twist bits. If I remember correctly (going back 40 or 50 years) the reamed hole is "cleaned up" by the upper part of the bit which is the ultimate hole size and non-tapered.

I haven't seen tapered reamers in years, many many years. Don't know if they still exist.

[reible]

I don't know but I do suspect that it occurred as a result of this series of posts on the forum. It was about this same time that Nick indicated that the trunnion bolt holes should all be 1/2".

When I looked at my main table that came as a 520 it has the milled triangle. I believe I ordered that late in 2005 and got in 2006 so it isn't to recent.... of course I can no longer remember just when I got mine so don't use that as a set point in history. All my paper work from them is now boxed up and without easy access.

Ed