Horizontal Boring

[a1gutterman]

Jim in Tucson,
That is a great idea! Thanks for sharing.

[charlese]

John, Chuck,

Please keep us posted on the fence-flex on the 510 when horizontal boring (I have encountered this at some times). Lately I have noted that the nice Shopsmith material on the "Song of the Great Lakes" banjo-making website includes a 510-->520 update section. In this case he liked the new 520 fence for the increased rigidity during horizontal boring.

Thanks

O.K. I'll keep you posted! Tomorrow I will test to see if I have deflection and if so how much. With all due respect to the gentleman that hosts "Song of the Great Lakes" - Also look at his page entitled "Table Saw Showdown". Here he compares a SS-510 against a top notch contractor's saw (General International) http://www.songofthegreatlakes.com/tsshowdown.htm Look at the bottom two photos on that page. The SS-510 is fence is pictured and noted as having no deflection.

I am aware that the 520 fence is bigger, stronger and has more versatility because of the superior table rails and more tie down slots. It is a darn good fence!!

The 510 fence has a "clamp" on the outfeed side, while the 520 has a "locking bar". Our issue here is about deflection on the 510 fence. Does it deflect in normal operations? I'll give it a good test tomorrow.

[ldh]

I am using the horizontal boring mode on the SS to bore a hole through a 2X2X8 inch stock. I start the bore in the center but it ends up way off center on the other end. How can I improve the accuracy? Should I be using the SS in drill press mode? Any suggestions would be appreciated.

Gary

Gary,
After you have checked all of the alignments suggested take a look at the simple jig (thread Depth Control on Drill Press) I use to keep my Fence/Table honest on my 500 when I drill with the larger bits. I find that even with sharp bits a large bit puts a lot of stress on the 500 table and fence. With just a little help here and their the SS can be one very accurate drill press.
ldh

[charlese]

Thanks for all the helpful suggestions. I am drilling into the end grain. Starting with a 1 3/4 inch Forstner bit 2 inches deep. Then switching to a 1 inch Forstner bit for the rest of the way. I started on slow speed and increased it to 800 rpms when I switched to the 1 inch bit. The feed was slow and yes, I did clean out the chips often. I used the fence for support of the stock. I haven't checked all my alignments but will do that first. I suspect that my fence is deflecting a little bit also because the bit seems to be always going downward in the stock. Thanks again to all. Really appreciate the help.

Gary

Hi Gary! I just now realized you are drilling an 8 inch long hole through a piece that is 2" X 2". You havent mentioned using your miter gauge to hold the wood square to the bit. Are you doing this while using the rip fence for back support?

[john]

Chuck:

No I haven't checked or adjusted the fence at the back end. Never thought of it, but then again maintenance is not my strong point. (I guess I shouldn't have said that!).

Jim:

Thanks for that tip. I will keep that in mind. It sounds better than trying to place a clamp on the table.

Of course I will tighten my fence first.

Have funn.

John

[charlese]

As promised, today I tried to make the 510 fence deflect while pushing with the quill. Photos included - -

I learned a lot while doing this! My 510 fence will deflect .030" at the outfeed end. Is order to do this test, I first set up the main table flush with the extension table (on the right side. With the locks locked and the extension table in place I was assured there would be no movement of the table. (or at least very minute) I set up the fence and made sure the outfeed clamp was snugged down. - Set a poplar board against the fence while the dial indicator was set to zero. I then extended the quill until the end face of the spindle pushed on the board. Then put on the pressure! I believe I was putting about 50 to 70 lbs pressure on the quill handle. Stopped there because didn't want to break the handle. Also this is much more pressure than I would give to a drill bit.

The Dial indicator moved outward from 0 to .70 - a distance of .030" This was repeated near the middle of the rip fence. This time the deflection was 0.018". This much deflection is not very much, but the fence does deflect a small amount. The deflection is caused by rotation of the clamp on the outfeed side.

Also need to say that I snugged down the out-feed clamp more than usual. (Not real tight, but a wrist twist on the socket extension) When releasing the fence from the main table, I had to pull upward on the outfeed side to allow the open camp to by-pass the table tube. Usually the clamp is not quite this tight.

Observations:
1) Usual use of the 510 Rip Fence for backup of workpiece in horizontal drilling with sharp drill bits, will present no issues, deflection is minor if the outfeed end is snugged.

2) For drilling a thru hole in a workpiece and having little (if any) tolerance at the far end - it would be best to both back up the fence with a clamped stiffener and use the miter gauge to assure a square drilling.

3) When drilling a long bore - it is possible and may be a good idea to drill from both ends - meeting in the middle. It is also possible to use the lathe for deep (long) boring.

3a) Another method of accomplishing this drilling job while using the horizontal boring method, would be to drill the thru hole prior to final shaping of the piece.
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[nuhobby]

Thanks, Chuck,
for contributing your study. Those look like sound recommendations.

Best Regards,

[Nick]

"I am drilling into the end grain. Starting with a 1 3/4 inch Forstner bit 2 inches deep. Then switching to a 1 inch Forstner bit for the rest of the way."

While all the advice on alignment and technique is helpful, I would submit that your fundamental problem may be that you have chosen the wrong tools for the job. Forstner bits although they are often mis-used to bore hardwood end grain are not designed for the job. The cutting edges of the lips are bedded at 45 degrees, the optimum angle for shaving long grain. End gain is hard to cut at this angle even when the bit is razor sharp. This, after all, is why they make low-angle block planes -- the standard 45-degree angle of standard planes is fine for long grain, but not for end grain.

Believe or not, you may have better luck with a spade bit with the lips carefully filed at 10 degrees. A spade bit scrapes the wood, an effective way to cut end grain -- ask any turner who has hollowed out a bowl. If smooth sides are important, purchase a spade bit with "spurs" that cut the sides of the hole before the lips scrape the bottom. Brad point bits are a good second choice, but they must be razor sharp.

You might also rethink the speeds you are using. Because you are drilling such large holes in hardwood, any bit you use is in danger of overheating. I suggest you set the speed as slow as possible and keep it there.

With all good wishes,

[charlese]

Excellent points Nick! I was going to mention lowest speed, but got lost in the deflection measurements. Spade bits w/ sharp angles - way to go for end grain!!:D

[muncyjohn]

all of the above is good advice but if I can offer one more suggestion, it is to secure the rip fence if you are using it as backup. I have noticed some deflection on my 510 rip fence when using to back up my work in the horizontal boring mode. It is even worse if you have a dull bit.

I now place a clamp behind the back end of the fence so it cannot move backward when applying pressure with the drill bit.

Good luck.

John

John,
Thanks for the tip on this problem, I also have that deflection!

Possible problem with horizonatal boring is most likely caused by pressure applied to the poor drill bits we buy!

Recently I read an article on a ww forum that told how stupid we can sometimes be, went something like "we are willing to spend a large sum of money on a drill press then buy the cheapest bits we can find, what we should do is buy the cheaper press and spend some money on good bits"

I plead guilty!