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tom_k/mo
09-06-2008, 01:38 PM
I have a brand new 520, and the first hole I tried drilling with it, I'm noticing that there seems to be some "slop" somewhere because it looks like my drill bit is getting some wobble at the end. I know Nick talked about the double bearing quill having less run-out than the single bearing, and a 520 should definitely be a double bearing, but I'm definitely seeing wobble at the end of the bit (it's a brand new bit and it's not bent). Feeling the chuck, it seems that the chuck isn't wobbling or if it is, definitely not as much as at the end of the drill bit. I went around all 3 holes on the chuck and tightened the chuck 3 times and went back and ensured that the bit wasn't seated in the chuck off-center. The adjustment on the back of the power head that sets a depth limit was not set or tightened. Could that have caused play in the quill? I was drilling 7mm holes in pen blanks to fit the brass tubes and I really don't need slop in these holes making them oversize. Anyone know what I'm missing?

beeg
09-06-2008, 01:56 PM
The ONLY thing I can think of is the bit wasn't centered, but you all ready checked that. The depth limit woudn't cause it. Take the bit out of the chuck, take the chuck off the spindle and reinstall them. Also roll the bit on a flat surface, just to make sure it isn't bent.

dusty
09-06-2008, 03:05 PM
The chuck has three fingers that close in around the bit. Close the chuck until the opening between those three fingers is just large enough to accept the desired bit. Tighten the chuck down on the bit and then tighten the chuck using the key. Tighten at all three holes in the chuck as you mentioned.

Turn on the Mark V and just look at the tip of the bit. If it is wobbling you'll be able to see it.

If you are not convinced that it is turning true, bring the drill bit down on a piece of scrap wood and just barely touch the wood with the tip of the bit. Inspect the track made by the bit when you did this. It should be a point. If it is a small circle you have wobble. If fact, you will have a problem that keeps this thread going for days. That is very unlikely.

Your quill is definitely a two bearing and I do not believe you will have any excessive runout on a new Mark V.

wa2crk
09-06-2008, 06:43 PM
Hi
Do you have a brad point drill bit? If you do chuck that bit into the drill chuck and try your test again. If the point of the bit stays still and does not go in a circle then it is OK. Is it possible that the drill bit you are using is not ground symmetrically, that is one cutting edge not at the same angle as the other? This would give the illusion of a wobble at the tip. Another way to checkis to chuck a V groove router bit in the drill chuck and turn the machine while observing the point of the bit while you run the machine through the speed range and see if ther eis really a wobble at the point.
Bill

tom_k/mo
09-06-2008, 07:16 PM
The bit is definitely wobbling. It's a brand new 7mm bit from Pen State Industries for drilling center holes in pen blanks. I will do a test in the morning to measure the amount of wobble at the tip. I have checked the bit, it is not bent/warped, and I have checked that it is mounted squarely in the chuck and that the chuck is tightened well. The only thing I didn't check was the mounting of the chuck on the spindle (Doh...). I'll check that too tomorrow.

Since I'm still new with a SS, this may be a dumb question, but bare with me for a second... When I took the saw blade and blade housing off, there was a silver knurled (if I remember right) ring still on the quill held on by a separate set screw. Should that stay on the quill?

charlese
09-06-2008, 07:22 PM
Hi Tom! I'm with the guys above! Try another bit just for a test. When you tighten the bit in the chuck make sure you do the tightening gently in each of the key holes. (just like you did earlier). If the test bit wobbles, then there is a problem somewhere. It is my guess the 7mm bit is slightly bent.

Of course, you have to check the chuck's position on the quill.

Good Luck! You shouldn't be having this issue!!

judaspre1982
09-06-2008, 07:37 PM
Yes, it stays on the quill shaft and any attachments to the quill shaft should be fully against the knurled collar as the collar spins with the shaft. I believe the knurled collar is what keeps the quill shaft centered and attached to the quill housing. My manual says to put all accessories on the quill shaft fully to get past the tapered section of the shaft to the flat section before tightening set screw and make sure set screw is centered on the flat.

Bruce
09-06-2008, 09:09 PM
Tom,
When you check the mounting of the chuck to the quill, also check the chuck itself to be sure it is clean and has nothing in it that could cause it to go on misaligned.

Bruce