Sunday, January 27, 2013
V4.4 - Does it shake your teeth?
Not the Boogie-Woogie…or firecrackers, I’m talking about wheel vibration in your stationary Bandsaw. Sometimes they get a little goofy and start rockin ‘n rollin worse than Elvis used to. Usually they are a 12”, 14”, or 16” size. For the purpose of this column, I’m talking about those Bandsaws that have a drive belt from the motor to the bottom wheel.
So, let’s say that you have one of those Bandsaws and you’ve always noticed that it seems to vibrate rather bad while you’re using it. You’ve taken the blade off and run it with just the bottom wheel in action and it still ‘shakes, rattles and rolls’. Or maybe you took the blade off and just running the bottom wheel shows that it runs as smooth as a Hunter ceiling fan. What to do?
First off, isolate the vibration – chase it down. If your saw is vibrating, take the blade off and run just the motor and the bottom wheel. If that smoothes it out, your problem is in the upper wheel. If you run the bottom wheel only and it still vibrates, the problem is in the bottom wheel or the drive system. Take the drive belt off and run just the motor. If it still vibrates with only the motor running, check the tightness of the motor pulley. If the pulley’s tight and yet it still has excessive vibration with only the motor running, I’d suspect you have a bad motor.
From this point, let’s say it smoothed out after you took the blade off. You’ve got the wheel guard open, so you can get to the top wheel. Give the wheel a good spin - enough so that it can rotate for at least 10 revolutions. When it finally stops, make a witness mark at the bottom of the wheel so that you can see it. Give it another good spin and let it stop again. Check where your witness mark is. If the mark is close to the same spot at the bottom, do the spin test again and see where the mark ends up. Do this 5 times and if the mark ends up stopping in the same area at the bottom of the wheel 3 times out of 5 tests, your top wheel is off-balance and needs to be replaced.
The test for bottom wheel balance is the same, but you will need to remove the drive belt before the test. The idea is to spin just the bottom wheel, not the motor and drive belt, too.
Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.
Saturday, January 26, 2013
V4.3 - Drill Press Hints
Ok, after a few weeks in never-never land, back to tools. I thought that for this week, I would just go over some of the little tidbits of information that I like to call ‘Tips & Techniques’, since we were discussing Drill Presses.
One of the areas that folks need some assistance with is that of choosing the correct bit speed for their particular project. The main rule of thumb is: ‘The harder the material, the slower the bit needs to turn.’ Right behind that comes this: ‘The bigger the bit, the slower it needs to turn’. How that plays out is like this. If you’re drilling the same size hole in wood and metal, the speed will need to be slowed down for drilling into metal because it is a harder material. By the same token, if you’re drilling into pine wood and making a ¼” hole and a 2-1/4” hole, slow it down for the 2-1/4” hole. It may be that not much speed change is needed between these two, but the idea is that you don’t usually want a 2-1/4” cutter turning as fast as a small ¼” bit.
Now, let’s talk safety. First and foremost, dress appropriately when using a Drill Press. Wear your safety glasses, roll up your long sleeves and pull your hair back out of the way (IF your hair is that long). I once saw a training film that showed what happened when a lady got her long hair tangled in the Drill Press she was operating. It was not a pretty sight. She reminded me of what Custer’s men must have looked like after being scalped.
After you have all those bases covered, here’s another ‘first and foremost’- ALWAYS clamp your work. I cannot over-emphasize this. Yes, it’s a pain and not always convenient but it IS necessary. I have a nice 2” long scar on my left wrist that is a constant reminder of the need to clamp your work. The very afternoon that I was going to drive my dirt track racecar for the first time, I was making an accelerator bracket and need to drill a hole in it. The bracket was just 8” long, ¾” flat stock, with one end bent at a 45 and that was where I needed the hole. So I go to my DP and hold the long part and place the bent area on the table under the bit. I started drilling the hole and OOPS…it grabbed and swung around 360 degrees and in the blink of an eye it made a few revolutions before I could get it shut off. Unfortunately, on that first swing, the top end of the stock sliced my wrist open and I wear that reminder to this day. It looks like I tried to commit suicide. So, I tell everyone - clamp your stock.
Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you
One of the areas that folks need some assistance with is that of choosing the correct bit speed for their particular project. The main rule of thumb is: ‘The harder the material, the slower the bit needs to turn.’ Right behind that comes this: ‘The bigger the bit, the slower it needs to turn’. How that plays out is like this. If you’re drilling the same size hole in wood and metal, the speed will need to be slowed down for drilling into metal because it is a harder material. By the same token, if you’re drilling into pine wood and making a ¼” hole and a 2-1/4” hole, slow it down for the 2-1/4” hole. It may be that not much speed change is needed between these two, but the idea is that you don’t usually want a 2-1/4” cutter turning as fast as a small ¼” bit.
Now, let’s talk safety. First and foremost, dress appropriately when using a Drill Press. Wear your safety glasses, roll up your long sleeves and pull your hair back out of the way (IF your hair is that long). I once saw a training film that showed what happened when a lady got her long hair tangled in the Drill Press she was operating. It was not a pretty sight. She reminded me of what Custer’s men must have looked like after being scalped.
After you have all those bases covered, here’s another ‘first and foremost’- ALWAYS clamp your work. I cannot over-emphasize this. Yes, it’s a pain and not always convenient but it IS necessary. I have a nice 2” long scar on my left wrist that is a constant reminder of the need to clamp your work. The very afternoon that I was going to drive my dirt track racecar for the first time, I was making an accelerator bracket and need to drill a hole in it. The bracket was just 8” long, ¾” flat stock, with one end bent at a 45 and that was where I needed the hole. So I go to my DP and hold the long part and place the bent area on the table under the bit. I started drilling the hole and OOPS…it grabbed and swung around 360 degrees and in the blink of an eye it made a few revolutions before I could get it shut off. Unfortunately, on that first swing, the top end of the stock sliced my wrist open and I wear that reminder to this day. It looks like I tried to commit suicide. So, I tell everyone - clamp your stock.
Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you
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