Friday, October 28, 2011

V2.28 - Care of your Bench Grinder wheels

Last week we talked about one of the staples in every shop, the Bench Grinder. This week, we’ll continue that theme and talk about the ‘care & feeding’ of your grinder.

Just for a bit of clarification from last week, my point about using a slow speed grinder (which is what a 1725rpm grinder is called in the industry) is that one needs to be careful when grinding metal and not heat the metal up too much. With a slow speed grinder, it is much easier to keep the grinding heat under control.

Ok, let’s talk about one of the natural problems with any grinder. After some grinding time, the face of the wheel will get ridges, or become tapered and one must “re-face” the wheel to get back to a smooth grinding surface. There are a couple of ways to do this.

Some grinders, the more professional models, usually have an accessory that is used to re-face the wheels. It bolts on in place of the tool rest and uses a diamond-tipped tool to re-face the wheel. Having one of these makes the task much easier. Unfortunately, not all grinders offer that. If your grinder isn’t that sophisticated, just buy the diamond-tipped tool and use it free-hand. The technique is not that hard to learn, in fact, if you have had enough grinding experience to get your wheel out of shape, you certainly have enough experience to re-face it.

So, let’s say that you don’t have the re-facing accessory and you must do it free-hand. The diamond-tipped facing tool I am most familiar with has a round shank, so that is what I will speak to. The technique is to place the tool on the tool rest as if you were trying to grind the diamond off of the end. Support it very well with your hands. In fact the tighter you hold it, and control it, the straighter your face finish will be.

Make sure you have your safety glasses on, and turn the grinder on. Put the tool on the tool rest. You would let the diamond tip touch the face of the wheel very lightly- you do not want to ‘deep grind’ this- and move the tool side to side as straight, and smooth, as possible. Keep the tool at 90degrees to the face of the wheel and realize that the high points of the wheel face will require a lot of material removal before you will get close to having a straight wheel face again. With patience and a bit of time, you will again have a smooth wheel face to use.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

V2.27 - Bench Grinders: one of the ‘must haves’

I would wager that most anyone who has a shop, or works in one, would be among the first to tell you that one of the most necessary tools in their shop would be their bench grinder. This may not apply for some specific woodshops, but since Toolsmartz is about ALL shops, we can cover it.
Bench grinders come in many different sizes and the major defining factor about them is the wheel diameter. Most people would not say, ‘yea, I have a one half horsepower bench grinder’. No, they will be saying, ‘yea, I have an Eight-inch bench grinder’. Even the bench grinder manufacturers set up their advertising literature in this fashion. The grinder’s horsepower and speed are somewhat of a secondary matter, after the wheel diameter, but don’t mis-understand, the horsepower and speed are critical factors when selecting the correct bench grinder, but what is usually seen is that as the wheel diameter gets larger, so does the horsepower. This allows the bench grinder to tackle harder jobs.

The deal is, when you have a large item to grind on, you really need a decent sized bench grinder. My personal philosophy is that if you have a large (meaning Ten-inch wheels) bench grinder and need to do a small job, it can handle it. On the other hand if you have a small (meaning Four or Six-inch wheels) bench grinder and need to do a big job, you can’t…or if you try to, you may burn up your small grinder. So yes, when considering what bench grinder to purchase, size does matter.

Another factor to consider is the bench grinder’s speed. This is also known as the RPM of the grinder. For most grinding operations, I prefer a speed of 1725RPM. Many grinders only come in a speed of 3450RPM, which is fine for many operations, but again, if you have a 1725RPM speed, you can pretty much always do whatever it is that you need to do. If you only have a 3450RPM grinder, I can promise you that you will overheat some items real fast.

As I suppose you have gathered, my personal favorite bench grinder is my Ten-inch, 1725RPM unit. It has no problem grinding small parts and it can handle all of my lawnmower blades without overheating them and burning them up.

Next week, we’ll continue this Bench Grinder discussion and get into some of the typical problems that you might encounter and recommendations for solving them.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

Thursday, October 27, 2011

V2.26 - Hospitals are pretty- from the outside

KIDNEY STONES. Yes, I know that is a strange way to lead off a column, but this is the month for Halloween and I can promise you that those who have had them just now felt that familiar stab of pain.
As I sit writing this, I was recently a ‘preferred customer’ of the Nashville VA Hospital for 3 days. I went to their Emergency Room last Monday and didn’t leave until Wednesday noonish. Just the fact that they let me come back home is a huge plus. According to their tests, I was ½ way to dialysis when I got there.
I had my first stone in 1994 and it moved out of my kidney while I was in a college class - THAT was the worst pain I had ever felt - someone snuck up behind me and stabbed me with a foot-long butcher knife. I just KNEW that was what happened. It wasn’t, but you understand. Between 1994 and 2007, there was nothing at all, but starting in ’07, every 6 months or so, one of those little buggers would get loose and it would find its way out over the next few days. So I’m thinking, ‘as long as they keep coming out, I’m OK’.
Well, I had another one get loose on the first of OCT…and I waited, and drank water by the gallon…and waited, and it never came out. The pain stopped, so I was functional. Until last Sunday night (10-9) and it hit me again. This time I couldn’t even keep water down. Monday morning it was no better, so off to the E-room I went.
I had discussed this with the folks at the Murfreesboro VA. They had even done a CT scan and had me talk to the urologist and he had told me that if something did not go right, go ahead and get to the Nashville VA. So I did.They started doing tests, did another CT scan and slammed me into the Hospital. I kept hearing words like ‘stent’, ‘laser’, Operating Room, etc. For sure NOT what someone wants to hear, but I was hurting and dehydrated and hungry..so ‘let’s go- do what ya gotta do’. And they DID.
It was not a fun time. I think the procedure was about 2 hours long- I really don’t remember most of it. Which was a VERY good thing – it HAD to hurt like crazy.
Anyway, long story shorter, my test results improved enough that they let me come home and God Bless the folks where I work, they told me not to come back until Monday. So, here I sit – recuperating and telling you about it.
Oh, one final word. When a nurse comes to draw blood, and begins to feel around in an area that you KNOW is a tendon and she is mistaking it as a vein (because you had this experience before) and you TELL her what it is and to don’t DO that…and she does it anyway- just go ahead and punch her in the nose, the pain can’t get any worse for you.

Tuesday, October 18, 2011

V2.25 - Getting good help when you need it

After 4 weeks of Bandsaw stuff, it’s time to take a sideways swing. I believe I have already mentioned that I am currently a consulting resource for DELTA Power Equipment Corp out of Anderson, SC. These guys are the brand new owners of the DELTA brand, and there is so much DELTA gray in my blood that if I can help them, I’m going to. The simple fact is that over the past 11 years, DELTA lost (I say ‘lost’ but as I spent a few weeks writing about, ‘gave away’ and ‘run off’ are also words that could be justifiably used) the great majority of its knowledge and documentation (old parts list, instruction manuals, etc). Seriously, I have more old catalogs, Parts Lists and Instruction Manuals in my garage than the new DPEC has inside their whole company. To a certain degree, this is because the initial company organizational setup has DPEC Service still being done by Stanley/Black & Decker. One would think that when Service is finally brought in-house (meaning DPEC controls it) that DPEC would gain access to the materials that S/B&D are currently using. I hope that turns out to be the case. If that happens, I’d still have more old catalogs, but their OLD Parts Lists would outdo mine.
Anyway, back to the topic at hand. I’m getting referral emails from people asking for Parts List and Manuals that go something like this: “I have a 10-inch table saw and I need a manual. Can you help me?” All well and good…except that DELTA made probably 100 different models of ‘10-inch table saws’ over the years. So here’s the meat for this week: When you’re looking for service on your tool, make sure you have noted the Model Number, Serial Number and Type Number off of the tool’s ID plate. This will go a long way to obtaining help on the first try instead of finding more questions coming back at you. Many stationary tools did not use a Type Number, that was used more in the Portable Tool world, but there are some, so that is important also. If you will pass that information along to the Service Provider, they can be better informed as to what you have and thereby be able to help you quicker. Truthfully, this advice can apply to most every product that you would get service for - washers, dryers, TV’s. Of course, cars have the VIN but the principal is still the same.
And one other thing, just within the past week, I have agreed to consult on the Parts Lists of new machines that DELTA is bringing to the market. I get to review them and see what parts should be offered as assemblies and how many should be in stock… and I get paid to do it!
Til next week…

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

Saturday, October 8, 2011

V2.24 - Calming your Band Saw down

Well, unless I hear from someone, we’ve about run our course on band saws. All that might be left is a column on how to keep them from walking across the floor. I’m talking about wheel vibration in your stationary Bandsaw. 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 is tight and yet it still has excessive vibration with only the motor running, I’d suspect you have a bad motor. But to be sure - take the motor pulley off and run it again – still shakin? Yep, the 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.

V2.23 - Choose the correct Band Saw blade.

Alright, we’ve got the saw cutting straight and the blade is tracking properly, but is it really cutting as good as it could? Let’s talk about that.

A band saw blade is a delicate piece of steel that is subjected to a tremendous strain. If you treat the blade right, you can get a pretty long life out of it. Basically, you’ll need to be sure to select a blade of the proper thickness, width, and temper for the material that you’re going to cut.
Always use the widest blade possible. Narrow blades should be used only when sawing small, delicate items or when making abrupt curves. Using narrow blades for resawing or heavy-duty work will just cause them to fail all the sooner.
Some band saws are made to cut ferrous metals (iron & steel) and the blades for that should be selected based on the particular job they are going to do. A metal-cutting blade should always have two teeth on the cross-section of the metal. For instance, if the cross-section of the metal is ¼” thick, you would want two blade teeth in contact with that, and since there are four ¼ sections in one inch, the blade should have 8 teeth per inch. If fewer teeth are used, the teeth will straddle the work and may be torn off and the blade ruined. If too many teeth are used (say, a 16 teeth per inch blade) the metal chips cannot clear out properly and the blade may overheat and ruin its temper… again making the blade worthless.
In general, the thicker the stock to be cut, the more teeth the blade needs to have and, in the case of a wood-cutting blade, they need to be larger teeth. Also, the thicker the stock, the slower the cutting speed needs to be.
So, what if you have used care in selecting the proper blade and you keep breaking your blades? Any one of a number of conditions may cause a band saw blade to break. Sometimes it’s just gonna happen no matter what you do, but most of the time, it can be traced to some basic things: 1- faulty alignments and adjustments of the blade guides, 2- forcing or twisting a wider blade around a short curve, 3-shoving the stock through too fast, 4 using a dull blade and trying to force it to cut anyway, 5- excessive tightening of the blade, 6- top guide set too high above the work being cut and lastly, but certainly not least 7– using a small 3-wheel band saw. Those little beasts just EAT blades… they can’t help it, they just do.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.