Saturday, November 24, 2012

V3.47 - Winter Time Static


You might have read this one before, but as we get into winter, static becomes and real issue so, here’s your (maybe twice yearly) reminder.

This week let’s talk about static electricity in your woodshop. I’m sure we’ve all experienced it when using our belt sanders, but it can show up on all rotating equipment and especially in your dust collector ducts.

Static electricity in a wood shop is mainly caused by two things. First is low humidity in the air. Static is especially troublesome in winter when the outside temperatures are low. A rule of thumb is the colder it is outside, the lower the humidity is inside a heated shop. As a result, static charge builds up easily and causes shocks when the electricity discharges through contact. The problem is even worse if a shop’s dust collection system exhausts its air outside the building. This builds an additional requirement for fresh air coming in and the fresh, cold air will have low humidity once it has been heated indoors.

The second thing that causes the static electricity problem is motion between two things. In the case of a belt sander, it is the motion between the belt, platen and pulleys that causes the build-up of electricity. In the case of the dust collector or Shop-Vac, it is the motion of the particles through the hose. There are two places where the charge can build up. One is in the machine the dust collector is attached to and the other is on the person who is operating it. Fortunately, grounding the frame of the machine will eliminate the buildup of the static charge. All fixed machinery, such as a table saw, jointer, planer etc., should have its frame grounded to a water pipe or at the very least, to the ground conductor or conduit sheath of the machine’s electrical wiring. Sometimes this is not possible, especially if the machine is electrically double insulated, as is the Shop-Vac.

Beyond grounding the machine, the best cure for static problems is to try to keep the humidity in the shop from getting too low. This can be done by using bag-type dust collectors that re-circulate the same air within the shop after the dust has been removed. These collectors will also reduce your heating bill. Other ways of adding moisture to the air, such as using humidifiers, are worth considering. Another thing you can do is wear shoes that bleed off the static charge rather than allowing it to build up.

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

Saturday, November 10, 2012

V3,45 - Straightening Warped & Bowed Stock


We were talking about Industrial Planers (IP’s for short) and snipeing, but there is so much more to them than just snipe. Perhaps we had better start at the beginning. Some of this stuff is going to be good info for ALL planers.

So, we’ve discussed that planers are really ‘thicknessers’ and to let them do the best job they can, they need a flat board to start with. Let’s talk about shop setup. I’ve often been asked ‘when I’m putting a shop together, what are the first machines I should buy?’ It does depend on what your shop’s purpose will be, but just for this week, let’s say that the goal is a decent little Woodshop.

Your shop’s heart is the Table Saw. You really can’t get anywhere without one of those and a 10-inch Table Saw will be fine for all but the largest projects. I believe the next purchase is a good Jointer. The bigger, the better if you will be doing larger projects. Naturally, if you intend to build model airplanes, a 4-inch jointer would be fine. After that, it’s the Planer. Again, you’ll need to choose an appropriate size. Follow this up with a good Drill Press and then perhaps a good Bandsaw. Most projects can be done with this group. Sanders, Shapers, Lathes and Hand Power Tools are also part of a complete Woodshop.

Alright, so you now have a basic woodshop and have this board you need to make flat, so you can run it through your planer. First, use your Jointer and surface one side of it. “Surface” is the technique of flattening one of the wide ‘faces’ until it is smooth and flat. Once you’ve done that, place your surfaced face against the fence and make passes until one edge has been jointed. At this point, you will have two parts of the board flat and smooth, and they will be 90degrees to each other.

Now, take your piece to your Table Saw, place the surfaced face on the table, and the jointed edge against your fence. Rip the board to the width you need. Now you have a board with 3 flat and straight surfaces. Now you are ready to place the surfaced face on the Planer’s bed, set your thickness adjustment and run the stock through the Planer.

You now have a straight board, that is flat and the proper thickness. All that remains is to cut it to the proper length. Remember, measure twice, cut once.

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

Sunday, November 4, 2012

V3.44 - The continuing saga of snipe


As I had said a week or two ago, I am still a rookie at the newspaper column business and it reared its head in my column from last week.

There was a very important paragraph that got mangled up because I used odd characters. Here is what came out… “In other words, if you need a _” thick piece, take your adjustment to 1” and bring it down to _. Do not start at _” and go up to _ and then plane it. If you do that, you are leaving the backlash in the lead screws & nuts and that will be increasing your chance of snipe.”

As you can see, the dimensions I was referencing got obliterated. I thought I had best rewrite the paragraph so that my meaning is crystal clear. Here is what I meant to say. ”In other words, if you need a Three-Quarter-Inch thick piece, take your adjustment to One-Inch and bring it down to Three-Quarter-Inch. Do not start at One-Half-Inch and go up to Three-Quarter-Inch and then plane it. If you do that, you are leaving the backlash in the lead screws & nuts and that will be increasing your chance of snipe.” Hopefully, you can see the difference and why it is important.

Alright on to new business - the Industrial Planer. Most Industrial Planers have bed rollers and they are height-adjustable. Ideally, bed rollers are for use when you are planning very rough or warped boards. Yes, planning warped boards is not a good idea; however, in certain instances (like sawmills) one needs to make a pass through a planer and then go on to other machines. In most IP’s, the bed rollers are directly underneath the infeed rollers. This helps put the ‘squeeze’ on the stock as its going through the planer. As I said, the bed rollers are usually height-adjustable and very rough boards can use a bed roller height at 5 to 10 thousandths. If one is trying to get a snipe-free surface, the height of the bed rollers should be level with the bed or even 1 to 2 thousandths below the bed. If a smooth surface is the objective, having the bed rollers above the surface of the bed can actually create snipe because of the upward force of the board as it bumps up onto the bed roller.

Yes, there are many issues with an Industrial Planer, and it’s gonna take quite a few columns to work through them. I’ve got time, do you?

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

Friday, November 2, 2012

V3.43 - Our ‘snipe hunt’ continues.


Last week, I gave you the most basic description of what snipe is and how it happens. The “why” it happens and how to minimize it, is the subject of this week’s column.

Setting the stage, your lunchbox planer has a movable head for depth of cut. It has no bed rollers, and the distance between the infeed roller and the outfeed roller is 4 inches. With that foundation, our snipe would be 2” long at the front and 2” long at the rear of the board. “Why” do you ask? Good question.

Here’s why- as long as the board is underneath both rollers, the head will be shoved upward by the force of the rollers pushing down against the board.

The early lunchbox planer designs were notorious for the problem of snipe. Later designs, and the ones most often found now, had a head locking mechanism made into the planer that allowed the operator to actually lock the head in place, which has pretty much eliminated snipeing on this design.

One thing that will do much to decrease your snipeing is [on the movable head style] to ALWAYS make your final depth of cut setting by moving the head downward. If you will do this, it will remove the backlash out of the lead screws [the threaded rods that the planer head moves up and down on] and their nuts. In other words, if you need a ¾” thick piece, take your adjustment to 1” and bring it down to ¾. Do not start at ½” and go up to ¾ and then plane it. If you do that, you are leaving the backlash in the lead screws & nuts and that will be increasing your chance of snipe.

On the early design lunchboxes, there were many different methods attempted to eliminate snipe. Some were easy, some were weird and most did not work every time. Once the planer makers figured out that customers were not in the mood to accept snipe as a way of life, they went back to the drawing board and did something about it. Hence, the head lock I mentioned earlier.

So far, we’ve been talking only about the lunchbox planers. Let me tell you straight up, snipe on industrial planers is a real happening, too. The Industrial planers have an inherent advantage because most of them have a movable bed, not head. This design difference makes snipe a lot easier to control, but there are so many adjustments that other things can go wrong. We’ll ‘go there’ next time.

Oh, and watch out for the kids that might be out Wednesday night...and/or the punks that might be armed with eggs…

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