Tuesday, 29 January 2013

bandsawing parts to rough sizing.

When band sawing parts remember to drop to a low safe point. About the half point of the thickness of your finger from the rollers to the top face of the part that your band sawing.

Section band sawed out on the 5mm offset band sawed line that runs around the 20mm offset section for veneering. The 5mm offset will be machined off with the circular saw on the guide trench later on.

The parts that were band sawed were 1 drawer box lid, 1 drawer box base, 1 front door flap, 1 back door and the panel panel section of the cabinet. Like I said previously once the 5mm offset is cut off they will be used as the template for the others to transfer the shape. After that than the 5mm offset will be drawn around it.

There are a few basic things to remember when band sawing. 

One of the reasons  as to why the band saw is lowered like this is to prevent the blade from flying outwards to the right if it snaps and comes off the 2 wheels that it runs on inside the machine. This is why its important to not keep your hand on the right side all the time. But the main reason its to prevent your self be proan to cutting your self. Always with any blade limit its exposure towards your self and others around you as much as you can. 

Depending on what your band sawing one hand should be used to steady the piece basically keeping it on track to the line that your cutting. Now the other hand is just being used to push the piece in. Directing it from starting cut to finish cut. Now like any other saw your not forcing it in with heaps of pressure. Let the machine do the work. 

Usually when your coming to the exit cut and its a small part your band sawing use a push stick to finish off the last push when coming to the finished cut. This again is a safety factor keeping your hands well away from the blade. A band saw is a lot stronger than a circular saw and with a sharp blade will cut through your finger or hand like butter. This is one of the reasons why they use band saws at butchers or slaughter houses. Great machine to cut through carcasses. 

If your having to push the piece in with some force most likely your blade is blunt. Best to just take your blades, router bits etc to a professional sharpening place if you don't know how to sharpen them. 

When placing a blade onto the two wheels inside there needs to be a tight tension but not two tight. The blade needs to be able to track properly. Two sloppy will cause the blade to sleep off the wheels. Too tight will place strain on the blade which can cause it to break or ware out the belt more and you will find you will need to get sharpened a lot more often. Now different width blades will be tensioned differently to one another. The blade must be tracking in the center point of the wheels. When setting up a new blade before turning it on give it a few turns to see if its tracking properly. If its too loose it will over shoot and move away from the center point and fall off the wheels. If its too tight will be hard to turn. 

Follow these steps in setting up a band saw http://home.vicnet.net.au/~pwguhttpild/i-bndsaw.htm 
There is a lot to know and remember for when setting up a band saw so follow these steps or the steps in your instruction manual if you have one. There are many good dvds on band sawing so obtain them if you need further help or ask some one for advice who is experienced in using band saws. There are many good you tube videos on setting up band saws and other machines I recommend looking up this guy. 
http://www.thewoodwhisperer.com/  He is very good a showing how to use machines and how to set things up a lot better than me. Long story short with any machine to properly show how to use it and set up will fill up too many blog pages. The information given here is the basic information needed to remember. Look at the above links or suggestions as that will give you more depth of knowledge in them. 

If your getting little notches on the cut line of your piece its either you have the blade around the wrong way remember teeth face down (you will know when you have it the wrong way, lol), theres a nick in the blade or it can be getting really blunt. Also again tension may not be correct with the wheels to the blade. A band saw when set up and used correctly should be able to make a cut as fine as a circular saw. 

Now some times its easy to get the teeth mixed up in the right direction. You may think that the blade is faulty when you see one when the teeth are facing down. All this means its that the blade needs to be flipped inside out. This I learnt after embarrassingly setting up the blade the wrong way one time at work. 

Band saw blades come in all sorts of thicknesses ( the ones we use at work are .6mm and .8mm) Also different widths. You will find the wider the blade better for ripping down huge stuff where a lot of bit is needed. The thiner the width will allow you to band saw complex curves. So remember like table saw blades band saw blades also have blades for specific jobs. If you have the space obtain a power large band saw for doing large ripping jobs (ie making your own veneer) and have a smaller band saw used for curves where power is not a huge requirement. 

Band saws are great for ripping down large pieces or really thick pieces that cant be done on the saw. Also to rip timber that is really dense or has a high moisture content. 

Thats why is great to have a rip fence with your band saw. Unfortantley this one at work doesn't. The one I have on  order from America through Laguna tools does. I had to use the one at work since I could not afford to wait for the one im getting. Plus this one was still suitable for that I needed to achieve. 

check this sight great for machines. http://www.lagunatools.com/ Now if your wanting machinery from this website go through this one if your local since this company is one of the suppliers they order from.

the woodworking warehouse is a great place to obtain machines (most of mine are from there). Ask for a guy called Ben he is pretty much there all the time. I tend to pick his brain a lot since he is full of all sorts of useful information. I can honestly say that his customer service has been the best that I have ever seen in this area. Its great since even though he is a retailer he comes from a wood working/ wood machinist back ground so he knows what he is talking about. 

Great idea when cutting cross grain on a band saw is to use masking tape on the underneath side. You can use a waste board like plywood scrap which does the same thing but i think masking tape is a lot easier. What this is doing is acting as a break. It prevents the cross grain from splitting when cutting through it. 

Here are some of the parts cut which will be taken back to my workshop reading to be cut with the circular saw than after that ready for hand veneering.

Began band sawing on the 5mm offset band saw line for the Ikebana base panel. Once the 5mm offset is cut off from the circular saw I will than use this as a template for the top drawer base panel since they are both the same shape. 

Did the same principal as before with using masking tape underneath on the cut line which acts as a grain splitting break.

About to band saw out the shape for the top carcass panel for the cabinet. Just laying down the masking tape which will act as a grain break to prevent splitting on the bottom of the panel.

Following same machining principals as before.

 Note: Interesting bit of information that I heard from a guy at work who is a master craftsman from France. This happened to him on  a job. He said to remove all pencil and texter marks on the substrate panels before any veneering is done. The reason for this is because there is a chance of it showing up through the veneer especially when oiled is added afterwards.

I don't really want to take any chances if this can happen since I'm using expensive veneers (never heard of this happening, I trust this worker since he knows a fair amount about this trade). Ill be sanding the panels any way before laying veneers down to open up the poors to provide a better glue bonding. So ill remove as much of the pencil as I can with the eraser and than sand away the markings. But remembering not to concentrate in one area since you don't want any dips.

Masked the under neath cutting out section of the cabinet base with masking tape that will act as a grain break. Usually like said before if you have a very sharp blade you don't tend to need to do this.

Follow same principals as stated before while band sawing parts.

Part cut on 5mm offset line and ready to be trimmed than veneered. Offcuts will be used for many other things within the project.

So I didn't have to spend time waiting I though of cutting some of the parts out to their 5mm offset on the scroll saw. I don't like using this scroll saw that much since its getting to the end of its life. The motor is going and some of the electronics are going as well.

Had to place masking tape on the exit cut so chip out would not occur.

First drawer box lid cut out to its 5mm offset.

Needed to place a spirit level on the work plate to obtain a better 90 deg cut.

All drawer box lids cut to their 5mm offset.

Sadly the electronics failed even more. The start button would only work if you pushed it in and held it there. I opened up the electronic starter box and re positioned the wires for the on button and it worked for a while than went back to not working properly. So for a quick fix yet not very safe clamped a small peg clamped with a nut that pressed onto the on switch to keep the machine running.

Just press the small orange button to release pressure which will turn off the machine.

Masked off the underneath exit cut with masking tape to avoid break out.

Needed to cut the shape out in a few different stages since it was too big for the scroll saw. I was planning on doing it on the band saw at tafe but really couldn't be bothered waiting.

Some of the lines are wonking because one of the blades snapped and the only blade I had left was a very bent one. The doors will be done on the band saw at tafe. In the end with the head ache of the scroll saw it still got the job done.

Cutting off the offcuts sections on the secondary doors. Some of the off cuts could be cut off on the panel saw.

This resulted in ripping and docking.

Time to mask off the bottom sections of the exit cut with masking tape before cutting on the band saw.

The Felder bandsaw at tafe is quite good produces a clean cut has a T riping fence and has a bigger work plate to work on.

Parts ready to have their 5mm offset cut off on saw/ router station back in my work shop.

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