Bandsaw

[Tom Bucanan]

How do you guys bandsaw your blanks round. I know that some people will make a cut on the outside bark area so that there are two flat faces parallel to one another. Is this necessary? I was hoping to just to cut the log in half and then bandsaw it round. Is there any jig I should build to make sure it is perfectly round (maybe a nail sticking up from a plywood base that the blank could turn on)? Any ideas?

Thanks in advance for any advice and happy holidays.

[Dennis Peacock]

Tom,

I use my BS to cut the small logs in half. I use the lathe to make it round. :)

On really large blanks, like 15-19", I just use my chainsaw and wack off the corners of the havled log and mount it on the lathe.

Cutting a blank round will cut down on how much time you are at the lathe, but it's for sure not necessary.

All this info and $5 will get you a coffee and a burger somewhere. ;)

[Ben Gastfriend]

I think that leaving the bark on would be OK. You might have to turn some of the bark off to reverse the blank in your chuck, but as long as you have one flat section, you should be alright.

As for bandsawing the blanks round, all I do is use a bunch of round plywood templates with a hole in the middle. Then I nail this into the blank, and use the bandsaw to cut around the template.

[Don Eddard]

It's not real important for the blank to start out perfectly round. The lathe will do that part for you. No jig is really necessary. I've done something similar to Ben, except used a paper plate instead of a plywood circle. I just tack the plate to the blank, and bandsaw around the edge of the plate. If the blade its the plate, it's no big deal.

[Jim Becker]

I use my BS to cut the small logs in half. I use the lathe to make it round.

Ditto, I rarely band saw a blank round as I prefer to put it between centers and find out what's in there before committing to what the plane of axis is.

[Jim Underwood]

If I have several, I'll set up my circle cutting jig on the bandsaw, and knock 'em out. I find it's safer than trying to do it by hand.

Just be careful because it's all too easy for a finger or thumb to be in line with the blade if the blank slips off the edge or splits. That's why I like the circle cutting jig. I can actually push away from the blade with my hands and still turn the blank into it.

Happy blanking!

[Richard Madison]

Recently saw (observed) a neat jig that my neighbor Mack made for his humongous Laguna bandsaw. It's a big sled, guided by a rail in the miter slot, with a saw cut from leading edge to the center. There is a row of 1/4" holes from the center to the right about 16" (he has a big lathe too), just like a circle jig. One drills a shallow 1/4" hole in center-to-be of flat side of the chunk and pins it to the sled with 1/4" pin. The sled plus chunk is advanced straight into the blade until blade reaches center of the sled (or vice-versa). At this point one clamps the sled to the saw table and begins to rotate the chunk around its center pin, as with a circle jig. Apparently works very well, and/but needs a stop block to stop sled travel when it reaches center. Requires one fairly flat surface, so the chunk does not rock while rotating.

Gonna make a teeny one for my teeny bandsaw.

[Steve Trauthwein]

I made a bunch of rounds of various sizes from poster board. I will just grab one closest to my piece of wood and tack it on, then use the diameter of the circle as a rough guide. You will also end up with an indication of the center from the nail hole.

I agree that it is not necessary to round a piece of wood before turning but it sure makes like a lot easier if you have a large piece of wood or something really hard. Simplifies life if you are cutting wood and not air. Just my .02

Regards, Steve

[Pat Doble]

I leave my blanks 'square' (allows me to stack them in any orientation I need to best fit them on my shelves) until just before I put them on the lathe. At that point, I just knock the corners off with the bandsaw (not very exact, but helps lessen the '4 corner beating' some blanks will give you if left square) and mount on the lathe.

[Rob Leslie]

For me, a little time at the bandsaw reduces a lot of time turning "air" at the lathe. And of course, a chainsaw is faster, but not nearly as accurate. Your mileage may vary.

[Reed Gray]

As a production turner, the rounder and more even/balanced the blank is, the better. You do want the top and bottom parallel. A big bandsaw works better and faster than a chainsaw, but both get the job done. You get less vibration when roughing out, and can start at higher speeds. If you are cutting the blank out with a chainsaw, then I cut the top and bottom by marking parallel lines on each end of the log (I have plywood strips from 1 to 8 inches in half inch increments for making the marks), then cut as close as possible to the lines. Then I scribe a line using a compass on the top of the blank. It isn't necessary to cut off all the bark, but you do have to watch for flying bark until it is all turned off. If you don't flatten off the bottom of the blank, then it is hard to lop off the corners because the log will roll. I find it easier to work from the top, as you can cut more accuratly. I don't use a circle cutting jig because all my blanks are different, and a compass works well, and I can cut to those circles easily and close enough to round. I don't think either method if faster than the other. You can use a circle blank on the bark side if you want to, and lop off the corners, but you will still need to find a center to mount your face plate. I do it this way only if I am doing a natural edge bowl. If you are cutting the circle on your bandsaw, it is important to have the face that the blank is sitting on be flat. If it rocks at all while turning the circle, you will bend or break your blade as it binds up. Also, if the edges round up from the bottom, it can and will rock to the side and bind the blade again, like what happens if you try to cross cut a round piece on the bandsaw.
robo hippy

[Dale Gregory]

I don't do it, but have seen some folks even tilt the blade so that the sides of the bowl are pre-shaped to eliminate having to spend time on the lathe doing it. I usually cut the log with across and down the middle with a chainsaw and then bandsaw a rough circle to the diameter I want, leaving the bark on the outside.
Dale

[Kim Ford]

It is interesting to read the different threads and the reasoning behind.

For me it comes down to size, type of wood, and the wood moisture content. Woods that tear easily or are very hard and have a tendancy to split are canidates for rounding ahead of time. I'm not a big fan of getting riddled with bark fragments and small chunks of log when roughing out a log.

Bandsaw or not is a personal prefence, however and Reed mentioned it, the really important part if you use the bandsaw is to put the flat side down on the table. Nasty and unpleasant things can happen if the blade binds.

[Jeffrey Fusaro]

if you are working on a small lathe, like a jet mini, cutting blanks as close to round as possible before mouting on the lathe will make life more enjoyable. light weight machines don't handle imbalance well, at all.

before i got smart enough to get a bandsaw, i had to put my lathe on the floor and chase it across the floor until the blank got somewhere near round and in balance.

might have been funny at the time, but not the smartest thing that i have ever done.

i'm not a big fan of getting hit with flying bark, or the larger chunks that can come off of the protruding corners of the blank.

also, regardelss of machine size, i wonder how that imbalanced rotating mass is adversely affecting the bearings in the head stock. if you have a very heavy lathe, or one that is bolted to the floor, all of the forces generated by the rotating mass are transmitted into the bearings, since the machine cannot wobble to counteract the rotational imbalance. i'm not sure that those bearings were intended to handle those types of forces and the associated 'four corner beating'.

then, there's the rest of the system that takes the 'four corner beating' - like the chuck/faceplate, the cutting tool, the tool rest, the banjo, the lathe bed ways, and finally, YOU.

makes 'more better' sense to start off as close to round as possible, unless you are intending to make a four cornered bowl.

just a few thoughts...

[Tom Bucanan]

I have a PM 4224 and want to rough out blanks on the bandsaw that are betweeen 8" and 18". I don't understand what the advantage is to cutting the two parallel sides (cutting off most of the bark) since you will be losing alot of wood by doing this. Also, I like the idea of a center jig, but does anyone have any pictures or know of any websites that show how to make one? Does the central pivot point (supposedly a nail or something) line up perpendicular to the blade or the teeth of the blade? Or does it matter?

Thanks for everything

[M Toupin]

Here's an example of a simple circle cutting jig.

http://www.cabinetmaking.co.uk/bandcircle.htm

The blade needs to be adjusted so the front edge of the teeth are in line with the center of the circle to cut correctly. Too far behind or in front of center causes the blade to defect and cut a spiral which is hard on the blade.

Mike