Ozbow

I finally got around to reading a book on bandsaws I bought a couple of years ago. In it is a description of a jig that acts as a fence, but has micro-adjustment. Thinking this would be useful for sawing kerfs and laminations, I decided to have a go.

In essence, it's two tapered components that when aligned, have parallel outer edges. As you slide the two blocks against each other, the outside edges get closer or further apart. bolt going through a bracket secures them in place. A vertical board becomes the fence face.

This was just a prototype. I think I will make another, such that the adjustment is even finer. This one has 2 mm of fence adjustment for every 10 mm of block movement. An adjustment ratio of 1:10 would be better.

Fence at the top, bird's eye view. This is at full 'contraction':



mid range:



As wide as it will go:



on the saw:



Incidentally, I think my current bandsaw blade is poor. The blade material is very, very thin. But that's not the problem. The problem is that the teeth don't seem to have much set on them. This makes for a 0.5 mm kerf, which is just barely wider than the blade. This, in turn (I suspect) is the reason that despite being 3/8" wide, this blade struggles to cut curves accurately, and struggles to cut straight lines unless the fence is set perfectly.

That aside, this jig is the execution of terrific concept. Micro-adjust fences can be quite expensive to buy, but this was all made from scrap I had lying around. I believe a jig like this can be made to be every bit as accurate as a manufactured one.

Dave,

The jig appears to be a lot of overkill to carry out a basic straight cut ‘x’ distance from the fence.

Realistically what is the tolerance +/- you are trying to achieve.

yeoman wrote:....The problem is that the teeth don't seem to have much set on them. This makes for a 0.5 mm kerf, which is just barely wider than the blade. This, in turn (I suspect) is the reason that despite being 3/8" wide, this blade struggles to cut curves accurately, and struggles to cut straight lines unless the fence is set perfectly.....

Unfortunately one blade does not fit all cutting applications and to get the best out of your bandsaw you will need a few blades of different widths and profiles.

Double check all the adjustments i.e. bearing guide tolerence on the bandsaw as well as having the correct blade tension.

There is a lot of information about bandsaw blades on the internet, a bit of research may save you grief further down the track.

Daryl.

Overkill in what respect? Took about an hour to knock up, and uses scrap. I built it to get within 0.5 mm or so when sawing lams (for whatever) and kerfs (for recurves). The idea is to saw a lam on waste material, against the fence, measure, then adjust the fence as appropriate to saw the desired thickness. It will also be good for sawing multiple kerfs in tips that need more than one, without having to re-adjust the whole fence.

I asked around on the woodwork forum about blades/kerfs/tooth set. It seems the lack of set is a large part of the problem.

I recently watched this video:

https://www.youtube.com/watch?v=wGbZqWac0jU

and following that advice finally managed to remove the drift from my saw. For a bit. The blade is, I think, most of the problem. The saw itself is pretty worn out too. It's only a 1/2 hp 10" model, and I've pushed it very hard for about 8 years. It's definitely time for an upgrade.

yeoman wrote:.....I asked around on the woodwork forum about blades/kerfs/tooth set. It seems the lack of set is a large part of the problem.

Dave, you will get more useful technical information if you check out the blade manufacturers web sites.

yeoman wrote:.......The saw itself is pretty worn out too. It's only a 1/2 hp 10" model, and I've pushed it very hard for about 8 years. It's definitely time for an upgrade.

Sounds like a good decision.

The vast majority of my band saw work is cutting laminations.

I do not need to be micrometer accurate at the saw as the laminations go through the lamination grinder to remove saw marks and then again with the tapering jig. It is during this process that accuracy is attained.

Running a 12” and 14” band saw does make life easier.

The simple fence guide below is surprisingly accurate. View original post below.

http://www.ozbow.net/phpBB3/viewtopic.php?f=2&t=10232

Daryl.

If you're looking for a new bandsaw, you might want to consider one of these -

https://www.timbecon.com.au/sawing/band ... le-bandsaw

It's comparatively cheap/affordable for a 14" bandsaw and my brother in the UK rates them highly (and he's somewhat of a guru when it comes to affordable tooling). 1hp motor does the job and I'm told the build quality is higher than might be expected for the price. I might have some real income from bowmaking soon so I'm considering getting one, maybe, bills & wife permitting! If I were to get another bandsaw, it would likely be one of these on a cost/value basis, given my brothers endorsement.

The Carbatec equivalent is a few hundred dollars more - https://www.carbatec.com.au/machinery-a ... ength-2553 - but, strangely, their two-speed 14" saw has a more powerful motor for about $800.

I've got a 16" 3hp Ledacraft saw which isn't actually that good. I was going to get a Jet saw but the local, independent tool salesman recommended the Ledacraft gear, which has been a mixed bag overall. For straight cuts it's fine but the blade guides are shocking (only designed for big rips, really) and I'm not able to effectively mount new, after-market guides. It's great for milling logs, etc, and is still my go-to bandsaw but I've found my old & well-loved 10" Ryobi still sees action for cutting curves and the like. I run a 1/4" blade on the 10" saw and 1.25" - 0.75" blades on the 16" saw.