Plans, projects and how-to's for home machinists

A Chip Brush for the Jet 5X6 Bandsaw

Pic 1This article was written by “Mikey” and it first appeared on the Yahoo 4x6Bandsaw discussion group.   I think it is a great idea and well presented so I asked him if I could republish it here and he graciously agreed.  It originally appeared as a PDF file that is formatted better and has larger pictures that you can download here.  — Rob

The Jet HVBS-56M is a capable saw for home use.  Quiet and powerful, this saw is quite accurate once it is properly adjusted.  Like most saws in its class it isn’t the perfect saw in that the supplied table for vertical cutting is inadequate, it uses an imprecise spring mechanism to control down feed, and it lacks a chip brush.

This last deficiency, the missing chip brush, is the subject here.

Every blade manufacturer advises that a chip brush is important to the longevity of the blade and the machine so this really should be addressed on our saws.  I mean,… “how hard could it be?”

A net search revealed surprisingly little on this subject on this class of saw.  I had some questions that needed answers:

  • What does a chip brush actually do?  Yeah, I know it knocks off chips but what is the actual functional result of this action?  Is this result important enough to make me design and build a brush?
  • Is a static wheel as good as a moving wheel?  If the latter, how can the wheel be driven?
  • What material should the wheel be made of – steel, brass, plastic?  How big a brush do I need?
  • If a single wheel will do the job, will two do the job twice as well?
  • Where is the wheel best located?  On my saw, where is it even possible to mount a brush?
  • How do you actually adjust a chip brush?

I was not able to find most of the answers to my questions on the net BUT I was able to look at some different types of brushes that could aid in design.  What I hope to do here is answer some of the questions above, at least to the extent that someone can decide whether to build a chip brush or not.  I suspect a lot of 4X6 owners must have entertained the same questions.

So, what does a chip brush actually do? It knocks chips off the blade as it passes the brush, the result of which is to reduce the amount of re-cutting the blade must do.  This cleaning action is thought to reduce stripped teeth, premature wear of the blade, chip welding to the teeth and rough cuts.

Which of the many types of brushes will be the most practical and effective on this saw? A static brush, one that just bolts in place and is rotated as it wears, is the easiest and cheapest to build.  It is the type Jet uses on its next higher class saw and would suffice in the home shop.  However, a rotating brush is almost as easy to build and is more effective at chip removal.  I tested a static and rotating brush to see which removed more chips by catching as many chips as I could in a tray while cutting 12L14 steel.  My eyeball meter suggests the rotating brush removed about a third more chips, probably because the chips are thrown out by centrifugal force as opposed to packing into the wheel on the static brush.  Hardly scientific but over the many linear feet the blade will run I think it is reason enough to make a rotating brush.

Obviously, a motor-driven brush is out of the question on this class of saw, which leaves only a blade-driven brush.  This means the brush is rotated by the blade as it passes across the brush.  Accordingly, and in the interest of longevity, ball bearing supports would be called for.  These bearings should be a sealed-type bearing given the environment in which they will work.

As to which type of brush is best I found no answer to this on the net.  Plastic would work but not for long.  Brass is soft and may wear the blade less but longevity is a concern.  For all practical purposes, then, steel is the answer.  Fortunately, they are also readily available and cheap.  As to size, the contact patch is very small so the smallest brush of reasonable quality will work – a 1″ diameter wheel with a 1/4″ arbor hole seems to work well.  There are fine and coarse wire wheels; I only tested the fine wheel and it will serve.

How many wheels do I need? On large industrial saws one often finds a two-brush, motor-driven design.  The brushes flank the blade in an area where the blade runs straight.  On the Jet such a place is hard to find.  I found no information on whether a two-brush is better than a single brush so I built both and found that the two-wheel version didn’t seem to clear chips any better than a single brush.  Moreover, it was very difficult to align the two-brush version because the blade curves in the only area where placing such a brush is practical.

Where can I put the thing? Locating the brush is feasible in only one place on this saw- just under the lower blade guides.  Here, it is out of the way of the cut and the saw’s body, clears chips at the earliest opportunity, and there are holes for a mounting bracket already located there.  The brush can be positioned so that the tiny amount of pressure it puts on the blade is countered by the thrust bearing that backs the blade in the only location where the blade is still running straight.

So, we need a small, cheap, easy to build single fine-wheeled chip brush that is blade-driven and ball bearing supported, located just under the lower blade guides. Continue reading A Chip Brush for the Jet 5X6 Bandsaw

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