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View Full Version : How to make a bandsaw rasp? (Shinto?)



Walt Caza
09-27-2008, 11:42 AM
Good Day to the Creek,
Well, I have been wanting to build one of those homemade broken band rasps.
Why do we always wanna call them bandsaw blades, when they are really just bands? (I seem to do it every time)
Anyway, the bad news is I finally twanged one, by horsing a deep resaw through white oak.
The good news, is that I now have a broken 1/2" Woodslicer, with about 4 teeth per inch,
and 154" long. (no blood and no bad kinks!)
It is .022" thin, with a 1/32" kerf, 3-4tpi variable pitch and super hard at Rockwell c65.
[sidebar- these are terrific, ran smooth and quiet on my MM16, I will buy more]

I searched back through the general forum, but could not find any references to
these homemade rasps.
I have seen them mentioned before, but cannot seem to plug in the right search criteria.

Can anyone either provide me with a link or a clue?
I recall someone mentioning you can rig a handle.
How would I best cut it? (springsteel?)
What would be a good length to make it?
What is a good way to hold the segments together?
Single handle? or one at each end?
Anyone find these to be useful?

Thanks for your help,
Walt

ps I was glad to have a spare Woodslicer up my sleeve for just such an occasion!

Mike K Wenzloff
09-27-2008, 12:43 PM
Hi Walt,

I made a rather crude one using hacksaw blades. I would think the WS BS blade would have tooth spacing much too great.

However, you can easily break them to a given length by just folding it back on itself. I usually break my old BS blades into lengths and throw them in the scrap barrel. The ends will have a slight curve where they break, so if you do it this way, plan on a little extra length so you can grind them back a little to a flat, straight section so the ends can be clamped together nicely for your purpose.

You can also lightly score the BS blade with a diamond wheel on a Dremel type of tool or use the edge of a grind wheel. You can easily snap them at the score line.

Do wear eye protection.

Length. Well mine was limited to the 12" or so that the hacksaw blades were. Longer would have been a tad more useful. It does take a goodly number of pieces to made a rasp from. Because I used hacksaw blades, there was a hole already in each end I used a piece of 1/8" piece of brazing rod to keep them in alignment. The ends were each inserted into a kerf cut into a piece of a large dowel. There were a couple brazing rods in the "body" of the band sections to keep the bands separated--but they didn't keep separated well enough.

The give a heck with these in comparison to commercial rasps of this type (Shinto) is spacing the bands for waste to evacuate. Mine worked, but not well. The Shinto rasps are pretty cheap. I wouldn't ever bother myself to make another.

Take care, Mike

James White
09-28-2008, 8:39 AM
Giving this a bump. I am very interested in making one of these myself. I tried some Google searches but am only coming up with vendors selling them. No how to info.

James

John Shuk
09-28-2008, 9:41 AM
What is a bandsaw rasp and what is it used for?

James White
09-28-2008, 9:44 AM
Perhaps Walt should change the title to Japanese or Shinto Rasp.

James

Walt Caza
09-28-2008, 11:19 AM
Hello All,
I looked into James White's suggestion that these were called Japenese or Shinto rasps.
I found a few sources that sell similar handtools.
From my understanding of his TOS interpretation, this link should be allowed,
according to moderator Steve S.
It is to a commercial site, but I do not stand to profit from it. (link)
http://www.japanwoodworker.com/dept.asp?dept_id=12881

As you can see, those differ from anything you would make at home.
The gaps are supposed to prevent clogging.

My understanding of how to make a rasp out of an old bandsaw blade,
is to cut and stack many segments, offsetting the teeth, and taping both
ends for handles. I imagine the segments to be at least 12" long.
They are supposed to cut very aggressively.

When I first got my bandsaw, it crossed my mind that when I break a band,
I could try to make one of these rasps.
Well, it took nearly 2 years to twang one, but now I have one to play with...
I have seen it mentioned in Creek threads, but cannot find them.
Any help appreciated,
Walt

Mike K Wenzloff
09-28-2008, 12:28 PM
Well then, cut and stack many segments and offset the teeth followed by wrapping the ends with tape.

I use rasps day in, day out. I cannot imagine what the need or utility of such a rasp would be.

The Shinto stype is far too agressive and or ill-profiled for my use, even when I made furniture. I suppose on large nearly flat surfaces where cutting to dimension isn't possible is one use such an agressive bandsaw blade rasp would find use, but it doesn't seem as useful as other means.

Let us know how you do and what you eventually use it for. I'm truly curious.

Mike

James White
09-28-2008, 8:07 PM
Walt,

Sorry about that. I didn't realize that you were asking about something different.

James