Author Topic: "jumping" spokeshave  (Read 5623 times)

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Offline Jodocus

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"jumping" spokeshave
« on: June 27, 2012, 09:34:54 am »
Hi all

Sometimes when I work with my spokeshave, the thing gets into a staggering, jumping kind of action, that feels real ugly, and worse, leaves bad tool marks on the surface. I can help it some by pressing the tool harder onto the wood, and by rotating it about 45 degrees so it cuts diagonal to its orientation (does that make sense?). Whenever this happens, after a while, some wood gets stuck between the blade and the tool as well.  >:(

I haven not qute been able to figure out why this happens, I suspect it's got something to do with the orientation of the wood fibers or the wood being not vised firmly enough?

Any help would be appreciated.
Don't shoot!

Offline lostarrow

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Re: "jumping" spokeshave
« Reply #1 on: June 27, 2012, 10:03:12 am »
It's likely the spokeshave itself being poorly tuned . Any "plane" needs the blade seated perfectly flat against the body or frog  of the plane . if you have any room for it to move , it will start to resonate(vibrate) and cause  chatter. Take the blade out  and file the bed of the spokeshave  so it is flat to the  blade (iron) checking your progress frequently. A thicker blade will also help . The tearing out of grain is because the grain itself is contrary ( near a knot?). the throat (opening) on most spoke shaves is usually quite large. It is meant as  a roughing out tool, the  step between a draw knife and a rasp or scraper. The rasp will fatten out the chatter you have and the scraper will smooth the tool marks from the rasp. Hope this helps.
Dave.

Offline aaron

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Re: "jumping" spokeshave
« Reply #2 on: June 27, 2012, 11:42:01 am »
yeah, mine does that too. like he said, tuning may help. Also adjust for a shallower cut. But a spokeshave will always do that to some extent, especially on wavy grain. Like lost arrow said- it's a roughing out tool.
Ilwaco, Washington, USA
"Good wood makes great bows, but bad wood makes great bowyers"

Offline Cbert

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Re: "jumping" spokeshave
« Reply #3 on: June 27, 2012, 12:18:34 pm »
You're planing against the grain. (hence the reason it's resolved when you rotate it 45 deg).  The chunks that you're ripping out while it chatters is litterally called tear out. It couldn't hurt to tune up your spokeshave, but basically you'll just have to 180 your work and hit it from the other way anyhow.

Offline Badger

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Re: "jumping" spokeshave
« Reply #4 on: June 27, 2012, 12:23:27 pm »
     Jod, as you practice more with a spokeshave you will automaticaly change the angle and rotate it to accomadate a good cut. Also a good idea to very slightly crown the area you are working on, should look flat but very slightly crowned will allow the spokeshave to work better, any tool for that matter. Good tuning, sharpening and adjustment are also imperative.
      If I do get an area that has gotten roughed up smetimes I stop and clean it up with a rasp or just work from one edge of it and in one stroke at a time till it is gone.

Offline cracker

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Re: "jumping" spokeshave
« Reply #5 on: June 27, 2012, 04:25:08 pm »
I'm with Badger he's got it figured out. Ron
If we can't help each other what is the point of being here?

Offline John D

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Re: "jumping" spokeshave
« Reply #6 on: June 27, 2012, 05:18:01 pm »
I've experienced the same thing and tried the same things with some success.  One other tactic that has been fairly successful has been to change my rate of cut.  Faster works but I feel more in control with slower.  It works when machining metals, so I thought I'd give it a try. 

Offline Jodocus

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Re: "jumping" spokeshave
« Reply #7 on: June 27, 2012, 05:42:51 pm »
thanks all, I've tried it all out except the tuning thing, cause I just did not get it, sorry.  ???

And it all helped, some. Quite alot all together. Crowning the surface was really a big difference. and not cutting the same surface too many times, just until it's smooth.

good on you for the advice



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Offline JW_Halverson

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Re: "jumping" spokeshave
« Reply #8 on: June 27, 2012, 11:38:32 pm »
Go take a look at your spokeshave.  When you are holding the handles and the tool is being drawn toward you peek down at the blade.  Can you see the bevel from above?  Or can you just see a flat surface from the cutting edge all the way to the adjustment screws at the top?  If so, try tightning the central screw holding the blade down to the bed of the tool. 

Now, if you can see the bevel from above you have a problem.  You have installed the blade upside down.  Take it out and flip it over.  This will present a much sharper tool angle to the wood. 

If you have a Stanley spokeshave, I will betcha dollars to donuts that the tool bed is not flat or flush.  In the past I have used Accra-glas bedding compound to match the two up.  Just doing that tightens things up a great deal. 

The next thing you can do is to hone a razor edge on the blade.  Sharp tools cause less grain tear out. 
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline zdogk9

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Re: "jumping" spokeshave
« Reply #9 on: July 07, 2012, 06:42:08 pm »
a slight arc to the cutting edge of the blade, say 1/32" or 3/64" will also help a lot.

Offline Jodocus

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Re: "jumping" spokeshave
« Reply #10 on: July 07, 2012, 06:49:16 pm »
concave or convex?
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Offline JW_Halverson

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Re: "jumping" spokeshave
« Reply #11 on: July 07, 2012, 06:50:49 pm »
Convex so that it bites in the center of the blade and the corners do not dig in. 
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline vinemaplebows

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Re: "jumping" spokeshave
« Reply #12 on: July 08, 2012, 02:15:42 am »
A slightly held angle when pulling will help a lot....  :)
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