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Posted: Tue Mar 29, 2011 1:41 pm
by JPG
fiatben wrote:Recommended procedure?? I can see putting it in a vise and ending up over-correcting or ending up with a wavy bar. Been looking for a replacement on evil-bay but too much moolah for my resources.
Yes that can happen!:( That is more likely with items that have been 'bent' rather than 'sprung', the difference being the extremeness of the kink. A bent part has acquired 'work hardening' and will bend more easily out of that work hardened area. I doubt the miter bar is 'bent'.
A careful location of the bar in a vise(so that the unbending stress is concentrated in the kink area and application of that stress so as to not apply it elsewhere. A pipe slipped over the end opposite the vise can be positioned to control the stress location.
Finally only try to 'bring it back to straight' a small amount at a time. That allows you go adjust the points of application of the stress. Do not expect 'perfection'!
Meanwhile, back to this biscuit joiner thingy
Posted: Tue Mar 29, 2011 2:53 pm
by fiatben
OK, my biscuit joiner is missing:
pin
pin setscrew
housing collar capscrew
I'm thinking I can make something to function as the pin, and the setscrew is a standard setscrew.
Does anyone know what size the housing collar capscrew is?
and another thing
Posted: Tue Mar 29, 2011 3:23 pm
by fiatben
One of the headless stop screws in themiter gauge's protractor is REALLY stuck. I've soaked it with penetrating oil and still no go. It is so stuck that trying to turn it is not only spreading the screw's slot but actually shearing the thing.
Now what?
Posted: Tue Mar 29, 2011 4:25 pm
by beeg
TRY a little heat on it.
Posted: Tue Mar 29, 2011 5:03 pm
by SDSSmith
http://en.wikipedia.org/wiki/Work_hardeningJPG40504 wrote:Yes that can happen!:( That is more likely with items that have been 'bent' rather than 'sprung', the difference being the extremeness of the kink. A bent part has acquired 'work hardening' and will bend more easily out of that work hardened area. I doubt the miter bar is 'bent'.
A careful location of the bar in a vise(so that the unbending stress is concentrated in the kink area and application of that stress so as to not apply it elsewhere. A pipe slipped over the end opposite the vise can be positioned to control the stress location.
Finally only try to 'bring it back to straight' a small amount at a time. That allows you go adjust the points of application of the stress. Do not expect 'perfection'!
Wow!!! Work hardened??? On the miter gauge bar???I have been out of school for a while so maybe I have forgotten these "technical" terms from my engineering studies.Seems to me that we used a term called "yield". But then again, I am not an electrical engineer.
Posted: Tue Mar 29, 2011 6:52 pm
by JPG
SDSSmith wrote:http://en.wikipedia.org/wiki/Work_hardeningWow!!! Work hardened??? On the miter gauge bar???I have been out of school for a while so maybe I have forgotten these "technical" terms from my engineering studies.Seems to me that we used a term called "yield". But then again, I am not an electrical engineer.
That too(but that is on the bend it in the first place sequence of events).
But then maybe my 'ME' vocabulary is lacking!:eek:
I agree yield is a better 'distinction'(I think(?)) but FGS educate us all!!!;)
Posted: Tue Mar 29, 2011 6:56 pm
by SDSSmith
[quote="JPG40504"]That too(but that is on the bend it in the first place sequence of events).]You are the "educator"!;) The wiki link I included in my last post provide more information on work hardening.
Posted: Tue Mar 29, 2011 8:17 pm
by JPG
SDSSmith wrote:You are the "educator"!]
OK! After all we ARE supposed to be DIY folks!;):D
Posted: Tue Mar 29, 2011 10:07 pm
by JPG
OK so sprung is the result of low stress magnitude force applied at widely distributed locations causing plastic deformation just beyond the elastic limit(yield point) and bent is the result of more localized deformation at a stress magnitude greatly exceeding the elastic limit which results in crystal lattice deformation SIMILAR to that created by repeated plastic flow.
Close enough???
Good grief!!
Posted: Tue Mar 29, 2011 10:27 pm
by fiatben
JPG40504 wrote:OK so sprung is the result of low stress magnitude force applied at widely distributed locations causing plastic deformation just beyond the elastic limit(yield point) and bent is the result of more localized deformation at a stress magnitude greatly exceeding the elastic limit which results in crystal lattice deformation SIMILAR to that created by repeated plastic flow.
Close enough???
Ya know, all I wanted to know was how to fix it easy.... sheesh!!
You guys crack me up!!! I guess that's why I hang around here so much...