Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Default Odd clamping jig/workholder

I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.

LLoyd
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On May 26, 11:38*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? *There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.

LLoyd



This seems to be a post in need of a question, "why?". Takes me about
5 minutes to sharpen blades and balance using a belt grinder. Using a
mill would seem to be a use of an inappropriate tool.

Stan
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On 05/26/2010 10:47 AM, wrote:
On May 26, 11:38 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings"& turbulence slots get in the way.

LLoyd



This seems to be a post in need of a question, "why?". Takes me about
5 minutes to sharpen blades and balance using a belt grinder. Using a
mill would seem to be a use of an inappropriate tool.


Ditto. Not only would a mill -- if you could use it properly -- be way
more precision than is ever necessary to whack a grass stem in two, but
if the blade is decently hardened at all you'd have to use some fancy
extra-hard cutter and hold the work a lot closer to the cut than you're
proposing.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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On 05/26/2010 10:38 AM, Lloyd E. Sponenburgh wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings"& turbulence slots get in the way.


Ignoring the more important issue (why???), are those turbulence slots
wide enough to get a bolt through, to use for clamping? 6" of overhang
is going to guarantee chatter -- possibly deathly to the milling tool --
regardless of the rigidity of the thing that's holding your springy
piece of metal that far from where the cut is being attempted.

How about casting a zinc or lead (or solder!) bed for the blade, and
clamping to that? Cast it over the back side of the blade, using a
suitable method* to keep it from sticking, then mill its bottom side to
the angle you want. Then use some sort of "reach over and push hard"
clamp to hold the work.

You definitely want something that snubs the metal up tight to the
working surface of the blade, or the darn thing will vibrate like a reed.

* Note that I don't know the best way to do this -- really wanting it to
stick generally works quite effectively when I'm soldering, but that's
hard to apply here.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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On May 26, 10:38*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),

....
way to clamp the blades at a "tilt", yet still hold them well enough


I've made aluminum blocks with vee slots, and tapped in wedges, to
clamp flat items in similar situations. If you can find a good
flat surface on a mower blade, that'll work.

Otherwise, bore a couple of holes in inconspicuous places, and
bolt the blade down to a block that's easy to clamp down (or hold
in a vise). You'll want to whittle the block to get the angles just
right. Don't use weak bolts.


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"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

snip

Sorry, that doesn't make good sense. A quick grind with an angle grinder or
a belt sander it a more appropriate fix. When I HAD grass, I alternated
between two blades, I bought the spare on sale for $5.00. Now I just have
flowers and river rock. I am planting a 8'x10' patch of grass for the
little doggy to ruin, I'll just weed-whack it.


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Default Odd clamping jig/workholder

On Wed, 26 May 2010 14:23:05 -0400, "Buerste"
wrote:


"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
.3.70...
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

snip

Sorry, that doesn't make good sense. A quick grind with an angle grinder or
a belt sander it a more appropriate fix. When I HAD grass, I alternated
between two blades, I bought the spare on sale for $5.00. Now I just have
flowers and river rock. I am planting a 8'x10' patch of grass for the
little doggy to ruin, I'll just weed-whack it.

For that size, you could use scissors and a ruler.
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Tim Wescott fired this volley in
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On 05/26/2010 10:47 AM, wrote:
On May 26, 11:38 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the
head just wouldn't work well in this app, because my Y travel isn't
enough), and the jig/workholder must be "indexable" in the sense
that I must flip the blades end-for-end to grind both ends, yet get
the same position from center each time.

No problem on the indexing, but has anyone a good idea for a very
simple way to clamp the blades at a "tilt", yet still hold them well
enough to reduce the chatter? There is a requisite overhang of
about 6" from the jig to the end of the blade, because there's
nothing on the ends you can clamp to -- little "lift wings"&
turbulence slots get in the way.

LLoyd



This seems to be a post in need of a question, "why?". Takes me
about 5 minutes to sharpen blades and balance using a belt grinder.
Using a mill would seem to be a use of an inappropriate tool.


Ditto. Not only would a mill -- if you could use it properly -- be
way more precision than is ever necessary to whack a grass stem in
two, but if the blade is decently hardened at all you'd have to use
some fancy extra-hard cutter and hold the work a lot closer to the cut
than you're proposing.


To both of you. These are high tip speed blades for a commercial mower.
The manufacturer _recommends_ milling them instead of grinding, and
offers suggestions for cutter inserts -- which I have. The tool and the
mill are already in my shop. I just need a way to hold the blades.

(and if you've ever looked, all commercial blades are milled, not ground)

LLoyd
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"Buerste" fired this volley in
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Sorry, that doesn't make good sense. A quick grind with an angle
grinder or a belt sander it a more appropriate fix. When I HAD grass,
I alternated between two blades, I bought the spare on sale for $5.00.
Now I just have flowers and river rock. I am planting a 8'x10' patch
of grass for the little doggy to ruin, I'll just weed-whack it.



Read my reply to the same above. The manufacturer recommends milling. I
mow 6 acres of Bahaia a week. That's a set to sharpen every week.

LLoyd
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On May 26, 12:38*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? *There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.

LLoyd


Two angle vises with spacers for the irregular surfaces?
http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3


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"Denis G." fired this volley in
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Two angle vises with spacers for the irregular surfaces?
http://www.use-enco.com/CGI/INSRIT?P...24730480&PARTP
G=INLMK3



Now, that's a good idea. Cut away part of one to make room for the fins.

LLoyd
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On 05/26/2010 12:31 PM, Lloyd E. Sponenburgh wrote:
fired this volley in
:

Sorry, that doesn't make good sense. A quick grind with an angle
grinder or a belt sander it a more appropriate fix. When I HAD grass,
I alternated between two blades, I bought the spare on sale for $5.00.
Now I just have flowers and river rock. I am planting a 8'x10' patch
of grass for the little doggy to ruin, I'll just weed-whack it.



Read my reply to the same above. The manufacturer recommends milling. I
mow 6 acres of Bahaia a week. That's a set to sharpen every week.


If that's the case then my suggestion to make a fixture specific to the
blade is all the more sensible. Keep it on a nail on the wall behind
the mill, and every week you can take it down and get the job done in
quickly and efficiently.

Only you probably want to use something more wear-resistant than lead or
zinc -- I was thinking you wanted this for a one-time deal; I hadn't
imagined that there were mower blades that demanded being milled instead
of ground free hand.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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On Wed, 26 May 2010 12:38:24 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.

LLoyd


How big an angle plate do you have?

Gunner


--


"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost
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"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"Buerste" fired this volley in
:

Sorry, that doesn't make good sense. A quick grind with an angle
grinder or a belt sander it a more appropriate fix. When I HAD grass,
I alternated between two blades, I bought the spare on sale for $5.00.
Now I just have flowers and river rock. I am planting a 8'x10' patch
of grass for the little doggy to ruin, I'll just weed-whack it.



Read my reply to the same above. The manufacturer recommends milling. I
mow 6 acres of Bahaia a week. That's a set to sharpen every week.

LLoyd


Well, that changes everything! Tear out the grass and plant Pot.


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In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

Tim Wescott fired this volley in
:

On 05/26/2010 10:47 AM, wrote:
On May 26, 11:38 am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the
head just wouldn't work well in this app, because my Y travel isn't
enough), and the jig/workholder must be "indexable" in the sense
that I must flip the blades end-for-end to grind both ends, yet get
the same position from center each time.

No problem on the indexing, but has anyone a good idea for a very
simple way to clamp the blades at a "tilt", yet still hold them well
enough to reduce the chatter? There is a requisite overhang of
about 6" from the jig to the end of the blade, because there's
nothing on the ends you can clamp to -- little "lift wings"&
turbulence slots get in the way.

LLoyd


This seems to be a post in need of a question, "why?". Takes me
about 5 minutes to sharpen blades and balance using a belt grinder.
Using a mill would seem to be a use of an inappropriate tool.


Ditto. Not only would a mill -- if you could use it properly -- be
way more precision than is ever necessary to whack a grass stem in
two, but if the blade is decently hardened at all you'd have to use
some fancy extra-hard cutter and hold the work a lot closer to the cut
than you're proposing.


To both of you. These are high tip speed blades for a commercial mower.
The manufacturer _recommends_ milling them instead of grinding, and
offers suggestions for cutter inserts -- which I have. The tool and the
mill are already in my shop. I just need a way to hold the blades.

(and if you've ever looked, all commercial blades are milled, not ground)


Well, I have a 21" commercial Honda mower, and yes the blade edges were milled,
but I clamp them with a bench vice and sharpen them with a BIG mill file. The
file has no problem cutting the blade metal, which is quite soft, so the blades
won't shatter when they hit a rock. Anyway, I would make a fixture out of a
hardwood like Oak (for the damping) with metal clamps of some kind, and use an
ordinary HSS cutter.

Joe Gwinn


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Joseph Gwinn fired this volley in
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Anyway, I would make a fixture out of a
hardwood like Oak (for the damping) with metal clamps of some kind,
and use an ordinary HSS cutter.


The wood jig is a good idea for its vibration damping characteristics.
Total rigidity isn't a really big deal, since finish isn't terribly
important; just angle and balance. One thing they state as important as
that there be no "camber" in the angle. It needs to be flat. Apparently
(from other searches I've done) mower manufacturers work quite hard to
optimize their blade edges for angle and lift.

But the HSS isn't the recommended MOSN PVD inserts recommended for this
particular alloy. And I have them already...

LLoyd
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I want to put mine on my surface grinder.

A mill - the blade is to hard for milling.

Sure someone can do it with the right horse power and process.
Quarts rock/sand is what rounds them over. Quarts is harder than steel.

A mill should have sine bars and sine bar type wedges of all sorts of
degrees.

Martin


Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
"Our Republic and the Press will Rise or Fall Together": Joseph Pulitzer
TSRA: Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Charter Founder
IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com/

On 5/26/2010 12:38 PM, Lloyd E. Sponenburgh wrote:
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings"& turbulence slots get in the way.

LLoyd

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"Martin H. Eastburn" fired this volley in
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I want to put mine on my surface grinder.

A mill - the blade is to hard for milling.


Horse ****, Martin. Lawnmower blades are deliberately made on the soft-
temper side to prevent them from shattering upon hitting hard objects.

I don't get it: A whole bunch of "metal" guys telling me that a tool
designed to hit concrete at 270MPH without breaking is also too hard to
cut with ordinary milling bits...

sigh

Of all the crap (I _mean_ crap) I've gotten from this post, there have
only been two constructive posts; both from guys who seldom post, but who
obviously read before they do.

The rest of the "experts" have decided that 1) the manufacturers of mower
blades don't know what they're doing, and 2) tools don't exist to mill
medium temper carbon steel.

I guess it give me a perspective on the guys who respond vs. the guys who
actually do metalwork.

LLoyd
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In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

Joseph Gwinn fired this volley in
:

Anyway, I would make a fixture out of a
hardwood like Oak (for the damping) with metal clamps of some kind,
and use an ordinary HSS cutter.


The wood jig is a good idea for its vibration damping characteristics.
Total rigidity isn't a really big deal, since finish isn't terribly
important; just angle and balance. One thing they state as important as
that there be no "camber" in the angle. It needs to be flat. Apparently
(from other searches I've done) mower manufacturers work quite hard to
optimize their blade edges for angle and lift.


I wonder how critical it really is, so long as both ends of the blade are the
same, so the blade remains aerodynamically and kinetically balanced.


But the HSS isn't the recommended MOSN PVD inserts recommended for this
particular alloy. And I have them already...


Which alloy is that? I expect that the Honda blades are 1018 or the like,
judging from the feel while filing.

But I'm sure your inserts will work just fine.

Joe Gwinn
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On Wed, 26 May 2010 12:38:24 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.

LLoyd


Lift wing turbulence slots are often a nuisance, aren't they!


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Joseph Gwinn fired this volley in
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Which alloy is that? I expect that the Honda blades are 1018 or the
like, judging from the feel while filing.


I don't know what the alloy is, they only state which inserts are
recommended for their blades. But yes, it does feel like 1018 or such.
Files easily, but has good toughness; mills like a dream if you limit feed
depth.

LLoyd
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Don Foreman fired this volley in
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Lift wing turbulence slots are often a nuisance, aren't they!


Heh! Well... they never really bothered me much before now, although I
admired them from afar. G

LLoyd
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It can be 4-500 BHN and still take a licking and eat up cutters.

I cut Abrasion resistant steel for a business. AR-400. It is easier
to grind than the good blade.

I bought a set of blades that didn't have a hole but a cloverleaf
to mount it. I'll have to grind it - but that won't be true to center.

So the steel will be used to harden surface needs.

You might have cheap blades that are not keeping an edge long.

I have a 54" triple blade mower myself.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
"Our Republic and the Press will Rise or Fall Together": Joseph Pulitzer
TSRA: Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Charter Founder
IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com/

On 5/26/2010 8:57 PM, Lloyd E. Sponenburgh wrote:
"Martin H. fired this volley in
:


I want to put mine on my surface grinder.

A mill - the blade is to hard for milling.


Horse ****, Martin. Lawnmower blades are deliberately made on the soft-
temper side to prevent them from shattering upon hitting hard objects.

I don't get it: A whole bunch of "metal" guys telling me that a tool
designed to hit concrete at 270MPH without breaking is also too hard to
cut with ordinary milling bits...

sigh

Of all the crap (I _mean_ crap) I've gotten from this post, there have
only been two constructive posts; both from guys who seldom post, but who
obviously read before they do.

The rest of the "experts" have decided that 1) the manufacturers of mower
blades don't know what they're doing, and 2) tools don't exist to mill
medium temper carbon steel.

I guess it give me a perspective on the guys who respond vs. the guys who
actually do metalwork.

LLoyd

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Buerste wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
I've got a tough-dog clamping job to do.

I want to mill my lawnmower blades, rather than grind them.

snip

Sorry, that doesn't make good sense. A quick grind with an angle grinder or
a belt sander it a more appropriate fix. When I HAD grass, I alternated
between two blades, I bought the spare on sale for $5.00. Now I just have
flowers and river rock. I am planting a 8'x10' patch of grass for the
little doggy to ruin, I'll just weed-whack it.



Just because your little doggie ruins your grass, is no reason to
weed-whack it. ;-)


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
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Default Odd clamping jig/workholder

"Martin H. Eastburn" fired this volley in
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You might have cheap blades that are not keeping an edge long.


A) You've apparently not ever cut dry Bahaia. 6-10 acres per sharpening is
about as good as it will ever get. The stuff's like cutting plastic-coated
wire.

B) Nothing Scag makes is "cheap" either in quality or price.

LLoyd


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Default Odd clamping jig/workholder

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

I want to mill my lawnmower blades, rather than grind them.

The blades must be mounted at an angle to the table (tilting the head
just wouldn't work well in this app, because my Y travel isn't enough),
and the jig/workholder must be "indexable" in the sense that I must flip
the blades end-for-end to grind both ends, yet get the same position from
center each time.

No problem on the indexing, but has anyone a good idea for a very simple
way to clamp the blades at a "tilt", yet still hold them well enough to
reduce the chatter? There is a requisite overhang of about 6" from the
jig to the end of the blade, because there's nothing on the ends you can
clamp to -- little "lift wings" & turbulence slots get in the way.



I went looking for a picture of your mowers blades. Not a very nice item to clamp on.

If yours look like the one I saw there is a very small flat between the sharp end and the
lift wings.

Which model so you have so I can look into this a bit more?

The one I looked at had a flat section under the edge that a tee shaped parallel and an
angle vise could hold.

Wes

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Default Odd clamping jig/workholder

Wes fired this volley in
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I went looking for a picture of your mowers blades. Not a very nice
item to clamp on.

If yours look like the one I saw there is a very small flat between
the sharp end and the lift wings.

Which model so you have so I can look into this a bit more?


It is the Scag Turf Tiger 61".

But I have the jig made, and sharpened two sets of three blades today.

So far, I'm just using step-block and tee-nut hold-downs on the work, and
it's fine -- no chatter or motion.

Since that worked, I'm going to drill the jig block for some permanent
built-in clamps, so I don't have to fiddle with the silly step blocks
every time I flip a blade.

The jig ended up being pretty simple. It's just a tapered "saddle" for
the entire business end of the blade. It's got a rear edge stop milled
in so that the work can be forcefully pushed down into the stop by the
clamps.

The wing end didn't turn out to be as tricky as it looks. A narrow hold-
down just fits in the valley of the bend, and is just barely out of the
way enough so that the mill misses it as it goes by the tip.

Works good!

I did one set that had never been re-ground with excellent results, and
almost no re-balancing to do afterwards. (same depth of cut on both ends,
means the same amount of metal is left after).

Then I re-did a set that had been "licked with a file", "belt sanded", or
"touched up with an angle grinder", as recommended previously here on the
list.

Of course, following human nature, the person who had sharpened them only
worked out the dull part - the part furthest out to the tip - leaving the
blades slightly tapered along the bevels.

That took more passes to fix, and now there's a distinct "inset" of the
cutting edge from the old leading edge. But they're straight, sharp, and
again, they balanced almost perfectly on the first try.

LLoyd
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