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| Bob Engelhardt... |
 Posted: Thu Oct 29, 2009 6:29 pm |
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I have a garden tiller (that I got at the dump). In use it leaves about
a 6" wide untilled strip in the middle. I want to reduce this by
extending the middle blades/tines. The easiest, fastest way is to weld
pieces on. But the tines are pretty hard, to resist being worn down,
and I feel that just welding on them will leave a brittle HAZ.
Will this work: anneal them, weld on the extensions, re-harden, and
temper? I hope so, 'cause the alternative is drilling & bolting and I
find that very unappealing. And sure to work loose.
Thanks,
Bob |
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| Winston... |
| Posted: Thu Oct 29, 2009 7:01 pm |
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| Bob Engelhardt... |
| Posted: Fri Oct 30, 2009 8:23 am |
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Bob Engelhardt wrote:
[quote]...
Will this work: anneal them, weld on the extensions, re-harden, and
temper? ...
[/quote]
Or, can I just weld without annealing, then temper to relieve the HAZ?
Bob |
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| RoyJ... |
| Posted: Fri Oct 30, 2009 8:34 am |
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The steel is likely some .7% to .9% carbon steel. That is going to be
high enough to give you nasty weld issues. But it also begs the question
of what stock are you planning on welding on? Some plain hot rolled bar
stock is not going to cut it.
Option 1 is to weld then completely heat treat. That will leave you with
a lower carbon section in the weld area, it will bend. Option 2 is to
preheat, weld, cool slowly. That will soften the tines, the whole thing
will bend. Option 3 is to weld, cool the joint as slowly as possible.
That will keep the HAZ to something moderate, still likely to bend. I
think I would just weld it up let the joint get hard, use the torch to
temper the joint to around 800 degrees, see if hold up.
Bob Engelhardt wrote:
[quote]I have a garden tiller (that I got at the dump). In use it leaves about
a 6" wide untilled strip in the middle. I want to reduce this by
extending the middle blades/tines. The easiest, fastest way is to weld
pieces on. But the tines are pretty hard, to resist being worn down,
and I feel that just welding on them will leave a brittle HAZ.
Will this work: anneal them, weld on the extensions, re-harden, and
temper? I hope so, 'cause the alternative is drilling & bolting and I
find that very unappealing. And sure to work loose.
Thanks,
Bob[/quote] |
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| Bob Engelhardt... |
| Posted: Fri Oct 30, 2009 11:49 am |
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RoyJ wrote:
[quote]The steel is likely some .7% to .9% carbon steel. That is going to be
high enough to give you nasty weld issues. But it also begs the question
of what stock are you planning on welding on? Some plain hot rolled bar
stock is not going to cut it.
[/quote]
I was to use some OCS (Old Chevy Spring). In fact, the original plan
was to use the OCS to make whole new tines, but there were complications.
[quote]
Option 1 is to weld then completely heat treat. That will leave you with
a lower carbon section in the weld area, it will bend. Option 2 is to
preheat, weld, cool slowly. That will soften the tines, the whole thing
will bend. Option 3 is to weld, cool the joint as slowly as possible.
That will keep the HAZ to something moderate, still likely to bend. I
think I would just weld it up let the joint get hard, use the torch to
temper the joint to around 800 degrees, see if hold up.
[/quote]
Thanks. Not what I *wanted* to hear, but what I needed to hear. The
bottom line seems to be that no matter how I do it, it's likely to be
soft somewhere. Then I'd be stuck & worse off.
Maybe drilling & bolting isn't that bad of an idea. Maybe pinning &
bolting.
Oh, wait - here's an idea: if I do the welding along the edges of the
tines & not across them, then with option 1 or 3 (softness in the HAZ
only) I wouldn't get bending. The leading edge would wear faster, but I
can handle that. Or use plug welds & avoid the soft edges too.
Thanks again,
Bob |
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| RAM³... |
| Posted: Fri Oct 30, 2009 11:58 am |
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Bob Engelhardt <bobengelhardt at (no spam) comcast.net> wrote in
news:hcdc9p02knd at (no spam) news6.newsguy.com:
[quote]I have a garden tiller (that I got at the dump). In use it leaves
about
a 6" wide untilled strip in the middle.
[/quote]
Just a stupid question here, Bob, but did the tiller come with its drag
stake?
This is a metal bar that is fitted between the sets of rotating tines to
both reduce the pullback force and to act as a "middlebuster" as it is
pulled through that untilled strip in the middle.
If it didn't have one, it *should* still have the bracket to which it
would be attached.
A suitable piece of bar stock (.250/.375 x 1.0) can be easily drilled to
make a replacement stake. |
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| Bob Engelhardt... |
| Posted: Fri Oct 30, 2009 12:21 pm |
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RAM³ wrote:
[quote]Just a stupid question here, Bob, but did the tiller come with its drag
stake?
This is a metal bar that is fitted between the sets of rotating tines to
both reduce the pullback force and to act as a "middlebuster" as it is
pulled through that untilled strip in the middle.
If it didn't have one, it *should* still have the bracket to which it
would be attached.
A suitable piece of bar stock (.250/.375 x 1.0) can be easily drilled to
make a replacement stake.
[/quote]
I think we have a winner! You're right - there is a "leg" in the
middle, with drilled holes, but something is missing. I didn't really
accept that the tiller was supposed to leave such a wide strip ... but
there it was.
Now, this "drag stake": would is it supposed to look like, geometry wise?
Thanks!
Bob |
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| TinLizziedl... |
| Posted: Fri Oct 30, 2009 2:15 pm |
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In article <hcfaoa01joq at (no spam) news7.newsguy.com>, bobengelhardt at (no spam) comcast.net
says...
[quote]RAM³ wrote:
Just a stupid question here, Bob, but did the tiller come with its drag
stake?
This is a metal bar that is fitted between the sets of rotating tines to
both reduce the pullback force and to act as a "middlebuster" as it is
pulled through that untilled strip in the middle.
If it didn't have one, it *should* still have the bracket to which it
would be attached.
A suitable piece of bar stock (.250/.375 x 1.0) can be easily drilled to
make a replacement stake.
I think we have a winner! You're right - there is a "leg" in the
middle, with drilled holes, but something is missing. I didn't really
accept that the tiller was supposed to leave such a wide strip ... but
there it was.
Now, this "drag stake": would is it supposed to look like, geometry wise?
Thanks!
Bob
[/quote]
I've seen them made similar to a miniature plow head (like a horizontal
arrowhead with a vertical bar attached at the midline) or built like a
simple "T" shape, with the flanges going to the sides, not front to
back.
It provides a certain amount of drag as it cuts dirt to compensate for
the speed of the tines, otherwise the machine would run away from you,
or on a tractor, it would be pushing you.
Some are adjustable (picture an adjustible hitch setup, where you pull
the pin to slide the bar up/down to set depth), some are fixed.
Geometry is usually designed to either simply provide a leg for the
machine to stand on- avoiding damage to the tines. Or it is designed to
actually dig in (arrowhead shape) and can be adusted for depth control.
Either design should slow down forward velocity and encourage digging by
the tines. Just don't angle the arrowhead too steep-- I would recommend
keeping it within 5 degrees of flat.
Good Luck!
--
Tin Lizzie
"Elephant: A mouse built to government specifications."-Lazarus Long |
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| RoyJ... |
| Posted: Fri Oct 30, 2009 3:50 pm |
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On mine the drag bar is angled at about 15 degrees off vertical, facing
forward. It is completely free to pivot forward, locked so it cannot go
past the operating position. In use you jam it into the ground to
counteract the tines, lift up slightly on the handlebars to let it claw
forward, then push down on the handlebars. When you come to the end of a
row you shut off the tines, pull back, the drag bar pivots out of the
way. For transport, the drag bar has an extra hole that lets you
position it out of the way, just drive it on the tongs.
My unit is buried (deeply ) in the shed, IIRC it is 3/8" x 2" plain bar
stock (not hardened) with a 45 degree cut on the business end, holes
abut every 2" for depth adjustment,and the aforementioned transport hole.
Bob Engelhardt wrote:
[quote]RAM³ wrote:
Just a stupid question here, Bob, but did the tiller come with its
drag stake?
This is a metal bar that is fitted between the sets of rotating tines
to both reduce the pullback force and to act as a "middlebuster" as it
is pulled through that untilled strip in the middle.
If it didn't have one, it *should* still have the bracket to which it
would be attached.
A suitable piece of bar stock (.250/.375 x 1.0) can be easily drilled
to make a replacement stake.
I think we have a winner! You're right - there is a "leg" in the
middle, with drilled holes, but something is missing. I didn't really
accept that the tiller was supposed to leave such a wide strip ... but
there it was.
Now, this "drag stake": would is it supposed to look like, geometry wise?
Thanks!
Bob[/quote] |
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| Bob Engelhardt... |
| Posted: Fri Oct 30, 2009 6:11 pm |
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TinLizziedl wrote:
[quote]I've seen them made similar to a miniature plow head (like a horizontal
arrowhead with a vertical bar attached at the midline) or built like a
simple "T" shape, with the flanges going to the sides, not front to
back.
It provides a certain amount of drag as it cuts dirt to compensate for
the speed of the tines, otherwise the machine would run away from you,
or on a tractor, it would be pushing you.
Some are adjustable (picture an adjustible hitch setup, where you pull
the pin to slide the bar up/down to set depth), some are fixed.
Geometry is usually designed to either simply provide a leg for the
machine to stand on- avoiding damage to the tines. Or it is designed to
actually dig in (arrowhead shape) and can be adusted for depth control.
Either design should slow down forward velocity and encourage digging by
the tines. Just don't angle the arrowhead too steep-- I would recommend
keeping it within 5 degrees of flat.
Good Luck!
[/quote]
I just took another look at my bar. It is L-shaped with the long
vertical leg drilled every inch or so for height adjustment (held by a
pin). The short horizontal leg has 2 holes that must have held the
breaker bar. E.g., a plow or arrow.
I had assumed that this was just a leg to keep the tines at a certain
depth. Although it didn't work real well for that.
Something I didn't mention is that the tiller is rear tined & self
propelled (driven wheels). So that it doesn't need to be held back - it
goes at the wheel speed.
Thanks,
Bob |
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| Bob Engelhardt... |
| Posted: Fri Oct 30, 2009 6:16 pm |
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Guest
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RoyJ wrote:
[quote]On mine the drag bar is angled at about 15 degrees off vertical, facing
forward. It is completely free to pivot forward, locked so it cannot go
past the operating position. In use you jam it into the ground to
counteract the tines, lift up slightly on the handlebars to let it claw
forward, then push down on the handlebars. When you come to the end of a
row you shut off the tines, pull back, the drag bar pivots out of the
way. For transport, the drag bar has an extra hole that lets you
position it out of the way, just drive it on the tongs.
My unit is buried (deeply ) in the shed, IIRC it is 3/8" x 2" plain bar
stock (not hardened) with a 45 degree cut on the business end, holes
abut every 2" for depth adjustment,and the aforementioned transport hole.
[/quote]
Thanks, I think that I have the picture now. Mine isn't angled (much,
at any rate) & doesn't pivot, for sure. And has a trailing leg that
held some kind of cutter, I think.
I'm going to make up a cutter to bolt on & try it. WAY easier than the
tine extensions that I was planning!!
Bob |
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| dan... |
| Posted: Sun Nov 01, 2009 8:33 pm |
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What's that Lassie? You say that Bob Engelhardt fell down the old
sci.engr.joining.welding mine and will die if we don't mount a rescue
by Fri, 30 Oct 2009 20:16:50 -0400:
[quote]Thanks, I think that I have the picture now. Mine isn't angled (much,
at any rate) & doesn't pivot, for sure. And has a trailing leg that
held some kind of cutter, I think.
I'm going to make up a cutter to bolt on & try it. WAY easier than the
tine extensions that I was planning!!
[/quote]
If you ever do need to weld something to high carbon steel, my old
welding text book says:
Pre-heat to 700-900 F., use a nickel rod for ductility, cool slow.
--
Dan H.
northshore MA. |
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