I have a General 50-185M1 table saw. The arbor is held to the top by 4
5/16 bolts, two in front and two in rear. Both of the rear bolts have
stripped the threads from the cast iron table top. One of the bolts had
obviously been cross threaded when the saw was manufactured. Saw is out
of warranty.
Does anyone here have experience with repairing something like this? I
would appreciate some advice on how to go about getting this fixed. I
have no experience with metal working.
Ray
On May 2, 1:27 pm, Ray Miller <margo68@ComcastdotNet> wrote:
> I have a General 50-185M1 table saw. The arbor is held to the top by 4
> 5/16 bolts, two in front and two in rear. Both of the rear bolts have
> stripped the threads from the cast iron table top. One of the bolts had
> obviously been cross threaded when the saw was manufactured. Saw is out
> of warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
If there's enough "meat" left in the cast iron, you could drill out to
the next larger bolt, then tap new threads. Another possibility might
be Helicoil inserts, rather expensive, available at your local auto
parts store. HTH. Tom
Wed, May 2, 2007, 1:50pm (EDT-3) [email protected] (tom) doth sayeth:
If there's enough "meat" left in the cast iron, you could drill out to
the next larger bolt, then tap new threads. Another possibility might be
Helicoil inserts, rather expensive, available at your local auto parts
store.
Helicoil, I couldn't remember the name. I think they're available
at real hardware stoers too. Should be able to get them on-line.
Might even be able to just tap new threads without drilling first,
depends.
Might be able to weld it, drill a hole, and tap new threads. But
for something that you're talking a professional doing the work and
expensive. I'd save this option for last.
Or, maybe you could just buy a new, or used, part.
JOAT
What is life without challenge and a constant stream of new
humiliations?
- Peter Egan
On Wed, 2 May 2007 17:26:15 -0400, [email protected] (J T)
wrote:
>Wed, May 2, 2007, 1:50pm (EDT-3) [email protected] (tom) doth sayeth:
>If there's enough "meat" left in the cast iron, you could drill out to
>the next larger bolt, then tap new threads. Another possibility might be
>Helicoil inserts, rather expensive, available at your local auto parts
>store.
>
> Helicoil, I couldn't remember the name. I think they're available
>at real hardware stoers too. Should be able to get them on-line.
>
> Might even be able to just tap new threads without drilling first,
>depends.
>
> Might be able to weld it, drill a hole, and tap new threads. But
>for something that you're talking a professional doing the work and
>expensive. I'd save this option for last.
>
> Or, maybe you could just buy a new, or used, part.
>
>
>
>JOAT
>What is life without challenge and a constant stream of new
>humiliations?
>- Peter Egan
If it vis a through hole what would be wrong with a longer bolt with a
nut? jesse
Thu, May 3, 2007, 2:28am (EDT+4) [email protected] (Jesse)doth query:
If it vis a through hole what would be wrong with a longer bolt with a
nut?
You asking me? Could well be, but being as I'm not really familiar
with his machine, or there to look at it, can't say for sure.
JOAT
What is life without challenge and a constant stream of new
humiliations?
- Peter Egan
The nut would probably get in the way of running a board through
the table saw. I would just as soon not have a hole drilled
through the top of mine. You do know that the arbor brackets are
fastened to the top!
--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
[email protected]
"Jesse" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 2 May 2007 17:26:15 -0400, [email protected] (J
> T)
> wrote:
>
>>Wed, May 2, 2007, 1:50pm (EDT-3) [email protected] (tom) doth
>>sayeth:
>>If there's enough "meat" left in the cast iron, you could drill
>>out to
>>the next larger bolt, then tap new threads. Another possibility
>>might be
>>Helicoil inserts, rather expensive, available at your local auto
>>parts
>>store.
>>
>> Helicoil, I couldn't remember the name. I think they're
>> available
>>at real hardware stoers too. Should be able to get them
>>on-line.
>>
>> Might even be able to just tap new threads without drilling
>> first,
>>depends.
>>
>> Might be able to weld it, drill a hole, and tap new
>> threads. But
>>for something that you're talking a professional doing the work
>>and
>>expensive. I'd save this option for last.
>>
>> Or, maybe you could just buy a new, or used, part.
>>
>>
>>
>>JOAT
>>What is life without challenge and a constant stream of new
>>humiliations?
>>- Peter Egan
> If it vis a through hole what would be wrong with a longer bolt
> with a
> nut? jesse
On May 2, 4:27 pm, Ray Miller <margo68@ComcastdotNet> wrote:
> I have a General 50-185M1 table saw. The arbor is held to the top by 4
> 5/16 bolts, two in front and two in rear. Both of the rear bolts have
> stripped the threads from the cast iron table top. One of the bolts had
> obviously been cross threaded when the saw was manufactured. Saw is out
> of warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
Sorry to hear about your troubles. Good advice from everyone
especially Paul.
IIRC Helicoils aren't that difficult to install but I've only
installed helicoils in Al heads for spark plugs. Kit came with a tap
that didn't require drilling (Al head) and an installing tool for
screwing in the coil. This approach, as was said, will depend on how
much meat is left around each hole.
Whatever you try GO SLOW, once something breaks off in the hole you
have cut you chances of a good fix drastically.
Also keep in mind that you can find a contractor saw on Craigslist for
around $100.
On May 2, 9:39 pm, Ray Miller <margo68@ComcastdotNet> wrote:
> Thanks to all responders. Looks like heli-coils are the way to go. I
> called a lical machine shop and they also agreed that was the best bet
> and they are willing to do it for about $30. Since they have the tools
> and experience with this product I will let them do it. They also can
> recover more easily if something breaks.
>
> Ray
Great deal! Let us know how it works out.
On 3 May, 02:21, Lew Hodgett <[email protected]> wrote:
> I would not try to do this repair with hand tools.
I would. An old hand-cranked flywheel bench pillar drill is the
_perfect_ tool for carefully and accurately recovering and tapping
holes in cast iron. A suitably modified baseplate and shortened column
allows you to "drill through its feet".
If you're regularly involved in resurrecting old iron (typically old
steam engines), then it's well worth setting up such a machine for
this task. They're not that hard to find (eBay, plant auctions etc.)
and the extra control of hand-crank over power is a better way to do
it.
Also remember that not all "helicoils" are genuine Helicoils.
Helicoils are a coil of shaped spring wire, most of the "spark-plug
recoverers" are solid bushes. It's well worth paying the money for a
real Helicoil compared to a cheapy, even if thise means paying for the
guy who already owns the magic Helicoil tap to do it, rather than
doing it yourself from a kit with a disposable tap. Wire spiral
inserts lose a lot less radius than bushes do. Helicoil's shaped wire
gives a much stronger installation into cast iron than a simpler wire
profile that uses a standard tapping thread.
Ray Miller wrote:
> I have a General 50-185M1 table saw. The arbor is held to the top by 4
> 5/16 bolts, two in front and two in rear. Both of the rear bolts have
> stripped the threads from the cast iron table top. One of the bolts had
> obviously been cross threaded when the saw was manufactured. Saw is out
> of warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
>
Have a competent machine shop look at the problem and suggest the repair.
Done.
Probable fixes are to fill the hole with threaded rod and re-tap or to
install helicoil inserts. Have a machine shop do them. Preferably one
where most of the guys look to have showered recently. Neither will be
cheap. Either will be cheaper than buying a new table top.
--
http://nmwoodworks.com/cube
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The Davenport's wrote:
> "LDR" <[email protected]> wrote in message
> news:[email protected]...
>> In article <[email protected]>,
>> [email protected] says...
>>> Ray Miller wrote:
>>> > Thanks to all responders. Looks like heli-coils are the way to go. I
>>> > called a lical machine shop and they also agreed that was the best bet
>>> > and they are willing to do it for about $30.
>>>
>>> I call that a VERY good deal.
>>>
>>> Lew
>>>
>> (piggyback)
>>
>> What nobody mentioned--probably because it likely would not work--is to
>> chase the thread with a same-size tap. More than once, I have thought
>> threads ruined and chasing brought them back to life. Anyway, the
>> machine shop must be owned by your brother; I can't imagine them doing
>> anything for $30. :-)
>
>
> Actually, this is about what we'd charge at the shop I work at. It is a
> pretty quick fix for people that do it on a regular basis. If you brought
> just the top in and it was ready to be fixed, it would likely be done before
> you could go to McDonald's and get a Big Mac.
>
> Mike
>
It's a lunch-time fix but I would probably charge him $10 a hole.
Bridgeport. Clamps. Indicator. Gage pin(s) to locate the holes. Drill.
Tap. Helicoil. Needing to eat my baloney sandwich when the boss wasn't
looking. Yeah ... about $10 a hole. ;-)
--
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Ray Miller wrote:
> I have a General 50-185M1 table saw.
<snip>
As has been mentioned by others, Helicols.
I would not try to do this repair with hand tools.
Knock the saw down so you can get the table in a drill press, better
yet, a universal milling machine, to install the Helicols.
You get one shot at this one, IMHO, do it right.
Have fun.
Lew
Thanks to all responders. Looks like heli-coils are the way to go. I
called a lical machine shop and they also agreed that was the best bet
and they are willing to do it for about $30. Since they have the tools
and experience with this product I will let them do it. They also can
recover more easily if something breaks.
Ray
Take the part to an auto repair shop or lawnmower mechanic and he will
heli-coil it which is a permanent fix. Or you can buy the kit and do it your
self. It involves drilling and tapping. If you don't have any experience
with this don't try it unless you practice on something else. Too bad you're
not close to Norfolk Ne. I'd do it for you cheap.
"Ray Miller" <margo68@ComcastdotNet> wrote in message
news:[email protected]...
>I have a General 50-185M1 table saw. The arbor is held to the top by 4
>5/16 bolts, two in front and two in rear. Both of the rear bolts have
>stripped the threads from the cast iron table top. One of the bolts had
>obviously been cross threaded when the saw was manufactured. Saw is out of
>warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
In article <[email protected]>,
[email protected] says...
> Ray Miller wrote:
> > Thanks to all responders. Looks like heli-coils are the way to go. I
> > called a lical machine shop and they also agreed that was the best bet
> > and they are willing to do it for about $30.
>
> I call that a VERY good deal.
>
> Lew
>
(piggyback)
What nobody mentioned--probably because it likely would not work--is to
chase the thread with a same-size tap. More than once, I have thought
threads ruined and chasing brought them back to life. Anyway, the
machine shop must be owned by your brother; I can't imagine them doing
anything for $30. :-)
Ray Miller wrote:
> I have a General 50-185M1 table saw. The arbor is held to the top by 4
> 5/16 bolts, two in front and two in rear. Both of the rear bolts have
> stripped the threads from the cast iron table top. One of the bolts had
> obviously been cross threaded when the saw was manufactured. Saw is out
> of warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
This is one reason I've always been a big fan of studs vs. bolts .. ..
screw in a stud with Lock-tite and it's there forever. Cast iron tends
to shed it's threads if over-torqued a few times.
That said, I would try to drill & tap for a bushing .. the size you
drill/tap will depend on what brand/type of bushing you use.
Heli-coil, keensert, several others to choose from. Unless you are
unusually adept at drilling/tapping perfectly straight holes in confined
spaces, it would probably be best to remove the top and perform these
tasks in a drill press.
If the through-holes in the trunnion are big enough, you may be able to
jump up a size or two, drill/tap and be done with it.
I would definitely not weld up the hole and try to drill/tap back to the
original size. Cast iron does not like to be welded .. .. cracks and
warping will happen if not done correctly.
Again .. once you get the bad hole repaired, I'd replace all the bolts
with studs, LocTite'd in place. If you ever need to make adjustments
in the future (and you will) the bolts take the punishment, not the casting.
Ray,
I agree that one approach is to use the helicoil. But be aware that
you will likely need a special tap for the helicoil. Some helicoils, not all
need a special tool to insert them. And you still have to drill the hole
out. Typically the helicoil approach needs more side wall material that can
be sacrificed to make the hole big enough to fit the helicoil in.
For the "other" approach, yes you will need enough side wall material to
tap to the next size. Just make sure you use the right size drill. Not
everyone has drill sets with the correct size. When you drill the hole out
make sure that you drill as straight on as you can. If you have the access
to a drill press, take the part off and use the drill press. The results
will be better. Also use a drilling lubricate such as "Tap magic". Holes
like this have been known to have the drill bit grab and then break. The
same goes for the taping of the hole. If the hole is not a through hole then
you will need a "bottoming" tap. This tap has a squared off head so you can
thread as close to the bottom of the hole as possible.
What every the approach used take your time. Do not drill at high speed,
less chance of the drill breaking. I figger you have one shot at fixing
this. Good luck
Paul
"Ray Miller" <margo68@ComcastdotNet> wrote in message
news:[email protected]...
>I have a General 50-185M1 table saw. The arbor is held to the top by 4
>5/16 bolts, two in front and two in rear. Both of the rear bolts have
>stripped the threads from the cast iron table top. One of the bolts had
>obviously been cross threaded when the saw was manufactured. Saw is out of
>warranty.
>
> Does anyone here have experience with repairing something like this? I
> would appreciate some advice on how to go about getting this fixed. I
> have no experience with metal working.
>
> Ray
On Wed, 02 May 2007 18:39:36 -0700, Ray Miller <margo68@ComcastdotNet>
wrote:
>Thanks to all responders. Looks like heli-coils are the way to go. I
>called a lical machine shop and they also agreed that was the best bet
>and they are willing to do it for about $30. Since they have the tools
>and experience with this product I will let them do it. They also can
>recover more easily if something breaks.
>
>Ray
Good decision!!
On Wed, 02 May 2007 13:27:50 -0700, Ray Miller <margo68@ComcastdotNet>
wrote:
>I have a General 50-185M1 table saw. The arbor is held to the top by 4
>5/16 bolts, two in front and two in rear. Both of the rear bolts have
>stripped the threads from the cast iron table top. One of the bolts had
>obviously been cross threaded when the saw was manufactured. Saw is out
>of warranty.
>
>Does anyone here have experience with repairing something like this? I
>would appreciate some advice on how to go about getting this fixed. I
>have no experience with metal working.
You're just going to have to retap the holes for a slightly larger
bolt and perhaps drill out the arbor mounting holes as well to accept
the larger bolt. Outside of replacing the entire top, that's really
your only option. Luckily, it's not that hard to do and I'm sure you
could find someone locally to do it for you if you wanted to go that
way.
In article <[email protected]>,
Ray Miller <margo68@ComcastdotNet> wrote:
>I have a General 50-185M1 table saw. The arbor is held to the top by 4
>5/16 bolts, two in front and two in rear. Both of the rear bolts have
>stripped the threads from the cast iron table top. One of the bolts had
>obviously been cross threaded when the saw was manufactured. Saw is out
>of warranty.
>
>Does anyone here have experience with repairing something like this? I
>would appreciate some advice on how to go about getting this fixed. I
>have no experience with metal working.
>
>Ray
A couple choices here: If the trunnion hangers will accept 3/8" bolts,
you can drill out the 5/16 holes in the top and tap them for 3/8-16 or
3/8-24 threads, or possibly an appropriate metric size. Another,
perhaps easier way, which will also make it easier to adjust the
trunnions, is to drill right on through the stripped holes, out through
the top of the table. Countersink or counter bore the holes on the top
side so the bolt heads will be flush or slightly below the table top.
--
The best argument against democracy is a five-minute conversation
with the average voter. (Winston Churchill)
Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org
"LDR" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> [email protected] says...
>> Ray Miller wrote:
>> > Thanks to all responders. Looks like heli-coils are the way to go. I
>> > called a lical machine shop and they also agreed that was the best bet
>> > and they are willing to do it for about $30.
>>
>> I call that a VERY good deal.
>>
>> Lew
>>
> (piggyback)
>
> What nobody mentioned--probably because it likely would not work--is to
> chase the thread with a same-size tap. More than once, I have thought
> threads ruined and chasing brought them back to life. Anyway, the
> machine shop must be owned by your brother; I can't imagine them doing
> anything for $30. :-)
Actually, this is about what we'd charge at the shop I work at. It is a
pretty quick fix for people that do it on a regular basis. If you brought
just the top in and it was ready to be fixed, it would likely be done before
you could go to McDonald's and get a Big Mac.
Mike