Atlas Shaper Gib Issues

[754]

If you recut the dovetail, made a fatter gib... would that fix everything ?

[Wheels17]

@754, the damaged dovetail is on the opposite side from the gib. I've lost about 20% of the very tip of the dovetail. I think the remaining 80% should be sufficient to carry the load. I'm not confident in my ability to properly recut the dovetail. If it doesn't work after I clean up the burrs, I'll have to dive into that.

The real problem with the gib is the galling and other damage.

[rkepler]

The original was from a low carbon flat stock. Get some PG low carbon stock from McMaster - $8.45 for a 12" chunk of 1/8 x 1/2 (pretty sure that's what I used when making a similar gib).

[Richard P Wilson]

Wheels17: If you make a new gib, please do your self a favor and make it from cast iron, or as a secondary choice, bronze. NOT STEEL OF ANYKIND. The locking setscrew was for a special application. This was probably done so the clapper would not raise up while cutting an internal keyway. If you will look carefully, your original gib was cast.

Sarge41

Sorry, I've got an Atlas shaper as well, and that gib isn't cast iron, its low carbon steel. A cast iron gib would need to be about double the thickness to avoid fragility.
The locking setscrew has got nothing to do with the clapper, it isn't even in the same component as the clapper or clapper box.
Its there to stop the toolslide from working down during a cut, and is a good idea, just that the moron who did it put it in the wrong place. Re-drill in the other side, so its in line with, and between 2 gib adjustment screws, not too near the end.

You don't have to, but I generally dowel my gib strips, just drill and ream an 1/8" hole through the casting and the gib strip at either end and pop in an 1/8" silver steel (drill rod) dowel. It stops any end movement of the gib strip and IMO does make the movement smoother.

[Doozer]

Sorry, I've got an Atlas shaper as well, and that gib isn't cast iron, its low carbon steel. A cast iron gib would need to be about double the thickness to avoid fragility.

Double thickness my eye!
I used to own a 1940s Atlas 10" lathe.
The gibs were cast iron.
Steel gibs are a horrible idea.
Just cheap junk designed to fail.
I know some joker on here will say
I had steel gibs for 40 years, blah
blah blah blah. Well keep it. Good
for you. Spin the wheel. Get your rocks
off at Harbor Freight. All I can say is
if you want predictable results with
making a new gib for your lathe,
make it out of cast or ductile iron.

-Doozer

[Tim Clarke]

[QUOTE=Doozer;1208513]Double thickness my eye!
I used to own a 1940s Atlas 10" lathe.
The gibs were cast iron.
Steel gibs are a horrible idea.
Just cheap junk designed to fail.
I know some joker on here will say
I had steel gibs for 40 years, blah
blah blah blah. Well keep it. Good
for you. Spin the wheel. Get your rocks
off at Harbor Freight. All I can say is
if you want predictable results with
making a new gib for your lathe,
make it out of cast or ductile iron.

Ya, I WILL keep it. But not my 40's Atlas lathe.... Still have my 40's Atlas Shaper. Both had steel gibs. Worked. You want to be an elitist, be my guest. You seem to have quite a bit of knowledge. People would respect you if you weren't so abrasive. So lighten up, let the blood pressure back off a little and enjoy life. It feels good, trust me.

[Doozer]

After Atlas used steel gibs for many years,
they started making lathes with plastic or
some kind of nylon gib strips. These were
the absolute worst. Even seen guys on
ebay selling brass(?) replacement gibs for
the plastic gib models. Long story short,
Atlas tried all sorts of cost cutting things.
Many bad ideas. Just because Atlas had
steel gibs for some time, does not mean
it was a good idea at all. It is not elitist.
It is what works, and iron gibs work.
If you are going to invest your time to
machine a new gib strip, make it out of
something that is known to work well.
Buy a piece of Durabar iron from the
McMaster Carr catalog or Metal Super
market. Not real expensive. This seems
to be a point about being too cheap to
get the right material. Hundreds of
machine manufactures use iron for gibs.
It is proven. Cold rolled steel is just
cheap. No self lubricating properties,
very high friction, and wants to gall
and cold weld itself. If I sound abrasive
it is because you sound like a cheapskate.
If you are that poor not to be able to
source a cast iron strip, metalworking
might not be your thing. I am trying to
help, but all everyone hears me say is
to spend money that you might not want
to spend. People forget their time going
down the wrong road is costly too.
I guess for some people the satisfaction
felt from doing a job cheap is greater than
their satisfaction from doing a job well.
Hey, whatever works for you, that is
great. I just like to put a little more up
front, to assure a predictable positive
result, that's all.

--Doozer

[J Tiers]

The Atlas shapers I have use steel gibs, and were shipped that way.
The Logan lathe I have uses steel gibs and was shipped that way.
The Southbend I had for a while had steel gibs and was shipped that way.
The Benchmaster mill I have has steel gibs and was shipped that way.
The Lewis mill I have has steel gibs and was shipped that way
All the Atlas products I have dealt with that HAD gibs had steel ones and were shipped that way.
Most of the machines I have rescraped parts or all of have had steel gibs and were apparently shipped that way.

Heck... I am pretty sure all but one gib on the Rivett 608 are steel, they are screw pusher gibs, the one CI gib is a tapered gib.

None of the terrible things that you assure us are bound to happen have happened to any of the million or so products made by the above companies with steel gibs. The damage to the OP's existing gib is obviously from an external cause, NOT from any form of galling etc. CI against steel does not do that.

For goodness sake... this is a gib on an Atlas shaper, in the downfeed (not a position that gets a ton of wear). It is a typical pusher screw adjusted gib. If it were a tapered gib I would agree with you.

it is running (slowly) against cast iron, and will NOT weld itself to cast iron. Especially with all the oil that is on the slideways. The gib style (pushed against the mating dovetail by screws) is not well suited to cast iron.

THE ENTIRE DESIGN IS CHEAP, if you want to be fussy about it, and using what you claim is the "RIGHT MATERIAL" amounts to putting lipstick on a pig, assuming that Ci is so much better (which it is not for these cases).

Nobody is saying CI is "too expensive", it is just not needed, and can be a pain to deal with in thin strips like these gibs.

You are doing the OP NO FAVOR by being a needless elitist insisting that he run off on a tangent and make thin cast iron gibs. Why not chill down and realize that ALL these machines use steel gibs, and this one can also?

[Doozer]

...And his original steel gib looks
like it was dragged down a bumpy
dirt road. Sure seems to have worked well.

-D

[QSIMDO]

Wouldn't Dura Bar be considered an improvement?
Doesn't seem that would be a huge sin and it'd be something to machine...pretty much why we're here, no?

[J Tiers]

He could do CI, sure.

Cast iron is not very strong in thin strips, so he'd have to be pretty careful with it. Those gibs are usually 1/8" thick, sometimes less, in thickness, pressed against the dovetail by several screws from behind, and cast iron is not the best material for that sort of situation, but he could do it.

The "sin" here is in demanding that the OP HAS TO use CI or else he is unworthy, and should try some other hobby (suggested in a post above). That's a pile of obnoxious BS, to put it bluntly.

...And his original steel gib looks
like it was dragged down a bumpy
dirt road. Sure seems to have worked well.

-D

I KNOW you are more intelligent than that.

That gib has (as I already said) damage that is OBVIOUSLY NOT any sort of "cold welding" or "galling". It looks as if it has been chipped with a cold chisel, possibly by the same guy who broke off the dovetail. There is a big burr raised on it like a chisel would raise... tell me how cold welding does that. Especially since the OP says there is no damage to the dovetail.

Possibly it was also never oiled... CI is pretty good, but with no oil bad things will happen.... just like in a car... CI rings and a CI cylinder will not last long without oil, and they will look pretty bad, too.

Have you ever SEEN a steel gib from a machine? Did it look like that one? EVERY steel gib I have seen (that had not had swarf get under it) looked like it was polished, with maybe some fine lines lengthwise, as any gib or bearing gets in the direction of movement.

As for the gib from the pictures.... Obviously things happened to that gob that did not happen with it riding on a smooth CI surface.... Given the other bright things that a previous owner did, it is likely that he is responsible for the damage.

[Richard P Wilson]

He could do CI, sure.

Cast iron is not very strong in thin strips, so he'd have to be pretty careful with it. Those gibs are usually 1/8" thick, sometimes less, in thickness, pressed against the dovetail by several screws from behind, and cast iron is not the best material for that sort of situation, but he could do it.

The "sin" here is in demanding that the OP HAS TO use CI or else he is unworthy, and should try some other hobby (suggested in a post above). That's a pile of obnoxious BS, to put it bluntly.



I KNOW you are more intelligent than that.

That gib has (as I already said) damage that is OBVIOUSLY NOT any sort of "cold welding" or "galling". It looks as if it has been chipped with a cold chisel, possibly by the same guy who broke off the dovetail. There is a big burr raised on it like a chisel would raise... tell me how cold welding does that. Especially since the OP says there is no damage to the dovetail.

Possibly it was also never oiled... CI is pretty good, but with no oil bad things will happen.... just like in a car... CI rings and a CI cylinder will not last long without oil, and they will look pretty bad, too.

Have you ever SEEN a steel gib from a machine? Did it look like that one? EVERY steel gib I have seen (that had not had swarf get under it) looked like it was polished, with maybe some fine lines lengthwise, as any gib or bearing gets in the direction of movement.

As for the gib from the pictures.... Obviously things happened to that gob that did not happen with it riding on a smooth CI surface.... Given the other bright things that a previous owner did, it is likely that he is responsible for the damage.

Exactly so. I've owned dozens of machines over the last 50 years, most of which had thin steel gibs, which worked perfectly well. I've never seen one in the condition the OP showed, so it certainly isn't the usual result of using steel against cast iron, which is commonly accepted as a perfectly OK thing to do. The only ones I've had with cast iron gibs, the gibs have been much thicker, say 3/8" or so, and its not uncommon for owners to find, on stripping the machine that they have snapped. Doesn't happen with steel ones.

[Doozer]

It seems my experience with machines and gibs is different than many people here.
Most all the machines I have worked on had iron gibs of some kind. Be it tapered
gibs or parallel gibs with set screws. So that is what I have come to know as what
works. Interesting the machines that Jerry notes with steel gibs. Even though they
are considered budget conscious machines, it is good to know that their steel gibs
were at least adequate for their imposed task. Now you have my attention, and
my interest is piqued on the use of steel gibs.
I actually have a Hendey lathe, with a short and thin tapered iron gib that goes on
the taper attachment follower block. It is broken, and I might be able to fixture it
and braze it back together. But now you all have me thinking that a steel replacement
might be a better idea, because it is short and thin, and for some reason the original
iron gib had been cracked and broken. For my application, it just might be a better
material after all.
And as for steel gibs in general, the few that I have seen, have been mangled, so
my opinion was swayed by that. On cheap cheap China lathes, I have seen steel
gibs that look like they were cut on a shear, with tear-out on the edges. I guess
it is all in the quality of the part and the implementation. I believe you all may
have opened my eyes to steel gibs being right for some applications, as you say
many have been used successfully for some years. Thank you for the insight
and because of that, it helps me to make better decisions with what material to
choose for different projects. I will let you know how my Hendey gib turns out
when I get around to making a new one.


-Doozer

[J Tiers]

I like the idea of iron for the taper gib.

For starts, I think it will be a lot easier to make the gib without it warping, if it is iron. Warping is not good in taper gibs, and CRS is prone to warping. Even hot rolled is not immune.

Also, Taper gibs are typically scraped to fit them, and scraping steel is not much fun, CI is lots easier.

[BCRider]

In reading through all the banter of the last couple of pages and seeing some calming of the waters gives me hope for peace on the board. So I went back and had another look at the damage to the gib.

I'm going to guess that by hook or by crook that the adjuster screw was pushed in. Perhaps to lock the slide? Or perhaps the locking nut wasn't tight and the screw worked its way inward and took up the room? And then the user of that ran the slide back up and into the high spot. But being a bit of a brute and thinking it was just gummy oil or something he forced the slide and plowed up that big wedge of material. This may also be the reason the gib bent as well. Or perhaps the screws backed off out of the shallow cuts that normally act as retainer pockets and the gib shifted and wedged against the screw? Same plowing as a result of course.

One thing that seems fairly clear to me though. If the gib were CI it's likely it would have flaked away from the plowing and shattered from the pressure instead of gall and bend as it did here.

There's also nothing at all wrong with steel against cast iron as a bearing surface for a use such as a gib. The steel and CI combination is/was a very popular combination used in a massive number of lapped fit model airplane engines from the early spark engine days prior to WWII up to currently. Other combinations have largely taken over for lapped fit engines but it's still an option found on some replica and home made engines. The combination has a good reputation for resisting galling and seizing. So much so that often engines that are tight and get set too lean by accident will sag off and cut due to seizing but other than some light scuff marks will run just fine and still have a good seal when cooled down.