Steel recomendations for bandsaw axle

The ball bearings and locknuts are shown in the first photo, but the appearance of the bearing housing does suggest that the saw was originally designed with babbitt or bronze bearings. I had a 36" Crescent saw that I bought at an auction of a furniture factory in VT in 1980 or so. I was surprised when I removed the wheels to move the saw that it had needle bearings where I expected to find babbitt, so I don't think it was unusual for a mfr to make this sort of change while continuing to reuse the old castings.

This is the same Crescent saw that I had, but it's old enough that it has babbitt bearings.

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Reply to
Ned Simmons
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Yes. I fixed the bandsaw about 20 years ago and don't remember it as well as the brass bearings on my front end loader, so I may be mixing the two jobs.

The 'bushing' on the reamer shank was probably a thick layer of aluminum auto body tape.

Some reamers work better than others backwards. They are ground with a bevel on the normal leading end and may have a short, imperceptible taper on the cutting edges. Without these they can chatter or not cut concentric with the drilled hole. I have a tool and cutter grinding setup that can bevel them to cut backwards. Presumably few others do and I don't know a good way to grind a reamer by hand. Lautard(?) mentioned a honing fixture for them but it doesn't control diameter.

You can make a D bit that serves as a reamer with simple equipment, possibly only a bench grinder. If you make it on the end of drill rod you can use the rod as the pilot. I think you would have to press in only one bearing first and bush the drill rod to the other opening. After reaming the first bearing you could use it to guide the rod for reaming the second.

I'm using my HDTV as the laptop's display since it shows two full .pdf pages at once. It's fine for reading (a download of Holtzapffel book1), sort of awkward for typing because it's so far out of line with the keyboard. Sorry for any missed typos.

jsw

Reply to
Jim Wilkins

Very interesting webpage. I assume that the "Georgia Agrirama" is a museum.

Joe Gwinn

Reply to
Joseph Gwinn

41L40 has lead in it to make machining easier. It is not recommended to weld because of the lead. 4140 can be easy or hard to cut depending on the sulfur content. I think the max allowable sulfur is .2% The more sulfur the harder it is to weld it, but the easier it is to machine it. If you get a piece with no sulfur in it machining will be miserable.

John

Reply to
john

The sparks are an indication of carbon content in the steel. If the sparks were more numerous than the steel pipe but of the same general color and shape, you probably had a shaft of 1045 steel. Alloy steel usually sparks less than mild steel. Try grinding the end of an old file and see the sparks. The file is usually 1090 steel, the xx90 indicating 90 points of carbon.

John

Reply to
john

Huh. It's interesting that a strict alloy like 4140 would allow enough difference in sulfur to have much effect on machineability. It's not something I have a lot of experience with, and most that I've turned probably all came from the same batch.

Reply to
Ed Huntress

I think I'm going to turn it into bolts for my RGG gatling gun. I turned some

1144 today at work. That was pretty nice to work with.

Not sure how this thread got brought back to life.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Reply to
Wes

Now, what in the HELL are you going to do with a Gatling gun? Are you doing Civil War re-enactments, or are you joining the Michigan Militia?

Somebody just checks in every once in a while, probably.

Reply to
Ed Huntress

I learned about the sulfur from hard experience. I was running a job making pins from 4140 and the job was going good. I would make about 500 at a run. Well one run was giving me a lot of grief. busting inserts, not holding size, and a bunch of other problems. I tested the hardness and checked the certs. I had the metal assayed and it agreed with the certs papers. The only thing different in this batch of material was that it had absolutely no sulfur content in it. ( it came from Romania) I guess the sulfur gives the necessary lubrication to make cutting it easy.

John

Reply to
John

It was me not paying attention to the dates of the last post. The bandsaw axle sort of got my attention. I bought a DoAll model C-80 out of the scrap yard for 400 bucks a while ago and had to make new spindles for it. The bearings had spun on the axles and they had to be replaced as well as the bearings. The metal I used was from some of the scrap of the pins I made of the 4140. I still have a barrel full of the out of tol. pins accumulated over the years. I just used another piece today to make up a lathe chuck wrench. By the way to get a good finish on the metal you have to take at least ten thou. per side and turn at least 300 ft/min.

John

John

Reply to
John

Is that the 4140 without sulfur? It's been so long since I've turned that alloy that I can hardly remember it.

Reply to
Ed Huntress

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According to my copy of the Jorgensen steels catalog:

steel In Percent

------------------------------

4140 C 0.38/0.43 Mn 0.75/1.00 P 0.035 Max S 0.040 Max Si 0.20/0.35 Cr 0.80/1.10 Mo 0.15/0.25

With the following note:

The analyses of the leaded grades are the same as above with the addition 0f 0.15/0.35 Lead (Pb)

For welding they say in part:

"Difficult to weld, but can be welded by any of the common welding processeds providing section is preheated, and stress relieved after welding."

along with some other comments.

Machinability (for 41L42) is about 75% of 1212, and 66% for

4142. Approximately 130 SFM for the 41L42.

Personally, assuming that the bandsaw axle runs in ball bearings, I would use whatever steel you can easily machine. No need to go for 4140 for that.

Enjoy, DoN.

Reply to
DoN. Nichols

I switched suppliers after that bad batch and had no more problems with cutting the metal. We had to supply certifications so I kept an eye on the sulfur content and made sure it was always on the high end of the limits. It ran on the high end of the permitted amounts, I only machined it and didn't weld on it. I think the percentage ran about .18 At that percentage it would run well at those speeds. The part we ran required holding +/- .0005 in. on 6 inch turn and once the machine stabilized it ran all day with almost no scrap. The only problem was the air chuck would sometimes not hold the piece properly and it would slip if we had the feed or rpm running too high. I made thousands of those parts.

Reply to
John

Machining a lot of metal in batch- or continuous production really gives one a feel for subtleties that we don't usually pick up in ordinary hobby machining. If you made thousands, you must really know the material.

Note what Don reported about the standard for sulfur content in 4140 --

0.040% maximum. Another thing that shows up is slight "modifications" to standard alloy specifications, sometimes done for a good reason. You may have run into one of those circumstances. I've heard of 4000-series alloys that contained more chromium and less carbon than the specs require, for the purpose of meeting the elongation specification, which apparently is not easy.

But, like most technical things about materials, I haven't spoken to metallurgical engineers for decades. It used to be a major part of my job.

Reply to
Ed Huntress

It is only a .22 . Maybe mount motors and a search/acquisition radar and it could be a Phalanx Close-In Weapons System (CIWS) for Michigan Mosquitoes. Caliber might be a bit small though. ;)

Wes

Reply to
Wes

I'll bet you're going to be hell on rabbits. They'll be pre-tenderized.

Reply to
Ed Huntress

The sad thing is, rabbits are not very plentiful where I live. We have too many coyotes now. I wish I had the patience for hunting coyote.

Wes

Reply to
Wes

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