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Thoughts about these cast iron lineshaft bearings.

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
I'm trying to get this Novo engine contractors saw rig back in modest service. I don't believe any of the pictured lineshaft is original to the saw rig. My question is, are these 3"cast iron bearing surfaces on 1 3/8" shaft suitable for 800 rpm. They are single ring oiled. 1 of the 2 is badly worn because of busted oil reservoir... My thoughts are boring it for a oilite bearing. Regrets, I can't get photos to post so I went with 3 minute video.

 
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blcksmth

Cast Iron
Joined
Nov 17, 2006
Location
Bowling Green, Ohio
You will probably find that the shaft is really an odd 1/16th of an inch in diameter. The bearings are most likely babbit and can be re-poured. You said that you could repair the oil container for the ring oiler so it should not be too difficult to put things back in working order. The worn area of the shaft, if you intend to use that portion, will be the most difficult, in my opinion.

Bob
WB8NQW
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
Thru my research before i posted I found a P-M post about cast iron lineshaft bearings being fine and durable. Nothing was mentioned about rpm limits (if any) with them. This is my first lineshaft project and trying to gather info before I start fixing stuff. I also don't understand the reasoning why lineshafts have to be in odd 16ths unless pulleys back in the day came that way, again trying to learn as much as possible. I'm prolly going to have a new shaft made as this 1 is buggered and short... If I find the other tool that came on it.. Thanks for your comment.
 

Joe Michaels

Diamond
Joined
Apr 3, 2004
Location
Shandaken, NY, USA
In my opinion, 800 rpm is fast for the type of lineshaft and type/diameter pulleys on it. Those are cast iron pulleys with what appears to be about 12" or more in diameter. The type lineshaft bearings were designed for lineshaft turning more on the order of 200-300 rpm. The bearings are being used to support a short piece of lineshaft, which is more of a 'jackshaft' or 'countershaft'. A lot of factors play into how this sort of thing will run. Namely: how good a fit and how concentric (how much runout) do the pulleys have on the shaft ? I'd at least use a fixed pointer (like a surface gauge) to see how badly the pulleys are running out on the rim and face. Running pulleys like the ones in the picture up at 800 rpm would require the pulleys to be running quite true to the shaft in both rim and face runout.

The other issue is the condition of the shaft. The type of lineshaft bearing supports in the picture are made for aligning line shafting when the bearing supports are mounted to a building or structure that might not be all that accurately built. These are not what could be termed 'rigid' bearing supports. Lineshafting, in service, will often tend to 'bow' slightly (deflect) due to a combination of belt-pulls, weight of the pulleys, and the shaft and pulleys wanting to move to a 'dynamic center' when the shaft is turning. The type bearing supports in this post address this, as well as alignment in a building which may do some moving on its own (settling of the building over time, increased floor loads on the floor above the lineshafting, wood framing moving with humidity). Line shafting, as 'commercially available' was never the straightest thing. It was OK for slow speed/long span applications as things were loose enough for it to run properly.

For wahtever reason, line shafting seems to have been made to odd 1/16th sizes, with 1 7/16" diameter being quite popular. I'd take the chunk of shafting to be used in this project and set it up in a 4 jaw lathe chuck. Indicate each end and put a center in it. Set it up between centers on the lathe and roll it over by hand and use a dial indicator to see how straight the shaft is. Running these types/sizes of pulleys at 800 rpm will require the shaft to be straight, aside from the pulleys running dead true on it.

As for the bearings, they were once cast iron bearings. Due to neglect or maybe running too tight belts and little or no lube, and maybe a lot faster than things should have run, the bearing bores are worn way far out of round. Two thoughts here: bore the bearings a bit oversize and babbitt them. They will need to be in good alignment and set up with a good close clearance and proper oil grooving to run a shaft with those pulleys at 800 rpm. Line shaft bearings made for more typical line shaft speeds (200-300 rpm) would not necessarily hold up in service at 800 rpm. This may be why the bearings in the photos are so 'wallowed out'.

I'd also suggest doing a static balance on the assembled shaft and pulleys. It is quite common to see balance weights riveted to the inside of the rims of larger line shaft pulleys made to run at higher speeds or being large enough diameter to have a high rim speed.

The 'magic number' for sawmill saws, buzz saws, and circular saws is 10,000 feet per minute for the rim speed (speed at the tips of the saw's teeth). For a circular saw to cut properly, 10,000 fpm is the number to shoot for to get good cutting. If the diameter of the saw is known, and the governed rpm of the engine is known, some simple math will determine if the pulleys on the jackshaft, saw arbor, and engine shaft are properly sized. I've been around lineshafting enough to know it is an 'interesting proposition'. The old shafting may be bowed or simply too worn at the journal areas to be used. A piece of turned-ground-polished stock would make a good high speed jackshaft if the old shafting is not usable. I've seen some real horror shows when people used cold rolled shafting on higher speed machinery and milled keyways into it. Cold rolled steel likes to 'self relieve' or you release 'locked in stresses' when you machine it assymetrically. Milling a few heavy keyways in CRS shafting all on the same side of the shaft really caused the shaft to warp and set up some hellacious vibration and knock the stuffings out of some ball bearing pillow blocks. In old mills and shops with long line shafts, the shafting is 'live' in use. Heavy wire rings are often placed around the shafting to keep dirt from accumulating on the shafting. In service as the load on the shafting changes, those rings literally dance up and back along the shafting, limited only by pulley hubs or bearings. As load changes, the distance and frequency the rings move on the shafting changes with it. Lots to consider when making a lineshaft, even a short one, intended to run at higher speeds.
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
My lineshaft bench grinder has cast iron bearings and it is designed to run at 1500 rpm so it would be fine at 800 but I would be surprised if it needed to run that fast.
My bearing casting is 1 piece, 5 1/4 long with 2" of bearing surface at each end. The center is open for the oiling ring to rotate.
If I figured right my blade arbor with its 4" dia. pulley is suppose to turn 4500rpm max for a 14" blade. The 24" jack shaft (thanks joe) pulley driving the blade is to be around 750rpm. The blade arbor bearings are 2 piece babbitt.
As I mentioned I believe this pulley setup is backyard and made to be run with engine or motor along with being portable.
Thanks for info.

beach1.jpg
 

Jim Christie

Titanium
Joined
Mar 14, 2007
Location
L'Orignal, Ontario Canada
I was wondering if there was enough material in your bearing hangers if not the current housings, to bore them out to accept one or two of these types of bearings (found in an image search) on each hanger.
Then you wouldn't have to worry about the speed especially if you replaced the shafting with a new piece of ground shafting material as suggested by Joe Michaels.
I know it wouldn't be original but maybe with a bit of imagination and with a couple of collars to hide the ball bearings you could fake it well enough that most folks wouldn't know the difference and you would have something that would last a long time.
Jim
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
My thoughts were boring out the 1 piece bearing castings for "plain bronze bearings". This way I can use these original castings which are made for the "stands". The stands are made in the manner to support with minor adjustment the bearings vertically. Will bronze bearings work 800rpm?

Bottom, actually this is the oil reservoir bolted to the bearing..

Top of bearing casting.
 
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Robert Lang

Stainless
Joined
Apr 3, 2007
Location
Minneapolis, MN
My theory on why shafting was on the 1/16. Before cold rolling was available the shaft would have been turned down the entire length so the rough forging was say 2" and then the finished shaft was cut to 1 15/16"
Not a theory. That is exactly why and how it was done.
There were a number of machine tool makers that made shafting lathes just for that.

Rob
 

blcksmth

Cast Iron
Joined
Nov 17, 2006
Location
Bowling Green, Ohio
In my opinion, 800 rpm is fast for the type of lineshaft and type/diameter pulleys on it. Those are cast iron pulleys with what appears to be about 12" or more in diameter. The type lineshaft bearings were designed for lineshaft turning more on the order of 200-300 rpm. The bearings are being used to support a short piece of lineshaft, which is more of a 'jackshaft' or 'countershaft'. A lot of factors play into how this sort of thing will run. Namely: how good a fit and how concentric (how much runout) do the pulleys have on the shaft ? I'd at least use a fixed pointer (like a surface gauge) to see how badly the pulleys are running out on the rim and face. Running pulleys like the ones in the picture up at 800 rpm would require the pulleys to be running quite true to the shaft in both rim and face runout.

The other issue is the condition of the shaft. The type of lineshaft bearing supports in the picture are made for aligning line shafting when the bearing supports are mounted to a building or structure that might not be all that accurately built. These are not what could be termed 'rigid' bearing supports. Lineshafting, in service, will often tend to 'bow' slightly (deflect) due to a combination of belt-pulls, weight of the pulleys, and the shaft and pulleys wanting to move to a 'dynamic center' when the shaft is turning. The type bearing supports in this post address this, as well as alignment in a building which may do some moving on its own (settling of the building over time, increased floor loads on the floor above the lineshafting, wood framing moving with humidity). Line shafting, as 'commercially available' was never the straightest thing. It was OK for slow speed/long span applications as things were loose enough for it to run properly.

For wahtever reason, line shafting seems to have been made to odd 1/16th sizes, with 1 7/16" diameter being quite popular. I'd take the chunk of shafting to be used in this project and set it up in a 4 jaw lathe chuck. Indicate each end and put a center in it. Set it up between centers on the lathe and roll it over by hand and use a dial indicator to see how straight the shaft is. Running these types/sizes of pulleys at 800 rpm will require the shaft to be straight, aside from the pulleys running dead true on it.

As for the bearings, they were once cast iron bearings. Due to neglect or maybe running too tight belts and little or no lube, and maybe a lot faster than things should have run, the bearing bores are worn way far out of round. Two thoughts here: bore the bearings a bit oversize and babbitt them. They will need to be in good alignment and set up with a good close clearance and proper oil grooving to run a shaft with those pulleys at 800 rpm. Line shaft bearings made for more typical line shaft speeds (200-300 rpm) would not necessarily hold up in service at 800 rpm. This may be why the bearings in the photos are so 'wallowed out'.

I'd also suggest doing a static balance on the assembled shaft and pulleys. It is quite common to see balance weights riveted to the inside of the rims of larger line shaft pulleys made to run at higher speeds or being large enough diameter to have a high rim speed.

The 'magic number' for sawmill saws, buzz saws, and circular saws is 10,000 feet per minute for the rim speed (speed at the tips of the saw's teeth). For a circular saw to cut properly, 10,000 fpm is the number to shoot for to get good cutting. If the diameter of the saw is known, and the governed rpm of the engine is known, some simple math will determine if the pulleys on the jackshaft, saw arbor, and engine shaft are properly sized. I've been around lineshafting enough to know it is an 'interesting proposition'. The old shafting may be bowed or simply too worn at the journal areas to be used. A piece of turned-ground-polished stock would make a good high speed jackshaft if the old shafting is not usable. I've seen some real horror shows when people used cold rolled shafting on higher speed machinery and milled keyways into it. Cold rolled steel likes to 'self relieve' or you release 'locked in stresses' when you machine it assymetrically. Milling a few heavy keyways in CRS shafting all on the same side of the shaft really caused the shaft to warp and set up some hellacious vibration and knock the stuffings out of some ball bearing pillow blocks. In old mills and shops with long line shafts, the shafting is 'live' in use. Heavy wire rings are often placed around the shafting to keep dirt from accumulating on the shafting. In service as the load on the shafting changes, those rings literally dance up and back along the shafting, limited only by pulley hubs or bearings. As load changes, the distance and frequency the rings move on the shafting changes with it. Lots to consider when making a lineshaft, even a short one, intended to run at higher speeds.
There are 2 balance modes that must be considered, static balance and dynamic balance which is an issue on longer shafts. If a pulley at one end is out of balance and another pulley at then other end is out of balance but on the opposite side, the shaft can be in perfect static balance, but will shake badly at speed.

Bob
WB8NQW
 

enginebill

Stainless
Joined
Feb 17, 2005
Location
Plymouth Meeting PA
My thoughts were boring out the 1 piece bearing castings for "plain bronze bearings". This way I can use these original castings which are made for the "stands". The stands are made in the manner to support with minor adjustment the bearings vertically. Will bronze bearings work 800rpm?

Bottom, actually this is the oil reservoir.

Top of bearing casting.
Bronze or Babbitt plain bearings will work at 800 or 20,000 rpm just fine, it's not about the material, it is about getting enough oil flow to remove the heat of the friction between the oil and shaft. I still think you should be cutting your speeds in half for the old saw.
 

Joe Michaels

Diamond
Joined
Apr 3, 2004
Location
Shandaken, NY, USA
I agree that bronze or babbitt will work for the bearings. However, I go back to my previous post and question the condition of the shaft in terms of straightness, as well as condition of the journals and fit of the pulleys on the shaft.

Cast iron is an excellent bearing material, and was used by South Bend for countless numbers of lathe spindle bearings. I've seen any number of 'loose pulleys' (tight and loose pulley combinations used as a 'clutch' on lineshaft driven machinery) which were simply bored cast iron running on the shaft. However, the bearings in the photos are so 'wallowed out' as to be beyond any use as they are. Not enough meat left in the cast iron bearing 'boxes' to bore out and run oversized shaft journals. My suggestion would be to build up the wallowed out areas using brazing, then bore the cast iron bearings to allow either babbitting or the use of bronze bushings. Bronze bushings (one piece bearings or 'sleeves') will require a hefty cash outlay for the bronze in that size. Boring out the bearing boxes by maybe 3/16" on each side and pouring with babbitt may be the more economical way to go. It also allows the use of split bearings (as per original), and allows for the use of shims to set the bearing clearance.

I do not want to sound repetitious, but starting with a good true-running shaft having good journals and checking the pulleys for runout and balance assembled on that shaft is vital. If the shaft does not run true (i.e., journals not concentric from one end to the other) or journal surface finish is rough, the shaft will pound the bearings (if journals out of true or pulleys not running true on the shaft), or chew up the bearings (rough surface finish on the journals).

Getting back to the choice of bronze vs babbitting: Assuming the OP could find 'cored bronze round bar' in the size needed, and find it as a 'drop' (remnant sold as the scrap or remaining piece after some job was run using the bulk of it), the cost would still be quite high. And, the bulk of the piece of bronze would wind up as chips rather than as the bearings. I've explored both options for some 1 1/8" diameter bearings I am making, and am going with babbitting vs bronze. A babbitt containing a higher percentage of tin will handle higher speeds and loads. Babbitt, to my own thinking, is a 'more forgiving' bearing for this type application than bronze. The bearings will be split bearings, adjustable for running clearance, and will not change much in the overall design from the original.
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
I'm still digesting all this and going to have new shaft made and pulleys rebuilt if I can afford it.. I'm not a machinist, the closest it get to it- is with a drill press and angle grinder. This project may not be worth that kind $ to me.

Joe mentions, "Boring out the bearing boxes by maybe 3/16" on each side and pouring with babbitt may be the more economical way to go. It also allows the use of split bearings (as per original), and allows for the use of shims to set the bearing clearance.

Joe, these bearings are a 1 piece casting, it looks 2 piece because the oil reservoir is bolted to the bearing thus showing the seam.

IMO, the wallowed out 1 is messed up in 1 direction because the the drive pulley from the engine was outboard of the left stand, plus that bearing had no oil. (busted reservoir). Look at 1st photo noting the rickety wood framed base. Nothing solid and barely attached to the saw frame. "Backyard"
I think the jackshaft drive pulley should be between the stands, maybe close to center as possible. (comments welcome)
thanks for info so far,
mike
beach2.jpg
 
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Joe Michaels

Diamond
Joined
Apr 3, 2004
Location
Shandaken, NY, USA
I watched your youtube again and studied the bearings as you showed them. My first thought is to take a pocket-knife or 3-corner scraper and try scraping the edge of the actual bearing (the part that includes the 'wallowed out' area). From your youtube, I think I see a joint-line between the cast iron bearing 'box' and the actual bearing. Try scraping the bearing itself with a knife or scraper and see if it is babbitted. I may well be 100% wrong here, but it looks like those bearings are babbitted in cast iron 'boxes' or 'shells'.

Regardless of whether the bearings were originally babbitted or not, I would go with re-babbitting them as the way to save them. Babbitted bearings do not have to be split, and are often poured as one-piece bearings. If the bearings are not originally babbitted, I'd suggest boring out the cast iron shell, perhaps 1/8" on each side, if material in the castings is available. I would not bother boring to the full 'wallowed out depth'. Once this boring has been done, since you are going with a new shaft, going maybe 1/8" undersized on the shaft journals would give plenty of babbitt thickness. A new shaft, machined with the journals 1/8" undersized from original diameter would then be made up. This would require re-locating pulleys so they are both located between the bearings. This is a sounder design than having what is known as an 'overhung load'.

I have an ancient (ca 1885) Barnes camelback drill press in my blacksmith shop. It is a smaller camelback drill and does not have split bearings on the top shaft or the bottom shaft. The cast iron mainframe included bearing housings, and these were babbitted as 'one piece bearings'. No adjustment of clearance possible. For an 1885 machine tool, this old drill seems in remarkably good condition with acceptable clearances in these bearings. I also have a Cincinnati-Bickford camelback drill in my shop. This is a heavier drill press. The bottom shaft with the cone pulley on it runs in babbitted one-piece bearings. Cast iron base casting was designed to include bearing housings, and these were bored & babbitted, no adjustment of clearance possible. This is a ca. 1917 machine with factory motor drive. The bottom shaft bearings are oiled via oil cups, and seem OK for clearance as well.

Babbitting the bearings on your Novo-Beach saw, at least to me, seems like the quickest way to go. Novo-Beach used a wood frame for the base skid and saw table frame. As you note, somewhere along the line, the factory built base skid was likely replaced with a Do-it-yourself version. Chances are the base skid, being wood, may have rotted out. I am sure that Novo-Beach used rabbetted joints to lock the connections of the wood framing tight together, as well as heavy bolting. The DIY skid base/frame was likely not framed so well. Probably just lapped or butted corner joints and cross member connections. The result was the base/skid frame was nowhere near as rigid as the original and may have allowed some movement of the bearing supports relative each other and to the engine and saw arbor. This movement, if it occurred, could also explain the severe 'wallowing out', combined with a lack of lubrication. Having the shaft running on an angle relative to the bearings due to the frame being loose or 'live' would be a good possibility.
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
Got the other bearing off, shaft and bore galled up. It'd turned fine and seemed tight but had to carefully use puller to get it off.
There's no babbit in there.



Mine has Bock Equipment tags on it.
beach5.jpg
 
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Joe Michaels

Diamond
Joined
Apr 3, 2004
Location
Shandaken, NY, USA
Holy cow ! that is some heavy damage to both the shaft journals and the bearings. Looks like the only recourse - assuming you want to keep the original bearings- is to bore the bearing shells and babbitt them. You have a real 'textbook' failure, galling, excessive wear, scoring. It is hard to imagine someone letting things get so far gone and continuing to run the saw rig. It's the exemplification of the old adage that starts off: "For want of a nail, a shoe was lost... for want of a shoe, a horse was lost... for want of a horse, a knight was lost... for want of a knight, a battle was lost... ending with the loss of a whole kingdom. In the case of the OP's saw rig, it was: "for want of a little oil..." Or, the belting got slack due to use and weathering, or shaft wear wallowing out the bearing made the belt slacken. The previous owner took a piece out of the belting or did whatever he had to do to get a really tight belt. Took up the play due to the wallowed out bearing and kept running the saw. With the belt way too tight, and a lack of oiling, the bearing and shaft journal damage took off like a rocket. The photos are a testament to this. But, that old saw rig is a lot like the old Timex watch ads: "Takes a licking and keeps on ticking". Some previous owner may have relied on the saw rig not as a table saw but more as a buzz saw to buck up stove wood. That being the case, he did not care if the shafting was cocked in the bearings so long as he could buck up wood with it. Probably never changed crankcase oil in the Novo engine and maybe dumped in used crankcase oil from his car or truck.

Another thought for the repair is to try to find a pair of similar line shaft bearings and brackets. The design is one that was in common use, and a variety of manufacturers made them. Since the skid base frame the saw and engine are on is not original, changing the bearings and brackets might be the easier way to go. Old engine swap meets and the like may be places where line-shaft bearings and brackets ('hangers') turn up.
 

wrenchguy

Plastic
Joined
Dec 5, 2011
Location
NW Indiana
Each bearing has 2 oil fill ports, none of the 4 had whittled plugs installed. Throw some sand in there and you FOD. Tomorrow I try to press the 24" pulley off what left of the shaft. thx.
 








 
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