Atlas 7B Disassembly and Teardown! Pic Heavy!

[Weldo]

IMPORTANT NOTE!

The shaft is not symmetrical.

Notice the spacing of the flat spots for the set screws.

This side is for the step pulley.

And this side is for the large single pulley.

Seen together you can notice the difference between the flat spots and the ends of the shaft. Make sure it goes back together in this orientation. In the below picture the right hand side is for the step pulley and brake pulley and the left hand side is for the large single pulley and collar.

Now all the parts are clean, ready to reassemble!

 

[Weldo]

Reassembly of the pulley shaft and bracket.

After cleaning, the parts slide together very nicely, no force is needed anywhere.

Here's a close up of the bearings. I can make out "USA 99026". Not sure if these are still gettable but maybe it'll help someone.

I got new felt seals. There's a seller on eBay that has them. Here's a link to their seller page. They also sell all kinds of felt wipers and other random tool related stuff. Check them out!

Instructions with the felts. Note the bottom where it says the 7" shaper uses oil instead of grease.

They fit perfectly! Very nice product!

The felts are well proud of the surface. A big improvement over the old ones.

At this point in reassembly the orientation of the shaft is critical. Below are a few pictures to make it clear which way it goes.

One side is about 13/16" from the end of the shaft to the first flat spot. This side accepts the braking pulley and the step pulley.

The other side is only about 3/8" from the end of the shaft to the first flat spot. This end accepts the collar and large single pulley. Also note that the flat spots are closer together than on the step pulley side.

Now that the shaft is correctly oriented we can slide the parts on to it. I started from the brake pulley/step pulley side. The brake pulley is slid on and set screw snugged. It tight enough to capture the pulley on it's respective flat spot but still loose enough to allow the pulley to move. Snug up the set screw and back it off a quarter turn or so. This slight movement will allow you to get some compression on the felt seals before the set screws are completely tightened.

The key goes in for the step pulley. The brake pulley has no keyway. You can see a little damage to this key. It's the one I messed up in disassembly.

Step pulley goes on again leaving the set screw only lightly snugged.

Now the bearings can be slid into the casting and the shaft slid through the bearings.

 

[Weldo]

The shaft was actually somewhat snug going back into the bearings. The bearings slid onto the shaft easily and the bearings also slid into the casting easily but I suppose when the bearings are captured in the casting there's very little clearance for the shaft. The rollers are essentially squished between the casting and the shaft so it was kind of a snug fit.

Before it was sent home I oiled the felts.

Upon sliding the shaft all the way through the casting, the shaft wanted to push the opposite bearing out with it so I used a piece of pipe to push the bearing back into the casting. No hammer was needed here, just hand pressure.

Now to assemble the single pulley side. It starts with the collar. The felt is oiled with way oil. The felt faces the casting, of course.

Again leaving the set screw loose.

Now the woodruff key.

And the large single pulley.

For whatever reason the flat spot in the shaft for the large single pulley doesn't line up very well with its respective set screw. But it should be good enough for keeping the pulley from walking off.

Now I held some pressure on the parts to compress the felts while all the set screws are tightened completely. The felts were not super compressed, I can still see some tiny gap between the collar/brake pulley and the casting.

 

[Weldo]

Now that the shaft and pulleys are done, the brake/clutch lever can be installed.

This is how it gets oriented. The rubber wedge rides in the brake pulley, thereby applying friction when needed.

The cleaned up lever shaft slides in nicely.

Here's how the brake system works. The wedge contacts the pulley when the lever is pulled sufficiently.

The two small pins can be tapped in to capture the lever shaft between the casting ears.

Complete!

Now it gets bolted to the machine.

There's 3 bolts in a triangular pattern. The single one goes upwards. To start the top bolt you must leave the bottom two bolts only engaged by a thread or two, this will allow the bracket to lean out at the top. See the small gap between the bracket and the machine column.

The top of the bracket needs to lean outwards because there's an interference between the pivot pin and the top bolt head. If the bracket is clamped tightly to the machine it will be impossible to start the top bolt. Alternatively you could just start the top bolt first, before the two bottom ones. It's just kind of awkward, not much finger room.

It was then that I discovered an interference issue with the brake lever. It rubs the column pretty hard.

A slight bend can be seen in the lever handle.

Originally I thought I could remove the pin that captures the handle to its shaft, but the end of the shaft appears to be tapered very slightly so the handle cannot come off from that end.

I had to remove the two pins in the lever shaft and slide the whole thing out. The bracket was able to stay on the machine. I did still remove the lever from the shaft. It's not really necessary but I already had the pin out at this point.

The lever was clamped in the vise, heated and bent slightly to allow clearance.

It's close but it clears!

 

[Weldo]

Now attention is turned to the motor bracket. Not much to say about this part, I just washed it down in the parts washer. No disassembly was necessary.

It bolts on here with two bolts.

The bolt pictured below is for adjusting belt tension between the motor and the counter shaft.

My motor bracket had this ball stud on it. It's not in the schematic and it looks shop made. Not sure what its use is/was.

Now the motor!

Motor in place. I wiped it down with solvent and it cleaned up pretty well.

Here's a question to anyone with one of these old Atlas motors. In the picture below, am I meant to lube this motor with grease or has someone replaced the old oil cups with grease fittings? Seems like they should be oil cups, and I know that most of the other cups on this machine were erroneously replaced with grease fittings. There's no lube info for the motor in the manual I have.

 

[Weldo]

The step pulley that mates with the counter shaft step pulley goes on next.

There's another interference with the feed mechanism.

I disconnected the link between the feed housing and the ratchet housing. That allowed the feed housing to pivot out of the way enough to get the pulley on.

There's a key here.

And the pulley goes on with a set screw. In hindsight there probably should have been a small lead shot or something similar between the set screw and the shaft. I neglected to do that when I put this pulley on so I might have a tough time getting it off in the future... As far as pulley position, I just eyeballed it to line up with the counter shaft step pulley. It may need adjustment once the belts go on.

The grease cup screws on. It's empty at the moment.

There's an accessory light that bolts to the ram ways. It uses a single slotted round head screw to bolt to the way.

Wire clamp.

The wire is kind of unruly here.

I'll probably get a clamp on this bolt to hold the wire more neatly.

Now the oil pan goes on.

I had to clearance it a little because it hit the brake lever.

 

[Weldo]

Belt fitting!

The belts that were on the machine seem a bit tight. There's a link belt for the motor and a rubber V belt for the step pulleys. The rubber one feels too tight so I'll make up a link belt for that side as well.

I still have to play around with tensions. The motor belt feels too tight to me. When I engage the clutch lever I can see the motor bracket flex just slightly. I may add a link or adjust motor tension with the bolt pictured in a previous post.

Below is a picture of the belt under tension and how much deflection it has. I had to push on it fairly hard to get that much deflection.

 

[frugalguido]

Now attention is turned to the motor bracket. Not much to say about this part, I just washed it down in the parts washer. No disassembly was necessary.

View attachment 348833


It bolts on here with two bolts.

View attachment 348834

View attachment 348835


The bolt pictured below is for adjusting belt tension between the motor and the counter shaft.

View attachment 348836


My motor bracket had this ball stud on it. It's not in the schematic and it looks shop made. Not sure what its use is/was.

View attachment 348837


Now the motor!

View attachment 348838


Motor in place. I wiped it down with solvent and it cleaned up pretty well.

View attachment 348839


Here's a question to anyone with one of these old Atlas motors. In the picture below, am I meant to lube this motor with grease or has someone replaced the old oil cups with grease fittings? Seems like they should be oil cups, and I know that most of the other cups on this machine were erroneously replaced with grease fittings. There's no lube info for the motor in the manual I have.

View attachment 348840

Mine has no grease fittings. I also noted that on the shaft that lifts the pulleys assy. to disengage the drive, that yours is very worn (the flat spots rounded over). Mine had this too, I made a new shaft and then heat treated it, so hopefully it won't wear like the original.

 

[Weldo]

Thanks for the info. So yours has oil cups or just holes?

I did notice the rounded over bits on the shaft but I didn't think it was really a problem. The final engagement points are unchanged so would it really matter that it's rounded over in the interim? I could probably dab a little hard face weld on there buy I didn't think it was very critical. Any thoughts?

 

[Weldo]

Got some belts on. I added one link to the motor belt to loosen it up a bit. Seems better now.

And I made up a link belt for the step pulley side.

I think I'm gonna source a rubber V-belt for this side since the link belt contacts the motor just slightly.

Also swapping the belt to a different pulley is kind of tight with the feed mechanism. The link belt is fatter than a regular V-belt would be.

The guards are on. The big one just uses a hinge pin through a bracket on the oil pan.

And the motor side guard slips onto a shaft on the oil pan and uses a small bracket to the oil pan bolt.