Atlas 7B Disassembly and Teardown! Pic Heavy!

[Weldo]

Honestly I never even thought about it. You're right though, it wouldn't be a bad idea.

They do all seem to be in great shape, however. No evidence of heat, scoring or abuse is visible on any bearing or race. Maybe due to the relatively low rpm and load? Or maybe because previous owners had kept it well lubed.

 

[ErichKeane]

Given some of your other discoveries, I would be afraid that they would be damaged in some way. With cheap bearings (basically anything but precision spindle bearings) I tend to replace them any time I have them accessible unless I remember changing them before

Typically these things take a bunch of work to get to, so the $5-$10 for a new bearing is worth knowing I won't be doing the teardown again in a month.

 

[frugalguido]

My bearings were fine too, even on the bull gear assy. Surprisingly the needle bearings on the counter shaft were good too, which are turning at a higher speed.
Amazed that you aren't going to paint it, since it is completely disassembled?

 

[Weldo]

I thought about it, but it seems like such a pain. I may still decide to throw on a coat or two after most of the internals are in. I just don't want to wait too long to reassemble since it's still kind of fresh in my head where all the parts go. To do a proper paint job I'd have to sand/scuff, prime, paint, then wait for another week for the pain to harden. I dunno, I just can't get excited about that part.

But like I said I may paint it just before I put the ram back on. I can mask a few of the shafts or faces that remain bare and probably brush on a coat of grey hammer tone like I did with my lathe. It would be cool if they matched! It looked like that's how atlas painted them back in the day, after assembly. That way they get the bolt heads and everything.

 

[Weldo]

Got some more parts on!

Today I did the crank gear carrier.

These are the related parts.

I lacked a wrench thin enough to hold the jam nut on the carrier, so I held the gear with some cloth covered channel locks. These nuts were still loose from parts washing disassembly. Be careful in the tightening, the shaft should spin freely after the nuts are cinched up.

Next the adjusting shaft can be slid into the carrier. This is the shaft by which you adjust ram stroke length.

Oil has been applied to the bushings inside.

Next there are a few small parts on the end of the shaft. First is a spacer. The chamfer faces out to clear the adjacent gear.

The small woodruff key and gear go on next.

And it's topped off by a lock washer and nut. This sub-assembly is now ready for installation.

The carrier bearing housing gets bolted on with six bolts/lock washers. Make sure the oil hole faces upwards toward the ram.

All tightened up.

Now the carrier is slid into place through the access door in the opposite side of the column. Somehow you must hold the carrier in place while you press the outer bearing onto the carrier shaft. In my case I used a small length of 2x4 and a piece of 3/4" plywood to wedge the carrier in place. This allowed me to tap the bearing home with a piece of PVC pipe. You can't really see the carrier in the pic below but it's being wedged up to the left side by the wood.

With the carrier wedged in place the bearing is tapped onto the shaft and into its race.

Carrier installed! It's easy to feel when the bearing bottoms out. There should be no play at this point.

Now it's ready for the crank gear and its related parts.

 

[ErichKeane]

Don't you have a collection of open-ended wrenches ground thinner for exactly this case? I have about a half-dozen wrenches over the years that are significantly thinner than when manufactured due to needs like this

 

[Weldo]

Haha, I could find any doubles that I could grind down! I have a crap load of random sockets though...

 

[Weldo]

Got the crank gear in.

There's a pin in the crank gear. It's at 12 o'clock in the picture.

It lines up with this hole in the carrier, also at about 12 o'clock. The other six holes are for bolts.

The gear must be loaded through the top since it doesn't fit through the access opening.

The pin locates the gear and bolts go in easily.

I used a small piece of metal to hold the gear teeth while I cranked the bolts with a cheater bar on an Allen key.

Now the plate can go in. I had to file some set screw burs on the brass post in order for the plate to slide on easier.

Set screw and lock nut tightened up.

Next the two bars that hold the plate in its slot would go on, but I'm gonna try and source new bolts. They are pretty chowdered up. Someone had staked a hell out of them at one point. I want to be sure they come out next time so I think I'll look into some new socket head bolts. Most of the Philips heads are badly rounded.

 

[Weldo]

So I was rootin' around in my "3/8 Bolt" bin and lo and behold! I found exactly what I needed! Saved my a trip to Home Depot and probably $10!

I found stainless flat head socket bolts in 3/8-16. The ones I found are 1" long versus the original 3/4" but they go in no problem. The holes are through holes and they are tapped all the way through. And the gear is thicker than the shank of the bolts so they don't protrude out the back side.

I hit the bars with an 82 degree countersink to get rid of any lumps from the old staking. I think the large divots I'm seeing is where someone must have drilled out the original staking to remove the bolts.

Installed! These bolts are a big improvement over the old Philips ones. When I ran the bolts in I gave a little squirt of oil into the threads but now I'm thinking I should have used some low strength Loctite. I think a liquid thread locker is a less permanent solution than staking. I may take each bolt out one at a time and apply some.

Slowly but surely it's coming together! I actually forget what comes next, gotta refer to the earlier posts!

 

[Weldo]

Got most of it back together! Pics and write up following!

Here's my take on the @frugalguido sliding block mod. I drilled out the vertical oil hole to act as a bit more of a reservoir and drilled some intersecting holes to the sides.

In the sides I used a Dremel cut off wheel to make oil channels. Not as polished as a small ball end mill but it should serve the purpose.

Before the block I installed the brass spacer I made.

Followed by the block.

And finally the crank arm itself.