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Atlas 7B Disassembly and Teardown! Pic Heavy!
- Thread starter Weldo
- Start date
- Joined
- Sep 7, 2019
- Messages
- 674
I thought so too, but I wasn’t sure about the loading. It’s been so long since I’ve seen it assembled I’m not even sure how it works anymore! Gonna have to refer to reference pics!
- Joined
- Sep 7, 2019
- Messages
- 674
Had a half day at work today so I did a little more work on the shaper part.
To make enough thickness for the screw holes I welded small chunks to the inside of the main housing. Here they are after filing flat.
I then used the mating part to locate the holes. Clamps and transfer punches did the trick.
Drilled and tapped to 10-24.
The mating part fits well! This is without the dowel pins.
With the dowel pins installed I had to open up the receiving holes one step, from 1/8" to 0.136" to get them to align. Not perfect but pretty close. The parts go together well with not any perceivable slop.
There's gap at the joint. I may try to tap the part flat with a big hammer. Not sure if that's worth the trouble.
The following pic is how the joint looks with both factory parts. The large end is better than the fit with my welded part but the small end is worse. Maybe it's not that important?
I'll do some investigating as to whether it's my welded part or the mating original part that is not quite flat. Maybe its a combination of both.
The last big step is to chuck up the housing in the lathe and open up the large bore ever so slightly. I think I'm around 0.002" or so small. I was waiting until all welding was complete before I machined it to the finished size. As of right now it doesn't fit the shaper, but it's very close. I'm looking for a perfect slip fit.
To make enough thickness for the screw holes I welded small chunks to the inside of the main housing. Here they are after filing flat.
I then used the mating part to locate the holes. Clamps and transfer punches did the trick.
Drilled and tapped to 10-24.
The mating part fits well! This is without the dowel pins.
With the dowel pins installed I had to open up the receiving holes one step, from 1/8" to 0.136" to get them to align. Not perfect but pretty close. The parts go together well with not any perceivable slop.
There's gap at the joint. I may try to tap the part flat with a big hammer. Not sure if that's worth the trouble.
The following pic is how the joint looks with both factory parts. The large end is better than the fit with my welded part but the small end is worse. Maybe it's not that important?
I'll do some investigating as to whether it's my welded part or the mating original part that is not quite flat. Maybe its a combination of both.
The last big step is to chuck up the housing in the lathe and open up the large bore ever so slightly. I think I'm around 0.002" or so small. I was waiting until all welding was complete before I machined it to the finished size. As of right now it doesn't fit the shaper, but it's very close. I'm looking for a perfect slip fit.
- Joined
- Sep 7, 2019
- Messages
- 674
I wanted to close up the gap in the two mating parts before final machining. Upon checking each part with the flattest surface I could find it looked like my steel part was very slightly banana shaped but the casting was worse. I decided to leave the steel part as is and address the casting.
My first thought was to lightly tap it straight but this would likely have led to a cracked part. I then thought of using heat to relax the part.
I clamped it up thusly...
And then heated the casting as much as I dare before it melted. I actually did it in two rounds with the second round a little longer and hotter.
Here's how it ended up, it's much better!
You can see some of the old paint has burned to a crisp but I managed to avoid melting the zinc. Now I'm finally ready to machine the ID.
My first thought was to lightly tap it straight but this would likely have led to a cracked part. I then thought of using heat to relax the part.
I clamped it up thusly...
And then heated the casting as much as I dare before it melted. I actually did it in two rounds with the second round a little longer and hotter.
Here's how it ended up, it's much better!
You can see some of the old paint has burned to a crisp but I managed to avoid melting the zinc. Now I'm finally ready to machine the ID.
- Joined
- Sep 7, 2019
- Messages
- 674
Sound the trumpets, it's finally done! It was a much longer process than I thought it would be, but the part is finally finished and fully functional.
I chucked it up in the lathe and removed about 0.010" from the ID. Holding it was awkward and indicating it was very difficult. I couldn't get it right on and had to find a happy median. The indicator was showing about 0.007" runout but I think I can attribute that to welding distortion.
After I cut it to spec I unchucked it and tried it on the machine but it still was too small. Actually it seemed to be slightly oval shaped. I'm guessing that's because of how I had to hold it in the chuck. It was difficult to tell if the part was being held tight enough without distorting the relatively thin section.
I didn't want to chuck it up again so I did this with the drill press.
Not exactly "machining" but I did get a very nice fit and a very nice finish with this method. It's probably not perfectly round though...
Here it is on the machine. It has a very nice sliding fit and moves freely with only the tiniest bit of slop. It should work!
Now I hope to finish up the shaper rebuild over Christmas break. I'll be off work from Christmas Eve until around January 3. I should be able to get it shapering. The last big part to disassemble and clean is the cross shaft and pulleys.
I chucked it up in the lathe and removed about 0.010" from the ID. Holding it was awkward and indicating it was very difficult. I couldn't get it right on and had to find a happy median. The indicator was showing about 0.007" runout but I think I can attribute that to welding distortion.
After I cut it to spec I unchucked it and tried it on the machine but it still was too small. Actually it seemed to be slightly oval shaped. I'm guessing that's because of how I had to hold it in the chuck. It was difficult to tell if the part was being held tight enough without distorting the relatively thin section.
I didn't want to chuck it up again so I did this with the drill press.
Not exactly "machining" but I did get a very nice fit and a very nice finish with this method. It's probably not perfectly round though...
Here it is on the machine. It has a very nice sliding fit and moves freely with only the tiniest bit of slop. It should work!
Now I hope to finish up the shaper rebuild over Christmas break. I'll be off work from Christmas Eve until around January 3. I should be able to get it shapering. The last big part to disassemble and clean is the cross shaft and pulleys.
- Joined
- Sep 7, 2019
- Messages
- 674
Finally it's time for some more reassembly. It's been months.
This is the collection of parts that are left to re-install.
The bare feed assembly shaft and hub.
My fabbed part fits well, so far...
The small woodruff key is added.
And the spacer. the spacer has a keyway cut into its ID.
Next is the retaining plate with its 6 flat head screws.
It's here that I ran into some minor troubles. The housing must be very slightly recessed in relation to the cast iron hub face. Otherwise when you tighten up the retaining plate it pinches the housing to the iron hub and does not allow the housing to pivot. The housing must be allowed to pivot freely as the shaper table moves up and down vertically.
The spec is 0.373"-0.375" from the inner surface of the housing (the face you see in the above pic) to the face of the large machined ring on the housing. My part varied as much a 0.007" or so, which I attribute to welding distortion. I had already chucked up the part in the lathe and took a cleaning cut but I had not actually measured this spec until now. Since the clean up cut on the lathe was pretty nice I knew the machined ring was flat so figured it was the backside that needed some clearancing.
I ended up using the Dremel with a cutoff wheel to grind the backside on the part as shown in the pic below.
I got in the ballpark by checking around the circumference with a micrometer, shooting for 0.373-0.375". I set the micrometer to the target number and used it as kind of a GO-NOGO gauge. Once the micrometer could pass over the whole circumference while set at 0.375" I marked up the housing with sharpie and installed it again. I then rotated it around the cast iron hub noting a few snug spots. Upon removal the sharpie was rubbed off where contact was still happening. Just a little more grinding and it fit very well.
The below pic shows the grinding that had to be done. It looks like more that it is. Based on mic readings I only had to remove something like 0.007-0.010" from a few areas. The worst was near the bottom by the triangle gussets I had welded on.
It now can rotate freely without any snug spots.
This is the collection of parts that are left to re-install.
The bare feed assembly shaft and hub.
My fabbed part fits well, so far...
The small woodruff key is added.
And the spacer. the spacer has a keyway cut into its ID.
Next is the retaining plate with its 6 flat head screws.
It's here that I ran into some minor troubles. The housing must be very slightly recessed in relation to the cast iron hub face. Otherwise when you tighten up the retaining plate it pinches the housing to the iron hub and does not allow the housing to pivot. The housing must be allowed to pivot freely as the shaper table moves up and down vertically.
The spec is 0.373"-0.375" from the inner surface of the housing (the face you see in the above pic) to the face of the large machined ring on the housing. My part varied as much a 0.007" or so, which I attribute to welding distortion. I had already chucked up the part in the lathe and took a cleaning cut but I had not actually measured this spec until now. Since the clean up cut on the lathe was pretty nice I knew the machined ring was flat so figured it was the backside that needed some clearancing.
I ended up using the Dremel with a cutoff wheel to grind the backside on the part as shown in the pic below.
I got in the ballpark by checking around the circumference with a micrometer, shooting for 0.373-0.375". I set the micrometer to the target number and used it as kind of a GO-NOGO gauge. Once the micrometer could pass over the whole circumference while set at 0.375" I marked up the housing with sharpie and installed it again. I then rotated it around the cast iron hub noting a few snug spots. Upon removal the sharpie was rubbed off where contact was still happening. Just a little more grinding and it fit very well.
The below pic shows the grinding that had to be done. It looks like more that it is. Based on mic readings I only had to remove something like 0.007-0.010" from a few areas. The worst was near the bottom by the triangle gussets I had welded on.
It now can rotate freely without any snug spots.
- Joined
- Sep 7, 2019
- Messages
- 674
Now that the housing is sorted out the threaded collar can go on to hold the gear in place. There's a set screw in the collar. The Atlas diagram calls for a piece of lead shot to be placed between the set screw and the shaft threads. Not having any lead on hand I cut a tiny slice of 1/8" aluminum welding rod. That seemed to work well.
Next is the feed adjustment gear with T-slot.
Below is the line up of parts.
The bolt goes in flush to the bottom of the T slot.
Brass/bronze bushing goes in from the back with a thin washer.
The bolt goes through the housing and also captures a link that's attached to the ratchet mechanism.
The ratchet link fits to the back of the housing.
And the bolt/gear assembly goes through everything.
Here I encountered another small set back. I noticed there was not much thread protruding out the back of the ratchet link. Upon investigating I found the thin washer didn't fit into the counterbore on my fabbed housing. It's darn close though!
A couple seconds on the belt sander reduced the OD of the washer just slightly. Now it fits in the counterbore. Hard to tell, but it's in there!
Now the bolt protrudes enough for a washer and jam nut.
Next is the feed adjustment gear with T-slot.
Below is the line up of parts.
The bolt goes in flush to the bottom of the T slot.
Brass/bronze bushing goes in from the back with a thin washer.
The bolt goes through the housing and also captures a link that's attached to the ratchet mechanism.
The ratchet link fits to the back of the housing.
And the bolt/gear assembly goes through everything.
Here I encountered another small set back. I noticed there was not much thread protruding out the back of the ratchet link. Upon investigating I found the thin washer didn't fit into the counterbore on my fabbed housing. It's darn close though!
A couple seconds on the belt sander reduced the OD of the washer just slightly. Now it fits in the counterbore. Hard to tell, but it's in there!
Now the bolt protrudes enough for a washer and jam nut.
- Joined
- Sep 7, 2019
- Messages
- 674
Next the T-nut is slid into place.
I bolted on the zamak cover and found another clearance issue. The gear just barely rubs the cover as seen in the shiny spots below.
There's really no good way to fix this one. When I designed this part I used the outside dimensions of the original housing. See below in the Blue square. I did manage to hit that number pretty close but I failed to recognize that the material thickness I made my part from is thicker than the called for 3/32" (see the Red circle). Thus I ended up with less than 9/16" on the inside (see the Red square). The total outside dimension should be right at 15/16". I ended up a bit shy of that. Now when I bolt the cover onto the housing, it pulls the cover slightly closer to the gears and they rub.
The solution I came up with was to place a washer in between the two mating parts to add some space. It's not great but it does work. Below you can see the fabbed housing on the right, zamak cover on the left and the silver vertical line is a #10 flat washer acting as a spacer.
The next part to go on is the link from the T-nut to the ratchet housing.
The square head bolt goes to the T-nut since it's the one you'd be adjusting with the little square drive wrench that comes with the shaper.
The large knurled nut can now go back on.
With that the shaper is mostly back together. All I have left is all the stuff that hangs off the back like the motor and related bracketry. I hope to get to that soon!
I bolted on the zamak cover and found another clearance issue. The gear just barely rubs the cover as seen in the shiny spots below.
There's really no good way to fix this one. When I designed this part I used the outside dimensions of the original housing. See below in the Blue square. I did manage to hit that number pretty close but I failed to recognize that the material thickness I made my part from is thicker than the called for 3/32" (see the Red circle). Thus I ended up with less than 9/16" on the inside (see the Red square). The total outside dimension should be right at 15/16". I ended up a bit shy of that. Now when I bolt the cover onto the housing, it pulls the cover slightly closer to the gears and they rub.
The solution I came up with was to place a washer in between the two mating parts to add some space. It's not great but it does work. Below you can see the fabbed housing on the right, zamak cover on the left and the silver vertical line is a #10 flat washer acting as a spacer.
The next part to go on is the link from the T-nut to the ratchet housing.
The square head bolt goes to the T-nut since it's the one you'd be adjusting with the little square drive wrench that comes with the shaper.
The large knurled nut can now go back on.
With that the shaper is mostly back together. All I have left is all the stuff that hangs off the back like the motor and related bracketry. I hope to get to that soon!
- Joined
- Sep 7, 2019
- Messages
- 674
I hope everyone had a great Christmas! I don't know about you, but I'm ready to get this shaper running! Let's get to it!
There were a few small things to address during re-assembly.
First there was a broken screw for one of the ram wipers. I drilled it out and was able to dig around with a small pick to remove the remnant. It's really hard to drill a screw out exactly in the center. I chased the threads and they work, just gonna use a longer screw than in the other holes. The broken bit inside was pretty short and the top few threads are questionable.
The next minor problem was a sticky table support leg. I removed all the parts and cleaned them up.
First you remove the square headed bolt then tap the clamping parts out with a punch. Normally they'd push out easily by hand but these were so sticky with dried up oil.
Here's the parts. The concave section clamps the support leg shaft.
And there's a captured nut on the back side for the bolt. These parts are cast zamak I believe.
After some cleaning with solvent, the parts slip back in easily and the support leg freely moves up and down.
There were a few small things to address during re-assembly.
First there was a broken screw for one of the ram wipers. I drilled it out and was able to dig around with a small pick to remove the remnant. It's really hard to drill a screw out exactly in the center. I chased the threads and they work, just gonna use a longer screw than in the other holes. The broken bit inside was pretty short and the top few threads are questionable.
The next minor problem was a sticky table support leg. I removed all the parts and cleaned them up.
First you remove the square headed bolt then tap the clamping parts out with a punch. Normally they'd push out easily by hand but these were so sticky with dried up oil.
Here's the parts. The concave section clamps the support leg shaft.
And there's a captured nut on the back side for the bolt. These parts are cast zamak I believe.
After some cleaning with solvent, the parts slip back in easily and the support leg freely moves up and down.
- Joined
- Sep 7, 2019
- Messages
- 674
Next up for cleaning was this mess.
Start by removing the set screws in all the pulleys/collars. There's a set screw in each pulley and one in a collar.
This one from the stepped pulley is longer than the others.
One in the braking pulley.
The large pulley on the opposite side mates up with the motor.
And there's one in the collar on the inboard side of the large single pulley.
Next I removed the brake/clutch lever. There's two small pins that capture it on the cast iron bracket.
They tap out easily.
Now the lever with its shaft can slide out to the right in the below picture.
Now the pulleys can begin coming off. These were very stubborn in my case. A 3 jaw puller would have been great and I've been meaning to get one for years. I actually lightly damaged a small woodruff key and some of the pulley IDs by trying to beat them apart. There's a small key that holds the large single pulley but the collar does not have a keyway cut into it so the key must be removed before the collar can come off.
Now the shaft can be removed with the step pulley still on it. It was easier to work on this way.
The roller bearings can be easily slid out of the cast iron bracket and the casting is bare at this point.
Now the brake pulley can be slid off.
This is the side that goes up against the step pulley.
And this side goes against the casting and the roller bearings. Note the completely flattened out felt seal. Not much sealing here anymore.
Here's the collar that was inboard of the large single pulley.
And its old felt seal.
Finally I managed to tap out the shaft. All the parts are now disassembled. Time for more cleaning!
Start by removing the set screws in all the pulleys/collars. There's a set screw in each pulley and one in a collar.
This one from the stepped pulley is longer than the others.
One in the braking pulley.
The large pulley on the opposite side mates up with the motor.
And there's one in the collar on the inboard side of the large single pulley.
Next I removed the brake/clutch lever. There's two small pins that capture it on the cast iron bracket.
They tap out easily.
Now the lever with its shaft can slide out to the right in the below picture.
Now the pulleys can begin coming off. These were very stubborn in my case. A 3 jaw puller would have been great and I've been meaning to get one for years. I actually lightly damaged a small woodruff key and some of the pulley IDs by trying to beat them apart. There's a small key that holds the large single pulley but the collar does not have a keyway cut into it so the key must be removed before the collar can come off.
Now the shaft can be removed with the step pulley still on it. It was easier to work on this way.
The roller bearings can be easily slid out of the cast iron bracket and the casting is bare at this point.
Now the brake pulley can be slid off.
This is the side that goes up against the step pulley.
And this side goes against the casting and the roller bearings. Note the completely flattened out felt seal. Not much sealing here anymore.
Here's the collar that was inboard of the large single pulley.
And its old felt seal.
Finally I managed to tap out the shaft. All the parts are now disassembled. Time for more cleaning!