Removing an SB7 shaft to remove the ram... what's the secret?

Clock work

Registered
Registered
Joined
Nov 25, 2016
Messages
175
Hi folks... I'm reducing my SB7 into major sections so my ancient "body" can hump it down into the basement from the garage.... I've followed the instructions in the Army manual for removing the ram (no way EVER I'd have figured that out). The set screw is out... the other stuff is done but the shaft doesn't seem interested in sliding out. This is a Gen 1 shaper and I'm unsure there's not some subtle destroyable retention feature in there someplace. Is this just something you push out with a drift? Thanks..

CW
 
Last edited:
I design things for a living and get on planes and fix other guy's designs and here's my reaction to the SB shaper. The guy who "designed" this should be shot. Hideous, unintuitive, undocumented and uncommon. I got this thing broken down so I can get it into the basement but I have one last mystery... the lead screw that moves the saddle up and down is still stuck in the base. It should be so extremely simple but I can't see a way to get that out of the base without exerting more force than Id be comfortable with. Anyone know the recipe? Thanks.

20180307_221321.jpg
 
CW,
Unfortunately, I have nothing to answer your question with, as I just got an SB7 myself, but I want to wish you well. Hopefully there will be another member that has some familiarity with the lead screw. I definitely understand your anguish with designs that oppose logic in their construction, some engineers were sadists that cobbled stuff together with blatant disregard for serviceability. Please share more info as you get this little bugger running.

Mark
 
CW,
Unfortunately, I have nothing to answer your question with, as I just got an SB7 myself, but I want to wish you well. Hopefully there will be another member that has some familiarity with the lead screw. I definitely understand your anguish with designs that oppose logic in their construction, some engineers were sadists that cobbled stuff together with blatant disregard for serviceability. Please share more info as you get this little bugger running.

Mark

Hi Mark... nice to meet you. I will definitely share if I happen upon anything useful (breath should not be held though!:). It worked great when I picked it up from the seller. I only did this so I could move it alone instead of dropping it down the hatchway with my backhoe which is my usual mode when it won't chew up the lawn. I'm in a lawn-vulnerable mode currently and it was growing visible rust on some machined surfaces so action was needed. I didn't plan to make it pretty but just use it and tweak the running gear toward precision over time but I'm now one step removed from the periodic chart as far as taking it down goes so... I guess I'd be insane not to add a few more hours and chase pretty as well. Safety green machine... safety blue cabinet as I'm OD'ing on gray at this point. Let my estate worry about any value drop:)

Not sure if you have a gen-2 model but if so, look up the admonition on removing the ram gibs at the right time as you will can break off the little semi-rigid plumbing that carries the oil up there.

You know... I'm going to feel WICKED stupid when I finally get that screw out and come back and look at this thread. It's coming. No other possibility. There's just SO bloody little there... gear on one side.... no fasteners I can see... collar on this side which I loosened and which now flops around. I think the collar is just there like sort of a backlash reducer but... something would have to be able to move once you loosened it for that to actually work. Going to put a little acetone/ATF on the affected elements (way faster than PBlaster in experience) and see if anything comes loose.

CW
 
CW,
Mine is one of the later versions with the flared front casting and the automatic oiler, it was built in OCT 1958. I lucked out and got an excellent example that won't give me an excuse to take it down to parade rest (as I typically do:grin:), so any disassembly will be limited to specific repairs as needed. I have seen reference to the gib/oiler fiasco and appreciate you mentioning it.

I did pull up the Army manual and page 32 shows the parts diagram. That shaft should drop out the bottom??? It's possible that the shaft had a burr or ridge that is holding it in place. Worst case drive out the TAPER PIN, item #49 to remove the gear and pull it out the top.

http://www.eurospares.com/graphics/Tools/shapers/sbarmy7shaper.pdf

Keep us informed and I wish you the best getting it spiffed up.

Mark
 
Oct 58? Why that's New In Box! :) My pleasure on the oiler. I have to seize any and all opportunities to sound like a non-idiot that show up!

So I went looking for that taper pin, as I've just never had to deal with that particular fastener type and frankly totally missed that in the exploded parts diagram (thank you!). It appears it's not the pin.. the gear is profiled to permit the worm to more fully engage it and I believe the worm is trapping the gear in position, first photo. So.. I have to pull the worm (no offense).

About taper pins... the next two attached photos show the upper taper pin (I am assuming) that holds the worm. One shows the protruding end.. the other the flush end. Can I draw any conclusions as to which end to strike with the drift from this?

Thank you again. Consider the taper pin question open to the community.

CW

20180309_182633.jpg


20180309_183406.jpg


20180309_183419.jpg
 
CW,
It looks as if the taper pin is tucked up in the casting. The gear appears to be concave and may not be coming out due to interference with the worm gear. That might have to go first. As it likely has taper pins also, use a caliper to see if you can figure out which is the small end. It may be simpler to just leave it in place and clean/paint around it rather than risk damage to anything. If you're comfortable to proceed with removal hopefully it won't put up too much of a struggle. Keep us informed.

Mark
 
CW,
It looks as if the taper pin is tucked up in the casting. The gear appears to be concave and may not be coming out due to interference with the worm gear. That might have to go first. As it likely has taper pins also, use a caliper to see if you can figure out which is the small end. It may be simpler to just leave it in place and clean/paint around it rather than risk damage to anything. If you're comfortable to proceed with removal hopefully it won't put up too much of a struggle. Keep us informed.

Mark

I had an idea... I think I said that right before the first time I broke my neck. I'll report back if it works and quietly allow myself to be forgotten if it doesn't:)
 
It looks to me that the top taper pin locks the worm gear to the shaft permitting the torque to be transmitted. The bottom pin holds the thrust washer in place. Whack the small end of the taper pin, well gently drive it out.
 
It looks to me that the top taper pin locks the worm gear to the shaft permitting the torque to be transmitted. The bottom pin holds the thrust washer in place. Whack the small end of the taper pin, well gently drive it out.

Thank you much. I ended up making a taper pin pusher (pix in the shop-made tooling forum) to forestall the cascading, run-away chain of rapidly bifurcating failure I was put on this planet to initiate when I encounter something new:)

CW
 
Back
Top