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SEB NEO Coaxial Unit Help Needed

windcall

Silver $$ Contributor
Purchased a SEB NEO the other day and picked it up from a shooter at Ben Avery in Phoenix. It wasn't the cleanest rest in town but I was eager to get a coaxial rest for a reasonable amount so I plunked down my cash. When I got home I proceeded to start cleaning it thoroughly, the previous owner actually greased the posts (dirt magnet) and at that point I found the coaxial unit wouldn't travel to the top of the rack post. Started searching on line and I ruled out the clutch, the rest moved cleanly for all but the last half inch of travel at the top. Further investigation suggested I check if the posts are parallel to each other. I used a machinists square and found both posts to be square to the base, but when I checked across the flats on the back of the posts, I found one of the posts was turned in. I think this is the problem. However, with the Coaxial Unit stuck on the rest, I can't think of a way to rotate the post back to being parallel with the other. My concern is that the pinion shaft has never been cleaned, and with the greased posts I'm pretty sure I'll find a mess inside. I sent an email to Ernie, but I'm not sure he is even an active dealer any more. Any suggestions would be most welcome. Thanks.
 
I rebuilt one i purchased a few years back. It also needed a lot of love.
You will get it sorted with some help and parts from Ernie as I did. Even Seb Email'd me with helpful
info. They are mighty durable and will last a lifetime with a bit of TLC.
 
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My biggest concern is how to realign the posts back to parallel while the coaxial unit is stuck in place. I suspect there is a .0015" or so press fit for the posts going into the base and I'm not sure how you budge that without screwing something else.
 
Purchased a SEB NEO the other day and picked it up from a shooter at Ben Avery in Phoenix. It wasn't the cleanest rest in town but I was eager to get a coaxial rest for a reasonable amount so I plunked down my cash. When I got home I proceeded to start cleaning it thoroughly, the previous owner actually greased the posts (dirt magnet) and at that point I found the coaxial unit wouldn't travel to the top of the rack post. Started searching on line and I ruled out the clutch, the rest moved cleanly for all but the last half inch of travel at the top. Further investigation suggested I check if the posts are parallel to each other. I used a machinists square and found both posts to be square to the base, but when I checked across the flats on the back of the posts, I found one of the posts was turned in. I think this is the problem. However, with the Coaxial Unit stuck on the rest, I can't think of a way to rotate the post back to being parallel with the other. My concern is that the pinion shaft has never been cleaned, and with the greased posts I'm pretty sure I'll find a mess inside. I sent an email to Ernie, but I'm not sure he is even an active dealer any more. Any suggestions would be most welcome. Thanks.
A short (still) video for me to see, please?
seb
 
The first picture shows how high I could raise the coax carriage before i cleaned up the posts and filed away some burrs. Second picture shows how high the coax carriage will travel before becoming stuck. I also loosened the set screws on either side that tension the pinion shaft. Third photo shows how far the left post is turned in. Fourth photo shows how far the right side post is turned in. I also checked with a feeler gauge the clearance on each side of the carriage when it is lowered to its lowest position at the base. Both sides are even. Another forum user suggested I heat the base up around each post to loosen the press fit in order to rotate the posts back to parallel. I'll wait until I hear from you on how to proceed. Thank you for reaching out. JH
 

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Have you confirmed that they use a press fit? Might be but I don't see the need and if so, it pretty much had to come that way and SEB would fix it, I'm sure. Yes, long trip, I know. It may be handled by Ernie, too. Either way, the .0015 interference fit someone else mentioned would be pretty huge and I don't even see it as necessary or even desirable, frankly. I'd be surprised but I don't know either so..
I'd think a good fit with some 609 or similar would be more than enough when tightened. If so, they should come out with about 350° of heat.

edit...the first pic shows what might be the problem. Looks like some vise grip marks near the top of the post. Have you tried filing those smooth? The out of "time" condition may not even be an issue.
 
Have you confirmed that they use a press fit? Might be but I don't see the need and if so, it pretty much had to come that way and SEB would fix it, I'm sure. Yes, long trip, I know. It may be handled by Ernie, too. Either way, the .0015 interference fit someone else mentioned would be pretty huge and I don't even see it as necessary or even desirable, frankly. I'd be surprised but I don't know either so..
I'd think a good fit with some 609 or similar would be more than enough when tightened. If so, they should come out with about 350° of heat.

edit...the first pic shows what might be the problem. Looks like some vise grip marks near the top of the post. Have you tried filing those smooth? The out of "time" condition may not even be an issue.
This video from SEB seems to confirm the press fit.
I'm awaiting word from SEB on how to proceed to bring the posts back to parallel.
 
This video from SEB seems to confirm the press fit.
I'm awaiting word from SEB on how to proceed to bring the posts back to parallel.
Appears that way. He builds them so I assume there's a reason but I don't see what it is. Doesn't look too bad to get them out but putting them back in and timed perfectly seems like the trick. I'm sure there's a reason or he wouldn't do it that way. I can see reasons not to but whatever I'm not seeing must make it necessary to the design. Just guessing it's timing of the teeth on both posts with minimal lash or clearance. I guess Seb would have to tell me as it's likely just part of his process that I'm sure he has well worked out by now. Mark might know why @majohnson
 
I am not very smart but it looks like the top of the threads are a little busted up, is that why it sticks and will not rotate upwards

seems simple to me but I am a bit of a simpleton

just asking from the pictures
 
I am not very smart but it looks like the top of the threads are a little busted up, is that why it sticks and will not rotate upwards

seems simple to me but I am a bit of a simpleton

just asking from the pictures
You are right, I'm working on getting the worst of the burrs filed out so the pinion shaft can engage, however, I don't think it is bad enough from keeping the coax carriage from moving at all. I think the bigger problem is how the posts are way out of parallel and I think that contributed to the thread damage.
 
You are right, I'm working on getting the worst of the burrs filed out so the pinion shaft can engage, however, I don't think it is bad enough from keeping the coax carriage from moving at all. I think the bigger problem is how the posts are way out of parallel and I think that contributed to the thread damage.
Get that cleaned up and we'll know for sure. I'm not sure yet. Some pretty good burrs or whatever on that post. Just speaking from a machinist's pov here but I can certainly see how even a slight burr could stop things, even more so than the rotational misalignment of the posts. Now, if they were leaning in or out to one another, that's different and would almost certainly cause problems. It all depends on how much clearance things have...and the math
 

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