Concentric Router Lift Issues

[steve-norrell]

I have one of MCLS's Quick Joint System (http://www.mlcswoodworking.com/shops...nt_system.html) and after several (many) tries can't seem to get acceptable joints. I tried bits from different makers and at least two different sets of hole adapters and nothing worked.

Upon close examination of the setup, I found that the the router bit is slightly off center, less than 1/16 inch -- but just enough so that the joints are less than perfect fits. The lift is a JessEm Mast-R-Lift with a Bosch 1617 router, held in place with a JessEm adapter.

The Quick Joint instructions include information about centering the router, but they don't seem to apply to the JessEm Mast-R-Lift, which does not appear to have any adjustment for concentric alignment.

The possible causes for the misalignment include, IMO, the lift itself, the router (its about three years old and could be a little worn), or the adapter ring for mounting the router. I have tried rotating the adapter ring to see if it changes the alignment and it does not.

Any comment and helpful suggestions would be welcome.

Regards to all, Steve.

[Black wallnut]

I'd be looking at the lift as that seems to be about the only thing that could cause this problem. One other possibility is a router motor with the shaft and collet off center and I find that highly doubtful. I'd be calling JessEm.

[LCHIEN]

are you using a bushing mounted on a insert mounted on the router plate?
Try seeing if the busing has any play when you loosen the holding ring for it. YOu might be able to center the router better by moving the bushing arouns and then locking in place when the router bit is centered. There are some cone-devices (Bosch sells one) that can be placed in the router collet to help center the router when doing these kinds odf adjustments.

[charliex]

What Loring said. The bit must be exactly centered in the bushing or you will have a double error in your cut. The problem will be more noticeable with a hardwood (oak, maple) than with softwood (aspen).

[steve-norrell]

Charliex, Loren, Mark,

Thanks for the input.

I have already tried Loren's suggestion and, in addition, checked alignment of the full range of lift adjustment (using a 1/4 in drill bit). No change from top to bottom.

I have a couple of photos, but I can't seem to get to the Attachment Management page. I'll try later.

I guess my next step to talk to the folks at JessEm.

Regards. Steve

[steve-norrell]

Here are the photos mentioned above. The photo with the centering cone (Cone 1) in place shows the lift to be off by a very small amount. However, the picture with the 3/16 in. straight bit (Bit 1) in place clearly shows an off-center lift.

One possibility I haven't checked yet is the collet and I will do that shortly, after that, I talk to the folks at JessEm.

Regards, Steve

[Uncle Cracker]

Calling Jess-Em is a good idea, and so is replacing the collet, as they are not expensive. Also, make sure the collet is seating cleanly in the bit holder, as there can sometimes be a bit of resin buildup in there... a swab with acetone should leave you a clean seating. Look also for a wallowed-out area on the inside facing of the collet nut.

I realize that the above suggestions are more likely to cause bit wobble, rather than eccentricity, but a close inspection of the router lift surfaces and components for stray particles or buildups could still lead to the cause of your troubles.

[pelligrini]

I doubt it is the Collet, that would also be easily checked by rotating the router shaft. If it does wobble then it's the router.

Have you checked the insert? The hole for your bushing might be off. Measure from your bit shank to the edge of the opening in the plate. If it checks out, then the problem might be with the insert.