Mark7 Routing

[algale]

Terminology-wise I'd describe that as a router bit not a shaper cutter and I'd be very surprised if you were using that in the Shopsmith shaper chuck, which is really called a shaper arbor. https://www.shopsmith.com/ownersite/cat ... rarbor.htm

Terminology aside, I suspect you are right that the bit is being pulled downward into the cut and the set screws in the router chuck are gouging the bit's shank and leaving the trails shown in your photo.

Just to make sure everything is correct with your set up, I suggest you post a picture of the router chuck you are using. Also, it might be helpful to pull out the set screws and post photos of those, too. Shopsmith uses many different types of set screws and it is possible the wrong type of set screws are being used in the chuck. This is especially true if the chuck came to you from a source other than brand new and directly from Shopsmith

By the way, I don't use the router function on the Shopsmith very often, but I have used both the 1/4" and 1/2" router chucks on my 520 without problem including just a couple of weeks ago.

[BuckeyeDennis]

I’m assuming that you’re using the 1/2” router-bit chuck. From the set-screw marks on the router bit shank, it certainly looks as if you are torquing them down hard. If they were slipping, I’d expect to see score marks in the radial direction on the shank. What I do see looks to me as if the marks were formed by tightening the set screws hard multiple times at slightly different bit depths.

Which direction is the cut drifting? Into the workpiece, or away from the workpiece? If away from the workpiece, it could be that your table lock is weak, and the entire table (and workpiece) is drifting downward on the way tubes.

[JPG]

I would place something between the end of the quill shaft and the end of the bit(inside the arbor adapter(chuck). A ball bearing comes to mind. Maybe a nut or two? Anything solid!

That would eliminate any shifting of the bit in the chuck.

[DLB]

I would place something between the end of the quill shaft and the end of the bit(inside the arbor adapter(chuck). A ball bearing comes to mind. Maybe a nut or two? Anything solid!

That would eliminate any shifting of the bit in the chuck.

Well that brings up something, though I'm not sure what. I have two samples, both look like 505597 Version 2 aka 514631 on Russ's pic earlier in the thread. On both, the bit normally seats all the way to the quill spindle and that barely engages the middle setscrew. Even a 1/4" or so of spacer between bit and spindle would result no engagement on that setscrew. I don't see an obvious way to get the bit in there far enough to make the marks in DadsSS' picture unless the chuck is not fully seated. Something I'm missing, that should "eliminate any shifting of the bit in the chuck." Different spindle, different chuck?

- David

[jsburger]

Stop collars on the table legs will prevent the table from shifting if that is part of the problem.

[JPG]

Well I previously had not considered the possibility of the bit slipping OUTward. Ain't gotta fix fer that!

[DLB]

Well I previously had not considered the possibility of the bit slipping OUTward. Ain't gotta fix fer that!

Presuming the marks on the bit shank are a result of movement in the chuck... Seems like a lot(!) of axial force. Can't imagine that being outward. But can imagine that being the whole problem. And still don't understand the location of the mark nearest the end of the shank. Is it 'standard' how far the spindle protrudes from the knurled aluminum thingee? I suppose it's feasible that the spindle moved too, but again that's a lot of force. IIRC my quill spindles protrude ~1-3/16". I'll confirm and edit if needed. If that sort of force is being generated, first thing I'd try is a good new or freshly sharpened 'spoil board' bit. Preferably four flutes and of fairly large diameter to get the cutter speed up. What's the material and grain direction of this butcher block?

Note - It can also be true that other versions of the chuck have a different setscrew location than I'm basing this on. It would still take a lot of force to make those marks on the bit shank if they are indeed caused by movement in the chuck while in use. On my machine and router chuck, I believe the quill spindle would have to protrude less to create the marks shown.

- David

[adrianpglover]

It looks like the bit he's using is the "Bottom Cleaning Bit" from Grizzly's site: https://www.grizzly.com/products/grizzl ... dia./c1261

Given that, I think he's performing an overhead routing operation with the bit directly above the work piece and the work piece sandwiched between the router bit and the table. I've never done this, but I would think there are likely a few different places that he's running into issues.

First, make sure that the table is supported by the telescoping legs and that you aren't having any play in the table, even with you pushing down or lifting up on it at any of the corners. It may not seem like a lot, but if you're leveling an end grain butcher block and hitting different species of wood with different hardness, if you push the wood too fast then the cutter may be putting force downwards on the table and causing it to flex.

Second, this is a Grizzly brand bit. I personally like their tools, but the steel used in the shaft may be a bit soft. Maybe this is causing a problem here? However, I agree with the prior posts and that if these marks were happening while the router was running then I would expect these marks to go around the shaft.

Third, when you're setting this up, are you adjusting your depth by putting the router bit directly over the work piece and then pushing the quill down to the work piece with any amount of force? It's possible that these marks are being caused by excessive pressure with the quill feed handle and you're creating the flat spots while setting it up. If this is the case then try changing the practice so you're not putting a lot of downward pressure on the quill feed handle.

Forth, just as a bit of general advice - routing on the Mark 7 is at max a 10k RPM operation, unless you have a speed increaser. In the specs for the 1-1/2" diameter bit (the largest diameter that Grizzly sells) they state a max RPM of 18k RPM. Your handheld routers run much higher speeds than 10k. Since you're running at a lower speed, go slow with pushing the router into the piece. This will help with the "reduced" speed of the Mark 7 as compared to a normal router.