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Routing w 1 1/2 round over bit
Posted: Tue Jun 09, 2015 1:57 pm
by c2h6o
I am getting ready to put a bull nose edge on a piece of 8/4 oak for a top to a night stand. I have the bit which measure nearly 3 in in diameter. I practiced with the bit in a horizontal position, taking very small cuts, but really don t like this. It looks like the oak gets pressed under the bit even with small cuts and the force can "grab" the wood as it nears the end of a pass.
Am now looking to do this with the SS in the horizontal position with above board routing. Have the PP with dual tilt. Would appreciate any comments suggestion on how best to do this.
Re: Routing w 1 1/2 round over bit
Posted: Tue Jun 09, 2015 2:04 pm
by c2h6o
I mean the vertical above table position
Re: Routing w 1 1/2 round over bit
Posted: Tue Jun 09, 2015 4:07 pm
by forrestb
While I have not done a bull nose using that large of a diameter, I have done smaller radii. I always use the under that table routing mode and have made a table with moveable fence so it acts like a normal router table.
Since you have the ability to do under the table routing, I would definitely recommend that. That large a bit on top personally scares me.
Try under the table and use the quill feed to incrementally get to where you want. When you get there, set the quill lock so you can return.
You will find that when you get to a change in grain direction you will be cutting into the grain and it will try to pull the work. Been there, done that.
As much as you normally never climb cut you may have to to prevent tearout and 'pulling.'
Forrest
Re: Routing w 1 1/2 round over bit
Posted: Tue Jun 09, 2015 4:31 pm
by reible
You didn't mention what sort of fence you are using. I would assume you have looked into that issue and know that you only want to expose part of the bit at a time.
I too would look to work with the powerpro below the table since you can hide the bit below the table and fence giving less exposure. The only issue here is I'm not sure a 3" bit fits the table insert hole???? In which case you would need to add a false table and extend the quill through the table. In that case you really need to get a stop collar the same size as the quill to make sure it can not retract once extended above the table.
It is very rare if ever that I climb cut and even if I were to do it it would be with extremely shallow cuts. If you are getting tear out then I would do scallop cuts first then do the profile along the edge.
With that big a bit things can go wrong very quickly and with a lot of force so perhaps you need to send us some pictures so we can verify what you are doing. If unsure it usually can mean unsafe........ just saying.
Ed
Re: Routing w 1 1/2 round over bit
Posted: Tue Jun 09, 2015 4:46 pm
by c2h6o
Thanks guys. The round off bit is to big for the normal insert, that is why I went to above the table configuration. For the fence I have been using the SS fence like that for a Mark VII. I will send pictures. If I do go to under table then I will have to make a special table and fence.
Re: Routing w 1 1/2 round over bit
Posted: Wed Jun 10, 2015 11:54 am
by c2h6o
Here is a picture of my set up
Re: Routing w 1 1/2 round over bit
Posted: Wed Jun 10, 2015 1:02 pm
by BuckeyeDennis
Your instincts were right on -- that is a very dangerous setup. Trapping the workpiece between the bit and the fence is a recipe for a severe kickback.
To avoid that, you need something configured like the
Shopsmith shaper/router fence.
Re: Routing w 1 1/2 round over bit
Posted: Wed Jun 10, 2015 2:05 pm
by edflorence
I just did some grooving in the rails/stiles for paneled cupboard doors in the under-the-table mode using the speed increaser and shopsmith split fence. Worked great and felt very safe. I completely agree that taking the time to make an auxiliary table with oversize hole for that big bit would be time really well spent. Just looking at that monster bit and imagining it spinning around above the table scares me. Looks even scarier than a fly cutter, which is already scary enough. With a bit that big I think it might also be worth while making some sort of a box that would bolt to the standard fence to cover all but the working edge of the bit.
I had an idea similar to that after I got the split fence set up the other day. I wondered if maybe I could have simply used the regular rip fence with two sacrificial pieces bolted on, leaving room for the bit between. In my case the bit was a 1/4 inch straight bit, so it would not have required the sacrificial pieces to be very thick. I think I would try to come up with some variation on this if I had to work with that 3" bit.
Re: Routing w 1 1/2 round over bit
Posted: Wed Jun 10, 2015 6:29 pm
by dusty
Not this guy!!! I don't even want to read about it. This is NOT the sort of woodworking that the Shopsmith (even the PowerPro) was designed to do.
I do wish you luck.
Re: Routing w 1 1/2 round over bit
Posted: Wed Jun 10, 2015 7:24 pm
by ChrisNeilan
dusty wrote:Not this guy!!! I don't even want to read about it. This is NOT the sort of woodworking that the Shopsmith (even the PowerPro) was designed to do.
I do wish you luck.
Chicken!

But I bet you have all ten fingers, and both eyes, and no scars from flying wood! It scares me. A few years ago I would not have known the dangers of this type of set up. I do now. Never too old to learn!