Shopsmith Forums

reible wrote:Hi,

A couple of other quick comments.

If you look at the original sketch you might note that the bit has a bearing....

Ed, the only reason the bit had a bearing is because I cheated and went to SketchUp's 3D Warehouse and found a router bit and merged it into my model, and that's what they had...

iclark wrote:Ed,

after I posted my reply, I got to remembering the jointech videos of routing dovetails on a router table where they use 90* bracket that slides in the fence and has the stock up against the fence. also, the set-ups that I have seen for using a router to cut a long slot/dado into the edge or face of a board. I am having trouble reconciling these set-ups with the warnings against doing this.

I went to your pointer for understanding and fig 10-4 and, especially, fig 10-19 look to have the work stock between the bit and fence and between the bit and table. neither figure seems consistent with the warning that I have seen from many experienced woodworkers. what am I missing?

Ivan

I have this problem almost every time I set up the router and there is a fence involved.

Why? I know why. I have sent a piece of wood flying across the shop on two different occasions where I had the stock being cut captured between the fence and the blade. Just believe me, that spinning router blade can catapult a piece of 1x3 moulding a lot further than you might think. I have been fortunate in that I have not been the non moving object that stopped the 1x3.

Fence and Bit on the same side - maybe OKAY. Fence and Bit on opposite sides - probably a disaster waiting to happen.

I'll try to directly answer Tom's questions.

- Fence 515511 is a two part fence that comes with the OPR and fastens to the OPR table with screws into screw inserts.
- The Sander/Shaper fence - http://www.shopsmith.com/ownersite/cata ... rfence.htm mounts to the 510 and 520 table by two mounting bolts that pass through the fence and through the pre-drilled holes in the saw table.

Concerning Tom's drawing - AS IT IS - IT IS TROUBLE!! - - If the feather board were turned around, so the feed of the workpiece was from the rear of the table, the method would be degrees more safe than shown. However if this method is to be used - there should also be a hold down clamped to the fence. Without a hold down, the workpiece may get pulled up into the router bit.. Still - this would not be the best way. Using no fence and a starter pin is better - and a bit hidden into a fence is safest.

Referring to the picture 10-19; Notice the feed of the workpiece is from the rear of the table. This makes the feed against the rotation of the bit. This way the wood will not launch across the room, the launching force will be into the miter gauge. I have used this method of routing with my OPR prior to getting the idea and making a sliding table with a slot. Now I always use the bit below the table. It's just safer than a totally exposed bit.

A couple of comments regarding 10-4 and 10-19.

10-4) The router is NOT working against the EDGE of the workpiece OPPOSITE the fence. The piece can NOT get WEDGED! It IS however climb cutting on the edge of the slot nearest the fence. Thus a slow feed IS recommended.

10-19) This illustrates a similar wedge condition, but between the bit and the TABLE. Critical to the safety aspects is that the feed is from the 'back' side of the table. When fed from the back, the cutter is plow cutting as opposed the climb cutting IF it were being fed from the front.

What is plow/climb cutting? This is a description used by machinists relating to milling machine operations. In the case of a milling machine EVERYTHING is very securely clamped down. The workpiece is fed by moving the TABLE upon which the workpiece is clamped. Either method is possible, BUT climb milling is potentially more hazardous and lighter cuts/feed rates are prudent.

The terms are appropriately applied to routing(or shaping). The first example in Ed's illustration in addition to showing edge cutting on the fence side of the work piece also illiustrates plow cutting. The cutter starts cutting at the INSIDE of the edge being formed by the cutter and cuts toward the outer edge. Ed's second example in addition to illustrating incorrect fence opposite cutting edge, also illustrates climb cutting. The cutting edge of the cutter contacts the outer edge of the workpiece first and cuts INTO the worlkpiece. This is a recipe for a workpiece LAUNCHER.

It is helpful to understand the difference between plow and climb cutting so as to avoid climb cutting with either a router or a shaper.

Now as to molding(with the molder head) operations. Climb and plow cutting also occur. The molder is potentially more hazardous due to the cutting radius of the knives. NEVER NEVER NEVER NEVER NEVER climb cut on the opposite edge from the fence as in Ed's second('incorrect') example! When cutting with cutter mounted like a saw blade and beneath the table(fence to the ADJACENT side of the workpiece you are actually plow cutting since the cutter cuts from INSIDE the workpiece towards the outside.

Remember up/down is not relevant to defining plowing of climbing. Cutting from inside out or outside in is the defining factor.

Inside out is PLOW cutting(OK).

Outside in is CLIMB cutting(BAD BAD BAD)!

I think I may be starting to get it. thanks all for the patience and clarity.

at the risk of hi-jacking the thread (sorry, don't mean to), can someone tell me why the fences keep being setup parallel to the rip fence?

why would it be so bad to actually use the extension tables and floating tables to support the workpiece being routed and feed the stock parallel to the bench tubes?

Ivan

iclark wrote:I think I may be starting to get it. thanks all for the patience and clarity.

at the risk of hi-jacking the thread (sorry, don't mean to), can someone tell me why the fences keep being setup parallel to the rip fence?

why would it be so bad to actually use the extension tables and floating tables to support the workpiece being routed and feed the stock parallel to the bench tubes?

Ivan

What are you using as a guide for the workpiece?

iclark wrote:I think I may be starting to get it. thanks all for the patience and clarity.

at the risk of hi-jacking the thread (sorry, don't mean to), can someone tell me why the fences keep being setup parallel to the rip fence?

why would it be so bad to actually use the extension tables and floating tables to support the workpiece being routed and feed the stock parallel to the bench tubes?

Ivan

Hi,

Use of the shopsmith fence is just an easy way to have a fence (or is it?). A fence can be set up at any angle so long as you have room to feed the stock through. If the stock is thin enough to feed between the way tubes that works... if you have a 505 and above you can put floating tables out in front or back (or both) of the main table on legs and gain some table area....

A fence can be as simple as a piece of wood with a straight edge clamped to the table. You will of course want to put a guard in place to protect yourself... If you go to:
http://lumberjocks.com/reible/workshop#
and look at the third picture you will see a piece of UHMW plastic and some clamps being used as a fence.

Ed

iclark wrote:I think I may be starting to get it. thanks all for the patience and clarity.

at the risk of hi-jacking the thread (sorry, don't mean to), can someone tell me why the fences keep being setup parallel to the rip fence?

why would it be so bad to actually use the extension tables and floating tables to support the workpiece being routed and feed the stock parallel to the bench tubes?

Ivan

Hi Ivan! Thought I'd be the second person to tell you fences don't have to be parallel to anything in order to route a straight line. In fact, here (at the bottom) is a photo of routing (as you asked) parallel to the bench tubes. I was routing a one inch long dado, 3/4" wide making a slot to accept the control rod for a shutter. I had to clamp the workpiece and also backed it up with a fence. The dado was cut by moving the table toward the way tubes.

Maybe more important is you question/concern about why is routing in one direction so different from routing in the other direction. We have received a good explanation of inside to outside - Good, while outside to inside is BAD!

Although I could always understand climb cut versus plow cut when thinking about edge routing, but was at a loss on how that applied to dadoes and grooves, until I thought of it a bit (no Pun) different.

If we think of groove and dado routing by looking only at the forward edge of the bit as it will pass through the wood. If that edge is rotating toward the fence - that action will hold the wood up against the fence. This will work while routing with an over arm or under table. The difference is, with an overarm grooves should be routed from left to right. Under table, the wood movement should be from right to left.

Since Chuck was the second person, let me be the third. The important thing is the distance from the fence to the bit. Other then that critical measurement, the fence position is irrelevant.

a1gutterman wrote:Since Chuck was the second person, let me be the third. The important thing is the distance from the fence to the bit. Other then that critical measurement, the fence position is irrelevant.

thanks to all 3 of you for the replies. I appreciate what you are saying and I understand it.

however...
the last time I needed to use a router, I was doing a 1/4-round round-over of 3 of the 4 long edges of a 2"x10"x10' board. I assembled my cheap router table (decent little steel table - worthless fence), mounted it on a Dewalt miter saw support cart, and tried to do the routing on the table with a support roller on each end. after one pass, I unmounted the router and did it freehand. there was not enough stiffness in alignment between the support rollers and the router table.

for that 10' long 2"x10", it seems relevant to me whether I have a 2' long router table (fence parallel to the rip fence) or a 10' long router table (fence parallel to the table connector tubes, jointech table on 520 rails, and 5' connector tubes in both directions used to build the SS table system).

Ed, your example has the fence parallel to the bench tubes, but you have gone to the effort to set up the router table as an outfeed table rather than mounting it between the main and extension tables. you avoided using the extension table or main table to support or interfere with the workpiece.

for small pieces, I guess it is handy to be able to walk around 3 sides of the router table, but, for longer pieces, it seems like assembling floating table, main table, router table, extension table, floating table on 5' connector tubes with legs would make an excellent long router table except for the ridges in the aluminum table tops.

it feels like I am missing something fundamental. SS gets put down because of the relatively small table saw table. SS could point out how small all the non-SS home shop router tables are compared to the 510/520 if we just turn the fence 90* from the traditional position. but they don't. and the experienced people here don't. (and at this point, I expect someone to offer me some cheese with my whine;) )

sorry to get so wordy,
Ivan