Topping out, clearance problem

[myxpykalix]

I have some 3" thick walnut i want to pocket out the center for a round box down to 2.75" and then profile cut it out of the wood at 3".
I have a 4" long .5 bit
I have just a little over 3" of the bit sticking out from the collet to reach the bottom to cut it out.
Problem is i only have less then .25" before it tops out.

The router is sticking up maybe a half inch from the top of the router mount. Any suggestions on how i can eek out some space to keep it from topping out?

I have done this before, i just don't remember how...:confused:

[feinddj]

Its like those tall trucks that you see at underpasses, let some air out of the tires. I have gotten some extra space by milling a pocket in the sacrificial board of the vac table and after the job putting a patch back in.

David

[Brady Watson]

Edit my_variables.sbc to reduce the safe Z height for C2 & C3. Also, reduce your safeZ in your part files down to something like .125".

-B

[scottp55]

Darn Brady, I knew half of that one!:)

[myxpykalix]

As it turns out, it is easier to just drop a couple of 2x6's into my indexer bay and put my board on top of that. That gave me a couple inches extra depth. I have to clamp it down and will cut it tomorrow.

[scottp55]

Brady, Never Knew my variables was there. Would Jack change C2 AND C3 to .125" as well as the program safe Z?

[Brady Watson]

Scott,
Yes - that is the general idea when you have little head room. Otherwise, the tool will top out when doing C2 or C3. Unless you have clamps or other obstructions to contend with, it should be a pretty safe affair. However, I would still go back after that job and change the values back to like 0.5 or something, or the defaults.

I know the Desktop has a short Z - and a lot of users routinely top it out (stalling the motor) and then they get confused why the Z values are off. I would put a prox switch on the Z to prevent this because it is hard on the nut when you top it out. It's hard on the gantry tools too - many times crushing the dust shoe. Prox on the Z is standard on ATC tools - I'd like to see them on all tools.

-B

[scottp55]

Thanks Brady, Got factory installed proximity switches(3 additionals) right at the get go(best $100 we spent). Need to follow up threads that popped up when I searched My_ Variables that I've never read so I don't ask anymore questions that have already been answered. Thanks once again for your help. scott

[srwtlc]

The current versions of SB3 and the related zeroing/homing routines now utilize the system variable for 'Safe Z' that is set in SB3 with VC (Cutter Values) so there's no need to edit the my_variables.sbc file for this situation.

I'm not sure at what version the change was made, but older versions used the value in the my_variables.sbc for the Safe Z instead of the one set in SB3, thus the need to change it in the my_variables.sbc file.

You still need to make sure your posted file has the rapid z gaps and home values set accordingly.

[cowboy1296]

I stole this idea few years back and it works fine. But grind down the bump (not sure what it is called) on the side of the router. This will enable you to raise the router up at least an inch inside of the sleeve that secures it.

[myxpykalix]

Here ultimately was the solution i went with. I just didn't have enough space without topping out no matter what, unless i wanted to change the position of my router carriage on my Z. That was too much work.

I just cut a 2x12 in half put a piece of plywood on and it lowered it by a couple inches in my indexer bay.

[Brady Watson]

Dude...pics of the box with weave on them!!! Where they "at" ??? :D

-B

[myxpykalix]

Brady,
I hate to disappoint you:( but after cutting the boxes out the grain patterns and knots and worm holes looked more beautiful then any carving i could put on there. I am going to make a carved lid though.

Fret not...since your efforts of drawing that illustration will not go in vain.:D
Since i have this set up i am going to cut some more out of a lighter less figured wood like poplar or maybe cherry. I think i have some thick pieces in the pile.

I know i have a big block of hickory i've pondered what to do with. And i have a bunch of Japanese maple i had to cut down from one of the houses but don't know what that might look like.
I am going to make your jig and use part of it as a "jam chuck" to put these boxes on the lathe in order to sand and finish.

So thanks again and i'll post some of the lighter boxes when i cut them.