Had an idea last night to split the rounded end toolpaths into two. Right now as the bit move around it goes from -x to +x direction, which always causes a little more vibration on the +x side.  Split them up so both move in the -x direction. and don't reverse direction during the cut.

I talked myself out of that idea this morning as one cut would be a climb cut but the other could be a conventional cut, and every problem I've had to date was during conventional cuts. 

Took my thumb drive down to the CNC.  The brass bar has been in place ready to be cut in my low profile vise with three clamps on it. Two t-track clamps holding it down and keeping it from moving toward the clamp. A c-clamp on the back side. 

The curve cut went fine.  Most minor vibration/ buzzing on the +x side of the cut, but no visible damage due to that vibration. 

Next came the notches to cut the angled corners.  The first one proceeded fine, although I maybe should have slowed it down a bit as it sounded a bit aggressive.  The second started fine, but about 3/4 down and something caught, the machine flexed and dug into the brass, and jerked the vise out of square which I didn't initially notice. I E-stopped the cut reasoning the I could clean it up with a file after cutting the part off the bar.  Started the machine and did a quick check to see if the machine had lost any steps in X or Y or Z direction. No.  I put my hand on the router to push/pull trying to see if there was any flex there.  What revealed itself was that I could push the router down, twisting the 60mm x 30mm gantry beam. Probotix has upgraded their machine with a beefier 60mm x 60mm beam of thicker walled extrusion.   I suspect this is why.  My machine just isn't tough enough to "easily" cut brass.  When it is working the cuts are smooth and sound efficient.  When the deflection in the machine finds opportunity something gets damaged.  I've got two test cut parts in brass that have damaged surfaces. 

The flex of the Z axis is the killer fault.   As I have a working aluminum press button depth stop collar I'm giving up on making one from brass.  The effort has already answered my curiosity about CNCing brass with my CNC.  The answer is "Not a good idea!".   

4D 

Wild idea of filling the gantry beam with expanding foam or concrete to stiffen it. Major surgery required. Abandoning wild idea. 

Looking for some place in my house to put this: https://taigtools.com/product/micro-mill-5019cnc/.   I can afford it. I can use it. I've got spare PCs and can dedicate one to it.  Looks like it'll cut steel too.  Might have to learn a bit about CNC cutting steel. Love to be able to cut stainless steel. I've got material on hand to make a bench to put it on. 

4D

Good friend of mine has one I can use anytime.  So far the Unimat adaption and the milling adapter for the 6z" lathe have sufficed so far.

If I had a heated garage I would have already order that CNC Taigtools mill.  In a corner of the basement room where I have my Probotix CNC I've got a small CNC I built with ball screws on all three axis.  All parts made from plywood though and I couldn't get it to work reliably with a tinyG controller I bought.  Might scrap that one, salvage all the hardware, and replace it with the Taigtool mill.  I'll never use it enough to justify paying for it, but I need a distracting tool to keep me awake. 

 

In contemplation of the Z axis deflection I realize the vibration on the high side +x moves was the bit climbing over what it was cutting, and able to do that because the Z axis could deflect in that direction away from the material.  The same deflection was why I could cut the top angle corner with no disaster as any desire to deflect was away from the material.  The bottom angle corner got bit because the bit deflected into the material.  Twisting on the gantry beam is worse in the middle of the beam away from the gantry vertical supports it is bolted to.  I'm going to move the vise close to the side and see if I can clean up/redo the brass to finish the part. I'll check for deflection of the router when it is near the side.  

4D

I went ahead and finished the collar.  Other than an over eager angled corner with a few scars and one broken router bit the collar looks fine in the dim light on the shadow side of my Wen drill press. It is a little thinner which doesn't matter but is because I milled off the chamfer edges I cut before I realize the vise had been kicked out of square.  I haven't cut a brass button for it, but instead used the button from the HDPE version that started this endeavor.   Best parts from all three version are likely the brass body and aluminum button.  Both have scars but those will remind me they barely survived being cut out by a CNC that never should have tried cutting aluminum or brass. 

Brass has been banned from my basement CNC room for now.  Both the CNC and the Wen drill press have bad memories from their brass experiences.  My CNC can't stay mad at aluminum as it is made from aluminum. The drill press wants me to banish aluminum to the garage shop area where any holes can be drilled out by the floor model Nova Voyager drill press that lives there.  

4D

Making progress.  Looks aren't everything.  If it works it works.

There may be a moral to this story of gaining experience through bad decisions

It is still a mighty nice looking part 4D

Thanks Cal.  I'm a devoted fan of new fabrication experiences.  Hard to know what you can't or shouldn't do until you've tried it.  I learned many years ago that I could cut aluminum with most woodworking tools.  I witnessed the large Multicam CNC we had in the fab lab trimming the edges and V-carving letters into the face of an aluminum plaque/sign.   I've known my hobby CNC had some deflection and minor backlash which never mattered in all the wood projects parts I cut with it.  Cutting aluminum and brass was the unknown. Although I solved my drill press depth stop upgrade with an HDPE version, my sense that it might fail/degrade over time prodded me to see if I could make the aluminum version.  Turns out that my CNC can cut aluminum and brass.   It unfortunately can also deflect into and grab metal parts it is cutting leaving scars on them.  When I was a student we had a milling machine and I was probably the biggest user of it. Often making aluminum details or brackets for furniture projects. Parts for a press button lathe tool handle that you could press/release to change the angle of the handle relative to the blade with.  Parts for press button seat height adjustment on Balans-style chairs I designed.  Etc..

 

I've got a 24" x 48" slab of 1.5" thick butcherbock. I've spent an hour or so this morning to see if I can figure out how to cut it to reconfigure it into a 33.9" x33.9" (or close) slab I can use as a table top to put the Taigtool CNC mill on. I've already got a square table base I can use.  This is a drafting puzzle that I "know" has a perfect solution.  So far allowing for the kerf cuts throw some imperfection into the puzzle. If I solve this my reward will be to order that CNC mill to put on that table. 

Checked the bitcher block slab and the package claims 25" x 48".  No sure I believe the 25" dimension as that's what my tape measure show the width of the outer packaging.  In any case I brought it in from the cold garage to let it warm up.  Cleaned up and reconfigured my CNC to handle the slab.  Hoping the Y axis extents reach to the back corner.  Front corner is limited by the chuck of my rotary axis.  If not then I'll have to flip the toolpaths as they don't currently extend to the front edge.  If the block is truly 25" wide then I have figured out two linear cuts that will divide the 25" x 48" block into 3 pieces that can then be glued back together as a square. 

 

4D

As I suspected the butcherblock panel was a little under 25" wide.  It also has rounded over corners which complicate this as two outer edges will butt together when the parts are rearranged.  I went ahead and cut the panel apart.  Switched out my CNC router for a smaller trim router which should lower the cantilever weight off the gantry beam.  I limited my cuts to 1.25" deep in the 1.5" thick panel. I don't have any router bits with cutting edges longer than 1".   All went fine.  I flipped the panel over and used a 1/4" spiral downcut flush trim bit to run through the groove and complete the through cut. Clean cuts all around. 

To deal with the rounded edge I took the smaller triangle to my little jointer to joint them off. First few passes  started taking more off at the lead edge than the rear, and made the square corner out-of-square.  I marked a line where square was and did a few tapering passes on that jointer to get back to a square and clean crisp edge.   I need to do the same to a short edge of the largest piece, and will likely use a large flush trim bit and a straight edge rather than try and manage it over a jointer. 

When all parts are glued together I'll need to trim flush one edge to where the mistakes all gathered.  The square panel will be 3/8" smaller in one direction than planned but not a critical loss.  The images show what I tried to do.  Imperfect dimensions and rounded edges just made the final square a bit smaller. 

4D

Went down this morning and glued up the square.  Small uneven edges show how not flat the initial Chinese made butcherblock panel was. When the glue is dry I'll use my track saw (for the first time) to trim the one uneven edge.   I'll make a template I can use with a router to put a 1" radius on all 4 corners.  I've got a monster scary flush trim bit that has angled blades that shear rather than scrape when they cut.  Feels a bit out of balance when spinning but does a nice smooth job. 

When that is done I'll haul the board out to my 19" wide open end drum sander and see how many passes it takes to flatten both sides. 

Square panel has been through my drum sander.   Took off roughly 1/16" on each side to get the panel truly flat. 

Back to my basement shop area to sand smoother, fill a few crack/gaps, and round over the perimeter with a 1/4"r roundover bit. 

Mixed results figuring what to make the base from.  Selection of useful scraps in my garage is diminishing. 8' long vinyl wrapped MDF shelves beg to be used for something, but I detest MDF.  Not enough redwood boards salvaged from a condemned previous deck remain.  Having thoughts about making more of a cabinet with drawers to store accessories for the Taigtool CNC mill.  Love to find something tool cabinet like already made I could repurpose as a machine tool base/stand.

4D

Been looking for some 4 x 4 cedar to make the legs for the tool table base.   HomeDepot.com has a perfect package of two 6' long pieces, although they don't have them in my local store.  Went to order them to be shipped to my house, but HD wanted me to sign up for an account, including coming up with a password.  No Guest option, so no business from me as I would forget whatever password I came up within 2 seconds after finalizing the purchase, and don't need another 20 emails from companies they would sell my buying pattern info to.   That makes three good reasons I'll never shop at HD again, and the 3rd time is the winner. 

I noticed that Mead Lumber has a new outlet on my side of town yesterday, so I'll give them a visit later today.  Shame they don't have a good website I could use to check availability with. 

4D

1 hour ago, 4DThinker said:

That makes three good reasons I'll never shop at HD again

 

Never say never 4D, when I say it is when it usually bites me in the behind

But I do hear you on Big Orange.  In my mind they always made (and make) it more difficult to obtain whatever reward or benefit they might offer.  Even today with the military discount; I've done everything I know to do to be able to use it, but it never works at the cash register.  Sometimes the cashier will give it to me, oftentimes after giving me a big hassle about it   As a result I normally check first with our local lumber store, second with Big Blue, and last... HD.

I had the discount problem at HD and usually could get someone to over ride. Finally got a VA card with barcode and it is much easier there now. Never have a problem at Lowes.

19 hours ago, Cal said:

 

Never say never 4D, when I say it is when it usually bites me in the behind

A friend called my HD complaint an official grumpy old man rant, and welcomed me to the club.  While I'm  normally a shrug it off type there are several recent tech trends that tick me off as I know they are designed to suck more info from me when I visit or use certain apps.  HD already knows what I look for at their site as within a few minutes of leaving it I get an email from them claiming they may have what I was looking for! (which of course they didn't).  That they want to make visiting their site more complicated has me truly puzzled.

I picked up two 8' cedar 4x4 posts at Mead Lumber yesterday. They even cut them in half for me so I could close my hatch with them in my car.  Those will do for the legs of my Taigtool CNC mill bench.   Picked up some casters that may be too large, and a set of soft close drawer slides.  I have a stick of old growth pine that I think is enough to make the stretchers for the bench from.  I'll order the milling machine when I have the bench for it done and in its final resting place.  Re-thinking the layout of my basement CNC room.

Went out to my garage shop today.  Temps a little warmer (in the 50s) and spent 1/2 hour or so changing the blade on my standing Jet bandsaw to a wider resaw blade.  While the previous 1/4" wide blade ran fine, the wider blade wanted to run forward off the wheels. Reset the guide blocks and backing bearing.  Finally had to loosen the tip adjuster of the top wheel and angle it back a few degrees to keep the new blade on.   Used the saw to split a long board of old growth pine.   Shoulda worn a dust mask as the saw has no dust collection port and that fresh cut pine started a sneezing fit.   Free-handed the cut following a center line I drew.  Did OK but using a fence I could have done better.  Resaw blade didn't seem to notice it was cutting anything. 

4D 

The split pine board halves were run through my drum sander until the rough bandsaw face was smooth. I ended up with boards 1/32" less than 3/4" thick.   Took the boards down to the CNC room. I cut them in half lengthwise. Set up bar clamps. Jointed smooth one edge of each board. Glued two sets of two halves together.  That'll be enough wood for 2 stretchers of my CNC mill table.  

Mission today is to find material to make two more stretchers from. 24" length needed, and that reduces the potential list of scrap candidates. 

4D

Edited February 5, 20233 yr by 4DThinker

Didn't take long to notice two 6' long 1x3 strips of white pine that came from the crate my electric motorcycle came in.  Cut them in half lengthwise.  Joined one edge on each piece and glued together two more boards for the last two stretchers.  These are a bit twisty, but glued together to counter that tendency.   Doubt it will hurt if a stretcher doesn't take a perfectly straight path from leg to leg. 

 

Struggling to envision a new layout for my basement shop room to make room for this new tool.  I've pretty well lined the perimeter with benches and tools to support post-CNC work from the CNC in the center of the room.   One 68 degree corner in the room is currently wasted.   The mini CNC mill could live there if I cut the square table to fit.  I may regret limited side access to the tool if it was tucked into that corner though.  My mind sees me wanting to CNC cut a detail/joint on the end or middle of a 4' or 6' metal round or square pipe.   Thinking about other rooms in my basement that might become the metal processing room. 

Cross town trip to my local Menards and I came home with 1/2" (nominal) 2'x4' and a 1/4" (nominal) 2'x4' pieces of plywood to make the drawer for the tool stand.  Not as cheap as I remember from before the pandemic, but will do.   I've already received the soft close drawer slides.  Next mission is to double check my drawings and start cutting parts.   The 1/4" plywood is, well, crappy.  I might use the 1/2" plywood for both the sides and the bottom.   I've got a good piece of maple in my garage I can make the drawer front from.  

 

I started clearing out my utility room.  Previous owner used it as a home office space.  Plenty of room for a few tools if I throw out boxes and outdated tech that accumulated in there.    Thinking metal chips should have their own space away from where I make wood chips and dust. 

4D

On a side note, I had my Milwaukee 6" saw in my car and when leaving noticed two women parked near me trying to cut a 4x8 panel down with a hand saw so it would fit in their car.  Offered to help and they were delighted for the offer.  2 minutes later their panel was cut and I headed home. 

Edited February 5, 20233 yr by 4DThinker