I had one aggravation when using my benchtop Wen drill press.   The depth stop was a knurled nut that had to be tediously spun around a fine threaded post to set a stop.  There are push button stops you can buy for some drill presses.  Pricey, and usually for the larger shafts on floor standing drill presses. I couldn't find one for the M12-1.25mm post on my Wen. 

I've made push button releases for a few past projects, so decided I could make my own depth stop for my Wen.  Photos below.  A more complete How-To is now live on my blog:  https://4dfurniture.blogspot.com/2023/01/making-push-button-depth-stop-for-my.html

I consider this a prototype.  Next is to see if I can make one from aluminum. 

 

4D

 

Cool! Thanks for the link to your blog 

Great solution. Did you hand machine that or 3D print?

5 hours ago, Grandpadave52 said:

Great solution. Did you hand machine that or 3D print?

This one I made from HDPE plastic sheet I had on hand.   I cut the body and the button using my CNC.  I do have a couple of 3D printers but do not think they are up to precision level needed for the fine threads and fit between button and body. 

4D 

I checked my Nova Voyager DVR drill press this morning. It already has a push button depth stop.  In use however it doesn't work.  When set it only take a little pressure, normal when drilling, to make it slip up the post.  Either the threads in the stop collar don't match the threads on the post, or the spring inside is too weak to keep them pressed together. In either case I've contacted the manufacturer to see what they can recommend.  The Post appears to 1/2"-13tpi, much coarser than those on the Wen. Their manual implies it might be M14.  If they've changed parts over the years since this drill first came out I can see a conflict of threads between depth stop collar and post. 

4D

 

Thinking back I don't think the Voyager came with a push button collar.  We have one where I worked an it came with two nuts.  I likely found this collar online and bought it thinking it would work with the voyager.   It doesn't.  I've ordered an M14-2.0 tap which I think is the right size, and when it comes I'll do a test to see if the tap fits in the collar and/or matches the threads on the post. 

Edited January 2, 20233 yr by 4DThinker

Teknatool support got back to me with a diagram showing a 5/8"-11 threads per inch post.    This does not match the depth stop post on my drill press.  My M14-2.0 tap arrived and matches the threads on the post perfectly.  I'm going to conclude that it is the conical spring behind the button on their stop collar that is too weak. This is something I can replace, so I might do that first.  

I replaced the thin wire conical spring with one of the thicker wire smaller conical springs I bought for my Wen depth stop collar and while it seemed better I could still overcome it with just a little more pressure.  The original spring was just a bit larger so I dropped it down over the smaller stiffer spring.  That looks like it'll work now with 2 springs under the button.  Still not too hard to depress, but a good firm engagement with the M14-2.0 threads on the post.  I'm calling this fix solved for now.  Given that Teknatool seems to be using a larger diameter post now I suspect they encountered the problem I had with the depth stop on an early model and revised the design. 

 

I have a small plate of 6061 aluminum coming which I'm going to try CNC cutting an aluminum version of the HDPE depth stop with.  Never cut aluminum on my CNC before, but have been doing some research on bit speed, feed speed, and plunge speed for cutting aluminum.  My router speed control can be set down to the speed I see recommended.  I've cut aluminum before using the wood cutting blade on my bandsaw with no problem.  The carbide or tool steel my router bits are made from should be much harder than the aluminum. If this test works I may do more aluminum cutting using the CNC.  I'd like to revise the router mount on my CNC for better clearance and making the revised parts will likely be next on my list. 

4D    

Mixed results trying to cut out a new body of the depth stop in aluminum using my CNC.  First toolpath was to pocket out the 12mm hole to slide over the post.  The bit needed to ramp down to each step, but within the 12mm hole there wasn't enough room for a 3/16" end mill to ramp easily down about 1/32" per pass.  It did cut the hole, but complained each new step when ramping down.  I suspect this put some wear on the bit tips.  

The perimeter cut was next.  I had it lead in from the side to avoid needing to ramp.  Cuts at the edge through just 1/2 the bit width proceeded fine.  The full with passes around the other two sides growled a bit,  I was getting clean chips so figured I had feed speed and bit RPM about right.  Through the first 3/8" of a 3/4" aluminum block the edges looked OK.  The bottom of each pass appeared as though the bit tip had broken or worn off but that area cleaned up on the following passes. With about 1/8" left to go I was getting bad vibration on the full width passes.  I eventually stopped the cut with about 1/16" left to go.  I cut the blank free using my bandsaw. The side showed serious oscillation waves from that vibration.  I used a flush trim bit on my Milwaukee trim router to clean the last 1/6" off, holding the part with a small C-clamp. 

With some file work I have a (slightly imperfect) part I can use. It needs two more pockets cut from the side. I think I'll drill out the center of those pockets on my drill press, and create CNC profile passes to open the holes up to final elliptical size.  I'll use a new bit, and no plunging. Just the side of the bit stepping over 1/64" or so each perimeter pass. I've known my CNC to have some potential deflection under load. Not enough to worry about with wood projects.   Something I'm afraid will be detrimental to any future cuts in aluminum.  Now I'm thinking about finding a small CNC mill. Something made to cut metals.

4D

 

Edited January 7, 20233 yr by 4DThinker

Cool beans 4D. Glad it worked out pretty well for you. Never know unless you try. Chatter marks should clean up OK. Looking forward to seeing it once completed.

2 minutes ago, Grandpadave52 said:

Cool beans 4D. Glad it worked out pretty well for you. Never know unless you try. Chatter marks should clean up OK. Looking forward to seeing it once completed.

The only critical parts are the holes.  The outer edge doesn't matter for utility or aesthetics on my shop drill press.  Just for ergonomics and only just.  The center hole slips over the depth stop post easily and looks pretty round to my eye, so it'll do. The holes in the sides are more critical.  Making the button to fit nicely and work is the most demanding of precision. I'm gestating on a few ideas for how to make that button from an aluminum rod I have. 

4D 

Checking the dimensions of the aluminum part, I have almost 1/16" of deflection that happened on the full width passes. What should have been a 1" x 1" part is 15/16" x 15/16".  The hole isn't centered side to side. 

Looking around the web I came across a service that will laser cut aluminum parts for reasonable prices.  Quick turnaround.  Send them a .DXF file to get a quote back.  I may use them to make the parts for updating my CNC. 

4D

I've spent the afternoon thinking about cutting another one, but applying what I learned from the first to see if I can get a better result.  Deflection happened on the full width passes. 

1. Eliminate full width passes.

2. Bandsaw cut out a small block from the larger piece, just 1/8" or so larger than the final piece. 

3. Where the 12mm hole center is, pre-drill a 1/4" hole and use it to bolt down the small block so it can be cut all around. 

4. Climb cut rather than convention cut.  Deflection, if any, would be outward leaving an oversized part rather than an undersized part. 

5. A final full depth profile pass should clean off any remaining material to leave a perfectly sized piece. 

6. Drill out the 12mm hole using my drill press. 

 

Problem:  I'm not sure a single bolt/nut through the center can keep the part from rotating once the router hits it. I can't put clamps against or on any side.  Thinking hot melt glue or superglue and blue painters tape.  That or comeup with a way to lock against rotation within a 12mm hole using a 1/4" bolt.

Not an engineering genius by any stretch of the imagination (nor do I play one on TV) but, could you thread the 1/4" hole and basically 'bolt' the part to the table then cut the 12mm hole later?

52 minutes ago, Headhunter said:

Not an engineering genius by any stretch of the imagination (nor do I play one on TV) but, could you thread the 1/4" hole and basically 'bolt' the part to the table then cut the 12mm hole later?

The idea was to drill the 1/4" hole and put a t-track bolt up through and use a ny-lock nut to hold it down.  Danger is that with the spinning router bit hitting the aluminum it might kick the block around.  Threading the hole may be one step better but still allow the block to "unscrew" when hit on the outer edge. I know from experience how much force a spinning bit pushed by stepper motors can take advantage of any weakness in clamping.   

I've been playing with the toolpaths, and divided the perimeter into the 2 bottom corners, and one upper curve.   While cutting the bottom 2 corners I can clamp a V block against the opposite and still square corners to keep it from rotating.  When the bottom corners are done I can put a block against that bottom face to keep it from rotating while the top curve is cut. 

I'll still use a bolt through a 1/4" hole first, then use my drill press to enlarge it to 12mm after the CNC work is done.  I plan to have the CNC use a V-bit to mark the center of the hole to make sure it is in the exact right place. I'll use a machined square corner of the original aluminum block as one corner of the depth stop body. That is 2 flat sides I don't need to cut. 

4D

My first thought would be to try and hold it down and secure using a small carriage bolt, tightened down the shoulders might indent the Al enough to secure it in place.

My second thought, are you trying to re-invent the wheel?  Have you asked a machinist how they would tackle a small part like this?  @HandyDan comes to mind...  I'm thinking a part like this has been done a time or ten and likely solutions have been found.

I know how to make this part. I've made press button stops for several past projects.  Not re-inventing the wheel but pursuing the limits of the tools I have at home.  Already made a working one from HDPE (dense plastic).  Never tried to cut aluminum on my CNC before this, but know many using CNCs do cut aluminum with theirs.  The first try revealed some weaknesses.  I could use the part I've made, but it has flaws due to deflection of my CNC when making full width passes through the aluminum.  Normally I'd give up but being retired now with nothing but time on my hands thought out-smarting my CNC would be a worthwhile challenge.  If I "master" this challenge with a perfect looking and working aluminum CNC cut depth stop it'll inform my future projects that might be best made from aluminum plate. 

A carriage bolt might engage the aluminum, but then just rotate with the aluminum block if the CNC wants to rotate it.  Dividing the toolpaths into two halves lets me clamp the outside half that isn't being cut, then move the clamps to the other side to cut the opposite side.   Should work.  Might work.  Will at least show me what doesn't work if that happens. I can then move on to making the other two holes in the side, and then making the button. Or at least take one more better informed try at making a better press button body.  

4D

Only suggestion I might make is to grind the boss flat where the stop lands.  Looks like it is hitting on one side when it lands skewing the stop in the threads.  Instead of the button a thumb screw to tighten it would surely solve the problem but ruin the scale.

 

 

 

I had exactly the same thought Dan and have already take a file to that area.  At one time I thought I might add a matching angle undercut on the stop collar.  

I've also been looking for a replacement post that doesn't have a flat face with the scale on it. If the post was threaded all around then the stop collar could be spun around to fine adjust its position. As it is now when the threaded part inside the collar hits that front flat area you can slide it up and down easily. Same is true with the push button stop on my voyager drill press.

4D

Edited January 8, 20233 yr by 4DThinker

Cut another aluminum depth stop body on the CNC today.  This time the CNC work came out precise within 0.01" in width and depth. That is within the accuracy I expect from how I zero off the block. 

What I didn't do was cut the 12mm hole on the CNC.  I marked the center of the hole with a V bit on the CNC.  At the drill press there must have been some desire of the 12mm bit to find it's own path through the aluminum.  The hole is off center by roughly .02", and very slightly angled through the block.   

 

What did I learn?  The CNC can be very accurate, but to attain that accuracy the properties of the material have to be understood and accounted for. Expecting the same precision from my drill press was a mistake. It can make a hole the size of the bit being used, but controlling where that hole is made requires more precise positioning of the work.