Depth regulator

Hello Boskap,

Do you mean a tool touch off probe or do you want to physically limit the depth with a hard stop?

Joe

 

You mean besides the 298,00 € price tag?? They appear to be machine specific and only fit that manufacturer's equipment.

It looks like something that would be fairly simple to do a knock-off however. It's just a simple spring balance with a foot at the bottom to ride on the surface of the material. The balance could be achieved with a $2 spring from the hardware store and a cap plate to hold it in place. The foot would be a little more difficult if you truly want a ball bearing but I would probably be inclined just to use some form of teflon guide.

 

Well I'll be damned. It is physical!
Could someone please enlighten me on the purpose of this contraption?

 

Joe, its for milling microscopic depths uniformly across a surface. Ideal for PCBs. And you really don't even need to the surface perfectly level as the glide that surrounds the cutting bit adjusts to elevational variations.

Peter, you need to give us a better idea where you are going with this. Do you plan to use a Kress or similar spindle or are you wanting something heavier like a trim router? How large of an area are you wanting to cover? You mention wanting an OX for both PCBs and wood milling. The problem is that these are kind of at opposite ends of the spectrum. While a floating head will be excellent for PCBs, it will be moderately useless with wood. PCBs also need a machine for fine movement while wood generally wants a machine that can cover large distances fairly quickly. Please give us a better idea what your ultimate goals are and what is most important for you. Ultimately you may be better off doing two separate, more specialized machines.

 

I believe this is what is called a floating head for a CNC mill. Lots of times they are used for engraving on things like concrete when the surface is slightly uneven.
Kinda like a heavy duty pen holder

 

Peter, it looks like you are headed in the right direction so far. The C-beam Z-mount may actually allow you do both mounts in one.

Let me think on it for a bit.

 

The 40mm depth of the Z-axis allows you to add another free moving carriage on the front side.



And by attaching the mount to that free moving carriage, you should be able to achieve both a soft mount and a fixed mount. Tighten the knob on the left screw and it cinches the carriage up against the bottom of the angle bracket, fixing the front mount in place to where it moves rigidly with the z-axis. Loosen the knob on the left screw and the weight of the front carriage goes to the spring, allowing the system to float. Lowering the z-axis to where the slide bearing at the bottom just touches will allow the bearing to glide across the surface with the spring carrying most of the load.

Please understand this is just a quick concept. There are no guarantees it will work as well as the $400 systems. And you will still need to do a fair amount of development. Finding the right stiffness of spring may take a significant amount of effort. You will also probably want to integrate a dust pickup system to keep the debris from affecting the slide bearing.

Sketchup file attached. Please don't judge the quality of it as this was just a quick concept and the drawing is somewhat cobbled together.

 

Here's a concept for dust collection and micrometer.



Dust collection is pretty much standard. You'll need access to a 3D printer. Micrometer is a fairly simple concept. Let the bit rest on the work surface, loosen the setscrew on the side to drop the sole plate until the bushing touches the surface, use the micrometer to raise the bushing the desired amount and then re-tighten the setscrew.

The bushing was already shown. If you have access to a 3D printer, you might ask for a sample of Tribo filament to make the bushing from.

As far as sizing of the members, you need to work through that on your own.

 

Peter, please view everything I have shown as purely representational. Nothing was truly sized, parts were merely dropped in to give you an idea of how such a system could be created. You will need to size all the parts to work with the system you are building. The dust shoe is also purely representational. It needs hollowed out to be functional.

Based on the size of your spindle, I would probably use M8 threaded rod for the screws and 12mm smooth rod to attach the sole plate. Spacing between rows of holes should be 99.7mm for the 80mm wide extrusion sections.

 

Start up a conversation with @Chris Laidlaw, he does plates for hire. He should already have the OX plates properly modified for C-beam systems. Just tell him you have a 3kg spindle and the plates need to be a little taller as shown in the concept drawings. He may also be able to create the spindle mount and sole plate for you.

 

Plates showing relevant spacings attached. I have not worked with C-beams yet so all spacings shown are based on information provided to me that I am unable to personally verify.

Front plate does not include holes for spindle mount. You will need to work that out on your own. Plates also based on gantry C-beam facing spindle.

OX side plates were taken from the second drawing attached which shows the overall layout of typical design.