Here we go again . . . MK4

[routercnc]

Next up was a little job I'd been putting off until I'd got to grips with F360. These are going to be inserts which fit inside the extrusion to connect the bed uprights. I'm sure there are many ways to make these parts but I decided to get some practice on adaptive tool paths. Here is the first of 16 parts:


It all started with a large 8mm sheet:


I then machined 2 edges so that the parts would be the right length:


Then over to the chop saw to rough them out to width:




Next part tool a while - machining the 3rd edge on each part in turn:


Not sure if this is good practice or not but the 4th edge I did in small batches:


All to size . . .


Then 6.8 mm holes machined (ready for M8 tap):


Now onto the angled sides. I made a fixture to hold the parts which had 2 datums for alignment:




The fixture was dropped into the vice each time and aligned in Y (fore/aft) by eye as this is not critical. It only needed to hold the blank in the correct X (left to right) and Z (up and down) position.

Then a 2D adaptive to rough it out. I had intended to do a cleanup but this doubled the machining time and the parts fitted fine with just the roughing:


The adaptive took about 2.5 minutes which was not too bad. I've done 8 parts, 8 to go . . .

[Clive S]

Nice work following with interest

[Nr1madman]

It's mechanical porno!! ;)

[routercnc]

Cheers guys. It's very satisfying when it all works so glad you are enjoying it too.
For anyone thinking about jumping to F360 then I'd say don't hesitate. Its a powerful bit of software and is daunting at first but start simple and go from there.

[routercnc]

I managed to finish all 16 inserts, so another job done:


All the Y and Z axis material has arrived from aluminium warehouse. All fine except they sent me 5" round instead of 5" square. This is to make the block which holds the spindle. Quick phone call and they sent me the 5" square for free and told me to keep the round:


So onto the Y axis sides. Here is the CAM:


Laying out the blank:


Holes:


Profiled:


Holes tapped:


Then the corners had to be filed square to take the stepper bracket:


Edge holes drilled and tapped:


The second one was made the same way but snapped a cutter with the adaptive being effectively too aggressive. Actually it was my fault as I did not align the blank quite right and so the cut was too wide as the stock was not where the software thought it was. Anyway, we got there.

Couldn't resist a dry assembly to check it all fits:



There will be a piece of bent sheet over the front and rear, so checking this will fit flush to the stepper bracket:


Then onto the Z axis. Here are the raw stock parts:


Top plate being set up:



All for now.

[Nickhofen]

Wow nice work so far!!!

[routercnc]

Thanks for all the kind comments.

Onto the top part of the Z axis. Main holes roughed out.


You will notice that it is all offset to the right and the front. I made an error setting up the job and started to worry there would not be enough stock. In Vectric Cut2D the job always starts at 0,0. So you need to find the stock edge, go in say 5mm, and then zero out there. Then run the part which will give you a margin around the edge. In F360 I defined the stock in the software (which was 5mm larger than the part) and should have zeroed out on the edge of the stock. But instead I used my old method (by habit) and moved in 5mm then reset. The net effect was that the part was 10mm over to the right, and 10mm forward. Would it fit on?

This hole was supposed to be 5.5mm from the edge - looks like I might be lucky!


Counterbores done and used to hold the part:


Profile cut - ooh, just fits!


Then I walked in the 2 holes for the linear bearings. This is in case I ever make the power draw bar spindle and holds the chrome rails which the PDB mechanism floats up and down on.


When I was machining these holes I was removing 0.02 mm at a time (from the diameter). I noticed it was consistently taking away material from the half of the hole nearest me, and nothing off the other side. Now these are small distances, and within the 0.05 mm ballnut backlash so could be that, but I did lots of passes and spring passes one after the other and it always cut on the side nearest to me, as if it was progressing / loosing steps in Y- direction.

Here is the part trial fitted (on top of the sides which are still raw stock):


You can see that this also has stripes where the roughing stepped down on each pass, even though I did a full depth finishing pass. I checked for play in the Y ballnut and ballscrew mounting bearing and all was well. I pushed and pulled the spindle and all seem OK (well, as stiff as it always was anyway). I'll keep an eye on it as the final few parts need total accuracy !