New day new project after having a few failures due to double-sided carpet tape failing to hold bits down I have decided to modify my sacrificial board. saw someone do this on a youtube video so i have decided to make my own.
Now as the board is bigger than max dims of the milling machine I am going to have to take some true measurements of limits of the machine. As the size of my sheet in the program.
I have these hammer in M5 t-nuts about 100 of them that brought a while back for this project. But then realized that the bed was smaller and my original plan would not work.
So I know the board size is 300 x 400 well according to the manufacture. the wasteboard is actually sized as 380 x 550. Now to home the machine then figured out limits. In mach3 start off by homing all then zeroed X & Y. I then moved y and x to there limits and noted down the size in my case this was 227.6 x 387 so this is the material size. There is an extra 20 mm in x and y if I wanted as soft limits stop 10mm from each axis but happy with that as gives me room. Now on to the design side.
This is double-sided job and my first attempt at one. So the first side is top side so going to my resurfacing tool to do a pass at .5mm as I know nothing has cut in that deep in the past. it will then do the edge bit
Then next up going to make a grid that is 25mm squares each square corner will have 6mm hole in it for bolt holes. To going to use v-bit to make grid followed by 6mm end mill to make holes the will stop 1.5 mm shy of the bottom of the board.
Side 2 will have 17mm x 1,5mm deep circles over the holes to allow for the nut holders to be recessed into the wood.
the rendered model looks a lot better.
I have already drilled 4 holes in the board to hold it in place i need to still get some shorter bolts and counter sink the nuts but that will be done after i have run the program
This is going to be a 3 tool change process. we are going to start with 22 mm surfacing bit to a depth of 0.5mm to clean off any damage done to board it will then run around the edge of the board, the second pass will be drill function using 6 mm end mill. Finally will run v bit to make the grove grid. and outer border.
One pass 6 mm end mill and the job is done. this pass will cut 1.5 mm depth 17 mm diameter circle so the trended inserts can be countersunk.
Running the program
So first up the skim. in with my surfacing tool and time to zero it. do love the z probe script written by Charlie look at my review on the CNC machine for more details. right all set up to go have no idea on speeds and feeds on this. ok first and the second attempt failed miserably think i know why my rpm was far too slow so gave up for the night. new day new vigour lol did some light reading overnight and found my Spindle will go up to 24000 rpm i was running way slow for bit size so have adjusted tool to 18000 rpm from 1800 will try this again today.
Ok i am dumb i have miss calculated the size of material doh re-run the edges then hit the soft limits so did some recalculations and then rehashed my board completely.
Luckily being CNC no damage done so the board adjusted the gcode and off again i went with the board skimming. so process 1 ended up as 3 processes dont worry have made adjustments to the master files.
Some pictures of the resurfacing process. in process.
The re designed board:
Next up the grid. so out with the 30 mm surface tool. in with the v bit and time to zero the tool.
right holes tomorrow and then time to flip the board. hopefully will line up not sure if i should enlarge cut out just as the flip is the unknown hopefully will work out
Now to swap tools and put the end mill in and zero the tool. before running the 98 holes that need cutting. all ready for me to press start later. as the son had his nap got vacuum over the baseboard.
Disaster forgot to enable the spindle when on a destructive path gouging through grid i then reset but it had moved waste board and then ended up drilling through the bed in 2 places destroying 6mm endmill in process. managed to save it by flipping board so going to start again and not be so tired when playing with CNC machines.
Redone first 3 stages now for the flip going to finish off by drilling manual thought 2 halves as not to risk damage.
Back on track and only another evening to waste on the board cnc humour.
continuing on with 6 mm end mill so no need to zero the tool final run of the cnc machine for this project. Well, i thought that was going to be the case but no i was wrong.
Right, this has gone a little wired on me as most of the circle are circle but some are not i think its to do with the soft limits stopping the bit from moving i think i am going to have t rethink side 2 of the board. Depth has not penetrated the holes so going to have to drill each one manually. oh and final fuck up they are not central to where i drill through the board.
So back to program and time to rethink design. the joys of doing things your self lol ill be worth it in the long run though lol. going to skim the board by 1.5 mm and then should be able to finish off machining of the board. I hope.
will run that tomorrow as had enough tonight and it is 1 am again one day i will go to bed early. its a curse.
Another day first up out with an electric drill and six mill drill 98 holes to do drilled and now am going bolt the board down and run the skim and dam it, I have miscalculated the skim by 0.25 mm so time to modify the program. and run it again went well till dust shoe dropped had to kill the cut 20mm from the end of the run. Right enough is enough mach 3 g-code editing here we go figure out where it turns to run the last side edited the code to start there and away it went job done.
98 t-nuts to hammer in to the wast board and its done.
The finished item only took week to run in the end all a good learning curve as most projects are already thought of my next project for the machine just need to get some aluminum and some M5 screws. also going to make some 3d printed ones as well.
Now to make some clamps over to fusion 360 to make my own as don’t want to spend out when i can design and make it my self metal and plastic
So that will be then next project should have 3d printed side done buy end of the week. that will be part one part 2 will be me teaching my self fusion 360 manufacturing.