possible methods to machine this piece

[sailhatin]

hey all. this piece will be machined out of mdf.   its about 12 x 12 and .5 inches thick.  and I would like to know what people think is the best option for something like this. I was thinking of pocketing the holes and then running a 3 d adaptive for the fillets, any suggestions would be great. ive cut dozens of items with 90 degree corners but ive yet to do anything with any curves vertically. thanks a ton in advance. JC

[Warmingup1953]

1/8" (or smaller) ball end mill and an eternity! Can it be done with a rounding over bit in a trimmer post CNC Cutting? Is it machined from just the one side?

[seth.madore]

Do you have a vacuum table, or do you have plans on using Tabs to keep it constrained? Could you share your Fusion file?
File > Export > Save to local folder, return to thread and attach the .f3d file in your reply

[sailhatin]

hey there. so here's the file you mentioned, im not sure why I originally didn't attach this. sorry.  I should use tabs as I have a standard hobbyist machine. while I was reading the other response I noticed that I could do this with my hand router. ive thought about that before and that could totally work, I just want to use my router for as much as I can. the file ive attached is a simplified type of file in contrast to the original I posted. what id like to do is to take out the bulk of the circles with a 2d pocket procedure. Im using a .25 inch downcut bit  ive attached an image of that procedure. that eats up about 20 minutes.  next im using a pocket procedure with a .25 ball nose bit. that takes a little over 50 minutes.

this is where I start to get confused. im going to be flipping this piece (which leads to a whole new question) so tabs would be awesome. I thought about doing a 2d contour with tabs outside of the edge of the body and then going back in with 3d adaptive clearing or who knows what? thats when I ended up turning to you guys. thanks so much for your time and I really appreciate your help. jonny 

[sailhatin]

that response above was meant to be sent to you, im not sure if I marked it as a "reply".  sorry about that

[sailhatin]

a round over bit post machining would totally work, I just wanted to see what methods I could use in fusion. my stock is actually only .25 thick so I didn't think it would take too long with a higher step over.  yes, two sided process. thanks for your response. have a great day.  JC

[seth.madore]

The question you have to sort out is how do you plan on profiling that out, machining the backside and then flipping it over. You might be able to do the following:

1) Solid square stock. Machine the square pockets in the backside, rough out the holes. Do NOT profile the part

2) Flip over, machine all holes and radii, profile the part out, leaving tabs in certain locations that permit you to take a bandsaw to them, sand the edges and done

How to take time out of it? What's your max rpm and feedrate? In MDF, 5000 rpm and 40 ipm is quite slow, do you have more oomph to give?

[sailhatin]

Awesome.  I’m pretty sure I can get up to 70-80 IPM.   10000-12000 rpm.  I didn’t change my setting in that procedure. I like your process here.  Thanks a ton. I’ll give it a go.  

[sailhatin]

ok, so I have my solid square stock exactly as the dimensions in fusion 18.165x18.165 x.25

from there I have two 2d pockets made. im starting on the bottom side so its the pockets for the squares around the holes and the actual holes. for the holes I used the bottom height selection from the  drop down in the heights tab. 

its here when I flip it that I dont know what to do on the other side. im actually not sure how to flip the piece or add the tabs while doing the fillets on the perimeter of these bodies.  the interior fillets are pretty self explanatory. any help would be awesome.  thanks. . 

[seth.madore · Accepted solution]

So, to flip it over, you're going to want to make sure you can place your part accurately where it belongs, or the other option is to have features in the "waste" area that you can verify are on position and in proper alignment. When dealing with "flip" features, I'll often have a hole or some other feature that I can probe (or indicate/check).

After that, I'd suggest using the Scallop toolpath to finish out the radii on the thru holes, followed by a Manual NC to add clamps down thru the holes. This should restrain it sufficiently to permit routing out the perimeter

 

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[sailhatin]

thanks so so much. this makes everything so much easier. I really appreciate the help from all of you guys. have a great week.