Hey guys, I’m diving deep and learning my new XXL, machining times are great, but I was curious how great I can get them. For a lot of projects, I need to clear out a LOT of material. I work mainly with woods and MDF. I’m always going under an inch in depth total, so I feel like a larger bit meant to clear material would do really well. I use Fusion 360 and I’d probably make it leave like 3 or 4mm extra stock from what it can hit just to be safe. Still, on larger projects that take close to half an hour to rough, I could probably pop that sucker in and do a quick tool change and come out ahead.
Can Shapeoko handle larger bits when cutting MDF? 3/8? 1/2"? Do they have a 1/8" shank? If so, are those any good?
Since you said you mainly do wood and mdf dont go crazy because you could knock out a chunk of wood with larger and overly aggressive passes. Sometimes people are doing relief maps and as you get to the top of the terrain you could break off a piece of a mountain top. All things in moderation.
For reasons I’m about to list below, feed speed and stepover are the only two things I can tweak
Yeah, this has been a balance and learning experience. If I did get a larger roughing bit, I’d leave a solid 5-10mm of additional stock on that toolpath just so it doesnt create any spindly mountaintops. That’s the main reason I can’t tweak my depth per pass too much and the roughing takes a bit of time. If I go too deep on depth per pass, it’s super efficient at removing material, but it turns mountaintops into tall towers that’ll snap off if the wind blows on them, nevermind future passes that cut them more accurate. They will all snap off.
The answer has been unfortunately to set the max depth per pass to around 2mm. So the rouging bit shaves off the top 2mm of the project, moves down, does the next 2mm, etc. This gives the islands and mountaintops a stronger base, carving them top down, rather than bottom up. Also, sometimes a ‘mountaintop’ is let’s say, 5mm down from the top of the stock. If I do a pass at 8mm, it’ll surround the base of that mountain at it’s ‘3mm down’ point, but that tower it creates will be 8mm high. Future passes will go over top and knock off the top 5mm, but a bit moving even incredibly slow (if i manually lower the feedrate to 10% for that part) moving over the top 5mm of an 8mm(Z)x4mm(X)x4mm(Y) tower made of MDF will absolutely snap that piece
So a larger more aggressive bit doing that same 2mm pass but leaving additional stock would lower that roughing toolpath from about 35 minutes to… I’m not sure. but less. ;p 35 minutes is quick, but… 10 would be quicker!
If you can share one of the Fusion360 projects that is a good example of your typical roughing needs, we may be able to optimize it “the way we would do it”, and then you can decide what approach is most suitable ?
I use a 1 and 1/8th surfacing bit when I need to make sure a wooden surface is flat. But that is all I have used it for. This tool does have a rather big flaw if you have a bit setter. There is no middle inside the bit, so it doesn’t push the bitsetter button down. I have to move the bitsetter over so one of the three cutting areas makes contact with the button. Then remember to move it back for the next tool. Just enough of a pain to make me wonder if there isn’t a better solution… so let us know what you end up trying.
I see what you mean, So the only way to increase depth per pass would be to increase the amount of material left on each pass. That would give you more stability. But the trade off would be that you would have to spend much more time on your finish pass. depending on the surrounding terrain, it may or may not be worth going this rout.
So this bit is hollow? When you switch to that bit, why not drape a piece of masking tape or something across the hole so it makes contact with the bitsetter button? Might work and save you some time. The thickness of the piece of tape shouldn’t make much of a difference depending what you’re making.
The project I just did I exported as G-code last night and I guess I didn’t save the fusion file. Blah! It cut out great but next time I’m making a project I’ll post it up!
