moebeast
Member
To limit the width, maybe you should mount your cross rails vertically and mount the z-axis off the side. You would lose the benefit of having the stepper motor between the rails. Probably not worth it.
Mark
Cutting foam sheets... with a needle!
- Thread starter dkj4linux
- Start date
To limit the width, maybe you should mount your cross rails vertically and mount the z-axis off the side. You would lose the benefit of having the stepper motor between the rails. Probably not worth it.
Mark
dkj4linux
Elite member
It's what I do...
I've actually been wrasslin' with the horizontal vs vertical orientation of the rails for a while now. The CoreXY laser engraver I built in my other thread (http://forum.flitetest.com/showthread.php?35285-MPCNC-inspired-CoreXY-laser-engraver) has the vertical orientation -- with the same rail spacing -- and I've been thinking of how much of this current design I might be able to use with it. Bearing assemblies, no problem... but the Z-lift stuff will be totally different. I've got it out there right in front of me -- all the time -- to study and ponder and a buddy is wanting a laser engraver... again. So, I'm thinking about how to get rid of that big green monstrosity of a Z-lift mechanism even now...
-- David
I've actually been wrasslin' with the horizontal vs vertical orientation of the rails for a while now. The CoreXY laser engraver I built in my other thread (http://forum.flitetest.com/showthread.php?35285-MPCNC-inspired-CoreXY-laser-engraver) has the vertical orientation -- with the same rail spacing -- and I've been thinking of how much of this current design I might be able to use with it. Bearing assemblies, no problem... but the Z-lift stuff will be totally different. I've got it out there right in front of me -- all the time -- to study and ponder and a buddy is wanting a laser engraver... again. So, I'm thinking about how to get rid of that big green monstrosity of a Z-lift mechanism even now...
-- David
moebeast
Member
I've actually been wrasslin' with the horizontal vs vertical orientation of the rails for a while now. The CoreXY laser engraver I built in my other thread (http://forum.flitetest.com/showthread.php?35285-MPCNC-inspired-CoreXY-laser-engraver) has the vertical orientation -- with the same rail spacing -- and I've been thinking of how much of this current design I might be able to use with it. Bearing assemblies, no problem... but the Z-lift stuff will be totally different. I've got it out there right in front of me -- all the time -- to study and ponder and a buddy is wanting a laser engraver... again. So, I'm thinking about how to get rid of that big green monstrosity of a Z-lift mechanism even now...
-- David
How about something simple like this:
It needs a rib or fillet to support the weight of the stepper, but it looks like it would work to me.
Mark
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dkj4linux
Elite member
Yuck!
I just don't like it. It's gotten pretty ugly fast...
First, I'm going to remove that old red carriage body and shim up the upper rails so the guide rod bolt heads clear the tractor motor... maybe it won't look so bad when I can move the carriage to the extreme left side, directly over the left-side tractor assembly. I'm thinking I'll also want to swap ends with the X-motor and idler (the orange parts), placing the X-motor inside the rails ends and directly over the right-side tractor assembly... that'll buy a couple of inches off the width of this thing.
I'm also going to look at a mount that moves the needle cutter out in front of the rails... still sitting side-ways but 180 deg from current. Right now, the needle sits a full 6" away from the extreme left side of the carriage... so a 180 deg shift and moving it out front would fold it up and move the needle as close to the left extreme of the carriage as I want.
As this last would be a fairly major change and adds considerable depth to the carriage, this would be a good time to take a long hard look at that vertical rail orientation we've talked about as well.
I may be a while... later :black_eyed:
-- David
I just don't like it. It's gotten pretty ugly fast...
First, I'm going to remove that old red carriage body and shim up the upper rails so the guide rod bolt heads clear the tractor motor... maybe it won't look so bad when I can move the carriage to the extreme left side, directly over the left-side tractor assembly. I'm thinking I'll also want to swap ends with the X-motor and idler (the orange parts), placing the X-motor inside the rails ends and directly over the right-side tractor assembly... that'll buy a couple of inches off the width of this thing.
I'm also going to look at a mount that moves the needle cutter out in front of the rails... still sitting side-ways but 180 deg from current. Right now, the needle sits a full 6" away from the extreme left side of the carriage... so a 180 deg shift and moving it out front would fold it up and move the needle as close to the left extreme of the carriage as I want.
As this last would be a fairly major change and adds considerable depth to the carriage, this would be a good time to take a long hard look at that vertical rail orientation we've talked about as well.
I may be a while... later :black_eyed:
-- David
dkj4linux
Elite member
That's quite similar to what I was thinking, Mark... and I think it would work like a champ! I'll get the chance to try it out soon, I'm sure, on that CoreXY machine...
I rearranged things as I last lined out and I'm really not as unhappy with it now that all the extra stuff has been removed... the needle is now within a couple of inches of the left-most edge of the DTFB...
I shimmed the upper rails so the guide rods now clear the left tractor and swapped X motor and idler end-for-end... everything now "stacks" above the tractors much better...
And I was off on my overall machine dimensions... this arrangement is currently less than 41" wide (the length of the upper rails). Even if I widen it to get those 2" or so to put the needle on the left edge of the DTFB I should be able to get this thing in under 44" wide... 14" of "overhead" to accommodate the 30" dimension of DTFB. That doesn't seem so bad now...
I'm going to continue to pursue this arrangement for now... I think it just might be workable
-- David
moebeast
Member
I have always just used the SD card reader. Never tried controlling it from a computer.
dkj4linux
Elite member
Repetier works fine... I use it quite a lot. I commit cutfiles to SD if I plan on cutting lots of multiples...
moebeast
Member
I have my tool defined as .5 mm diameter, so I don't think it really matters much. I've done everything as engraving which is easy, but now I use inside for holes, outside for parts, and engraving for scores and reference marks. Estlcam 10 will automatically arrange the cut order to do your engravings and holes before the part is cut loose. This also doesn't matter much, since only the smallest pieces (like slots for tabs) ever move while cutting.
I've started using the tab function for things I cut for someone besides myself to make them easier to transport.
dkj4linux
Elite member
I usually set the bit/needle diameter to 0.7mm and use inside and outside cuts as appropriate... but centerline will work as well. Foam is so forgiving/flexible that it usually makes little difference. -- David
I use ESTLCAM and only use engraving because inside/outside only work on closed polygons (unless that's changed in 10 and I haven't noticed since I haven't tried using them on open cuts yet.) Engraving is a centerline cut and allows for non closed shapes so I can do things like hinges and other cuts that don't form a polygon.
My process setting up the CAM is outlined here:
That skips the first 7 minutes or so of the video which is prepping the PDF in inkscape to convert it to DXF/PNG for CAM.
That was an older video though with ESTLCAM 9 and my older cutter. With the new cutter I've revised my tool settings quite a bit as can be seen in this video (again skipping the first 15 minutes which are inkscape)
I used to set the toolsize to 0.9 since it didn't really matter as I only do engraving/centerline cuts. But with the new upgraded tool I've set it to 0.62 - the actual size of my needle - since it makes the views a little nicer (smaller path around the cuts.) I have used inside/outside (part/hole) cuts but usually don't bother since I can just stick with the engraving tool and not have to switch tools. Though I do sometimes switch from automatic to manual depending on the way the file is drawn and how well estlcam detects the lines.
I also save my files to SD and run from there. My controller is a bit far from my computer to stay tethered and I don't trust windows not to crash or screw up timing during a cut anyway.
I'm still not sure what moebeast and I are doing differently...but I have zero need for tabs, my parts are fully cut and I get clean edges...but they have to be popped out of the foam. I think he may be running a thicker needle than me but I'm not sure.
I've been trying to collect some photos/video to do a video on the benefits of the needle cutter. With all the talk about the Rascal on FB and people asking how they plan on cutting foam I want to help spread the gospel of the needle over the spindle I like my spindles...but not for foam.
Reasons?
First a word about spindle options:
My spindles are all routers, I don't have an actual spindle. But a DW660 is only $50 on Amazon so it's a very affordable spindle option while a DWP611 is about $130. The 660 is also smaller and lighter. The 660 is 5amps so about 500w on 110v. The 611 is rated as 1.2hp so about 900 watts. So you do get more power from the 611. But...the 660 includes both 1/4" and 1/8" collets and you'll usually be using 1/8" bits on these machines. The 611 only includes a 1/4" collet and a 1/8" collet is about $30. So that bumps the price of the 611 over $150 to actually be usable. The MPCNC also doesn't have many mount options for a 611 though they are popular on shapeokos and other desktop CNC's. Oh, the 611 is also variable speed which the 660 is sadly lacking - you can use an external speed controller on a 660...but...it probably will shorten the tools life since it also slows the cooling fan.
I don't know exactly which spindle they're running on the rascal (I'd really love to see some of the guys working on it chime in here - Nerdnic, Sponz - you out there?), but it looks like the "standard" cheap Chinese 500w spindle. Those run about $130-$150 (Though banggood has one for just $80) The reviews I've heard about those have not been super encouraging. They do tend to be quieter than the routers from what I hear...but the power supplies/controllers are questionable and the spindles tend to have more runout than either dewalt option. They're lower RPM...but honestly the 660 is higher RPM than needed (and that lower RPM is probably a big part of the sound difference. The 660 does ~30k RPM while the Chinese spindles only do about 12-15k) I've been tempted to pick one up a few times...but they just seem to be a fairly big gamble...I've seen lots of people happy with them. But I've also seen a lot of people go back to a router because of the issues they experience with the cheap spindles. They also look like they're probably lighter...but I can't find any reliable numbers to confirm.
1) Sound. My needle cutter cutting is 5db quieter than any of my current spindle options free-running. The chinese spindle as I state above is almost certainly quieter than my spindles...but I doubt it's much quieter when actually cutting. I can't really demonstrate this point with photos
2) Mess. Cutting foam with a spindle makes a mess. That foam dust is really obnoxious. It gets static charged and sticks to everything. I really don't like having it in my shop, I worry about breathing it and it gets on everything even if I follow the bit with a strong vacuum while it's cutting. I've been meaning to get some photos/video showing this...but I really don't want to make the mess it requires Here's the mess the needle cutter makes:
It's hard to see...but you can see some small dust on the board there. Honestly...most of it is dust that was on the foamboard before I started cutting it (mostly dust created in my shop from cutting MDF with my spindle) and the needle just makes it more obvious since it bounces around while the foam is being cut
I occasionally get a bigger "dust bunny" like this from my cotton ball oiler shedding a bit. This thing is still tiny. And a quick puff of air blows it away.
The tip of my needle cutter does collect some fine dust while cutting. A quick wipe every now and then easily keeps it under control.
But overall the needle cutter just doesn't generate much mess, It mostly pushes the foam and fibers of the paper aside. And the majority of what it does displace gets pushed down into the spoil board.
3) Accuracy/Precision - Honestly neither is quite the right term. It's more the VERY fine kerf that I'm trying to express. It is accurate and precise ( I get cuts the size I expect repeatedly ) but what I really love is how that fine kerf allows for very clean cuts that beat even a laser for DTFB and in some ways even beat most handheld knifes. Photos show this best:
Note - these photos are extreme closeups the edges may look a little rough on some of them (my needle could stand to be sharpened and I have been running my feeds a little higher than what gives optimal quality) but that's mostly due to the extreme closeness of the photos. Even "clean" exacto blade cuts don't look perfect this close up.
A spindle even with a 1/32" bit isn't going to do that. 1/32" is ~.8mm which is about .2mm thicker than my needle. Now, my needle does have a tiny bit of play in it...but that Chinese spindle is going to have some runout as well so we'll call that even. That V on the left would be an "outside" cut with a spindle - so the CAM software won't go all the way into the vertex of the V since it has to account for the size of the tool. (1/32" bits aren't cheap either and are easy to break...but that's part of my next point)
Here's that same cut completed. It's hard to tell but the deepest part of the V was actually cut twice. Once going in and once coming out (remember I use engraving/centerline cuts) Basically where the V goes in up to where it meets the score line on the left that line was cut twice.
Speaking of accuracy. I've got my Z dialed in now where I can do marking cuts that don't even pierce the top-paper. They just lightly dent it
You could come close with a rotating bit...but you're not going to dent the paper without cutting it.
This ultra fine kerf also simplifies workholding. I could use a vacuum bed - but really don't need one. By placing the foam so the corners curve up and then pinning the corners it lies flat enough I can get more than enough accuracy for RC planes. And with the fine kerf parts don't "fall out" so there's no need to hold parts in place after they're cut. I still want to build a vac bed for the really warped sheets of foam...but I try to avoid using those for planes anyway. I mostly want a vac bed to go with my spindle for cutting wood where work holding is considerably more difficult.
4) Cost - The cheapest spindle option is a $50 DW660. The cheapest "real" spindle is about $80. Better spindle options like the 611 and nicer Chinese spindles you're looking at $150-$200. And then there's bits. A decent endmill runs about $4, you can get cheaper ones from banggood/aliexpress but they're not a lot cheaper and they're generally not nearly as nice. drillman1 on ebay has the best deals I've found on quality endmills. I got some cheaper endmills off banggood and they don't cut as clean, don't hold an edge as well, and overall just weren't a deal despite their low cost. These small endmills are also remarkably easy to break. Now to be fair we're cutting foam - so an accidental move has to be pretty big to break one ( like down into the worktable big.) But when you're dealing with 1/16" and 1/32" bits...they're crazy delicate. I broke one by dropping it - $4 of kyocera goodness down the drain and never even got to try it The point is - the tooling is expendable - and while you can resharpen a knife blade (or a needle) resharpening an endmill is not something most people will tackle in a homeshop.
The needle cutter on the other hand...is made from stuff that most RC hobbyists probably already have on hand. If not a $8 motor and $8 ESC are all you really need. The 3D printed frames are nice but not 100% necessary - David built one of his from a dollar store mousetrap - and you get more than one mousetrap in that package for $1! The bearing guides I'm using are nice...but a few strips of wood work as well and are probably even quieter. The MIG tips are great, and you can get 10 for $5 at harbor freight - that's more than a lifetime supply for this use - so share with a friend and save even more Or just get a $2 pack of sports inflation needles - they don't last as long but they're cheap. Bottom line, you could spend more than $50 building a needle cutter...but you'd probably have to try pretty hard to do it.
Yes, needles are an expendable item just like rotary bits. But...they're easy to sharpen, and enough wire to make about a dozen needles is <$4 at just about any hobby shop. So for the price of one endmill you can have a close to lifetime supply of needles. And if you've built many RC planes you probably have suitable material on hand already cut from the ends of your control rods (though the 0.62mm stuff I use is a bit less common unless you're into DLG's or something like that! The slightly thicker wire will work but you'll get a slightly wider kerf and possibly less life out of the needle.)
Being able to mount a spindle on your CNC rocks. They're great for cutting wood, plastics, CF, and some soft metals (and if you're REALLY patient and have a stiff enough machine even some harder metals.) But if you're looking to cut foam...IMHO it's just the wrong tool for the job.
I love my spindle. Later this weekend I'm probably going to be cutting some MDF plates for a friend who's building a C-beam based CNC machine. But I love my needle cutter more - it's so much more enjoyable to use and so much easier to learn with. Foam is cheaper and more forgiving than wood in so many ways.
My process setting up the CAM is outlined here:
That skips the first 7 minutes or so of the video which is prepping the PDF in inkscape to convert it to DXF/PNG for CAM.
That was an older video though with ESTLCAM 9 and my older cutter. With the new cutter I've revised my tool settings quite a bit as can be seen in this video (again skipping the first 15 minutes which are inkscape)
I used to set the toolsize to 0.9 since it didn't really matter as I only do engraving/centerline cuts. But with the new upgraded tool I've set it to 0.62 - the actual size of my needle - since it makes the views a little nicer (smaller path around the cuts.) I have used inside/outside (part/hole) cuts but usually don't bother since I can just stick with the engraving tool and not have to switch tools. Though I do sometimes switch from automatic to manual depending on the way the file is drawn and how well estlcam detects the lines.
I also save my files to SD and run from there. My controller is a bit far from my computer to stay tethered and I don't trust windows not to crash or screw up timing during a cut anyway.
I'm still not sure what moebeast and I are doing differently...but I have zero need for tabs, my parts are fully cut and I get clean edges...but they have to be popped out of the foam. I think he may be running a thicker needle than me but I'm not sure.
I've been trying to collect some photos/video to do a video on the benefits of the needle cutter. With all the talk about the Rascal on FB and people asking how they plan on cutting foam I want to help spread the gospel of the needle over the spindle
I like my spindles...but not for foam.Reasons?
First a word about spindle options:
My spindles are all routers, I don't have an actual spindle. But a DW660 is only $50 on Amazon so it's a very affordable spindle option while a DWP611 is about $130. The 660 is also smaller and lighter. The 660 is 5amps so about 500w on 110v. The 611 is rated as 1.2hp so about 900 watts. So you do get more power from the 611. But...the 660 includes both 1/4" and 1/8" collets and you'll usually be using 1/8" bits on these machines. The 611 only includes a 1/4" collet and a 1/8" collet is about $30. So that bumps the price of the 611 over $150 to actually be usable. The MPCNC also doesn't have many mount options for a 611 though they are popular on shapeokos and other desktop CNC's. Oh, the 611 is also variable speed which the 660 is sadly lacking - you can use an external speed controller on a 660...but...it probably will shorten the tools life since it also slows the cooling fan.
I don't know exactly which spindle they're running on the rascal (I'd really love to see some of the guys working on it chime in here - Nerdnic, Sponz - you out there?), but it looks like the "standard" cheap Chinese 500w spindle. Those run about $130-$150 (Though banggood has one for just $80) The reviews I've heard about those have not been super encouraging. They do tend to be quieter than the routers from what I hear...but the power supplies/controllers are questionable and the spindles tend to have more runout than either dewalt option. They're lower RPM...but honestly the 660 is higher RPM than needed (and that lower RPM is probably a big part of the sound difference. The 660 does ~30k RPM while the Chinese spindles only do about 12-15k) I've been tempted to pick one up a few times...but they just seem to be a fairly big gamble...I've seen lots of people happy with them. But I've also seen a lot of people go back to a router because of the issues they experience with the cheap spindles. They also look like they're probably lighter...but I can't find any reliable numbers to confirm.
1) Sound. My needle cutter cutting is 5db quieter than any of my current spindle options free-running. The chinese spindle as I state above is almost certainly quieter than my spindles...but I doubt it's much quieter when actually cutting. I can't really demonstrate this point with photos
2) Mess. Cutting foam with a spindle makes a mess. That foam dust is really obnoxious. It gets static charged and sticks to everything. I really don't like having it in my shop, I worry about breathing it and it gets on everything even if I follow the bit with a strong vacuum while it's cutting. I've been meaning to get some photos/video showing this...but I really don't want to make the mess it requires
Here's the mess the needle cutter makes:
It's hard to see...but you can see some small dust on the board there. Honestly...most of it is dust that was on the foamboard before I started cutting it (mostly dust created in my shop from cutting MDF with my spindle) and the needle just makes it more obvious since it bounces around while the foam is being cut
I occasionally get a bigger "dust bunny" like this from my cotton ball oiler shedding a bit. This thing is still tiny. And a quick puff of air blows it away.
The tip of my needle cutter does collect some fine dust while cutting. A quick wipe every now and then easily keeps it under control.
But overall the needle cutter just doesn't generate much mess, It mostly pushes the foam and fibers of the paper aside. And the majority of what it does displace gets pushed down into the spoil board.
3) Accuracy/Precision - Honestly neither is quite the right term. It's more the VERY fine kerf that I'm trying to express. It is accurate and precise ( I get cuts the size I expect repeatedly ) but what I really love is how that fine kerf allows for very clean cuts that beat even a laser for DTFB and in some ways even beat most handheld knifes. Photos show this best:
Note - these photos are extreme closeups the edges may look a little rough on some of them (my needle could stand to be sharpened and I have been running my feeds a little higher than what gives optimal quality) but that's mostly due to the extreme closeness of the photos. Even "clean" exacto blade cuts don't look perfect this close up.
A spindle even with a 1/32" bit isn't going to do that. 1/32" is ~.8mm which is about .2mm thicker than my needle. Now, my needle does have a tiny bit of play in it...but that Chinese spindle is going to have some runout as well so we'll call that even. That V on the left would be an "outside" cut with a spindle - so the CAM software won't go all the way into the vertex of the V since it has to account for the size of the tool. (1/32" bits aren't cheap either and are easy to break...but that's part of my next point)
Here's that same cut completed. It's hard to tell but the deepest part of the V was actually cut twice. Once going in and once coming out (remember I use engraving/centerline cuts) Basically where the V goes in up to where it meets the score line on the left that line was cut twice.
Speaking of accuracy. I've got my Z dialed in now where I can do marking cuts that don't even pierce the top-paper. They just lightly dent it
You could come close with a rotating bit...but you're not going to dent the paper without cutting it.
This ultra fine kerf also simplifies workholding. I could use a vacuum bed - but really don't need one. By placing the foam so the corners curve up and then pinning the corners it lies flat enough I can get more than enough accuracy for RC planes. And with the fine kerf parts don't "fall out" so there's no need to hold parts in place after they're cut. I still want to build a vac bed for the really warped sheets of foam...but I try to avoid using those for planes anyway. I mostly want a vac bed to go with my spindle for cutting wood where work holding is considerably more difficult.
4) Cost - The cheapest spindle option is a $50 DW660. The cheapest "real" spindle is about $80. Better spindle options like the 611 and nicer Chinese spindles you're looking at $150-$200. And then there's bits. A decent endmill runs about $4, you can get cheaper ones from banggood/aliexpress but they're not a lot cheaper and they're generally not nearly as nice. drillman1 on ebay has the best deals I've found on quality endmills. I got some cheaper endmills off banggood and they don't cut as clean, don't hold an edge as well, and overall just weren't a deal despite their low cost. These small endmills are also remarkably easy to break. Now to be fair we're cutting foam - so an accidental move has to be pretty big to break one ( like down into the worktable big.) But when you're dealing with 1/16" and 1/32" bits...they're crazy delicate. I broke one by dropping it - $4 of kyocera goodness down the drain and never even got to try it
The point is - the tooling is expendable - and while you can resharpen a knife blade (or a needle) resharpening an endmill is not something most people will tackle in a homeshop. The needle cutter on the other hand...is made from stuff that most RC hobbyists probably already have on hand. If not a $8 motor and $8 ESC are all you really need. The 3D printed frames are nice but not 100% necessary - David built one of his from a dollar store mousetrap - and you get more than one mousetrap in that package for $1! The bearing guides I'm using are nice...but a few strips of wood work as well and are probably even quieter. The MIG tips are great, and you can get 10 for $5 at harbor freight - that's more than a lifetime supply for this use - so share with a friend and save even more
Or just get a $2 pack of sports inflation needles - they don't last as long but they're cheap. Bottom line, you could spend more than $50 building a needle cutter...but you'd probably have to try pretty hard to do it. Yes, needles are an expendable item just like rotary bits. But...they're easy to sharpen, and enough wire to make about a dozen needles is <$4 at just about any hobby shop. So for the price of one endmill you can have a close to lifetime supply of needles. And if you've built many RC planes you probably have suitable material on hand already cut from the ends of your control rods (though the 0.62mm stuff I use is a bit less common unless you're into DLG's or something like that! The slightly thicker wire will work but you'll get a slightly wider kerf and possibly less life out of the needle.)
Being able to mount a spindle on your CNC rocks. They're great for cutting wood, plastics, CF, and some soft metals (and if you're REALLY patient and have a stiff enough machine even some harder metals.) But if you're looking to cut foam...IMHO it's just the wrong tool for the job.
I love my spindle. Later this weekend I'm probably going to be cutting some MDF plates for a friend who's building a C-beam based CNC machine. But I love my needle cutter more - it's so much more enjoyable to use and so much easier to learn with. Foam is cheaper and more forgiving than wood in so many ways.
dkj4linux
Elite member
Thanks for the great summary of benefits, Jason. Makes the needle cutter sound like the real deal
I've never found tabs necessary either... depending on the feed/speed there are "zillions" of microscopic threads of uncut foam left in the kerf that are easily broken when "popping out" the pieces. Even if the foam was absolutely cleanly and completely cut -- absolutely no little attachment threads at all -- "fallouts" don't generally occur simply because the perfect kerf is so narrow relative to the thickness of the DTFB... and the "loose" cut-out will generally rock/fall/wedge itself somewhere around the periphery. They will occur more often, the thinner the material... :black_eyed:
I've never found tabs necessary either... depending on the feed/speed there are "zillions" of microscopic threads of uncut foam left in the kerf that are easily broken when "popping out" the pieces. Even if the foam was absolutely cleanly and completely cut -- absolutely no little attachment threads at all -- "fallouts" don't generally occur simply because the perfect kerf is so narrow relative to the thickness of the DTFB... and the "loose" cut-out will generally rock/fall/wedge itself somewhere around the periphery. They will occur more often, the thinner the material... :black_eyed:
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Sold on the needle cutter. Gonna use a a .025" wire (just happened to have that on hand).
I have not made the first cut yet or even finished the machine. But i have been prepping some of my files.
My planes are designed in Sketchup and i produce PDF plans from there. I have Sketchucam and the Phlatboyz stuff looks pretty easy. Got a couple planes ready to go. I was curious about the inside/outside because reltive thinness of the needle. I did not figure there would be an appreciable difference in either one.
It sure is going to be nice to go from design to cutting and skipping the create, print then tile PDF's. No transfering then cutting. Yeaaaa!!!!
Thanks for all the input.
I have not made the first cut yet or even finished the machine. But i have been prepping some of my files.
My planes are designed in Sketchup and i produce PDF plans from there. I have Sketchucam and the Phlatboyz stuff looks pretty easy. Got a couple planes ready to go. I was curious about the inside/outside because reltive thinness of the needle. I did not figure there would be an appreciable difference in either one.
It sure is going to be nice to go from design to cutting and skipping the create, print then tile PDF's. No transfering then cutting. Yeaaaa!!!!
Thanks for all the input.
moebeast
Member
Thanks for the great summary of benefits, Jason. Makes the needle cutter sound like the real deal
I've never found tabs necessary either... depending on the feed/speed there are "zillions" of microscopic threads of uncut foam left in the kerf that are easily broken when "popping out" the pieces. Even if the foam was absolutely cleanly and completely cut -- absolutely no little attachment threads at all -- "fallouts" don't generally occur simply because the perfect kerf is so narrow relative to the thickness of the DTFB... and the "loose" cut-out will generally rock/fall/wedge itself somewhere around the periphery. They will occur more often, the thinner the material... :black_eyed:
As for tabs, I was referring to my Flite Fest experience with people loosing pieces as they walked away. For home use they are absolutely unnecessary.
I also think the Rascal is overkill for someone who just wants to cut foam. But it is a nice option for an all around machine for those without a 3D printer. They just need to put a needle cutter on it.
Sold on the needle cutter. Gonna use a a .025" wire (just happened to have that on hand).
.025" (.635mm) should be great. I think that's what I'm using but K&S labels it as .62mm - they probably just do the conversion a little sloppy
That machine is looking close though! I'm sure we'll have you cutting before you know it
Sketchup and I just don't get along very well. I've used it for some projects in the past and was able to get them drawn...but something about it's interface has just never sat well with me. Thankfully there isn't one right way to do things and we have options so can find what works for each of us
I tried to get the sketchucam stuff going but ran into issues with the version of sketchup I was running, finding the correct version of sketchucam, and my general issues with sketchup. I had already tried estlcam for some machining of plates for one of my quads so went that way with the needle cutter as well and found that it works well for me. I wasn't big on having to actually buy software...but there aren't a lot of free CAM options and ESTLCAM is just so competent and easy to use it wasn't hard to justify the $75 price. (and it looks like he's dropped the price to just $60 now. Nice! It had gone up before I bought it so good to see it back down even if it kind of stinks for me
I'd love to have an all in one solution like that where my cad and cam are in the same package. I want to like Fusion360 for the same reason but just can't get very good performance out of it on any of my computers...and Fusion's CAM is a lot less simple than sketchucam or estlcam. Which is nice if you're doing fancy stuff...but for what we're doing it's so much overkill it just makes things trickier and raises the entry barrier.
I did get an email from onshape about a new cloud CAM package that's integrating with them. They have a couple of CAM plugins but they all looked too complex or used external programs and/or weren't free for hobbyists. Not sure about the long term viability of this one but I signed up for the beta and got an invite the other day. Just need to find some time to sit down and try it now
https://www.onshape.com/cad-blog/ho...s_email&utm_medium=email&utm_content=56083785
It's kind of like magic the first time
My big problem now is cutting them is so easy I've wound up cutting and assembling more planes than I know what to do with. Most of them I've ended up turning into chuck gliders for my daughter since I haven't had time to actually put servos and motors in them
I think you and David are doing a good job working towards showing that even the MPCNC is overkill for just cutting foam
I really do like the Rascal mechanically. I don't really see anything that sets it apart from a number of other C beam style machines out there - but they haven't released enough details to make that kind of judgement yet. My friend has been working on an OpenBuilds Sphinx for awhile (slowly collecting parts) and that's what I'll be cutting plates for later today, it seems to be a VERY similar project. His plan is to build his machine with 3D printed and MDF plates (he had initially asked for 3D printed plates but most of them look like 6mm MDF would be fine and I can mill all of the plates in MDF in less time than it would take to print one of them) with the few that don't look like MDF would be strong enough being 3D printed instead (though we're also considering machining them out of cutting boards or something similar.) Then once it's build use it to cut new plates for itself out of increasingly stronger material - eventually aluminum.
If you have a 3D printer I still think the MPCNC is more economical and already has a large user community which IMHO is key to most DIY projects of this scale. I'd love to see the Rasal gain that large of a community as well. But if you don't have a 3D printer the Rascal will be about the same price it looks like and should be a slightly more compact machine.
I'm kind of putting off going outside to cut those plates though...just because it's such a mess running that spindle even with my new dust shoe
Instead I've been working on drawing up a vac table again:
And with the wasteboard removed:
Still very much based on moebeasts...but it's not quite done yet. I still need to add a channel for connecting my vacuum line - which I plan on doing off the side instead of the bottom using one of my offset tip customizable vacuum nozzles: https://www.thingiverse.com/thing:1776239
The yellow parts are a wooden frame that holds the pink foam air-chamber. I'm planning on adding T-nuts under the pink foam so I can use the threaded inserts in my table to mount the vac table just like I mount my particle board waste table for laser/spindle machining. Right now the main reason I hate switching between foam cutting and other tools is I use carpet tape to stick my pink foam waste board to the table and it's a messy pain to pull up and tedious to apply new tape and stick down.
So I'm hoping a vac table that can mount with screws will make it quicker and easier to switch between waste boards depending on what I need.
The one thing I'm still debating is how to hold the pink foam into the wooden frame. I could just run some screws in from the side. But I want the pink foam to be easily removeable so I can access the screws under it. I could just leave holes in the pink foam to access the screws - but that seems inelegant. What I'm currently leaning towards is adding some holes in the bottom of the channels in the air-chamber so the vacuum can hold the pink foam to the wooden base as well as holding the waste board and workpiece. Just not sure how well it will actually work. But I think it's what I'm going to try.
Just dreading machining the pink-foam air chamber. That's a lot of material to remove (between the channels and the pocket for the waste board to fit in) and that pink foam is even messier than DTFB to machine with a spindle
I could make it out of more pieces. Just machine the grooves and then make a rectangular "frame" that gets glued on to form the pocket...but that would result in a deeper pocket than I want. Not the end of the world but could be much quicker/cleaner to make.
As usual here's my in-progress onshape project if anyone wants to play with it:
https://cad.onshape.com/documents/2...61ba7ba677c6945dd3/e/65a8732f39d37d38af388dcb
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