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MPCNC or LowRider... FoamRipper

#1
Hello FliteTest Forum Community,

I LOVE building DTFB planes (or any plane for that matter, like 3D printed ones, but my flying skills typically limit me to foam board :ROFLMAO::ROFLMAO:), both FT, community, and some of my own designs, but absolutely HATE having to print out the plans, cut them out, tape them together, and then cut out the foam by hand. It feels like that whole process takes longer than the planes typically last. So, I've seen on the forums here the "cutting foam with a needle" thread and love the idea! There's just one problem. I don't have a CNC mill. I do, though, have a 3D printer and (I'd say) a decent amount of tinkering ability to assemble/build a CNC machine, though don't have the $1000+ to buy a "nice one" and I've been thinking about building one of the V1Engineering variants for some time now (I would use it for more than just cutting out planes, but that would be it's main purpose probably).

With that all being said, my question for you fine folks is which machine, the MPCNC or the LowRider, would you recommend? I'm thinking the LowRider myself as I don't have a ton of space and being able to "push the machine out of the way" and still have access to the table it's on sounds convenient and space saving, but i haven't seen either machine in person to know if one is "better" than the other or anything. Also, I believe finding tubing that works with the MPCNC is a bit easier (3/4 in EMT matches the 23.5mm parts) compared to the LowRider.

Either way, if you have experience with either (or both) machine, please tell me about you experiences as any info is helpful!
 

dkj4linux

Well-known member
#2
Hey, Nathan! Welcome!

Either of those machines can indeed be fitted with a needle cutter... MPCNC or LR2. The MPCNC big enough to hande DTFB tends to be big and bulky, however... and at the size may not be rigid enough to handle anything more than light loads; i.e. needle cutter, laser, pen/marker, drag-knife, etc. The LR2 OTOH was designed originally to handle full 4'x8' sheets of plywood... though many/most are probably built smaller. There have been needle-cutters designed for use with it, as well... Jason Hitesman (@jhitesma) designed one to fit in the router location on the LR2 carriage plate.

Another option I'll mention, because it's even more inexpensive than MPCNC or LR2, is the ERC TimSav foamboard cutter... which has its own thread right here on FT. Edward Chew (TimSav creator) actually offered this machine as a KIT and sold a fair number as fast as he could get them kitted up... until this Covid-19 pandemic disrupted the supply of parts and he needed to turn his attention to his other business interests. But his documentation is so complete that it should be straight-forward to source all the parts listed in his BOM for the machines... to put together your own. Indeed, I ordered one of the first batch of machines he sent out and then built a _second_ TimSav machine out of my stash/junkbox... to put together a hot-wire machine I called TimSavX2. I documented my builds (both "stock" and "hot-wire" versions) in both the ERC TimSav and needle-cutter threads.

The beauty of the TimSav is that it is a "minimalist" design that is not only very inexpensive (easily < $200... and less than half the cost of either MPCNC or LR2) but also quite light-weight and portable, easily set up and taken down as needed. It's primary purpose is for needle-cutting... though it could probably be readily adapted/used as a laser-engraver or pen-plotter as well. Take a look...



Any of these machines can be made to do what you want. Just let us know how we can help. And, again... welcome to the party! :)

-- David
 
#3
Any of these machines can be made to do what you want. Just let us know how we can help. And, again... welcome to the party! :)

-- David
Thanks for the warm welcome. It's not my first post on the FliteTest forum, just my first in the CNC/3D Printer/Laser Cutter section.

I did in fact see the Edwards Foam cutter, and I thought it was a great idea, but I plan on using the machine for more than just cutting foam (plan on doing some 3D wood relief/sign making and other custom stuff). Really, I've been thinking of building some sort of CNC mill for a while, but also realize that most of the cutting I'll do is foam board planes.

I was thinking the same thing about the MPCNC being quite large/cumbersome if big enough to cut a full 20x30 sheet of foamboard, and knowing that the lowrider was designed for a full plywood sheet cutting made me think it was probably the better choice. The problem I've run into is sourcing 1" OD stainless tubing as it's super expensive everywhere I've found it ($100 for just the tubing, which totals like 15 feet in length).

On top of all of that, I have a decision making problem, where I'll "weigh the pros/cons" of each machine until I'm on my death bed (I'm currently 22)... If I could justify it (both money and space), I'd just build both and sell the one I didn't want, but I have excess of neither (I just graduated with an Aerospace Engineering degree, but currently the Aerospace industry is on the toilet due to the virus).

Anyways, I'm gonna keep poking around and hopefully find someone who has built a DTFB cutting variant of either to see which they'd recommend and where they sourced the tubing.
 

dkj4linux

Well-known member
#4
Thanks for the warm welcome. It's not my first post on the FliteTest forum, just my first in the CNC/3D Printer/Laser Cutter section.

I did in fact see the Edwards Foam cutter, and I thought it was a great idea, but I plan on using the machine for more than just cutting foam (plan on doing some 3D wood relief/sign making and other custom stuff). Really, I've been thinking of building some sort of CNC mill for a while, but also realize that most of the cutting I'll do is foam board planes.

I was thinking the same thing about the MPCNC being quite large/cumbersome if big enough to cut a full 20x30 sheet of foamboard, and knowing that the lowrider was designed for a full plywood sheet cutting made me think it was probably the better choice. The problem I've run into is sourcing 1" OD stainless tubing as it's super expensive everywhere I've found it ($100 for just the tubing, which totals like 15 feet in length).

On top of all of that, I have a decision making problem, where I'll "weigh the pros/cons" of each machine until I'm on my death bed (I'm currently 22)... If I could justify it (both money and space), I'd just build both and sell the one I didn't want, but I have excess of neither (I just graduated with an Aerospace Engineering degree, but currently the Aerospace industry is on the toilet due to the virus).

Anyways, I'm gonna keep poking around and hopefully find someone who has built a DTFB cutting variant of either to see which they'd recommend and where they sourced the tubing.
Another possibility, falling somewhere between TimSav and LR2, cost-wise and in simplicity, is Moebeast's Foam Ripper. Loosely based on LR2, Mark designed this machine to be the cheapest possible foam cutter after coming back from FliteFest/East 2017... he even wrote a FT article about it.

Mark's FoamRipper is a simpler, cheaper, build than LR2 and still uses 3/4" EMT... and is better suited to dedicated foam cutting and other light duty chores and a not-too-large work area. I built a variant of Moebeast's Foam Ripper and I must admit I enjoy using it more than any other machine in my stable of machines. I documented my build of Mark's machine in my needle-cutter thread starting about here and scattered through following posts... and, after having built it essentially "stock", I then designed an alternative Y-carriage and Z-axis for it ( and TV "thing"), that allowed me to mount a different needle-cutter design, a pen , and a laser. Here's my machine in action... pen and needle on left side of carriage, laser on the right


This build isn't terribly difficult but did require a bit of ingenuity and a few more bits and pieces (mostly printed spacers and bushings) here and there. The existing documentation lacks build detail but, with your technical/engineering background, you may actually enjoy working your way through the build... as I did.

Thoughts? -- David
 
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#5
I was in your exact scenario about a month ago. My thought was that it was easier to push a 35x49" wheeled stand into a corner than to add a 4/8' table to my workspace that I would need to work around. My wife instantly had some projects to add when i told her what i planned to build. I also designed the stand with the option to tilt the table to make it slightly smaller for storage. I'm still printing parts so haven't tested my theory yet though.
 
#6
My ERC TimSav Kit arrived today! Well worth the money for Edward's kit. Its a real shame that he had to stop production. But you should easily be able to procure your own parts for a reasonable price. Like mentioned before >$200 and you'll be up and running. My brother built one by sourcing his own parts and it came out to about $160 (mostly from bang good).
The community of those that have built and operate one is very helpful.
 
#7
Another possibility, falling somewhere between TimSav and LR2, cost-wise and in simplicity, is Moebeast's Foam Ripper. Loosely based on LR2, Mark designed this machine to be the cheapest possible foam cutter after coming back from FliteFest/East 2017... he even wrote a FT article about it.

Mark's FoamRipper is a simpler, cheaper, build than LR2 and still uses 3/4" EMT... and is better suited to dedicated foam cutting and other light duty chores and a not-too-large work area. I built a variant of Moebeast's Foam Ripper and I must admit I enjoy using it more than any other machine in my stable of machines. I documented my build of Mark's machine in my needle-cutter thread starting about here and scattered through following posts... and, after having built it essentially "stock", I then designed an alternative Y-carriage and Z-axis for it ( and TV "thing"), that allowed me to mount a different needle-cutter design, a pen , and a laser. Here's my machine in action... pen and needle on left side of carriage, laser on the right


This build isn't terribly difficult but did require a bit of ingenuity and a few more bits and pieces (mostly printed spacers and bushings) here and there. The existing documentation lacks build detail but, with your technical/engineering background, you may actually enjoy working your way through the build... as I did.

Thoughts? -- David
Ooooooh, I really like the looks of that FoamRipper, and for $200 it's hard to . Do you think it's strong/stiff enough to mount a Dremel or similar to and do some carving? I'm assuming that a full size router is out of the question due to weight, but my Dremel is (kinda) light. The fact that the EMT is like $7 for 10', so like $15ish (maybe) total is waaayyyyy cheaper than the $100 of total cost for Stainless Steel tubing.

I was in your exact scenario about a month ago. My thought was that it was easier to push a 35x49" wheeled stand into a corner than to add a 4/8' table to my workspace that I would need to work around. My wife instantly had some projects to add when i told her what i planned to build. I also designed the stand with the option to tilt the table to make it slightly smaller for storage. I'm still printing parts so haven't tested my theory yet though.
I probably wasn't going to go full 4'x8' cutting area right off the bat, but probably go for something more like 4'x4' or something, as with the LowRider, as long as your carriage is wide enough (X-Axis), making Y-Axis longer is basically just getting a longer table. Also, with the LowRider, when it's not in use, you can push the gantry off to one side of the table and then still be able to use the table basically obscured outside of the y-axis belts on the side. With the MPCNC, you basically have to fully commit the table to the machine due to the frame structure.
 

TEAJR66

Flite is good
Mentor
#8
I'm biased. I built the MPCNC and love it.

The lowrider and the timsav are enticing, but, I like to do more than just the needle cutter on foam. With the MPCNC you can mount a spindle and do some wood, also.

Already having a 3d printer makes the MPCNC a pretty logical choice. Source your conduit, print the appropriate size parts, order the rest from V1. Simple like that.
 

dkj4linux

Well-known member
#9
Ooooooh, I really like the looks of that FoamRipper, and for $200 it's hard to . Do you think it's strong/stiff enough to mount a Dremel or similar to and do some carving? I'm assuming that a full size router is out of the question due to weight, but my Dremel is (kinda) light. The fact that the EMT is like $7 for 10', so like $15ish (maybe) total is waaayyyyy cheaper than the $100 of total cost for Stainless Steel tubing.
Nathan,

The FoamRipper is, as designed, a foam-cutter first... and other, similar, light-weight loads (laser, pen, etc) can be readily added. And while you might get away with a Dremel tool... I can't imagine doing anything very large with it, in a reasonable time-frame (or lifetime of the tool!). OTOH the LR2 _is_ designed to carry a full-size router... and its increased size, weight, and use of larger, more rigid, SS tubing is reflective of that.

Realistically, you are talking of jobs tending toward opposite ends of the spectrum... and building a multi-purpose machine to do jobs a both ends is a near-impossible and expensive proposition. While a heavier-duty machine might sometimes be called on (and has been!) to do a light-weight task... it's not realistic to believe the opposite is true. FoamRipper and TimSav are as inexpensive as they are because they are "minimalist" machines that use light-weight, easily-obtained, materials and are primarily designed for a single light-duty task. MPCNC and LR2 are a bit more expensive because they use more and/or heavier materials and generally more complex construction... and were designed from the ground up to carry a router and do routing/light-milling tasks.

In short, build a machine for the primary task you envision it doing. It is IMHO far simpler, faster, and cheaper to design for a single task... and better to have several inexpensive, single-purpose, machines than one expensive, multi-purpose, machine. And avoid the temptation to over-build or over-engineer... that only drives up the time/expense to completion and, more often than not, reduces performance. In the realm of DIY, KISS is king!

My $0.02.

-- David
 
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TEAJR66

Flite is good
Mentor
#10
Nathan,

The FoamRipper is, as designed, a foam-cutter first... and other, similar, light-weight loads (laser, pen, etc) can be readily added. And while you might get away with a Dremel tool... I can't imagine doing anything very large with it, in a reasonable time-frame (or lifetime of the tool!). OTOH the LR2 _is_ designed to carry a full-size router... and its increased size, weight, and use of larger, more rigid, SS tubing is reflective of that.

Realistically, you are talking of jobs tending toward opposite ends of the spectrum... and building a multi-purpose machine to do jobs a both ends is a near-impossible and expensive proposition. While a heavier-duty machine might sometimes be called on (and has been!) to do a light-weight task... it's not realistic to believe the opposite is true. FoamRipper and TimSav are as inexpensive as they are because they are "minimalist" machines that use light-weight, easily-obtained, materials and are primarily designed for a single light-duty task. MPCNC and LR2 are a bit more expensive because they use more and/or heavier materials and generally more complex construction... and were designed from the ground up to carry a router and do routing/light-milling tasks.

In short, build a machine for the primary task you envision it doing. It is IMHO far simpler, faster, and cheaper to design for a single task... and better to have several inexpensive, single-purpose, machines than one expensive, multi-purpose, machine. And avoid the temptation to over-build or over-engineer... that only drives up the time/expense to completion and, more often than not, reduces performance. In the realm of DIY, KISS is king!

My $0.02.

-- David

David will never steer you wrong.
 
#11
Nathan,

The FoamRipper is, as designed, a foam-cutter first... and other, similar, light-weight loads (laser, pen, etc) can be readily added. And while you might get away with a Dremel tool... I can't imagine doing anything very large with it, in a reasonable time-frame (or lifetime of the tool!). OTOH the LR2 _is_ designed to carry a full-size router... and its increased size, weight, and use of larger, more rigid, SS tubing is reflective of that.

Realistically, you are talking of jobs tending toward opposite ends of the spectrum... and building a multi-purpose machine to do jobs a both ends is a near-impossible and expensive proposition. While a heavier-duty machine might sometimes be called on (and has been!) to do a light-weight task... it's not realistic to believe the opposite is true. FoamRipper and TimSav are as inexpensive as they are because they are "minimalist" machines that use light-weight, easily-obtained, materials and are primarily designed for a single light-duty task. MPCNC and LR2 are a bit more expensive because they use more and/or heavier materials and generally more complex construction... and were designed from the ground up to carry a router and do routing/light-milling tasks.

In short, build a machine for the primary task you envision it doing. It is IMHO far simpler, faster, and cheaper to design for a single task... and better to have several inexpensive, single-purpose, machines than one expensive, multi-purpose, machine. And avoid the temptation to over-build or over-engineer... that only drives up the time/expense to completion and, more often than not, reduces performance. In the realm of DIY, KISS is king!

My $0.02.

-- David
Those are some valid points you make. I think I'm going to go with the FoamRipper for now, as it will at least give me a general understanding of the mechanics and intricacies of that style of "roller" machine. That, and the fact that is shares most of the same electronics as a LowRider should means transferring to the larger machine in the futures shouldn't be too hard.

Thanks for the insight!!

Now, I guess it's time to start printing.
 

dkj4linux

Well-known member
#13
Parts for the FoamRipper are printed (only took a day and a half). Need to order the hardware now. Might scavenge an old 3D printer for the electronics.

Let me know if I'm missing any pieces
I think you are okay so far...

Most of the "extra" parts you will need (that aren't in Thingiverse) will be spacers and bushings that mount wheels and motor guide bearings to the endplates. When I did my FoamRipper build -- going on 2 years ago -- the provided DXF file had issues... so I created some test endplates. I simply made corrections in CAD... but Mark later put a new DXF out on Thingiverse (which I did not use).

192643_69d427e4d18f23649cd86b316efc49b1.jpg


Since I was feeling my way along, I had not thought through, and resized, the mounting holes in the endplates when I milled them. So, as I started assembly and found mounting and alignment mismatches, I simply printed bushing/spacers to adapt my parts to the plates. Here you can see the white/yellow printed parts I used to get the motor guide bearings and skate wheels mounted and aligned.

193173_a86785c091fed2189b801952c31f8ff2.jpg
193161_b1c9e43a0407af99a801c28767725765.jpg


You will also discover other printed parts that will help... here corner brackes that capture the ends of the belts. I don't remember where I found these or what mods I might have made to them... just remember to mirror two of the parts. Also, an interior door makes a great worksurface...

20200528_123121.jpg


20200528_123137.jpg


20200528_123202.jpg


Not long after building a pretty much "stock" FoamRipper, I designed and built my alternative Y-carriage/Z-axis/needle-cutter. So I don't remember a great deal of the detail of the "stock" carriage build. Please refer back to the build links I posted previously to see what I did that might be helpful. Good luck!

-- David
 

rockyboy

Skill Collector
Mentor
#14
Lots of excellent advice in here - as is mentioned above "David will never steer you wrong!"

For more lowrider specific questions and info, I've got a build thread on mine over here: https://forum.flitetest.com/index.php?threads/lowrider-cnc.36066/

I've done some light routing with a 1/4" trim router on it, but mostly it runs a needle cutter designed by Jason. I also have a 3.5W laser module in a bag that needs to find it's way to the carriage plate soon :D

Bottom line, I love my Lowrider and it's worktable is a centerpiece of my workshop space... er.. well. at least the center of the right hand side of the workshop space! :D

IMG_20200524_200338_copy_1024x1365.jpg
 

Merv

Well-known member
#15
Which one you choose may depend on how much space you have. I’m building a TimSav inspired machine due to the ease of storage and transportation.