Question on accuracy with current firmware

No Judgement
1

So, a couple of weeks ago I was ready to jump on the Maslow immediately when they went out of stock lol. Now after 2 weeks of researching and such, I’m kind of nervous about the Maslow honestly.

I read a lot of stuff about the inaccuracy problems, especially at the lower corners apparently. I see some go with a 12 foot top beam to help with accuracy, but seems like that would only help with accuracy at the top, and make it worse near the bottom where the chains are that much longer, no?

I see people talking about inaccuracy anywhere from 1/16th of an inch, up to 3/8th. 1/16th I might could live with although it’s a little higher than I’d like in some situations. 3/8th would definitely be unacceptable though. Really I don’t think I could tolerate anything higher than 1/16th and even that would only be tolerable in certain projects.

I also see people having problems with the sled lifting in some situations when trying to drill or route holes. Which was my first question when I saw the design, how does it keep from lifting the sled…

So, what kind of inaccuracy is there realistically in the Maslow currently? I post this asking these questions now risking them going out of stock again before I decide to order, which sucks lol. But I don’t want to get stuck with a 700 dollar overall costing machine that I’m not happy with. I did quite a bit of research today and I could build a basic 3 axis stepper motor driven system for not much more really. Around 300 for the electronics, and another 250 - 300 for the frame and hardware, plus whatever router I used. So overall it’d really only be around 100 - 150 more than the Maslow, but would theoretically be capable of sub 1 mm precision uni-formally across the entire 4’ x 8’ sheet. The biggest effect on precision being just how well I build my rails. At that price I was thinking rails that were basically just some angle or edge ground flatbar and v-slot wheels. Timing belts for drive system on the 8’ axis, lead screw for the other two. The idea would be to keep it as a vertical system other wise I could do timing belt on the 4’ axis as well. The vertical nature is one of the most appealing aspects of the Maslow to me as I’m working in limited space.

Don’t get me wrong I’m not trying to knock the Maslow design or anything like that, I’m just trying to make the best decision for my needs. I’d like to figure out if the Maslow is going to be accurate enough to satisfy me, or if it would be more worthwhile spending a couple hundred more for potentially a more accurate system.

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2

So, a couple of weeks ago I was ready to jump on the Maslow immediately when
they went out of stock lol. Now after 2 weeks of researching and such, I’m
kind of nervous about the Maslow honestly.

I read a lot of stuff about the inaccuracy problems, especially at the lower
corners apparently. I see some go with a 12 foot top beam to help with
accuracy, but seems like that would only help with accuracy at the top, and
make it worse near the bottom where the chains are that much longer, no?

the problem isn’t the length of the chain, it’s the angles of the chains, the
closer to horizontal or vertical you get the more problems you have, going to
12’ top beam significantly improves the angles in the bottom corners without
hurting it much near the top center.

I see people talking about inaccuracy anywhere from 1/16th of an inch, up to
3/8th. 1/16th I might could live with although it’s a little higher than I’d
like in some situations. 3/8th would definitely be unacceptable though.
Really I don’t think I could tolerate anything higher than 1/16th and even
that would only be tolerable in certain projects.

note that these are absolute accuracy errors, the maslow is very repeatable, so
if it’s off by 1/16" in one part of the work area, it will still always cut in
the same (1/16" off ) location.

I also see people having problems with the sled lifting in some situations
when trying to drill or route holes. Which was my first question when I saw
the design, how does it keep from lifting the sled…

gravity and using the right bits. the frame is angled back, so gravity holds the
sled down to the workpiece.

So, what kind of inaccuracy is there realistically in the Maslow currently?

it varies from person to person and how carefully the machine is made.

I post this asking these questions now risking them going out of stock again
before I decide to order, which sucks lol. But I don’t want to get stuck with
a 700 dollar overall costing machine that I’m not happy with. I did quite a
bit of research today and I could build a basic 3 axis stepper motor driven
system for not much more really. Around 300 for the electronics, and another
250 - 300 for the frame and hardware, plus whatever router I used. So overall
it’d really only be around 100 - 150 more than the Maslow, but would
theoretically be capable of sub 1 mm precision uni-formally across the entire
4’ x 8’ sheet.

note that 1/16" is 1.5mm, so sub 1 mm isn’t that much better (unless it’s a lot
below 1mm)

also, I think that you will find that making a solid frame that will support a
router across a 4’x8’ bed is a lot harder than you think and will either be not
as rigid as you expect (hurting accuracy) or more expensive to get running.

The biggest effect on precision being just how well I build my
rails. At that price I was thinking rails that were basically just some angle
or edge ground flatbar and v-slot wheels.

I’ve got a 2’x4’ CNC like that, and while that works fairly well, you are going
to have to get a bit better to get good accuracy and rigidity.

Timing belts for drive system on
the 8’ axis, lead screw for the other two. The idea would be to keep it as a
vertical system other wise I could do timing belt on the 4’ axis as well.
The vertical nature is one of the most appealing aspects of the Maslow to me
as I’m working in limited space.

If you do go this route, look at the coreXY approach, it’s a bit better.

you also don’t want to have rails across the bottom, they will collect sawdust
badly enough with a flat (traditional) design, with a vertical design FAR more
sawdust will hit the rails, and that will cause the v-wheels to not roll
smoothly and can even get embedded in aluminum rails.

Don’t get me wrong I’m not trying to knock the Maslow design or anything like
that, I’m just trying to make the best decision for my needs. I’d like to
figure out if the Maslow is going to be accurate enough to satisfy me, or if
it would be more worthwhile spending a couple hundred more for potentially a
more accurate system.

hard to say. when doing woodworking, a mm or so of error is usually not bad. and
you seldom need sub mm accuracy and large format cutting (usually when you are
cutting large things, you have a little more leeway)

the best I can say is look at the projects people have been making, it works for
them.

3

Hello @Steven_Hickerson.

I’m a CNC junkie and here is what I will say on Maslow accuracy. The Maslow is a set of instructions and parts, it is not a complete product, it’s a kit. As such each individual will get a diffrent result out of it, it depends on your skill set in building it. You can gauge by others experiences, but you can’t get a hard number. The workflow you develop will influence the out come as well. I have been seeing issues with some of the post processors in Fusion360 for example causing errors. For myself I like tinkering with the Maslow. The cost of the system reflect the project. I can get used stepper motors and cheap ramps board and make it something else. It would be just that something else. You could spend more and get a turnkey system. Most here are excited by the value of this and getting their hands dirty. I will point to @Dustcloud as a good example. I have seen a 4 x 8 commercial Cartesian system for $1000. I never thought twice about it, it requires a dedicated 14 ft space, it has no information and is a bear to move. I read it as please take my expensive liability off my hands and maybe you can fix it. So it’s about the experience you want and your budget. For around $300k you can have a pretty nice ride with CNC. For $600 - $700 you can have a Maslow and I think it’s a good ride. I’m pretty sure there are several choices in between. If you choose a Maslow we are here for you.

Thank you

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Doesn’t the length of the chain make it easier for the router to shift or walk due to the bit pulling in a direction?

Sub 1mm is just a quick estimate in my head. Truly it should be cable of more like .1 mm accuracy with low end railing and such. If I built something high end with more sturdy railings and carriages I could achieve .01mm. My current 12" x 12" has .001mm accuracy, and I have built a 30" x 30" work area machine with .001mm accuracy as well. I don’t have it anymore due to the aforementioned limited space hehe. Those are around 1k - 1.5k machines though using higher quality frames and rails.

Hmm, Looks interesting, but I don’t immediately see any examples of it in a vertical system. Seems like it’s asking for problems over time if you used timing belts in a vertical setup. Supporting the weight of the entire gantry on a timing belt system would stretch and wear them pretty quick I’d think. That said, maybe it’d be possible to use something else like chains similar to the maslo, timing belts are just what I have experience with hehe :slight_smile: That is why I was thinking to use a lead screw on the 4’ axis, so that a timing belt isn’t supporting that weight (and that would’ve just been the weight of the router and it’s gantry, not the entire 4’ gantry).

That is a good point that I had not considered. And building on my previous statement, I’m now considering how a hybrid would work. Something that uses motors similar to the maslow with chains to raise and lower the gantry, but then have another motor or stepper to move along the router along the gantry instead of the corexy belt system that does both. Although, making an 8’ gantry rigid is going to make much more difficult than a 4’ one. I suppose I could rotate the entire thing 90 degrees and have the work area 8’ tall and 4’ wide, but then I run into potential height issues in my garage lol. And I think it’d also make it have a larger footprint due to the slope for the increased height of the work area. Still, worth considering.

It also depends on just how OCD you are :stuck_out_tongue: But realistically, 1/16 on some large format projects can be bad. Take for example a chair, I’ve seen a couple images of chairs people have done, but if it’s out 1/16 in the wrong places, say two legs diagonal from each other are both 1/16 shorter than the other 2, it could create a small wobble in the chair. Something like that would drive me crazy (I’m one of those people that if there is a rattle in my car I’ll tear apart the entire dash to find it and silence it). So, at the very least it adds another element that has to be considered in the design process. You have to know your machines inaccurate areas, and plan out your cuts according to where you can sacrifice that accuracy.

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5

This is key, and really should be considered with any machine.

CNC machinists have been doing high-precision parts at the corners of their machines for years… to minimize the affect of flex out in the middle of a long beam.

The Maslow has shown itself to be highly predictable, so a symmetric mirrored layout of parts (in the X axis) should result in equal error.

6

Doesn’t the length of the chain make it easier for the router to shift or walk due to the bit pulling in a direction?

not noticably. the force of the bit is surprisingly small

Sub 1mm is just a quick estimate in my head. Truly it should be cable of more
like .1 mm accuracy with low end railing and such. If I built something high
end with more sturdy railings and carriages I could achieve .01mm. My current
12" x 12" has .001mm accuracy, and I have built a 30" x 30" work area machine
with .001mm accuracy as well. I don’t have it anymore due to the
aforementioned limited space hehe. Those are around 1k - 1.5k machines though
using higher quality frames and rails.

that “higher quality materials” is exactly what I’m talking about,

Hmm, Looks interesting, but I don’t immediately see any examples of it in a
vertical system. Seems like it’s asking for problems over time if you used
timing belts in a vertical setup. Supporting the weight of the entire gantry
on a timing belt system would stretch and wear them pretty quick I’d think.
That said, maybe it’d be possible to use something else like chains similar to
the maslo, timing belts are just what I have experience with hehe :slight_smile: That is
why I was thinking to use a lead screw on the 4’ axis, so that a timing belt
isn’t supporting that weight (and that would’ve just been the weight of the
router and it’s gantry, not the entire 4’ gantry).

you don’t have to use belts, the key thing in coreXY is the path, those can be
chains almost as easily as belts (you do need to change the plane of the chains
enought to let them pass each other in the top center, but that’s not hard)

That is a good point that I had not considered. And building on my previous
statement, I’m now considering how a hybrid would work. Something that uses
motors similar to the maslow with chains to raise and lower the gantry, but
then have another motor or stepper to move along the router along the gantry
instead of the corexy belt system that does both. Although, making an 8’
gantry rigid is going to make much more difficult than a 4’ one. I suppose I
could rotate the entire thing 90 degrees and have the work area 8’ tall and 4’
wide, but then I run into potential height issues in my garage lol. And I
think it’d also make it have a larger footprint due to the slope for the
increased height of the work area. Still, worth considering.

It also depends on just how OCD you are :stuck_out_tongue: But realistically, 1/16 on some
large format projects can be bad. Take for example a chair, I’ve seen a
couple images of chairs people have done, but if it’s out 1/16 in the wrong
places, say two legs diagonal from each other are both 1/16 shorter than the
other 2, it could create a small wobble in the chair. Something like that
would drive me crazy (I’m one of those people that if there is a rattle in my
car I’ll tear apart the entire dash to find it and silence it). So, at the
very least it adds another element that has to be considered in the design
process. You have to know your machines inaccurate areas, and plan out your
cuts according to where you can sacrifice that accuracy.

how much sanding does it take to take off 1/16" of material? how much
sanding/finishing are you planning to do on your project?

at some point, the error of the machine gets down to a couple swipes with a
piece of sandpaper and you will generate more error from a different number of
strokes in different places?

1/16 is 1.5mm, thick cardboard is that thick, the chair may wobble when it’s
empty, but as soon as there is some weight in it, the wood will flex and it will
sit solidly.

Back to your question about what to build, I think that you will find that
getting a gantry system that will be rigid enough over 8’ will end up being much
more expensive, and much heavier than you are expecting, this will then mean
that you need heavier motors and motion components, which will then mean you
need beefier stepper drivers. All of this will drive the costs up, probably far
more than the couple hundred bucks difference you are expecting.

you also have the issue of cutting all the parts for this machine accurately :slight_smile:
I wouldn’t be surprised to find that buying a maslow and using it to cut
aluminum parts for your gantry machine ended up cheaper than buying all the
brackets or getting a local machine shop to cut them :slight_smile:

David Lang

7

I wouldn’t try to build an 8’ gantry. That would definitely be to much. A 4’ one though, I don’t think it’d be that hard honestly to achieve enough rigidity to exceed 1/16" accuracy. I mean obviously it’s going to depend on a lot of factors like cutting speed, depth, bit used, etc. But I’ve seen 4’ x 8’ horizontal machines made entirely out of wood that could achieve higher than 1/16" accuracy.

That said, yes 1/16" in large format can mostly be handled. As you pointed out for my one example, you could sand 1/16" off the other legs. But, it was just that, an example. Part of the usefulness in a CNC is to reduce the work you have to do by hand. A huge number of projects that you do on a CNC could be done by hand with drills, jigsaws, skill saws, or just a hand guided router. And there are many situations where doing it by hand might be faster even. So, if I need to say for example cut 40 of the same shape out of 1 piece of 4’ x 8’ playwood, I don’t really want to have to spend an additional couple of hours sanding them all into the same shape if the accuracy is a problem for it. Sanding 1/16" off one or two things, not that big of a deal, 40 though and it starts to become something of an annoyance.

Is the Maslow really capable of aluminum? I would think if it has trouble in some situations with cutting a hole without lifting, aluminum would be even worse to try and go into without lifting.

And with all that said… I’ve already went ahead and ordered a kit earlier. If I’m not happy with the accuracy I can achieve with it, I’ll just put it up for sale, or re-purpose the components for something else. I already know what my first project will be once I get it calibrated. I’ve been slowly working on a speaker box for my car, using 3/4" MDF and a stacking method to construct the box. But, I’ve only cut one piece out using a template that I made with a jigsaw and a router by hand before I got to busy on other stuff. So, I’ve got like 8 pieces left to cut out and I’ll break in the Maslow on that :slight_smile: 1/16, of inaccuracy on that will not bother me in the least. As long as the pieces line up enough to glue together and seal, it’ll be fine. The box will be hidden in my car so no worry of seeing something that doesn’t line up perfectly.

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8

Is the Maslow really capable of aluminum? I would think if it has trouble in
some situations with cutting a hole without lifting, aluminum would be even
worse to try and go into without lifting.

people have cut projects in aluminum (the first one back when we had FAR larger
sources of error), the key is to slow down and test the capacity of the machine.
you may want to drill holes everywhere you are going to plunge in a first pass
for example.

And with all that said… I’ve already went ahead and ordered a kit earlier.
If I’m not happy with the accuracy I can achieve with it, I’ll just put it up
for sale, or re-purpose the components for something else. I already know
what my first project will be once I get it calibrated. I’ve been slowly
working on a speaker box for my car, using 3/4" MDF and a stacking method to
construct the box. But, I’ve only cut one piece out using a template that I
made with a jigsaw and a router by hand before I got to busy on other stuff.
So, I’ve got like 8 pieces left to cut out and I’ll break in the Maslow on
that :slight_smile: 1/16, of inaccuracy on that will not bother me in the least. As long
as the pieces line up enough to glue together and seal, it’ll be fine. The
box will be hidden in my car so no worry of seeing something that doesn’t line
up perfectly.

this should work quite well.

Also, we know where the problem areas are, if you avoid cutting in the bottom
corners, you avoid most of the error. Unless your parts are larger than 4’, you
can just shift the workpiece on the machine so that you avoid cutting in the
outer 1/4 on each side.

the top center is just a matter of doing a test cut in a material similarly hard
and then lowering the feed rate (or raising the top bar) until it cuts it
without problems.

David Lang