Using the CNCDepot spindle, Z-20 gantry rework

Anybody out there using a FM30 from these folks?

I have my 2’nd 1F coming an Elite Foreman with the Z-20 and looking to do the ATC route. I looked long and hard at the Jianken solution (thanks TMToronto) but upon review wife my CFO/CTO/EE/Wife she gave the China solution a hard pass.

By the looks of things the FM30 overall upgrade may not be that much more then the Jianken solution.Things like: Import Duty, Upgrading my compressed air etc

I am currently looking at the FM30 … it’s mounting is different. Basically it wants a flat plate mount. Is the spindle mount on the Z-20 attached to the gantry or is it “integral” i.e, I get to machine a big piece and replace the existing spindle mount by disassembling the Z-20.

I am thinking I want to use the Z-20 because it is “pre-integrated” with the Masso and Stiffy systems.

Those are nice spindles, with several options of RPM, bearings, etc. Also have the larger tool holders and American made if that is a plus for you.

I was considering going this route, as they offer a nice package with quality cable, tool holders, etc, but the challenge and cost, in my opinion, is the need to make or purchase a new Z axis assembly. The two I like would cost me well over $800CA. Depending on what you buy, machining would also be required to mount the spindle to the new Z axis assembly, as well as mounting the Z axis assembly to the Onefinity X axis blocks. Having someone do the machining was cost prohibitive, and I didn’t trust myself to have my Woodworker/Makita do the work at the time.

If you decide to get their package, and the Hitachi WJ200 inverter, I highly recommend checking out Clough42’s build video. He shows how to set up both of these, including all important VFD parameters and the electronic/pneumatic components and wiring - it guided my own build a great deal.


Hey Carl and Lynn,

The X carriage is flat and you have the threaded holes with which you can mount the Z assembly at different heights, so removing the Z assembly and attaching something else is easy, however you have a lot of choices for a Z assembly with Z slider that are offered separately.

You might be interested in this:

By replacing the Z assembly and the Z slider, you may also get a slider more chatter-safe, because unlike the Onefinity Z sliders (both models), which have only one linear bearing per rail, …

I don’t know if you can machine aluminium, but if you look at this video, this is a Z assembly that the video author made himself. To see how the plate looks like at its back you got to go one video up in the playlist and start at #1.

See also

1 Like

Hey @Aiph5u
Would be interested in your thoughts on z axis design - moving carriages or moving rails?
I even found a fairly robust DIY aluminum build that uses a combination of both…

1 Like

Hey Tom,

Thanks for sharing the link to the video!

I already had that thought. It makes the base plate wider in any case. For the Onefinity I would avoid that, but on a newly designed machine, you can take this into account. My preference at the moment of my (very early) planning is rails on the spindle mount plate.

I agree that for the Onefinity a width matching the X axis blocks is more appropriate.

There exists quite the discussion and debate as to which z assembly design is best wrt carriage/rail mounting - from what I have learned they each have their pros and cons, and really depends on the goals you have for the machine you are building.

In a future build I can see myself making a wider z assembly, in part to mount other components such as dust collection and perhaps an oscillating tangential knife. No need for a new machine at the moment, however I still have plans to design and machine a more rigid Z assembly, as I believe my current build can do it, albeit with careful attention to machining parameters. Unfortunately I do not have the confidence or experience yet to undertake the challenge - soon perhaps :smiley:

1 Like

Well it seems I am not the only one looking to attach an FM30. I found a gentleman on Facebook who is doing the same thing,

I understand the concerns about the Z-20’s rigidity. But I will put my faith in 1F’s design work, that it is sufficient to carry the loads. For me the big issue is that 1F has already considered the overall integration and operation of the assembly. I looked at the Rover unit and it certainly is beefy, but if it is banging into things all over the place it is not worth it at half the price.

I have to agree with other folks here that I would think presenting a flat face with mounting holes for a number of different actual mounts would be nice feature. I think this is done for two reasons 1) and the big one is this approach cuts down on warranty work. Somebody would mount a 67 Chevy to it, break it and send it back under warranty 2) this “feature” keeps you from straying from the 1F ecosystem. i.e your mount might cover up the suckit mounts.

I also read this thing is a bear to disassemble. Tips on that front will be welcome.

Well it looks like I wait for it to arrive before I can start my CAD models for it. (yes I saw the previous STL files but I assume the Z-20 has different dimensions.

Thanks for the comments guys

Can you explain your comment re the Rover " …banging into things all over the place…" .

If I understand correctly, you are going to design and machine just a replacement for the spindle mount, the one that integrates with the bearings? if so could I recommend you make it at least as tall as the linear bearings.

One drawback, I believe, will be any design will place the end mill further out from the linear rails, which will add to the deflection. I need to be very mindful of machining parameters with my Jianken ATC spindle, and the FM series are about 2.5kg heavier, so perhaps even more care will need to be taken to manage lateral forces and deflection.

I look forward to seeing your design.

The banging into things was a reference to the overall width of the Z gantry. Taking it to the extremes if the Z gantry were 3’ wide you would effectively reduce the X axis travel. Any time you replace a component I am concerned with those “corner cases” in design where you just miss a design constraint.

Yup just a replacement mount, that way to be as compatible with 1F as possible. At first blush, I am hoping to reduce the “y” offset of the spindle, getting it closer to the x frame.

You mention deflections, I see two types here: ( please don’t think I am talking down to you but I will try to explain like I am talking to the grandson)

  1. Z deflection this is just the pure vertical deflection of hanging a weight. Think of a shelf deflecting form books place on it.

  2. A torque is applied to the X gantry because the weight is hung off the gantry at an offset. This torque will twist the X gantry rotating it.

Now 1F could have done a Finite Element Model (FEM) so they could predict deflections and bearing loads… But that could/would be a lot of work. Or, the could have followed standard design practices’ which is equally valid.

There is a lot of technical info that 1F does not provide … for example weight and size limits. My wife was asking for the “mean time between failures” numbers for the components … I chuckled.

I have the stiffy option on Foreman so that should help with the deflection. In addition I will not be installing other clap trap like lasers or go-pro cameras. All of these extras are mounted at a further offset so the moment arm is longer.

I will like do the time honored approach and build it hoping for the best. I will try not to be too stupid.

Well all of this keeps me off the streets at night.

1 Like

Hey Carl and Lynn,

did you already have a look at this and this and this. It covers not only the best milling motor solution for hobbyists and semiprofessionals, but also what is the main difference between Onefinity Z sliders and the Z sliders of other CNC machines: The fact that the Onefinity Z slider is not able to protrude beyond the lower end of the Z assembly. Most CNC machines usually do, as you maybe observed (except one well-known hobbyist machine that also uses the hand trim router).

This is because the machine was designed to use a hand trim router (like another, very known hobbyist machine does) as milling motor, and those hand routers like the Makita RT070x have a long cylindrical mounting surface, which allows not only to accomodate your hand to hold it, but also to attach some accessories like bases that are clamped to it and can be slid up and down, and when mounting such a hand router like the Makita into the Onefinity router mount, you can slide it much downwards, so that it is not the Z slider that protrudes beyond downwards beyond the end of the Z assembly, but just the router or the spindle, and you even have to slide it that much into the mount because (at least on Original Series) if you don’t, the router’s back will bump the stepper cage when trying to reach topmost Z position. But the main reason why you have to slide and clamp it that much downward into the mount, is that otherwise you would not reach the workpiece in case it has a low height, which is because the Z slider is not able to protrude the lower end of Z assembly.

And after there was a strong demand by the users to be able to use 80 mm spindles, Onefinity simply offered a mount that looks the same, but with 80 mm inner diameter, but did not change anything on its design, which means the capability to reach the workpiece despite the fact that the Z slider is not able to protrude beyond the lower end of the Z assembly is achieved only by sliding the router or spindle much downwards into the mount, thereby increasing leverage force and thus possible chatter. Also one big difference is that usually Z sliders on other CNC machines have two linear bearings per rail, but the Onefinity only one:

So what you have here, is a Z slider that was made for a hand trim router and that was just offered with a slightly larger inner diameter. The design wasn’t even changed for the new Elite Series, just the chrome-plated steel hollow shafts were made bigger with 20 instead of 16 mm and the Z travel increased from 133 to 163 mm.

So when we bought our Onefinity, it was already clear we would mount another Z assembly to hold our spindle.

1 Like

I did go back and look at the “dedicated milling motors” … they strike me as a middle ground between routers and spindles. That and Mafell seems like a cousin to Festool … and that addiction has already cost me enough. I know cry once :wink:

I am also:

  • going the ATC route so that is an issue.
  • looking to run 1/2" bits

You say “So when we bought our Onefinity, it was already clear we would mount another Z assembly to hold our spindle” What did you buy/make and is it compatible with an Elite?

As far as the Rover CNC Z gantry, I like the design. But too many unknowns, and quite a bit more cost. If 1F offered something like it I would buy it. From a seat of the pants perspective I think the stiffy would do just fine… but my pants have been wrong before. (I do like that rover gives you an actual drawing!!! Bonus pts)

With regards to the Z height … extending the actual mounting face down the Z axis with an additional … oh I don’t know 3" and then trim to fit. I know you are a FreeCad user, if you like I will run the model by you for comments. Flip bytes is quicker and cheaper than cutting chips.

Hey Carl and Lynn,

Nothing yet, as we originally planned to be in a house with a large workshop for the CNC and a few other big machines when the Onefinity arrives, but something came up that prevented that so we’re still stuck in an apartment :frowning:. But what I plan as Z assembly will look like above but a little smaller for the Onefinity. It will have the HIWIN linear rails and bearings in any case. Maybe instead of making my own I will simply buy the Sorotec Z-Axis Kit “Alu-Line” which is from a CNC parts supplier in my country, that also offers entire machines, assembled or as kit.

1 Like

I found some notes and back of the envelope calculations I had made - a long time ago now - that compared a few z assembly options.
I was comparing the Avid and Rover options, and found the Rover won out slightly as to how far the spindle centre was relative to the Onefinity X axis block. Although I did like some of the design features of the Avid better, but it was wider than the Rover, with the later being just about the width of the Onefinity Z assembly.

When I looked at the numbers my spindle centre is about 95mm out from the X axis block (the Onefinity design does a good job of keeping the spindle close to the X axis IMO), and with the Rover mount this distance increases to about 145mm (I estimated the thickness of the back wall of their 80mm mount was ~10mm).

I have a preproduction Z-20, which I imagine is similar in dimension to those shipping. From a simple sketch design I feel the best I could do making a FM30 integrated mount would be a spindle centre to X axis block distance of about 115mm. This is with very little material in front of/enclosing the linear bearings. Fortunately the mounting hole locations on the FM30 are well clear of the linear bearings, otherwise much more material would be needed there, adding to the spindle’s extension out from the X axis gantry.

Hey Tom,

if only the Onefinity Z assemblies had more travel! I liked our discussion in this thread and imagine with a Z slider like this, that is able to protrude downwards beyond the lower end of the Z assembly, you would be able to keep the spindle center very close to the X carriage. But I would prefer to have two bearings per rail instead of one, and I fear that even the slightly higher Z-20 slider would not satisfy because its height is not enough for that.

I agree with your earlier statement regarding the design being fundamentally to support a lighter weight router, and I believe geared mainly for the wood milling market.

There is something about everything connected by a narrow spindle mount at the mercy of 2 ‘standard quality’ linear bearings that has always concerned me. I still very much like the overall design - and I know I have been accused (rightly so) of naively/unrealistically expecting micron tolerances with my machine :smiley: I will say though that the slip fit I achieved with my steel locating pin in aluminum was very satisfying :grin:

I had looked at the Sorotec design in the past - no way I could justify the cost (exchange, shipping, etc.), but I can see where it would definitely be worth it given the materials used. Interesting design though - am I seeing it correctly, that the mass of the motor is added to the spindle on the sliding portion of the assembly?

Hey Tom,

yes, unfortunately. this Alu-Line “Heavy Gantry” user also says he bought servos but they didn’t fit. He doesn’t say why but I don’t think I really would use this Z-assembly. I rather meant I could buy something ready-to-use, but at the moment, none of those I linked are totally satisfactory. What I find convincing, is what Marcel made and it’s so nice that he makes so good videos and he works with much perfection. It’s just the question, will I try to use the Onefinity in stock configuration (but with my Mechatron spindle) to mill the Z assembly parts myself, and will they be exact enough, or will I try to find a service that mills the parts for me.

Hey Carl and Lynn,

here you can see what it looks like if a spindle is in a Onefinity spindle mount:

And here a spindle when in the recommended Mechatron mount on a CNC machine with a Z slider similar to the one shown above:


Oh this guy is a hoot

I liked the control cabinet with breathalyzer test :slight_smile:

European equivalent of This Old Tony :grin: