Saturn 2 4x4 w/ Nema34 closed-loop - In Canada

[wmgeorge]

Does the machine cut and rout accurate work? If your chasing .001 just for the thrill of the chase or are you putting out boards that are not routed or cut to reasonable standards for woodworking? Are you tossing a lot of wood into the burn pile? If the machine is not capable of doing the work you require then send it back.. My machine is more capable than me.

Some people have sent back, got a refund and are still not happy. Some have sent back entire gantries and had it replaced and still not happy. If you think the spec's are not correct and it makes crappy doors or widgets for you, sent it back.

Bottom lIne. If your not happy take Nate at his word.... and send it back and buy a machine elsewhere or do what GME is doing build the prefect machine.

[GME]

I was thinking about this yesterday and one thing that came to mind is that they all could very well be welded in a jig and held to the tolerance of the jig/fixture. But if the fixture isn't very accurate or has changed then the resulting frames will be out, as well.

David

David

I wondered about it too. Clearly, there is something very wrong going on. I have no idea how the jig is built, but it has to be stout enough to keep things in position during welding, and handle the Saturn's weight. I doubt it is the sort of thing that you would expect to change much, if at all, over time. I can understand your frame being okay, given that it was the first. Ditto for others build in the same time frame. I cannot help but question whether the maker stopped stress relieving at some point. That might explain at least some of the build problems.

I think Bill (wmgeorge) had it right when he observed that is not particularly uncommon with machines build in China. The prototypes sell the distributor on the product, then quality ceases to be a priority and badly built machines follow. If Nate was able to have someone onsite during manufacture, he could ensure QC and refuse to accept sub par machines. However, given that FLA is a part time endeavor, that isn't going to happen. What surprises me is the Saturn still being offered for sale. The quality issues probably explain why the 8 footer has never appeared on the site. I'm guessing the maker couldn't get the prototype right.

Gary

Does the machine cut and rout accurate work? If your chasing .001 just for the thrill of the chase or are you putting out boards that are not routed or cut to reasonable standards for woodworking? Are you tossing a lot of wood into the burn pile? If the machine is not capable of doing the work you require then send it back.. My machine is more capable than me.

Some people have sent back, got a refund and are still not happy. Some have sent back entire gantries and had it replaced and still not happy. If you think the spec's are not correct and it makes crappy doors or widgets for you, sent it back.

Bottom lIne. If your not happy take Nate at his word.... and send it back and buy a machine elsewhere or do what GME is doing build the prefect machine.

Bill,

IMO, it goes beyond the question of whether it is cuts well enough. Some seemed satisfied with the accuracy, at least at first, but experienced very premature wear. I believe for MICKNM, it was bad enough to ruin a linear bearing block after minimal use. That sort of thing is entirely predictable, when when a machine is far out of spec. Many of us make smaller parts. Even significant manufacturing defects wouldn't necessarily be obvious and the parts seem fine. Again, that appears to have been MICKNM's experience. It wasn't until he tried to run 3d parts did the problems surface. I could see someone running a lot of parts and never see anything wrong - until the rails, bearing blocks, gears self destruct way sooner than they should..

I, for one, am not unhappy after sending my machine back. I am grateful that it turned out well, although it was a load of inconvenience. I'll call it a learning experience. What makes me unhappy is seeing folks with machines that should have never been sold, and watching them struggle. That some folks are left with a bad taste is hardly surprising - especially with the poor service for which Nate is so infamous.

Gary

[wmgeorge]

Sorry, I might have said things rather strongly.

But I would have paid more If the machine was made completely in the USA, as I thought in the
beginning. Now finding out the machine appears if it was Jig welded it was not done well. Yet we see some must have been correctly. Sorry Gary the only complaint I had on mine was the hole sizes for mounting the frame to the factory stand. Yes I did need to drill and tap some mounting holes for routing a senser cable.

I have cut some large jobs, one involved 2 24 inch diameter circles cut in MDF, and routered without my dust collector operational.

No I am sorry, I did not check and adjust my machine to hold .001 over 48 inches. But I have cut some large jobs and they were right on and thats all that counts.

[GME]

Sorry, I might have said things rather strongly.

But I would have paid more If the machine was made completely in the USA, as I thought in the
beginning. Now finding out the machine appears if it was Jig welded it was not done well. Yet we see some must have been correctly. Sorry Gary the only complaint I had on mine was the hole sizes for mounting the frame to the factory stand. Yes I did need to drill and tap some mounting holes for routing a senser cable.

I have cut some large jobs, one involved 2 24 inch diameter circles cut in MDF, and routered without my dust collector operational.

No I am sorry, I did not check and adjust my machine to hold .001 over 48 inches. But I have cut some large jobs and they were right on and thats all that counts.

Bill,

I think you may be missing the point. I'm not talking about holding a .001" tolerance. The point: Any given machine may seem to cut fine. Cut tolerances may be exactly what you expect. However, if the machine is not put together correctly, stuff like gears, bearings, rails and the like wear out prematurely, or flat out break when they shouldn't.

I'm guessing that for the hobbyist, linear rails, bearing blocks and gear racks should last pretty much for the life of the owner. Aluminum gears, probably not as long, but should last a long time. You're not going to get that on a machine that's put together badly - especially a welded machine with virtually no flexibility.

I couldn't be more pleased that you are satisfied with your machine and it meets your expectations. However, without taking measurements, it's a crap shoot how long the components will last. If you've had to buy linear rails and bearing blocks in the past, you know how expensive they are. I bought Hiwin for my new machine, but the lower priced ones are still pricey.

I wish that having to drill out a mounting hole for the stand was all I had to deal with. Even as picky as I am, that would not have been deal breaker, or even a big deal. BTW, dollars to donuts, it wasn't the frame mounting hole that was the cause of your problem. It was leg kit. I had to drill out a whole bunch of holes in the brackets, because the screw holes in the legs didn't line up. The brackets and holes in them were all consistent, so it was definitely the legs. Some of the threaded holes in the legs were drilled at a nasty angle. When the screws were threaded in, only a small point on the head made contact. I wasn't happy, but I would have lived with it, but for the other problems.

Gary

[wmgeorge]

Sorry again but my stand kit went together without an issue, it was the mounting holes in the stand that were the problem. All my holes lined up and were tapped correctly. I had one of the first (I think) stands shipped in June 2018.

I dropped my Z,Y and X motors down and away from the gear racks, and ran by hand and had no binding. Zero. That was done months ago. I'm sorry no complaints and the machine works. I do not obsess over things that "could" happen in the future.

I had forgotten in my build Thread I did need to redo a limit switch block and remount another.

Please find my other Thread where I have posted some smaller 3D work and the detail on it.

[wackocrash5150]

Ok so I didn't have a whole lot of time last night but I managed to take some measurements before I got sidetracked with dinner and whatnot. What I decided to to measure was the distance of movement on the Y axis to see if it was equal and was not surprised to find out that it was not. Now take into account that I have not fine tuned the steps-per-inch in Mach3, but my method was to home the machine, take a measurement from the hard-stop, then move the axis +30 inches and remeasure from the same hard-stop points. Here's what I came up with:

On the Y side
- distance from hard-stop to aluminum mounting plate when at Y0.0 = 0.96875"
- distance from hard-stop to aluminum mounting plate when at Y30.0 = 30.875"

On the A side
- distance from hard-stop to aluminum mounting plate when at Y0.0 = 0.84375"
- distance from hard-stop to aluminum mounting plate when at Y30.0 = 30.8125"

I also decided to take a measurement on the Y side again after I'd pressed the E-Stop to release tension from the rack and gantry.
- distance from hard-stop to aluminum mounting plate after E-Stop = 30.8125"

A few things to note. When I home the machine and hit the E-Stop, there is NO tension on the rack or gantry. It does not move at all when the E-Stop is pressed at Y0.0. Also, in hindsight, I should've also measured the A side after hitting the E-Stop when at Y30.0

So what do these numbers tell me? They tell me that when I move the gantry, the Y and A axis are not moving the same distance. At a glance, there's a difference of 1/16th when powered and 1/8th when not; and that's only at +30 inches, let alone the entire 50+ inches of travel. I know it only gets worse the further you go because unless the rack tension spring is quite tight, it will actually skip a tooth around the 40 to 45 inch mark.

What got me thinking to check this was Bill's comment of "Does the machine cut and rout accurate work?"*
Although I've done nothing but the spoil-board, my answer at this point would be "probably not". The spoil-board was done by taking measurements with the machine itself, not a designed file.**




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[trm1980]

Now take into account that I have not fine tuned the steps-per-inch in Mach3

But are the motor steps exactly the same for the y axis drive and the slave drive?

Tim

[wackocrash5150]

But are the motor steps exactly the same for the y axis drive and the slave drive?

Tim

Yes. As are the physical driver settings concerning the steps-per-revolution. I went as far as thinking that there might be a manufacturing defect in the rack itself. Swapping with the X-axis rack yielded the same result. The same thought went for the entire R&P/stepper assembly; Swapped and same result.

[wmgeorge]

Like Gary said earlier I do not think the metal stop plates are the thing to measure off from. Mine comes up kisses the stops and then moves backward under power? I think anyway. But I have decided just to limit my cuts or work to the spec'd 48 inches inches and not push the "Limits" so to speak. Is the gantry binding with out the gears and motors engaged? That would or could give your answer.

[wackocrash5150]

Like Gary said earlier I do not think the metal stop plates are the thing to measure off from. Mine comes up kisses the stops and then moves backward under power? I think anyway. But I have decided just to limit my cuts or work to the spec'd 48 inches inches and not push the "Limits" so to speak. Is the gantry binding with out the gears and motors engaged? That would or could give your answer.

The reason I chose the stop plates is because they make it simpler to measure from and are stationary. The measurements from the stop-plate to the aluminum gantry mount are consistent each time after homing. Different measurements on each side yes, but consistent. Hence the reason for the different numbers when measuring from stop to mount when Y=0.0 . I was only trying to measure for a difference in distance traveled.
The gantry does not seem to bind right up when the pinions are not engaged, but it does seem slightly stiffer at the far end. Close enough that it could be my imagination.
For some reason, I thought I remember measuring once distance traveled when pushing from the center of the gantry by hand, and those numbers not jiving as well. I'd have to do it again to be sure. Surely not exact but if it was way off ....

[wmgeorge]

To be honest I really do not know what to measure off or not. But the gantry should move freely without binding from one end to another, same on the X side. I am going to run a job this afternoon for my grand daughter, I will try to pay attention. But when you over a certain age point it gets more of a chore to remember the details.

[Ntl]

You can't measure off the hard stops period. They are not perfectly square mine were about a 1/8 of a inch off. Once I squared up my gantry I shimed up the aluminum blocks so they were very close. I used a laser level to mark the liniar rails and squared the gantry initially off those marks, then ran the test where you insert a pen in the spindle and draw a large square and based on the diaganal measurements it tells you what direction the slave side of the gantry needs to go. After I made the adjustment which was 0.03 off from my initial squaring, I remarked the liniar rails and shimed up the hard stops. Mine is perfect now. The only lingering issue I have is that y liniar rails aren't perfectly level and flat so I had to leave the bearing blocks loose otherwise the gantry binds. I still need to find a way to level out the liniar rails so I can tighten up the bearing blocks.

[wackocrash5150]

You can't measure off the hard stops period. They are not perfectly square mine were about a 1/8 of a inch off.

Off? Off of what?
Ohhhhhh .... ok. I think I know where the misunderstanding is. I'm not trying to square the gantry off the hard-stops. Nope. I realize the tube end they are fastened to are not square so that would be very difficult. I get that; however they are stationary. I was only trying to measure distance traveled on each side of the gantry.

Here's my thought process:

Say hypothetically that my steps per inch in Mach3 is bang on correct. AFTER homing I measure from hard-stop plate (not rubber) to the aluminum gantry mount on the Y axis side and it's 0.75" and then I measure the same on the A axis (slave) and it's 0.50", yes they're not the same but I have a reference for each side because the hard-stop plates, although not aligned with one another, do not move. Now if I tell Mach to move +30" on the Y, my new measurements in a perfect world should should be 30.75" on the Y and 30.50" on the A (slave) when measured from the same spots. When I subtract my reference measurement from the measurement taken after movement, they should both be equal, (in this example 30"). In my case they're not.

[Ntl]

Put a v bit in the spindle put a 48" ruller on the table, with the spindle at x0 line up the v bit with 0 on the ruler, now command y48 see what travel you get. Now go to maximum x travel in my case since I have a 2x4 router it's 25.3, so I would assume yours is around 50" now repeat the test. If one side is off then you either have a problem with losing steps some how possible binding, excessive backlash, or the paired axis drives aren't set up the same. If you get the same travel then move on to squaring the gantry, but if it isn't close to being square initially, it can cause binding and lost steps. Also if you have the rack and pinion to tight it will cause strain and possibly lost steps.

[wackocrash5150]

Because of the closed loop steppers I'm using, the only way for it to lose steps without my knowledge is when the rack gear actually skips a tooth. When steps are lost with the closed loop motors, it will try to "catch up" for a second and then alarm out. It does not alarm out but it will skip a tooth unless the tension adjustment is quite high.

The first part that you posted is pretty much lead me to discovering this can of worms.

[GME]

Leon,

How strange. It's hard to account for why the two sides of the Y axis move different distances. As long as the steps per on Y and A (Y slave) are set the same you would think the distance moved would be the same. Also, I believe Mach3 sets the steps for the slave to the same steps as Y Master, except when homing, regardless of what steps the slave is set to. As you point out, closed loop steppers should error out, so that one source that can probably be ruled out.

Backlash could account for a few thousand's error, but I doubt as much as you are measuring - especially given how tight to the racks you have drive gears are set. Even excessive wear on the drive gear shouldn't account for such a large error in a machine that hasn't had a lot of use.

+1 on the technique you are using to measure distance. Even if the hard stops are not aligned in the same plane, and they surely aren't, I agree that it isn't as though you were trying to measure for square from them. Like you, I believe the relative distances moved should be the same. Unlike you, I am surprised that they aren't - especially to the degree you measured. If you were skipping a cog, you'd hear it. You already know what it sounds like. I am probably overlooking something obvious, but I'm scratching my head over this one. Something is very wrong, but what? If Ger21 stops by, he may have some good insights.

Skipping teeth is a big issue. The rack tension needs to be tight, but not excessively so. The need for excessive tension seems like a symptom of a larger problem, and is going to wear parts fast.

In another current thread, micknm found that his racks were bowed (inward, I believe) and had to be shimmed. The frame had to have a bow in it. Might bowed racks explain the tooth skipping, at least in part? If memory serves, you and micknm both have skipping teeth in common, although michnm's problem didn't surface until he started running longer 3d jobs. He thought things getting warmed up might have been a cause for the delayed reaction. Do you have a decent straight edge to put along the racks to ensure they are laying flat without any bowing inward or outward? It wouldn't necessarily have to be a precision ground one, if you are just trying to see if there appears to be a problem. However, if you actually wanted to shim, a precision ground straight edge and a good set of feeler gauges would be more appropriate.

Your machine and the one I had have one thing in common: the more we look, the more problems we find. Feel that knot in the pit of your stomach?

Gary

[Ntl]

Can you move the gantry easily with the motors dropped, not engaged? It should be very smooth and easy to move. If it's not binding then it has to be something with the motors not getting enough current or noise if they are set up properly with the software. Were you the one that was having a motor moving in the wrong direction? I don't remember. If there isn't a mechanical problem with binding it has to be something else that is making the motors get out of sink. Did you try loosening up the gantry where it bolts to the aluminum plates and run the test to see if you're getting the proper movement. If you're skipping teeth on the rack and pinion than the gantry is either out of square or preloading the bearings is causing binding, or the pinion isn't tensioned properly. After dealing with mine, I could tell you real quick what's going on if I saw it in person. Just be patient and start with loosing up the gantry and checking for gaps between the gantry beam and the aluminum plate. If you have any gaps then when you tighten everything up something has to give and it's going to be the aluminum plate and then it's putting a preload on the bearings since they don't have much play.

[Ntl]

Oh yeah one other thing I personally don't have encoders but I have read of people having a problem with not having the encoder count set properly. I'm not sure what type of drivers or motors you have, but some have software that you set them up with. Are you positive that the drivers are setup the same? Is it possible that one of the steppers has a different encoder count than the other one? I'm just trying to think of the simple things that could go wrong with the machine. I would think that if it was mechanical it would be obvious once you dropped the motors and tried to move the gantry by hand.

If you already checked for binding and you already squared up the gantry and have the pinions tension set properly and you're 100% sure that you aren't having any issues with your controller or encoders. Than I have no clue what the problem could be causing one side to travel further than the other side. Maybe post a video of your test so we can better understand what could be causing the problem. If you're skipping teeth under normal travel with proper tension then the gantry has to be binding or you're losing steps for some reason and then because you have encoders it catches back up and pushes the gantry out of square

You really need to square up the gantry so you can mark the frame, that way its easy to see if you are getting out of square do to lost steps.

[GME]

Can you move the gantry easily with the motors dropped, not engaged? It should be very smooth and easy to move. If it's not binding then it has to be something with the motors not getting enough current or noise if they are set up properly with the software.

Dan,

I beg to differ. You could drop the motors, find that the gantry runs as smooth as silk, and still have a problem unrelated to the gantry, interface mounting, etc. Take a look at micknm'a thread. His problem was related to a warped frame, which, in turn, caused the gear racks to be bowed inward. Once the motors are dropped, they are disconnected from the racks. You would never know that the racks were the problem. More to the point, it wouldn't have anything to do with the motors.

If you were talking about the observed distance moved, binding shouldn't affect that, unless it was bad enough to cause missed steps or tooth skipping. As Leon pointed out, he has closed loop steppers that would correct for lost steps or error out.

I don't have experience with closed loop steppers, but as I understand how they work, low current or noise would cause them to try to correct or error out. I suppose my understanding could be completely wrong. Leon probably knows.

Having said the above, there have to binding issues, even of somewhat subtle ones. You will note in earlier posts that Leon found that the the linear rails were angled inward. In such a case, some degree of binding is a given unless you loosen the gantry mounting bolts and shim out the error between the gantry mounting and interface plates. Also, it is a given that linear rails out of parallel (more than about .001" to .0017", depending on the source) cause some degree of binding, regardless of whether you can perceive it through feel.

Gary

[Ntl]

He already had a problem with the motors changing direction on him. I have no idea how he did his electronics or how it was wired or anything about his electronics. My point is that nothing mechanical can cause one side to move further than the other unless one of the pinion gears was a different size than the other one. The guy who had a problem with his rack not being level didn't have a problem for a year and it was wearing out parts prematurely. My machine has the same issues and it's because steel tube has a dip in the middle, it's the type of material that was used. Also the paint creates inconsistencies as well as grinding the welds down. My point was and is that if the gantry moves easily by hand is squared up to the liniar rails and the pinion gears are not over or under tighted the only way one side can move further than the other would come back to something either software or hardware related. It's impossible unless the whole table was built at a angle and if it was insert gantry binding here. I'm willing to bet it turns out to have something to do with the electronics if like I said multiple times there isn't anything binding. I absolutely wouldn't be surprised if his gantry is warped and causing the problem heck I wouldn't be surprised if one of the pinion gears is a 16th of a inch bigger than the other one or has a extra tooth on it. I'm just trying to give him things to look for and not over analyze how the machines are out of spec. Just trying to help the guy out since I have the same machine just a smaller version. We all know that you are building your own perfect router we're all looking forward to seeing it finished. Unfortunately for us we have to be problem solvers and fix the issues that these machines have. It would be fantastic if Finline would jump in and offer some solutions since they are getting paid not us.