Are you experiencing flex on the X rod on the Nomad aswell?

(RaXor) #1

Hey,

So I don’t remember how is called that middle rod, but I’m experiencing huge amount of play.

You can look at the video below:
https://drive.google.com/file/d/1K_OWrVzgEozQxWlNro0KBby1Fqb5ZiTI/view?usp=sharing

A few ago, when I first received the Nomad, I was finding I was having an excessive amount of vibrations compared to videos on YouTube., I communicated with the support showing a few videos of that weird noise and I ended up just lubricating the rod, which changed the tone but the noise was still there.

So we didn’t went further, and I thought the vibrations were pretty normal.

This morning I went cleaning the Nomad and while wiping the excessive grease I found out the rod of the X axis wasn’t fixed, I can move it by hand with no force at all.

Are you guys having the same problem ? Maybe we all do, but maybe not at the same degrees, on my side it seems a lot to me, but I’m no engineer.

This is the noise I’m talking about:
https://drive.google.com/file/d/1CCrUS8AktabyKFrpD9DJthuruGFRCKlX/view?usp=sharing

I sent an email to the support aswell regarding this matter, I’m just looking to hear if others are having the same or not.

Thanks!

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#2

The motion visible in the first video is radial. A bit of radial play in the lead screw is not a big issue, and is specified for many applications to prevent binding, but I do not know if this is excessive here. Axial play in the lead screw, on the other hand, would affect accuracy as backlash. I am not near my machine (at work right now) so I can’t check the assembly, and I do not recall what the left end support provision is for the lead screw.

The strident noise sounds like something is loose and rattling against a structural element or the case. I have had the same a few times on my machine, due to loosened fasteners and due to loose material getting in where it wasn’t visible, and every time it was easy to deal with: look and listen until whatever is loose is found, then tighten it or remove it, as appropriate. I can’t tell what is causing yours, but take a look and listen around. The whine due to the steppers is normal, as far as I can tell from the video.

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(RaXor) #3

Thanks for your feedback, by axial if you mean the lead screw of the Z axis, then it does have a little bit of play on the bottom.

I wasn’t worrying about the whine of the motors,I learnt about coil whine been a while back before getting into CNC.

I also thought something is loose, I already took a look around the spindle and everything seems properly tightened, I will take a further look at the bottom side and also wait for feedback from Carbide3D.

Oh, on a side note, the bottom of the backside isn’t tightened to anything, I mean the HDPE white panel hiding the controler board, it’s basically loose on the bottom, only the top part is tightened to the structure of the machine, I wonder if that was intended.

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#4

The lead screw axis is the line around which it is intended to rotate. The radial plane is the plane perpendicular to the axis line.

Axial: along the length of the lead screw, so axial play could occur with any of the three axes. In this case, the X axis. There should be so significant axial play for ANY of the lead screws.

Radial: For the x-axis lead screw, movement up and down or front to back is radial, as the radial plane is parallel to the sides of the machine. A small bit of radial play is normal for lead screws in many types of machine, as without it, insignificant alignment issues can lead to binding. How much is acceptable I can not answer.

The buzzing: I had a little from one or another of the case panels and snugged it out with the appropriate screw. I also put a foam edge on the plexi cover so it would a) close tighter and, b) not rattle. I don’t recall where the screws are on the back, but nothing says you can’t use a little piece of foam or double sided tape if it is rattling. I have also had the aluminum/plastic cabinet bottom (with the slots for the Y-axis bed support) rattle, as well as bits of material I missed when cleaning up, broken bit pieces, and so on, that get caught in corners, especially in the corner behind the vertical supports. There are a lot of possibilities, but the only way to know is identify the source.

Again, I don’t recall what the left end support for the X-axis lead screw is. It is possible something there is vibrating, but I have not seen that. If no one else follows up before I get home (late meetings today), I will check later.

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(RaXor) #5

Oh okay, sounds clear! Thanks man!

Funny I just put the foam around the edge of the plexi cover, I was getting too much aluminum chips out of the enclosure.

Yeah right I’ll add some foam on the back tomorrow

Alright! Thanks again!

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#6

just got home (took forever… downed wires all over due to 100-125Km/h wind) and looked at my nomad (OK… started a job)

Mine is the white HDPE case: the rear case has 5 small socket head across the top, one about 50mm down at the mid, then three more about 125mm from the top on the right side. There are two button head sockets at the bottom holding the back to the lower rear frame rail.

As my job proceeds, I do hear a little of the strident buzz, but not much. I can’t identify a source, and I am not real worried to find it. The left end of the X-axis lead screw is just loose in a pocket, so there is a bit of radial play.

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(RaXor) #7

Damn where you’re at with such wind ?

I’ve got the HDPE case aswell, so I think this could be from where the rattling is coming from, I do have the two button heat sockets on the bottom, but they are going through the backpanel, they are completely useless as they don’t hold anything at all and I was wondering what were they made for.

I’m going to put some foam to fix that.

OK good to know, so that’s normal. Haven’t got a response from the support yet but I guess they’ll say it’s fine.

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(Phil Gorsuch) #8

You may find this thread of interest:

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(RaXor) #9

This thread seems to be exactly what I was talking about, the excessive amount of vibration I had while cutting aluminum.

I guess I know what to do now, he even shared the CAD of the part to fix that thing, awesome.

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(Chris) #10

Just make the part from the cad out of plastic. Ive got around 1000 hours with that bearing in. One day im goimg to take the machine apart and do the y axis to. It cuts so much better with the bearing.

The issue is the polycarbonate part wares on the end of the screw and allows the vibration to start witch intern makes the issue worse. It also plays hell on the anti backlash nuts. Also check your belt aligment on your spindle. It can make some odd noisy sounds if its off.

After cutting aluminum check your motor mounts. I had my y axis mounts come loose. was seing .020 changes. I just put the machine back togher with some lock tight. havent had the issue since. Good luck.

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(Phil Gorsuch) #11

I just had a chance to fire up and jog around - I hear similar noises but not nearly to the same extent as yours. @g-host1010 has some good suggestions - I will be trying that first!

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(RaXor) #12

I just made the part out of delrin with the Nomad, the tolerance are about 0.1mm off, will that work off ?

Also, I forgot but what’s the thing inside that part in your thread ? Is it the ball bearing that’s inside the original plastic part or do I need to get that thing aswell ?

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(Chris) #13

Wow .040 off. On witch axis? I measured off my nomad. It was an older model. Sorry about that. If you tell me where I’ll fix the CAD.
A skateboard bearing fits in the hole that the lead screw fits on the inside of it. Please post a pic.

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(RaXor) #14

No 0.1mm it’s 0,004 inches, I believe you thought it wasn’t fitting for me right ? But I haven’t tried to fit it yet, I need to find a skateboard bearing first.

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(RaXor) #15

which abec is your skateboard bearing? I wonder which one should I buy, I don’t know much about bearing

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(Chris) #16

Any will work. The higher the number the longer the run out on the bearing is. Abec3 5 or 7 is fine. Just something cheap. It’s not taking any load or drag. It’s just acts as an idler holding the shaft in place.

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(RaXor) #17

Well, I just installed it, disassembled one side of the machine, remounted it back, and found out that the screws aren’t at the same location as your model, so I guess you’ve got the Nomad 883 Classic.

I now need to disassemble it again and take the measurement, damn.

Edit: I just measured it and it was quick to adjust, should do just fine, I’ll mill it tomorrow. Just a question, what’s the reason for making it 9.525 thick half of it and 3.175 the other half ? I think I’ll make the whole thing 8mm thick unless there’s something else I’m not aware of.

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(Chris) #18

I had someone else on an older irc with the same issue. I didn’t get the dimensions that worked for him. If you can measure on your original plastic part center to center of the big hole to a screw hole. The center of screw hole to screw hole I will revise the CAD and post it for everyone. Unless it’s so minimal it didn’t matter.
Taking the side apart is not to bad. Except for the screws in the back. My machine they were tight as hell.
I dont rember why I did the steep on the part. Please post a picture.

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(RaXor) #19

You can see that on my side it’s not making much sense, so I’m guessing you did that form to make it fit on the Classic version.

I measured the holes using the polycarbonate part and a caliper, all others dimensions are identical to your CAD.

About disassembling one side, I’m pretty sure the aluminum plate used as the pillar is glued using loc tite or some sort of strong glue, even with all the screws removed I just coudn’t remove it, but I managed to fit the delrin part.

I’ll mill the thing hopefully today and post the CAD for the Nomad 883 Pro if my measurements are correct.

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(Chris) #20

Cool. I looked at mine I think I did that to fit the part in. The screws were short or something. I’ll lift that side on the part on the CAD and post it. Thanks for checking the holes.
Looks good.

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