[Novakon]

UPDATE!

Last main concern is wow the head and spindle sure get hot. Any grease points I'm not seeing. I definitely don't want anything wearing or burning up in the spindle assembly.

Most likely all you need is a spindle bearing rebuild. No telling how many hours are on it from the original owner.

Regards,
Novakon Team

[Whizbang]

Most likely all you need is a spindle bearing rebuild. No telling how many hours are on it from the original owner.

Regards,
Novakon Team

Is there any documentation or a procedure for this on the novakon website? I mostly found overall blue prints no real technical instructions.

Thanks

[Whizbang]

I took this picture quick but didn't look at it prior to closing the computer back up after cleaning out the dust. I think I have Gecko G203V drivers but would like a confirmation from someone that the NM200 series is in fact equipped with the Gecko G203V. can this driver power any Nema 23 or 34 stepper motor? I currently have a KL37H280-45-4A and I would like to hook it up with my 4th axis.

Attachment 199164

Also I need to know what the port in the picture is and where I can find more of them.

Attachment 199166

Does anyone have any spindle rebuild/cleaning/lubricating techniques if it is getting pretty warm?

[Whizbang]

So, I discovered when jogging the machine, it travels beyond the Z max limit switch (it can also travel past this point while machining, MACH has a pop up that tells you that you’re beyond machine coordinates or something along those lines). I managed to pull the oil line out but put it back in with no problems. Is there a way to make my max limit a “hard” limit so to speak? I want my top Z limit to halt the travel so I cannot risk pulling out my oil line again or risk running my slides off the rails. I know the slides can creep off because I have done it before but I don’t want to test my luck.

The first photos shows the slide I am talking about and the second photos shows the limit.

Attachment 228418
Attachment 228420

[SCzEngrgGroup]

If you're using Mach3, just setup soft limits, and Mach3 will not allow you to move past the specified machine coordinates. If you're using the built-in prox sensors as limit switches, I suggest you adjust them so they trigger about 1/4" from the hard stops, so you CAN'T over-shoot them.

Regards,
Ray L.

[UniqueMachining]

Just to clarify what Ray stated, when under Mach control "Running a program" Mach will honour soft limits to prevent over running an axis.
However when jogging it goes where you send it, soft limits are ignored. At least that's my experience. If I have missed something please feel free to correct me.

John

[Whizbang]

I am wondering if I added a Pokeys board if I could allow for another estop input. I would then 3d print a bracket with a limit switch and then when the sliders are just about to come off hit that switch. Better yet is if there is a way to make it just stop the z. axis and not have to reset the system etc. I know that hoss has been using a pokeys board I may shoot him a pm to see if he thinks that will work.

The reason I am not content with the soft limits. is many times if I just have to face something or put a few holes in I don't home the machine. I just use the pendent. So this question was really for when I am just doing quick work and not paying attention to where my z axis head is.

Thanks guys

[LeeWay]

You could mount a mechanical switch on it rather than the optical. Not only Novakon machines have issues with this type switch. I have seen many builds have issues. Really not a reliable design or maybe just poor quality switches, however they look great.

I have used some low cost switches on my plasma cutter that are pretty reliable. They are covered switches and have adjustable roller arms that can be positioned 360 degrees. They are plenty accurate for these machines. At least as close as the OEM ones. I don't think they would be too much trouble to install and you could use the existing wiring.

[Hirudin]

Mach3 stops at the soft limits when I'm jogging. If it's not doing it there must be an option turned off or something.

[Whizbang]

Mach 3 is stopping because you originally homed the machine. if you don't home the machine and just set your zeros on you dro it will not stop. Also I believe there is an option to be able to beyond your soft limits with out the machine stopping. I have not found that yet. I remember I used it once on my cnc router. Either way if while changing tools or setting up a fixture one can easily manually over travel the machine. I am still going to pursue the limit switch at the end of the linear rail up top.

[Hirudin]

This button controls whether Mach3 adheres to the soft limits, no?

[Whizbang]

Hey everyone,

So I have finally found some time to play, and it hasn't turned out to well.

I have a bracket I drew up in AutoDesk Inventor for a 3-D printer, meaning its a relatively small bracket. I am machining it out of 6061 Aluminum. I cam'd the part in Inventor using the HSM Works software that I have used before without issue (simple stuff but successful cutting with no broken tooling). This time I used G Wizard for the the first time to set up my tooling parameters, feeds, speed, etc. My tool was a HSS 1/4" flat endmill with 4 flutes. I wanted to machine in the conservative side since it's been awhile since I ran anything and I didn't want to do damage. I was cutting at 4000rpm with a feedrate max set to 18 in/min. The dept of cut was set to 4mm since G Wizard had a cut depth set to .1875". Dry runs all went well, when I started to cut actual metal I was only going at ~30% of my feedrate. After a few passes I was confident that all was well, so I increased the feedrate a little, then a little more after another pass. When I hit ~80% of my feedrate the cut started to look gummy, then the endmill got stuck and snapped. I was not running flood coolant but I was manually spraying down the part with coolant from a spray bottle while it was running. My spindle got hot and maintained the heat for a long time. Honestly it looks as though the endmill over heated (some discoloration visible), but I thought with a light and conservative cut set up my G Wizard I would be ok without the flood coolant, my previous parts cut in a similar fashion cut just fine with only manual coolant from a spray bottle.

Attachment 233410

Attachment 233412

Attachment 233414

Attachment 233416

Once cooled I removed the spindle nut (left hand threaded) with great effort, only to discover a shard of metal. I am not sure if it was once a washer, if its a piece of metal from else where or what. It does not appear to be threaded and none of the spindle components look damaged or appear to me missing pieces of metal from anywhere. I have no idea how long that piece was there and I found no signs of the theoretical remnant needed to make a theoretical complete washer (if it is even a piece of a washer)

Attachment 233418

Attachment 233420


Thoughts, answers, recommendation anything is appreciated.

Thanks,
Whizbang

[SCzEngrgGroup]

Your cut went wrong for many reasons:

1) NEVER use 4-flute endmills for roughing aluminum - use a 2- or 3-flute. 4-flutes don't have enough flute area to get the chips out, and the result is exactly what you got.
2) That looks like a pretty long tool, which requires reducing depth and feedrate, due to tool flex. Always used the shortest tool you can.
3) Slotting with depth >= tool diameter is asking for trouble. When slotting, depth = 1/2 diameter is more reasonable
4) Use proper coolant, even mist will do a decent job

I don't believe GWizard would have given you 4000RPM/18IPM for that cut with all the right parameter entered. One of the 8 billion parameters must have been set wrong.

Overall, you're much better off with a shallower cut, and faster feedrate, but always maintain a reasonable chipload. A light chipload is often worse that a heavy chipload, as it puts the heat in the tool, while a heavy chipload puts the heat in the chips. Try something more like a short 2-flute at 5000RPM, 0.125" DOC, 20 IPM. If you're using HSMXpress, use 2DAdaptive as much as possible for fast material removal. With a 1/4" HSS endmill, you can run 6000 RPM, 0.25" depth, 0.05" stepover (HSMXpress "optimal load"). But, without proper coolant, you'll have to back way off on depth to avoid problems.

There should be a thrust washer between the drawbar and the top of the spindle, and that washer must be coated with anti-seize every few weeks. Hard to tell from the photos if that washer is there or not, but it NEEDS to be there.

Regards,
Ray L.

[Whizbang]

Thanks for the input. With my current spindle I can only get 4500rpm max, but I am looking into a new motor. As for the thrust washer. Definitely nothing there. I assume the metal scrap (which I attached more detailed photos of) is the remnants of the thrust washer. But as stated I have no idea where the additional pieces may have landed if anywhere. I can only hope that the previous owner damaged the thrust washer and the piece I found was jammed up in the nut and they didn't realize and the rest was removed and new one was never put in (fingers crossed on this theory because I don't know where the shrapnel could be at this point).

With that said what dimensions of thrust washer do I need? I am hoping to pick one up tomorrow at Fastenal. I didn't see any on the Novakon website. And while I am pretty certain I know where it goes I would really appreciate a schematic showing the spindle and the location of said thrust washer.

Attachment 233458



Thanks,
Whizbang

[SCzEngrgGroup]

The thrust washer is an oddball size - you won't find anything like it at Fastenal. Contact Novakon, I'm sure they can sell you a new thrust washer and drawbar for very little $.

Regards,
Ray L.

[LeeWay]

I just bought a couple of three piece thrust bearings yesterday to use on my HF 6x48 belt sander. They will go behind the belt tracking knobs. Straight nut to iron as it comes from the factory which requires a tool for adjustment. I am hoping the thrust bearings will eliminate that need.
I got them from McMaster Carr. I am pretty sure you can find what you are looking for right there. I would probably get a high grade Mil spec washer. You won't wear out one of those.

[Whizbang]

So while I am waiting on a response from Novakon regarding some new parts, including the necessary thrust washer and draw bar. I took a closer look at my draw bar and realized there seems to be more damage than I had originally thought. The first piece of metal came out when I removed the left hand threaded draw-bar nut, The draw was still in place, so i was a bit confused what the washer was intended for it appeared to be sitting on top of the shoulder of the draw-bar between it and the nut. Removing the draw, the shoulder is badly worn and semi-distorted and there is a broken washer/bearing/something slipping around the shaft. Now this other piece which is broken but still attached more or less seems to sit where I would have assumed the thrust washer was needed, but I cannot tell if it was originally thick or was warped from no lubrication and excessive tightening of the draw-bar/collet. So am I missing multiple pieces? And does anyone have specs on the thrust washer? I understand it may be odd ball, but I am sure I can find something close while I am waiting. So any rough dimensions would be great.

Attachment 234158

Attachment 234152

Attachment 234156

Attachment 234154



Thanks.
Whizbang

[SCzEngrgGroup]

Your drawbar, and thrust washer are both trashed. I'd bet the top of your spindle is as well. The bottom of the drawbar head should be perfectly flat, with a roughly 0.200" section that is larger OD than the rest of the head. The thrust washer also is about 0.200" thick, and the same OD as that larger part of the head. Your thrust washer is virtually gone and the large OD portion of the head is almost completely worn away.

Here is what it should look like:



I would:

1) Use a file to clean up the top of the spindle - it should be perfectly flat. If it's not really badly damaged, you can clean it up by turning the spindle on to about 1000 RPM, then CAREFULLY use a file to flatten it.
2) Put the drawbar in a lathe, and clean up the underside of the head, so it's flat again.
3) Use a lathe to turn a thick washer, to take the place of the thrust washer. Due to all the missing material, I'd make that washer at least 3/8" thick, the OD just smaller than the OD of the top of the spindle, the ID just larger than the OD of the drawbar shank, and a shallow recess on the top to help center the drawbar head.
4) COAT the thrust washer, and drawbar threads, with anti-sieze, and re-coat it at least every couple of weeks.

Regards,
Ray L.

[LeeWay]

I would also inspect the threads on it before I took the time to turn it.
I make my own draw bars using Grade 8 stock and after a while, even those threads will start to show wear.
Otherwise good advice from Ray as per norm.

[SCzEngrgGroup]

Otherwise good advice from Ray as per norm.

Lee,

"norm"? Who the he11 is "norm"?? :-)

Regards,
Ray L.