[John Gamble]

Just when I thought all was well, I loaded another screen set and Mach stopped working again.
Of course my first thought was that the obvious culprit had to be the most recent change.
Even restoring a good backup would not solve the problem. With hat in hand, I finally called Novakon. John agreed to pop up and check it out.
Fortunately, it turned out that Mach3 had for some unknown reason, become corrupted.
A simple re-load of Mach cleared up the problem. No, the new screen set was not the problem.
Being a software issue it turned out not to be a Novakon issue.

I had, just a week ago, done a fair amount of engraving with a 1/16” ball end mill. From experience a depth variation of just .002” is readily noticeable. All but the last bar were quite acceptable. I showed John the last sample which displayed definite depth variations and partial missed strokes.

John suggested we check the axis ball screws. Z was loose by 3 revolutions, Y by 1 and X was just about dot on. John was perturbed particularly by the suddenness and extent that the Z axis was out. I have been doing a fair bit of deep peck drilling which may have exacerbated the issue.


The best guess as to the cause was break in / usage. Similar to a new car, it loosens up particularly the first 500 miles. Normal maintenance is required to keep it running at spec.


As a result, John decided to create a series of Tech Tips to be published on their web site. Tech Tip #1 is likely to be a recommendation for an inspection and adjustment (with how to instructions), of the ball screws and re-calibration of each after xxxx hours of operation.

This particular issue was obviously not an original setup problem but related to vibration etc. during operation.

Kudos to Novakon, thank you.

John

[Dynoray]

Just when I thought all was well, I loaded another screen set and Mach stopped working again.
Of course my first thought was that the obvious culprit had to be the most recent change.
Even restoring a good backup would not solve the problem. With hat in hand, I finally called Novakon. John agreed to pop up and check it out.
Fortunately, it turned out that Mach3 had for some unknown reason, become corrupted.
A simple re-load of Mach cleared up the problem. No, the new screen set was not the problem.
Being a software issue it turned out not to be a Novakon issue.

I had, just a week ago, done a fair amount of engraving with a 1/16” ball end mill. From experience a depth variation of just .002” is readily noticeable. All but the last bar were quite acceptable. I showed John the last sample which displayed definite depth variations and partial missed strokes.

John suggested we check the axis ball screws. Z was loose by 3 revolutions, Y by 1 and X was just about dot on. John was perturbed particularly by the suddenness and extent that the Z axis was out. I have been doing a fair bit of deep peck drilling which may have exacerbated the issue.


The best guess as to the cause was break in / usage. Similar to a new car, it loosens up particularly the first 500 miles. Normal maintenance is required to keep it running at spec.


As a result, John decided to create a series of Tech Tips to be published on their web site. Tech Tip #1 is likely to be a recommendation for an inspection and adjustment (with how to instructions), of the ball screws and re-calibration of each after xxxx hours of operation.

This particular issue was obviously not an original setup problem but related to vibration etc. during operation.

Kudos to Novakon, thank you.

John

Yes, the first line in the Novakon instructions should be to disassemble and at least tighten EVERYTHING as NOTHING is tight as they come. On mine, the X axis ball screw nut was 0.5" away from being tight.
Your just scratching the surface and you'll have issue's like these non stop unless you just take the time right off the get go to tighten and set everything up as it should be.
It's sad for a new machine, but you won't have any thing worth running untill you take it all apart, replace the chitty parts, replace the parts/bolts that are missing and tighten everything.

[John Gamble]

Dynoray

Please refer to my 3rd to last line.
"This particular issue was obviously not an original setup problem but related to vibration etc. during operation."

My machine has operated satisfactorily since February. I did notice that during a grooving operation, repeated 40 times over 20”, the groove was .002-.003 off at the end of the 20”. (Still well within advertised specs).
If others are as picky as I am and want near professional performance from a hobby machine, I would recommend:
1. Check the tightness of all axis.
2. Check backlash.
3. Calibrate all axis using a known accurate 4-6" bar and dial gauge. By adjusting the Motor Tuning "steps per" the accuracy can be improved from ".001-.002" to ".0002" approx. My machine came with the steps per on all axis set to 10160. I understand this is a calculated figure based on thread screw size. This will provide a basic level of accuracy.

Because my current project requires accuracy of < .002" (preferably .001") over 20", I invested 2-3 hours yesterday to see if I could exceed the published tolerances. By adjusting the steps per +/- 1, I was able to achieve the following repeatable tolerances.

Axis Steps Per Tolerance Distance
X 10152 .0000-1 4"
Y 10164 .0001-2 4"
Z 10159 .0001-2 4"

As my dial gauge only measures to .001 the forth digit is approximate.
Depending on axis tightness, a change of "1" in Steps per, is approx. .00025" (your mileage will vary)

While I am not privy to Navakon’s sales figures, if we assume 100’s of sales , it would appear that the silent majority is satisfied with the performance of their machines. I have and continue to speak to a number of them. May I respectfully suggest, that your issue with them, while it is by no means insignificant, is also not the norm. I do believe that your constant negative comments, particularly where they do not apply, will hinder not help your cause. By no means do I wish to trivialise your experience, you are obviously very dissatisfied. I do however believe you have stated your case quite frequently and emphatically.
In my original post, I specifically stated that this was NOT a setup problem. While I appreciate your frustration, I believe your comments in this case were not constructive and were uncalled for. Perhaps a separate post providing a periodic update of your machines status would better serve your purpose.
I and certainly other people on the board very much appreciate your knowledge and the suggestions you have posted to solve specific problems. I look forward to more of them in the future.

John

[MetalShavings]

I love a happy ending regardless of the brand name involved.

I know that the more parts a machine is made of the higher the probability of encountering problems. But, I still cringe when ever I read of problems encountered by a new or experience CNC owner.

I have yet to order my CNC mill and being a newbie to CNC in general, machine problems (no matter how large or small) tend to make one apprehensive about shelling out thousands of dollars to buy one; regardless of the brand.

I'm glad to hear that Novakon stepped up to the plate on this one.

HollowPoint

[Dynoray]

Dynoray

Please refer to my 3rd to last line.
"This particular issue was obviously not an original setup problem but related to vibration etc. during operation."

My machine has operated satisfactorily since February. I did notice that during a grooving operation, repeated 40 times over 20”, the groove was .002-.003 off at the end of the 20”. (Still well within advertised specs).
If others are as picky as I am and want near professional performance from a hobby machine, I would recommend:
1. Check the tightness of all axis.
2. Check backlash.
3. Calibrate all axis using a known accurate 4-6" bar and dial gauge. By adjusting the Motor Tuning "steps per" the accuracy can be improved from ".001-.002" to ".0002" approx. My machine came with the steps per on all axis set to 10160. I understand this is a calculated figure based on thread screw size. This will provide a basic level of accuracy.

Because my current project requires accuracy of < .002" (preferably .001") over 20", I invested 2-3 hours yesterday to see if I could exceed the published tolerances. By adjusting the steps per +/- 1, I was able to achieve the following repeatable tolerances.

Axis Steps Per Tolerance Distance
X 10152 .0000-1 4"
Y 10164 .0001-2 4"
Z 10159 .0001-2 4"

As my dial gauge only measures to .001 the forth digit is approximate.
Depending on axis tightness, a change of "1" in Steps per, is approx. .00025" (your mileage will vary)

While I am not privy to Navakon’s sales figures, if we assume 100’s of sales , it would appear that the silent majority is satisfied with the performance of their machines. I have and continue to speak to a number of them. May I respectfully suggest, that your issue with them, while it is by no means insignificant, is also not the norm. I do believe that your constant negative comments, particularly where they do not apply, will hinder not help your cause. By no means do I wish to trivialise your experience, you are obviously very dissatisfied. I do however believe you have stated your case quite frequently and emphatically.
In my original post, I specifically stated that this was NOT a setup problem. While I appreciate your frustration, I believe your comments in this case were not constructive and were uncalled for. Perhaps a separate post providing a periodic update of your machines status would better serve your purpose.
I and certainly other people on the board very much appreciate your knowledge and the suggestions you have posted to solve specific problems. I look forward to more of them in the future.

John

Hello John, as far as your statement
"This particular issue was obviously not an original setup problem but related to vibration etc. during operation."

If that helps you sleep at night, keep telling your self that, LOL
But, ball screw mount nuts don't work loose, once they are tightened and locked. They just weren't tightened at assembly of the machine.
The steps per, have to be set for the resolution of the stepper and pitch of the ball screw, if you have to adjust from there to make up for bad ball screws, you'll probably find if you check at 3 different points of the travel, you'll get three different readings.
It's just when someone gets TOLD something, that isn't right about a problem and a fix and they believe it just because they don't know enough about it to know other wise, does that make it allright? Not to me it doesn't.

What would you do if you just bought a new car, on the way home it quit's 5 miles down the road. You call the dealer ship and they tell you to pay to have it towed in, they look at it and get it going but tell you "It wasn't a manufacturers problem and you should have stopped every mile on the way home to check all nuts and bolts" Would that make you feel better about it quiting?
I have spoken to many Novakon owners as well and seems there are two groups, those whom use their mill and have many problems (with little or no warranty support) and those that don't use them but think they are great.

If I affended you by my posts, I'm sorry, but we don't stand very well with getting screwed, doesn't matter if it's $12,000 or $120,000.
ANY product should do what it's advertised to do and if you advertise a 1 year warranty, you should at least return phone calls and E mails. If to say "we don't know what we're doing, bear with us" at least a small effort for some type of response.

[John Gamble]

Dynoray

I will not pretend to understand the intricacies of steppers, ball screws etc. Do appreciate the explanation.
I'm strictly results oriented. If the machine performs to the specification required, I'm a happy camper.
For example, today I machined five 3" pockets .060 deep across 20.5 " in the X axis. I then engraved inside the same pockets, using a 1/16" ball end mill. They came out near perfect. It only takes .001-.002" to visibly distort the text.

See attached photos. Unfortunately the photos do not due justice to the part.
Picture "5-Bar" is the full run of 5 Parts. The remaining three pictures are the leftmost, middle & rightmost bar.
Close up examination of the engraving & cutoff lines, clearly demonstrates little discernable variation (perhaps .001") in the depth across the full 20.5".

If the "steps" per had to be adjusted minutely to make up for minor manufacturing variances (.000788% worst case, 10152 vs 10160 steps per) so be it. I would be delighted to be able to produce parts to this tolerance. There's theory & practice, if it works in practice go for it.

I suspect that neither of us has spoken to the vast "silent majority" of users. As long as they are silent, we can only assume they are not unhappy.

Fortunately, my machine managed to go a lot farther than 5 miles before requiring maintenance. Checking & re-calibrating every six months or 10,000 miles I can live with.

Again, I appreciate that your experience has left you with a bad taste. I sincerely hope that an amicable & reasonable solution can be found.

My main point is simply, that your experience is not representative of the majority. I would not want existing or prospective users to conclude that Novakon machines are sub standard.

Hopefully, Novakon’s recent post re tracking phone calls & emails will assist.

John

[newton009]

Yes, the first line in the Novakon instructions should be to disassemble and at least tighten EVERYTHING as NOTHING is tight as they come. On mine, the X axis ball screw nut was 0.5" away from being tight.
Your just scratching the surface and you'll have issue's like these non stop unless you just take the time right off the get go to tighten and set everything up as it should be.
It's sad for a new machine, but you won't have any thing worth running untill you take it all apart, replace the chitty parts, replace the parts/bolts that are missing and tighten everything.

I fully agree. Clean and tighten everything! I have experience with both NM200 and NM200 V2. The same could be said for both machines. Disassemble, clean, repair or replace missing parts, and tighten everything.

This has been said over and over gain, but seems generally to fall on deaf ears or the nonbelievers. If the machine was set up properly from the start it would not have become sloppy in such a short period of time.

One small example. On both mills the taper pin blind holes that hold the z axis ball nut mount in place were so filled with debris that the pins could not be set. It is the taper pins that counter the shearing force on all the axis ball nut mounts. As well as provide locating.

Good luck to the unwary.

Regards,