[Pually]

Hi everyone. I'm Paul. I have a Chinese 6040 router I bought a couple years ago and have always had a problem with the Z axis maintaining the correct elevation throughout the cut. Example: I start a model with the maximum depth of 3mm on the first pass. It will run for a while maintaining the 3mm depth. But after a bit, the spindle starts cutting deeper than 3mm, although the DRO in MACH3 still says it's at 3mm. If I let it continue to cut, it will soon be down to 10 or 15mm while the readout still says it's at 3mm. Anyone hear of this before? Any ideas where I can look for a solution?

Thanks for any help
Paul

 

[jw2170]

G'day @Pually , welcome to the forum.

If you post your query in the CNC section, you may get a better response..

 

[old55]

Welcome to the forum @Pually

 

[Red]

Welcome to the forum.

Red

 

[Pually]

G'day @Pually , welcome to the forum.

If you post your query in the CNC section, you may get a better response..

Oh ok. Thanks JW

 

[difalkner]

If you post your query in the CNC section, you may get a better response..

I moved it for you.

Welcome to the forum, Paul! Is it mechanically slipping downward or can you see the drive mechanism lowering it as you cut? I would think if the drive mechanism is lowering it then you'd see that on the DRO.

 

[Bentley]

Maybe you guys should start buying quality CNC machines instead of the Chinese JUNK. There are so many posts on here with issues from these Chinese junk machines. I learned the hard way. Bought a CWI Professor HDX with supposedly good parts. It was junk.

 

[John Smith_]

Mr. Bentley, this is true. But, unfortunately most of the members here do not have the financial ability to start from scratch with a new top-of-the-line machine.
You yourself said you "learned the hard way". so please don't admonish those that are following in your footsteps.
Please feel free to start your own threads with photos of your shop and your machines and share some of the projects you have made so you can lead by example.

 

[Bentley]

Mr. Bentley, this is true. But, unfortunately most of the members here do not have the financial ability to start from scratch with a new top-of-the-line machine.
You yourself said you "learned the hard way". so please don't admonish those that are following in your footsteps.
Please feel free to start your own threads with photos of your shop and your machines and share some of the projects you have made so you can lead by example.

Thanks for replying. What I'm trying to do is have these cheap Chinese manufacturers which usually have a guy over in North America distribute and profit off the hard working people over here give us a decent product. They flood the market with junk. Even though most of the parts of these machines are made in Asia, some make good products. I myself have complained to some of them and have gotten results. I just wish I was younger and had the resources to start my own CNC manufacturing business. I would be putting together a quality product with quality parts for everyone at a decent price.
I started off with a kit, Routakit actually. It was a piece of crap. Next was my CWI HDX Professor. Poor quality and high price. I was going to build another kit but in Canada its pretty hard to get good stuff. Then I added an Axiom Precision AR6 Basic. I still have that machine as my backup. I sold the CWI and kept the Axiom and Purchased the ShopSabre 23. Now if anyone out there needs to ask any questions on the last 2 machines feel free to ask. They are both great machines. Axiom, made in Taiwan- excellent build quality and accurate. ShopSabre 23- made in USA. Excellent all around. I'd buy either one again in a heart beat, especially the ShopSabre. I'd love to show some of my projects but in this market I'd be shooting myself in the foot and have more competition than I already have. My wife and I have a small business and during the last 4 months of each year I literally can't keep up with orders. I'm retired and want to stay that way. But if anyone out there would like some advice on future purchases on a CNC feel free to ask.
Bentley

 

[Cncest]

Is it possible the cutting tool is slipping in the collet and dropping down? Tighten or replace collet.
Have you tried slowing down stepper motor speed? I find best results running at 80% in Mach3.
I use Win10 with Artcam and Mach3 to run a Chinese 6040 CNC router. I get excellent results making 3d reliefs.

 

[difalkner]

I find best results running at 80% in Mach3.

So I'm curious, if 80% works then why not just slow the feed in your CAM program. If the designated speed is 100 ipm, for instance, instead of changing it in Mach3 to 80 ipm just set it to 80 ipm in your CAM program and you won't have to adjust anything. Or am I missing something here...?

 

[Cncest]

I'm sure that would work just as well.

 

[gdonham1]

Most belt driven machines that lose steps are one of several reasons.

1. Z belt tension. Belt must be tight. If your Z stepper motor set screws are not can cause inconsistent depths.
2. V wheels not adjusted properly. V wheels need to be snug but not crushed.
3. Retract height is too high. If retract is set too high z hits stop and looses steps.
4. Router bit slipping in collet. Bit should marked so you can quickly see if bit has moved. A thin permanent marker works well.

 

[RainMan 2.0]

Thanks for replying. What I'm trying to do is have these cheap Chinese manufacturers which usually have a guy over in North America distribute and profit off the hard working people over here give us a decent product. They flood the market with junk. Even though most of the parts of these machines are made in Asia, some make good products. I myself have complained to some of them and have gotten results. I just wish I was younger and had the resources to start my own CNC manufacturing business. I would be putting together a quality product with quality parts for everyone at a decent price.
I started off with a kit, Routakit actually. It was a piece of crap. Next was my CWI HDX Professor. Poor quality and high price. I was going to build another kit but in Canada its pretty hard to get good stuff. Then I added an Axiom Precision AR6 Basic. I still have that machine as my backup. I sold the CWI and kept the Axiom and Purchased the ShopSabre 23. Now if anyone out there needs to ask any questions on the last 2 machines feel free to ask. They are both great machines. Axiom, made in Taiwan- excellent build quality and accurate. ShopSabre 23- made in USA. Excellent all around. I'd buy either one again in a heart beat, especially the ShopSabre. I'd love to show some of my projects but in this market I'd be shooting myself in the foot and have more competition than I already have. My wife and I have a small business and during the last 4 months of each year I literally can't keep up with orders. I'm retired and want to stay that way. But if anyone out there would like some advice on future purchases on a CNC feel free to ask.
Bentley

Do you have an Etsy page ? Asking for a friend lol

 

[gdonham1]

I have not been too active on this site lately. The reason is in the above responses. The poor guy asks for help and instead of help he gets grief about what kind of machine he has.

This forum has some really good advise and some really knowledgeable help for many

If you cannot say something nice and/or helpful please pause and log into facebook or twitter and let the venom fly over there.

Everyday life tries to kick you in the teeth. Lets not help with the teeth bashing here. Try to be supportive and not so negative. Please remember if you cant say something nice dont say any thing and all. Lets try to be more helpful and less judgemental.

God takes us all as we are.

 

[MikeMa]

I haven't been on this group for awhile either, and I recently got my CNC running that I started building 4 years ago, and wanted to check in. I am kinda saddened by the response here.

I know this is an older post, but this may help others. That said, I did research some of the Chinese CNCs, as I own a Chinese CO2 laser that works well, and was comparing them to my build. There are versions of the CNC that OP has that have supported SBR rails with ball screws for all 3 axis. (What I used on my CNC) Before doing ANYTHING, make sure EVERY single screw is locked down TIGHT!! It does sound like there is some slippage, and possible the ball screw nut is missing some bearings. The first thing I would check is to see if a small amount of force, with everything powered down and try to move the Z Axis carriage up and down with a small amount of force. It should not move. If it does, you may need to repack the bearings in the ball screw nut or replace the ball screw completely(what I would recommend). If there is no movement, I would wonder if you are skipping steps, which usually caused by too much speed as others have said. If there is still an issue, then I may suspect a faulty stepper motor. It may take some fine tuning, but I suspect you will get your CNC running well.