Cool tables and spindle ordering fun #6 - Brakpan, S.Africa

[domino11]

Kobus, Love the saw motor idea! Check out this link K2 CNC Saw Motor

[Kobus_Joubert]

The concept works like a dream....will make and upload a video next time I try it out.
Today I got a halfnut...actually 2 x halfnuts... as I have lost the original that was on the motor.
When I got home this afternoon I could not wait to try it out. I fitted the blade and put lock-tite on both to make sure it stays in place

I do however have a lot of SPARKING on the brushes of the motor...more when it is cutting under load (deep cut)
Maybe the brushes must SEAT IN after I worked on it ?? Any Ideas please let me know.

This cuting was not as scary as I thought. Took it nice and slow and never felt that there was a danger situation. One needs to be careful and don't put your hand close to the blade...and don't feed to fast.

Still have to play with feeds, as I had to touch it up with sandpaper after the cut. Maybe I must increase the speed the wood is turning and slow down more on the feed of the blade cutter.

First try was a 26mm square piece 450 mm long. Took 3 minutes to do.

DSC01630.JPG

[domino11]

Wow, looks great. Will wait for the video!

[Kobus_Joubert]

I have a question for guys that have done some turning on their indexing systems.
Vectric Aspire suggest one uses the centre of the workpiece to set Z=0.
If my piece of wood is in the lathe...how do I get it to be in the centre of the piece....the piece is 100mm thick.
I setup my router bit to be running along the Y-axis, therefore zero the bit in the centre of the piece and on top.
There is no way for me to zero on the centre with my setup.
My way works( zero on top), but I could have variations if my stock piece varies in thickness.
I can zero the Z on the middle, but then my bit must be positioned on the side of the piece of wood, but this does not work 100% for me.
Any suggestions to help me understand this Z=0 on the centre of material is appreciated.

[Alan_c]

How about, set zero on the top surface of the work piece, move off to the side, do a G0 move to Z-50 and reset as Z zero (assuming a stating job size of 100mm), is that workable?

[Alan_c]

Just had another thought, The centre pount of the indexer should not change, so make up a spacer the correct distance between the bed and the centre point of the indexer, then set Z zero on top of this before loading the job, then irrespective of any variation in the size of your blank, it will always be set to the centre???

[KenC]

I don't think you can physically touch off the Z of any object in its center...
touch off Z at the top of the job, then use G92 to change the Z0 position.
This is what I will do with my EMC2.

[Kobus_Joubert]

After a long discussion with AlanC this morning I see his point. I was always working by hitting ZERO-ALL once I get to my 0,0,0 points.
He pointed out that I should zero the Z-Axis on the centre of the lathe. Then pick up the router, and go to my X and Y zero point.
Then only Zero X and Y....all so easy, will go and check tonight.
Sure it will work...just got to remember to setup Aspire to work off the centre of the workpiece.

[riesvantwisk]

Kobus,

you could make a touchoff plate (block?) that is stationary on the center of the workpiece.
This way you can do toolchanges, and still touch off in the center, and you can even do this with a auto-z system if you have one.

Would something like that work?

[Gerald D]

Does your indexer still look like this?

I agree with Ries (and Vectric) . . .looking from the top down (his right side sketch), the touch point is to the side of the workpiece.

[Kobus_Joubert]

Yes Gerald, it is still the same indexer...just added a new self centring 4 jaw chuck.

What I did this afternoon after work was the following.

I brought my cutter on top of the LIVE CENTER...that is 38mm diameter.
I then told Mach that this is Z=0
I then took the gantry away from this point towards X=100...to give me space to drop down on the Z-axis.
I then dropped the Z-axis another -19mm...this is now CENTRE in the lathe.
Again I did a Z=0...actually I Zero'ed ALL the axis at this point.
I then picked up Z to +60 to clear my workpiece.
Then jogged to the centre of my workpiece (X=0) and to the start of my workpiece (Y=0).
I then only did a X=0 Reference and a Y=0 reference.

This worked and the machine started to do it's cut.
I was not happy with the toolpath that it followed and stopped the Mach-3 during the cut.
I then hit GO TO Zero...
Guesss what happened...it went to X and Y zero, but tried to go to my Z= - something....the centre of the lathe.

In the past when I used the top of the workpiece and did a ZERO on all axis at this point I could easily get back to my start point...time and time again, but with this offset of the Z in the -direction, I am missing something.

So in short, the touch plate is not the issue...what sequence must I set up my reference points to get this working, so that I can get back to 0,0,0 ?
Boy, I am slow to grasp this offset thing, but point me in the right direction and I will FLY....

[riesvantwisk]

Kobus,

I am not vert familiar with Mach3, but in EMC2 we call 'Go Zero' 'Go Touchoff', in Gcode terms that is G0 X0 Y0 Z0.

May be it's a good idea to create or program a button called 'Go Home', that is usually a place on your machine 'out of the way'. In my case with the MM that's on the lower left on my machine, ususally this place is 0,0,0 in Machine coordinates. The place your machine goes to with G0 X0 Y0 Z0 are called work (offset) coordinates.

Machine coordinates => place on the machine references to the machine itself
Work coordinates => Place in reference to the workpiece.

In EMC I created two buttons
1) GO Home
2) Go to touchoff

However I programmed it in such a way that I always go to a area where Z is high enough' to fit my largest mill. So my GO TO TOUCHOFF button looks something like this sequence:
G0 Z160
G0 X0 Y0
G0 Z 40

so I first move my spindle as high as possible.
Them move to my touchoff X/Y coordinates
Then I lower my spindle 40mm above my workpiece.

Such a button should be-able to get programmed with Mach3 aswell I think.

Ries

[Kobus_Joubert]

Thank's for the input Ries. I am sure Mach-3 can do it, just that I don't yet know how. There are a lot of options in Mach to modify and do, but I got stuck to the basics and never went any further.

[hennie]

Die ouderdom !!

[Kobus_Joubert]

Decided to keep on with my old way's. Zero everything where I can see and understand it.
Then let old BBB and Aspire do it's magic.

DSC01646.JPG

DSC01650.JPG

[Brad Maritz]

Very Very Very Nice.

[hennie]

Someone needs a dust extraction attachment."Ek like dit"

[KenC]

Love it!

[domino11]

Nice

[Surfcnc]

The patina just lifts the piece no end.

PS that saw is a crazy bit of kit

Regards
ross

[Kobus_Joubert]

As they are killing all our Rhino, I have to make sure we remember them in the future.

These are all test runs on pine. Once I am confident that I can do it without wasting good wood, I will do it on something nice.
DSC01653.JPG

[Kobus_Joubert]

Now that I looking at upgrading to a spindle....more for the noise part than raw power.... I re-looked at the 2.2kW Chinese spec's....it show's 8.5 Amp.

As the Omron VFD that I have is only 6.5 Amp, I think I will have to go for the 1.5 kW spindle.
Are the Chinese VFD's really that bad, because I see some good bundle deals, but don't want to buy one and have to change it at a later stage..and because I have a good 1.5kW VFD I feel it's a waste of money to not use it.

Doing more research I see the 1.5kW has a ER11 collet ...mmmmmm Maybe the 2.2 kW with ER20 is still the answer.? Decisions decisions....

[Gerald D]

The 6.5Amp Omron VFD will happily drive a (rated) 8.5Amp 2.2kW spindle. But it will only drive it up to 6.5Amp and you will get around 1.7kw out of the spindle. Nothing wrong with that if you already have the VFD. (Very little chance of ever burning out anything)

[Kobus_Joubert]

Thank's Gerald...as I have no knowledge of VFD's I am relying on your wisdom. Thank's for clearing it up....So back to getting the best price for a 2.2 kW spindle.

[AuS MaDDoG]

Hi Kobus,

My thoughts are that the 1.5Kw is a good unit and is nice and quite whilst running compared to the 2.2kw monster.
After all the hard work Ross has done I don't think the Chinese Vfd's are that bad especially if used with the correct Opto-Isolated Converter. The Chinese Vfd's have worked fine and consistently under fairly hard testing on Ross's MM and recently on both of ours once we got the right converter.
Long term use I cannot yet say.
The only other thing I will comment on, is that if you wish to use some larger cutting bits it sure is nice having a larger shaft on the bit rather than the 1/4" used on the 1.5kw spindles.

Cheers
Tony.

[KenC]

It all depends on what you are looking at, $$$ or brand...
With the price, I just have to live with lesser tech support... so far it is still spinning upon request.,
I regularly drive my chinese 2.2kw spindle to the vacinity of 8~9A range & peaks at about 11A without frying the VFD... that meant a R25 bull nose into 6mm deep cut on solid nyato wood panel @23000rpm @6500mm/min. My next spindle will be 4.5kW ...
BTW, I operate the VFD fully manually via its control buttons... it gets the job done.

[bradm]

Kobus, I believe you actually could run the 2.2kW Chinese spindle with the Omron VFD - with a corresponding loss of power.

The HuanYang VFD that I experienced had no safety margins and shoddy workmanship. If you're willing to tolerate and coddle a device that creates more electrical noise than necessary, can barely cool itself, has its power electronics running at their limits, and has imperfect documentation in order to save a little money, go for it. If your time has any value at all, I'd stay away from it. It is clearly a loss leader provided to ease the sale of the spindles. The spindles are to all accounts decent. The HY VFD is not, even when it works.

So, I think you find a spindle with an ER20, and shop for the VFD from a source that competes on VFDs, not one that throws them in as a condition of sale. I know firsthand that the Hitachi VFDs are well engineered, and I'm sure there are many others. For example the VFD that factorymation.com calls the 7300CV looks solid.

[hennie]

Kobus,There is a company called "sew eurodrive" I don`t know their nr.they are situated at the showgrounds offramp from Maraisburg side.I have seen one of their VFD`S and I think it will be the one.Also try Siemens ,My edgebinder had one in and it looks solid.

[Kobus_Joubert]

Got VFD, need spindle

[Kobus_Joubert]

Fixed up old chair...think it is Maple...Made copy of front legs to make another set later on my indexer.
DSC01656.JPG