New MechMate painted, with experimental control box - Atibaia, Brazil
 

Hello,

My name is Fabio Gilii, and sorry if my English is not so good!

The machine will have 2000 x 1300 mm utile area, and is going well until now.

Attached some photos of the structure and material - I'm waiting for laser cut parts this week!

Thank you Mr. Gerald for your verý well detailed plans and attention...(sorry for the quality of the photos)

Welcome Fabio

Looks like you are off to a great start - I envy your well equipped workshop.

What are the specs on those stepper motors, how big is the spindle?

Alan

Alan,

Thank you for the wellcome!

These motors are Nema 34 size and 3.5 Nm only, but I'll mount them with a 3.6:1 belt reduction each, running 20 teeth pinion on 1.5 modulus rack (20 teeth mod 1.5 is equal 30mm primitive diameter and 94.2 mm perimeter)

The spindle is a Brazillian brand spindle rated at 18000 rpm (1CV), angular contact bearings, with ER16 nose to install ER collects.

The inverter is WEG brand rated at 300 Hz top frequency...

My shop is very small (as you can see in the photos) and making that big machine is being a little problem of space to use the manhines..

I have two lathes and two knee milling machine (one selfmade and one 1959 Brdgeport)

can you tell us more about the spindle ?

model and manufacturer ?

Dave

Welcome Fabio!

The WEG name has become very strong in South Africa. They also have very good prices on inverters for us. (Alan, the agents are "Zest" in Montague Gardens. They are my first choice in motors for the factory)

Hi Fabio... welcome to the mechmate forum too...
It's good to see that there are more people in Brazil building the mechmate.

Leandro

Dave,
I believe these motors are based on a famous Italian brand named Elte.

The manufacturer is named "Tecmaf", and attached is a PDF doc with some motor specs...(model TMM-10-0110)

It's my first buy from this manufacturer, and i opted to buy it based on the fact that is a local manufacturer (guarantee, pieces and maintenance) even if the price is a little bit high - equivalent to US$850,00

Gerald,
I believe that WEG is the biggest electric motor and electric components manufacturer here in Brazil, and probably in South America!

Is also my first choice when ii think in electric motors...

Leandro,

Nice to see you here too!

Fabio, which drivers and bob are you using? Are the motors bipolar or unipolar, and they are from action motors?

Best regards

Leandro

Leandro,

Yes - the motors came from Action Motors - they are bipolars (8 wires), 3,2 Nm.

The drivers are bipolar also, and rated for 3,5A/phase and 45VDC (or 32VAC)

The bob have full opto insulated I/O and can drive 3 relays (two 10A and one 20A)

Well,

Two weeks ago I was dealing with a very big frame being mounted in a very restricted area, and a laser supplier that forgot to cut some pieces and some internal details!!! Incredible how some persons have the capacity to make wrong things...

After some hard work I'm still figthing against space (the lack of :) ) and now i'll start do deal with the belt gear reductions and electrical installation...

Next week I want to send entire machine (dismantled) to sand blast and powder painting...

The last photo is the solution I found for "X" rail because It was impossible do find a good "U" beam as plans claims and the one I found has a big radius at corner...

Some pictures so far (sorry the poor quality...)

Hello MM fans,

I hope next week will be time to make chips!!!

I'm only waiting some pieces arrive to conclude MechMate Machine... :)

I hope you enjoy!

Fabio,

The machine looks great! Interesting color for the y car :D
Keep us posted on the chip making.

aren't you worried about sawdust in you control panel?

Greg,

Well - I put two "grills" (sorry - don't know the name in English) with air filters - one in each side of the panel.

There are also a fan that pumps air from inside to outside - installed in the right hand...

I hope sawdust stay outside for a while... :) (in the photo, left grill is still without filter)

It looks beautiful Fabio. Congratulations.

WOW. That was a quick build.....and what a nice machine! Now I wish I had a really nice spindle....Sean

Fabio, it looks pretty, but I expect serious problems with your control box. That transformer makes a lot of noise (electrical interference) and heat. The spindle drive (VFD) makes even a lot more electrical noise (also some heat). Your control break-out board is directly under the motor wires, and close to the VFD and the big transformer. Let us hope that you do not have problems . . . . .

Doug,

Thank you !

Sean,

I talked to Gerald about spindles, and soon I'll post some ideas in the advertising section regarding spindles - maybe will be a strong possibility to you finnaly own one !

Gerald,

Yes - I know it's a risk to put VFD together with stepper drives... but I decided to experiment to see what will happen...

I'm prepared also to try an idea - to create a "Faraday Cage" and put the VFD inside!
I don't know if will work in fact, but i's valid to prove a concept...

For the heat, I hope the fan take a good parcel to outside - it's also another experiment...

If I take VFD and transformer outside the gabinet, it's OK, but will be Ugly :) (functional but ugly)

Hello all,

These are photos taken this weekend - the machine is ready to rock with all the belt reduction installed and tested.

It's soon to say but the best thing I discovered was the VFD inside panel did not interfered in any moment with the drivers...

The spindle motor became quite hot after 30 minutes running at 12000 rpm when was doing ligth cuts to experiment, and this week will talk to the manufacturer about this, but it proved to be very powerfull...

The maximum velocity reached 21 meters/minute (830 in/minute), but i limited to near 15 meters/minute (590 in/minute)

I hope you enjoy...

Well done Fabio - looking good.

Nice neat bit of engineering on the reduction drives.

When you say the maximum speed was at 21m/min was that the max possible from your computer system or did you start losing steps. With those stepper motors and spindle what do you expect to be your fastest practical cutting speed?

For the hot spindle, you can also try a "reactor":

http://www.galco.com/scripts/cgiip.e...promo=200MTERL

I use the reactor on somebody else's recommendation, and I don't know exactly how much different the temperature.

http://www.ekstromcarlson.com/router_packages.htm

Hey Gerald...that looks familiar. And darn it's heavy:)

Sean, I have past experience of Galco including a slab of chocolate in the box. . . . . . . . :)

Alan,

Thanks - this was the solution I found in place for very expensive ready made commercial planetary reductions...

It took me 3 ou 4 days on my old milling machine, but I liked the final results...

21 m/min was the maximum before loose steps, but the curious was that only in the "X" axis - at "Y" axis I did not noted any tendency to loose steps.

I choose to derate maximum speed to near 15 meters/minute, because I think this is good to move at G00...

I start to build some router bits (tungsten carbide) to start speed tests, but I expect something near 7 or 8 meters/minute @ 14000 (to 18000 top speed), a very respectable speed for me...

Gerald,

Thank for the link.
I don't know if this kink of equipment I can find here in my country, but sure i'll search...

Let me ask you a question, because it's the firs time i use a spindle fast as this (with VDF):
Is it normal that spindles like Elte, Colombo, or any other like that to heat when is working?
In the upper part of the spindle (the back plate) there is a small fan, but even blowing some aiir over the motor, the temperature was unconfortably high...

I think that I could hold my hand on our spindle for longer than 5 minutes. Some of the other guys measure their spindle temperatures daily to check the bearing life, but I have forgotten what typical temperatures they measure.

My Colombo spindle has bearings that are rated up to 140F. I try to hold the temperatures to a more moderate 120F by reading the spindle's housing regularly with an infrared thermometer. When the spindle is running too hot, sometimes the best solution is to increase the chipload. The wood chips carry heat away from the cutter. If the cutter is running cool, it won't pass heat along to the spindle. At least one Colombo user burned up the bearings on his spindle in a matter of hours by running the spindle at high RPM with the feed speed low.

Gerald and Mike,

I'm very impressed with your experience with spindle temperature - after a 30 minutes run I doubt i can hold my hand over spindle housing for more than some seconds...

140F is equivalent to 60° Celcius - it's very "cold" - my spindle is far more hot than this...

Ok - this week I'll send to the manufacturer to see if it's everything Ok..

That is extremely interesting !! I never would have thought to increase the chipload to decrease bearing temp.

Can the same "thing" be said for routers?

Greg,

Increasing the chipload to decrease bearing temp is very interesting indeed!

I think that will be true to big routers with lot of power...

When my feed speed and spindle RPM are 'right on', the cutting sounds like someone is tearing paper. When I hear that sound, I know that everything is running perfectly. Almost always when I hear that sound, I also have large heathy looking chips.

allot like drilling metal. Those long spiral slices let you know that the pressure is just right.

Geez, I can't wait to start making wood chips :D I'm 60 to 90 days away. My buddy that's making the rails will have them done this Sunday. Only charging me 1/2 a new cutting bit.

Greg, is he milling the rails?

Nils,

I cut one leg of the 2.5 inch x 2.5 inch x 1/4 inch [63.5mm x 63.5 mm x 6.35 mm] angle down to 1.00 inch [25.4 mm] with my steel cutting saw. Very easy.

My buddy will machine the 45 degree edges with his end mill.

Hello MM fans,

Last week I faced a new challenge: The machine was loosing "altiture".

During a cut, the "Z" axis move down a little - maybe one or two steps down at each program line...

Also, I noted that when I tryed to jog (i'm using Turbocnc on pure DOS), when one axis is moving (any axis), other axis (not only the "Z") suffer a kind os "flickering" (sorry - don't know the rigth word in English)

I verified if there is some trouble with the pneumatic spring, but there was no problems, because my spring is a little "positive", sending the entire spindle plate in up direction...

Than the second providence was test and review all grounding arround entire machine, but everything was Ok...

Then I remember Gerald saying that VFD together with drivers and BOB will bring troubles, but this behaviour occur even with VDF turned Off!!!

The next step in direction to discover the problem, I tryed to loose the tension springs of all four motors and "disconect" the gear from the rack, and the problem gone!

Well, I said, the thing is a kind of poor grounding (or even some troubles in earthing), and revised all eathing and grounding again, and even created a new earthing pole (sorry again) in another place far from the first one, but look what I discover:

With all gears not in contact with their racks, I stated do place first Z axis back to the original place, and test the movement - no interference, then "Y" axis and again no interference and then one of the "X" motors and again no interference, but when i just "touched" the last "X" axis gear against rack, that vibration appeared again!!!

I tried to change the order of reposition the motors, but the problem repeated when i touched the last motor in it's rack, and mainly in "X" axis...

After two days trying everything I know and I became very disapóinted because the problem persisted, I decided to remove the electric pannel from it's position - fixed below the table near the front of the machine - because I was ready to dismantle every electric/electronic connection and redo all again to see if it's a short of something like - and for my surprise, the problem dissappeared!!!

Yes - all that stange behavior completelly dissapeared when the electric pannel wass removed from contact with the machine chassis...

I tryed to touch the pannel in the chassis, and the problem appeared again.

I want to hear from you what you think about this, but I have my conclusions:

- When the pannel was bolted under the table, the mechanical vibration from the movements made some interference over the electronic driver boards;

- When the pinions just touch the racks, steel vs steel frictioning one against other generate a kind of "electric noise", but the most impressive is even with grounding the racks, the problem persist...

Now the pannel was fixed in the wall nex the machine, and no more problems!

HI Zeta,

Whats happening with ur machine, any more troubles which u have overcome?

RGDS
IRfan

Hello Irfan,

Yes - I had problems due to vibrations and perhaps some "electric noise" caused by steel against steel pieces, but aparently solved when I installed the Electric Panel in the wall - it was in direct contact with the machine structure...

Now the machine is working very very fine, and I'm very happy with the professional looking results...

Some time ago I was preocuped with the spindle motor temperature, but I solved just touching up some configurations in inverter programing, and now the temperature is stable in near 65 degrees Celcius...

Now I must find time to cut some "MECHMATE" logo !!!

Have a nice New Year!!!

Old-newbie questions ?
 

Hi Fabio,
All the best & health to you & love ones for this new year !
I bow to your work, nice & clean.
Have you ever fiddle with making CNC before?

Few newbie (never built one YET! ) question, if I may !?
I’ve been lurking from the back ground on & off for too long ( give & take 2yrs), now I’ve taking the “new year resolution by the horns” and kick my self to go with it this year, busy or not with work !! ( Being a self employed woodworker in business, woodworking is not the best revenue business but heck… I’m VERY passionate about it.
One of my best moto is : Wood not live with out Wood !!
So… Questions :
A - May you tell me more about your controllers & BOB as they seem different than the PMDX & other I’ve seen & flirt with?
B – I’m interested to learn more about your spindle choice.
Why TecMaf… less expensive than the classic Penske, Colombo, Elte and HSD to name a few !!
Or simply because their made in your country !?
Do you fell confidant to this point with it ?
I've notice you selected the 900watts – 1.2cv. Not that bigger is always better…but why not just a tab more… like their 2CV or 4CV ??

Thanks in advance for your time to my new(old) quest !
Amicalement, Robert

Fabio ,

happy new year to u too!

Regards
Irfan

Robert,

I studied Precision Mechanics and even being a Toolmaker for some 10 years I worked as system integrator for a company that sells cnc machines for the garment industry, and my function was to install and teach complete production systems for new customers...
My experience in cnc is not too much, and in a very small toolroom I made some automatic dispositives and very small cnc routers for PCB milling.

Now for your questions:
That drivers are very simple bipolar ones only capable to make half steps and to deal with 3,5A maximum.
They are based on the pair "L297/L298" IC from ST microelectronics...
The BOB is eigther a very simple opto isolated unit with no "charge pump" circuitry but with 3 relays.
Those boards are some of the commercial options made here in Brazil - For me is very difficult to buy things like Geckos and any other foreign products...

For us is there a lot of taxes and customs barreers, and importing goods are very expensive...

Now for the spindle, the choice on Tecmaf was based after some searching in the market and for my surprise I discovered that is very difficult to find vendors or sales representatives for known brands like Colombo or Elte, and with my difficults to buy imported materials it was a natural way to use a national brand and of course prices - a good amount less if compared to an imported unit...

I don't know Penske and HSD...

The only I found here was "Elte", but the prices was very high and there is no technical support...
I must confess that I don't have experience in woodworking, and for me 1,2CV is a lot of power if I compare to my 3/4 CV Bridgeport knee milling machine...

Ok - I know it's different to use direct drive but the work is ligth and I'm very impressed with the motor...
The machine is doing simple cuts and carving relief in MDF and soft wood, like insignias and letterings...

I believe that if the necessity is heavy cuts with wide tools and deep passes, 1,2CV is not too much, but I can change to another motor with more power....

I hope I understood all your questions and answered well!

Regards,
Fabio