New Obsession....

[Moondog]

Smoker..

With a Twin Ballscrew setup you have 2 Ballscrews, one either side for your X Axis. The Ballscrews do not rotate and are fixed into support brackets.

Motors are on each side and drive the Ballnut thru belts and pulleys.

I have attached 2 photos showing a Twin Ballscrew setup on a large router. This machine is used to cut MDF doors and cut around 600 + per day.

Hope this helps.

[Netjams]

WOW!

What a insperation this thread has been!

[Moondog]

Around 3 weeks ago my Z axis motor (Reliance 660 Servo) burnt out. Not sure of the cause but it appears the bearing failed causing the rotor to stick thereby melting everything. This meant production was halted. Damm.

I must admit I was never very happy with my original setup. Relaince Servos and Rutex drivers. I often found that the motors/drives lost position. I know they say that Servos always know where they are... but that is only true in a PROPER closed loop system. Most so called closed loop are really on Hardware closed loop meaning they are closed to the extent of the drivers and therefore the software (Mach) doesn't know if the drives lost position.
A True Closed Loop Servo system is many thousands of dollars and if you go that far you should then use Brushless Servos as well. Beyond my budget.

As the machine is the lifeblood of my business I decided I needed to have a system that was 1, Reliable and 2, was warranted and serviced within australia.

Previously I had many discussions with Steve from LowCostCNCretrofits and always found him to be very helpful and knowledgeable on this subject.

After several phone calls discussing the merits of systems I engaged Steve to build me a reliable system including motors, drivers and power system. I wanted a system from one source and that was matched to my needs.

We decided on using large steppers. 1 Mycom 1300ozin for the X drive and 2 MAE 1070ozin for the Y and Z axis. This was a large increase in Torque over my Reliance motors.

It meant I could change the gearing on my X and Y axis for greater speed and cutting ability. My original X drive was geared to high before so we went from a 27:1 down to a 9:1 reduction which basically meant that for every Motor Revolution my X travel would be 1 inch.

My Y axis was always a concern as I had an Allthread with approx a 1/8 inch pitch which meant high rpm's and whip. Decided to change to a NSK Ballscrew I inch diameter with a 1 inch pitch. The ratio for the Y Axis is is 1.5 : 1 which results in a Y travel of approx 18mm for every motor RPM. As stepper are high torque in the lower range I could afford to have this gearing.

If I find I want more speed in the Y axis I'll change the ratio to 1:1.

con't next post...

[Moondog]

I left the Z axis the same as it would already travel at over 100mm per min, more than enough for a Z axis.

Steve from LCCRF (Lowcostcncretrofits) put all of the new drives into his new Steel controller box and we also asked him to make us a industrial quality pendant.

In the photos below are photos of the Logitrol Contoller box and the Industrial Pendant that Steve made for us. The pendant is in an Aluminum box with a flexible metal conduit. Very sturdy.

more pics next post.

[Moondog]

In the first photo is the X Axis Drive.

specs....

Mycom 1300ozin
Pulleys: 20T, 25mm wide belts and 5mm tooth.
60T, 25mm wide and belts 5mm tooth.

Using a series of 2 this gives me a 1:9 ratio. As the final belt drive is 300mm of of X travel I felt the ratio would give me lots of speed and grunt.

Next is 2 photos of the Y Axis showing the new NSK 25mm Ballscrew and Nut. Purchased this from Action Bearing in Melbourne who also machined the ends to my specs. All done within 1 week. Great Service.

Y Axis specs:

MAE 1070ozin
Pulleys 20T and 30T. 10mm belts and 5mm tooth.

[Moondog]

well we come to the last lot of photos.

These are some photos of the Z axis and the Gantry system. I apologise for the quality of these and previous photos. Bad light and in a hurry.

For anyone contemplating building a new system of retrofitting I can not recommend highly enough to speak to Steve at www.lowcostcncretrofits.com for a matched complete system. Steve spent many hours on the phone with me in setting up my new system and is always willing to discuss.

If you are looking to build a relaible Industrial quality machine, don't scrimp by buying bits and pieces from ebay etc... if you build cheap.. that what you will have.. a cheap unreliable system.. especially if your livelihood depends on it... A lesson learnt the hard way.

Now I need to get back to work and clear my large order backlog...

[lgalla]

Hey Moondog.
Must say you have been an inspiration to get off my As:_$#&5.and start a build.You really need a spindle to match your machines capability.
Try www.ekstromcarlson.com
Larry