Hello Guest it is May 22, 2019, 01:14:52 AM

Author Topic: Prima Lathe conversion  (Read 27388 times)

0 Members and 1 Guest are viewing this topic.

Re: Prima Lathe conversion
« Reply #40 on: December 23, 2013, 10:05:30 AM »
Wow, the overall look of the finished lathe is so simple & uncluttered Zafar!  A sign of great design & engineering.  (...but we knew that already.)

I really like the covers you've made for the carriage & servo mountings.  How did you make them?  I can't tell from the picture; are they machined from large plastic blocks or....?  That must've been a large project by itself! :o

I noticed it still has the compound fitted and a 4-way tool post.  Is it up to the customer to fit his own QC tool system or ATC?

Thanks very much for taking the time to post your work Zafar but we need more pictures and details to feed our lathe lust! ;D
Milton from Tennessee ya'll.
Re: Prima Lathe conversion
« Reply #41 on: December 23, 2013, 01:30:06 PM »
Dickeybird,

The covers are sheet metal with powder coating. Bent and welded with hand tools. Customer is contended with this tool post at this time. I have offered him a Chinese turret tool post though. I'll post more photos after customer's training on it is complete.

Zafar

Offline vre

*
  •  20 20
    • View Profile
Re: Prima Lathe conversion
« Reply #42 on: December 27, 2013, 05:08:53 AM »
What ballscrew/ballnut(is better single or double ?)/pulleys/timing belt have you used for Z axis ?
Do you know some tutorial/webpage how to design a breakout board ?
I have some knowledge in electronics so i believe that i will do it myself..

Offline vre

*
  •  20 20
    • View Profile
Re: Prima Lathe conversion
« Reply #43 on: December 28, 2013, 07:51:02 AM »
I see that you have a big transformer in the box.
What doing this transformer ?
If the drivers are 3 phase 230Vac and my supply is 3 phase 400Vac or 1 phase 230Vac what can i do ?
3 phase transformer 400Vac to 230Vac of 1 phase 230V conected L1-phase L2-neutral L3-phase and add extra electrolytic caps after the bridge in driver ?
Re: Prima Lathe conversion
« Reply #44 on: December 31, 2013, 09:47:12 AM »
vre,

The transformer is for getting 220V from 380V mains. The drives and the PC can run from 220V single phase, but I didn't want to introduce a neutral phase into the system to avoid line fluctuations. That's why the three phase transformer is there. Nut on my Z axis screw is single and on the x axis is double. No big reason behind that besides they were the only ones available at the time of assembly. For breakout boards I'll ask my friend Nooruddin, who did the electronics mumbo jumbo, for any tips.

Zafar

Offline vre

*
  •  20 20
    • View Profile
Re: Prima Lathe conversion
« Reply #45 on: February 19, 2014, 04:28:04 PM »
What type pulleys/timming belts have you used ?
Have you any backlash with these pulleys/timing belts ?
Finally reduction is 1:2 and ballscrews 10mm pitch on both axis ?
Re: Prima Lathe conversion
« Reply #46 on: February 21, 2014, 11:16:36 PM »
What type pulleys/timming belts have you used ?
Have you any backlash with these pulleys/timing belts ?
Finally reduction is 1:2 and ballscrews 10mm pitch on both axis ?

I am using 3/8" pitch L sized belts and pulleys. No backlash. 1:2 reduction on both axes. 10 mm pitch on ball screws.

Zafar

Offline vre

*
  •  20 20
    • View Profile
Re: Prima Lathe conversion
« Reply #47 on: February 22, 2014, 05:10:15 AM »
The 10mm pitch ballscrews have good accuracy from your testings ?
Or would be better with 5mm ballscrews and 1:2 reduction ?

With this setup you have 15m/min rapids  is this speed in usable range or it is so much for conventional prismatic ways ?
Re: Prima Lathe conversion
« Reply #48 on: February 22, 2014, 08:58:42 PM »
The 10mm pitch ballscrews have good accuracy from your testings ?
Or would be better with 5mm ballscrews and 1:2 reduction ?

With this setup you have 15m/min rapids  is this speed in usable range or it is so much for conventional prismatic ways ?

You are right. The max rapid is too much for the conventional ways. I have fixed it to a slower 5000 mmpm. A 5 mm pitch screw would be better for this machine.

Offline vre

*
  •  20 20
    • View Profile
Re: Prima Lathe conversion
« Reply #49 on: March 09, 2014, 11:58:38 PM »
My ballscrew is 2m 32mm diammeter and from this calculator http://www.nookindustries.com/EngineeringCalculator/MetricCriticalSpeed (30mm root/Length 2000mm/type B fixture)
the critical speed before ballscrew begins to oscillate is 907 rpm so would be better to take 10mm pitch ballscrew to get the desired rapids without the risk of oscillation ?

Also what end supports do you have for Z and X axis ? Iam planing to put for Z bk25/bf25 and for X fk12/ff12 is that ok ?
« Last Edit: March 10, 2014, 12:01:41 AM by vre »