Hello everyone,
For the past 3 years or so, we are building our own hobby machine shop.
It happened after (too) many years of watching this forum from the sidelines, dreaming of our own CNC machines, waiting for the right opportunity.
In that process, we've renovated a Spanish made Kondia K-76 CNC powermill.
Kondia CNC knee mills are quite a rare breed these days, so we thought its worth sharing here.
We wanted a machine that could cut carbon steel and stainless with decent speed and accuracy.
It meant that we had to find a tough, robust, heavy cast iron machine.
After looking for a long time we were lucky enough to get our hands on this Kondia, she looked and felt like she had a relatively easy life, so we bought it on the spot, no questions asked.
This machine is an early 80' model (not sure which year), and as far as we know she was used only for prototyping and small scale manufacturing in 2 small shops over the years, and never for series production.
Due to that fact ,the motion components are in pretty good shape, with no major play or wear in the ways/screws/spindle that is observable to the
naked eye (and basic indicator testing, we shall see the accurate numbers in the future).
For a 40 year old machine, that’s quite rare.
At least on paper, she's a perfect candidate for such a renovation/restoration.
Also, she's got all the right specs for our needs :
Specs:
Dimensions – 1610X1378 mm, Height: 2010mm.
X Travel: 600mm
Y Travel: 300mm
Z Travel: 125mm
Knee Travel: 395mm (with motor).
Weight : a lot.
X-Y Ballscrews : 32 mm, double nut (factory).
X-Y ways : Square.
Spindle power : 2.2Kw, 3 phase 400V. pneumatic brake.
Spindle speed : Motor controlled variable speed gearbox,
Low Range : 60-500, High Range: 500-4000.
Tool Holder: BT30, with Power Drawbar.
The key steps that were taken so far, in a nutshell :
1. Motors : originally the mill had DC steppers (Slo-Syn ,200 step per rev) and an ancient control system that was installed locally, which we've gotten rid of as soon as we've found out that its super hard to find replacement parts for it, or even find the steeper drives that it requires (a whooping 30A DC drive).
The replacements were 1.8kw ST110 Chinese servos.
2500 PPR encoder, 3000 RPM.
Which weren’t a direct fit and had to be machined into place.
2. Control : the control board/software of choice is the all popular Mach 3.
3. Electrical System : We rewired the entire machine from scratch, which was quite a challenge since it was an odd duck to begin with, a 110V system in a 230V mains country (Israel).
the end result is a hybrid 12dc/110/230/400V system.
4. Pneumatics: renewed the entire system.
5. Auto lubricating system :5. Auto lubricating system : flushed, cleaned and serviced the pump, regulator and metering devices (the ones that were accessible without a major disassembly).
6. Changed all the oils/grease.
7. Coolant pump : rebuilt the pump.
8. Bought a second k76 machine for replacement parts.
9. Software : we bought the license for all the softwares needed.
we were already proficient in CAD, so we invested a lot of time learning CAM and configurating Mach 3.
10. Machine Computer: sourced one with the required parallel port, since we decided to use a Mach 3 card with that connection (had good results with it in the past, more on this later).
11. Cutting /Clamping/Measuring tools: Bought most of the required tools for the basic operations.
That alone took months to source, garage sale after another, and of course Amazon/Ali/Ebay.
We will detail all those steps in later posts on this build thread, as well as future improvements.
But for now, since the mill is already in working condition, I think we should let the pics and videos do the talking, and continue this discussion later.
Until next time…
Yam