KRV 2000 converted to run with Mach3. 4 axis capable including some tools

**komatias** · 17-07-2016

Hi All,

in light of a container load of stuff about to be delivered, I need to clear further room in the garage. One motorcycle has gone and now the KRV mill needs to follow urgently.

Bought the KRV from a used machine dealer for (£2500+ VAT and +400 delivery)with the view of using it to sort out a Chester bench top bed mill way back in 2012. Did part of the job but then got thinking that since I had already converted the KRV to single phase, why not go full hog and convert to CNC.

Selected this one as the halfmoon texture on thesaddle ways was still visible and as opposed to some of the Bridgeports in the shop, it hada better overall condition.

The machine runs off a Ethernet Smoothstepper (included) and Mach3 but can be modified to run with a parallel port or Linux if need be.

For the motion we have:

-C3 2505 ground ballscrews to P3 preload (from Gary at Zapp )on X and Y (accruacy of 0.008/300mm). Preload is not just zero backlash. (~£1300) still have the accuracy reports.
-2 Nema 34 leadshine closed loop steppers on X and Y geared 2:1 with HTD belts (~£280 each set)
-Precision angular contact bearings specifically for ballscrews by Carter Bearings, (£65 each, 4 in total)
-Precision locknuts for the X and Y ballscrews with locking on the front face (~30 each)
On the Z I have used a Nema 34 with 1:1 gearing onto a 1605 cheap C7 ballscrew and mounts. The drive is a 80V one from CNC4you. 4^th axis stepper drive is also wired up and included.

The VFD is a Teco L510 wired with a remote pendant to allow: forward, reverse, speed and jog mode as well as FWD/REV on M3 and M4 gcode.

The mill itself came with a Newall Spherosyn DRO that had a blown power supply. I have fixed this and only requires a new CPU battery to ensure it keeps the last known position. Easy and cheap job to do.

I have done quite a bit of work on reconditioning the head too. The spindle is new as it is cheaper to replace the spindle and bearing than to replace the bearings. The variable speed belt and the tappered variable speed discs, keys and bearings are also all replaced. I have a new worm gear and wheel to replace the tramming assembly of the head to go with the mill as well as an X & Y gib strip should you feel you need them.

On the head of the mill I have installed a pneumatic power drawbar and use that with the QTC tooling that I sell and of course any other R8 taper tooling you would want to use. 3 second tool changes are a real joy.

The original autolube pump has bitten the dust so I have replaced that too.

The machine is not light but I have managed to place some U section steel under it and have it on brick to allow me to move it around on a pallet truck as needed. The U sections were also very handy to use rollers to move it in my previous garage.

With the machine I am happy to give the following as they will be incompatible with my new machines:
-full set or ER40 imperial and metric collets,
-ER40 collet chuck, a clamping set,
-3 insert 50mm facemill
- keyless drill chuck with 16mm capacity
-Aluminium fixture plate drilled reamed and tapped with over 100 M12 grub screws and extractable dowels. Makes cleaning a much easier job.
The tooling plate fixture has been used because the bed of the mill itself was not in the best condition when I bought it. But a vice sits true and you can tram the head to that.

Unfortunately time has been against me so although I have done a decent number of machining jobs on the machine for myself, friends and some clients, to my shame I have not managed to fully finish the conversion. The bits I have been putting off are, tidying and labelling the cables in the enclosures, adding limits and home switches to the X and Y (yes I know, I am a bad person) changing the spring in the head that holds the brake pads open and some others.

In my defence though I am including 5 Honeywell lever type switches and 5 proximity switches to help the prospective buyer finish the job. The Z axis has limits and home switches and I use those with the TTS type holder all the time.

I am also trying to figure out why the motor is suddenly leaking current and tripping the RCD. This is under investigation and will be solved with either fixing this motor or buying a new one.

All original parts are also available: X&Y leadscrews, 2x quill levers manual draw bar, DRO manual.

To get the machine working you will need to supply the computer to run Mach3/Mach4. An XML or a list of parameters will be supplied though.
To me this machine has cost a small fortune and it has made me back some money but I need to sell it quickly.

My target price would be £2000 but I know that people will gawk at the cost of shipping it to its new home so I am happy to accept £1750 from a forum member. This machine will be advertised at an elevated price on Ebay. Considering the accuracy achievable with the DRO and ballscrews if nothing else it is a very good manual milling machine.

Any questions feel free to ask through the PM system. I can arrange for this machine to be sent anywhere in the world at cost but I would very much like to get it moved before the end of the month if possible and hence the low asking price.

Now some disclaimers: This is a private sale, no warranty is implied or given. Machine tools are dangerous and although I have taken every step I could think of to make it safe from an electrical stand point, it is up to the user to not stick their hand on the cutter and keep the E-Stop in mind.