KX1 CNC Mill Clearance Offer

Thanks for the reply Neil hope you get your KX1 plugged in and making chunks of metal smaller soon! It is a great little machine, the KX3 is a much bigger lump, too big for my space.

I use the KX1 in manual mode by simply using the jog buttons on the keyboard. I think if there is one draw back to most CNC machines is that they need a computer to operate them, maybe this is why converting manual machines to CNC is popular because there is an option of keeping the handwheels. But once you get used to no handwheels you won't miss them.

Oh I got my 4th axis yesterday! I can do a lot of damage with another axis! Does anyone know how to work these things?

Thanks for the encouragement folks

Neil

Sort of! There are two basic modes of operation. One, using the 4th axis as an indexer, ie, the table makes a rotation and then a cut in X, Y and Z, followed by another (none cutting) rotation and so on. Like this setup for machining a bevel pinion:

Two, continuous where the 4th axis rotates at the same time as, and in sync with, movements in X, Y & Z. Like this setup for machining a worm:

As ever the problem is creating the code. The bevel pinion G-code was generated by CAM, the worm G-code was hand written.

My CNC mill doesn't have hand wheels so I can't use it in manual mode. I've played with the MDI interface, but if the cut is simple enough to do with MDI then it's going to be a darn sight quicker to do it on the manual mill. I prefer to keep the manual and CNC mills separate. Part of the planning for machining an item is to decide which operations will be manual and which CNC. The decision depends upon time needed, number of parts, and practicality.

Andrew

It seems the hints paid off and my KX-3 arrived this morning, it's a big crate standing about 1.2m tall

Not quite so massive once opened up and worth it for the little toolbox alone

I think Ketan mentioned damage Jason is it just cosmetic or the workings of it.

Jason, that machine will slow your building projects down a bit while you get to grips with cnc !!!!!

Emgee

Ron A quick look in the back does not show anything obvious and the need moves when I manually turn the ballscrew so will probably have to power it up to see what may be the problem. As it is something on the Z-axis I won't lift it onto the bench until that is sorted as it is far easier to get to while on the pallet.

Emgee, just think how fast I might be with that running while I'm making other parts on the lathe or manual mill at the same time

Congratulations with your new toy Jason, I guess you will keep us posted on your CNS progress.

Thor

Andrew;

For quite a while I worked at a research site that had a machine shop about the size of a football pitch.

2 friends worked there. One of them left years ago, then a year or two ago I left.

Anyway, friend #1 - "what do you have a manual mill for? All ours are CNC. You want to make one-offs - come over here and I'll show you conversational programming" (my eyes went wide open!)

Friend #2, has a shop @home, 2 CNC mills, zero manual mills. "why would anyone have a manual mill??"

These guys are machinists by profession (doing precision research projects, not metal bashing), and I'm not. So when these well trained guys ask a question and show me how a pro does it... I'm all ears.

Jason;

With regards to having 2 machinists (one a CNC robot);

I've found that I can't concentrate on doing complex stuff when my CNC is running. Cleaning the shop, doing the washing up in the kitchen; that kind of stuff I can do.

I've always got an ear open listening to the CNC for "strange sounds" like material coming loose, cutter dulling, etc.

I don't know why; the little KX1 (running LinuxCNC) runs for hours and hours without issues. I'd presume that Mach3 would have the same reliability, but no experience with that SW so can't comment.

Maybe it's just me being paranoid. I'd (honestly) like to hear on how others do with leaving the CNC mill running, while going and doing something else complex.

Note that I did have ONE problem with the KX1. Actually, my software and hardware; I had set up the software (hand-tuned by me - yeah right! bad idea!) so that pulses to the stepper controllers were right at the limits according to the spec sheets, and one of the stepper controllers missed a pulse (about 1 in a million) when stepping one direction. Backing off the minimal numbers solved the problem. Lesson - never trust the minimum numbers on spec sheets!

That's a nice set up Andrew, I don't think I'll be attempting anything like that for a bit! Last time I made bevel gears was as an apprentice many years ago! So for my set up to get me started I took a trip out to Chester tools yesterday (saw the new Beluga take off from Airbus as a bonus!) and bought a 80mm 3 jaw for £30 quid, which will hold stock accurate enough for a bit of rotary engraving. Next trip will be for a ER25 collet chuck plate for a set up similar to yours. I'll be using Vectric VCarve and Mach3.

Ian

I've never been comfortable leaving the CNC mill just getting on with things, probably through lack of faith in my own programming. But once, when I was making a collet tray from a lump of MDF with just a grid of holes, the code being generated by a CAM program (G_Simple since you ask), all went well until the last hole where it decided to do a G00 move (feed at max rate) down into the hole rather than G01 (move at specified feed rate). As far as I could tell that was the software which did that not me! No damage done fortunately, and was just wood (ish) not metal being cut.

But I remember getting very bored when the machine was engraving some nameplates - took over an hour per part!

My collets are 5C. I think the chuck was from MSC but the backplate is homemade. A point to bear in mind is that my custom version of Mach3 completely ignored feedrate values when combining rotary and linear movements in one line. For machining the worm I ended up using G93 - inverse time feedrate.

Andrew

While it is facinating to watch I get bored so I leave the CNC mill to get on with it. I don't actually go out, but I'll make tea, work in the study or go outside and cut the grass. If a cutter is going to go ping I'm not going to stop it by watching so I might as well be productive elsewhere. The bevel pinion shown above took over two hours and some parts take four hours or more.

However I double check my CAM generated code. Experience says that the toolpath the CAM program displays is not always the toolpath the G-code produces. So I independently check the actual G-code with a backplotter program (NCPlot). This also has a useful feature of listing maximum excursions in all axes which is a quick and easy sanity check, especially when the work is mounted direct on the table.

Andrew

That's one way of looking at it, and I have used machine shops professionally that don't have any manual machines. But I wouldn't necessarily agree. I can definitely do some things quicker on the manual mill than on the CNC mill. I can also do things manually that I can't do CNC, either because of capacity/horsepower issues, or I can't create a 3D CAD model in the first place.

It could be a case of chicken and egg; after all if you don't have any manual machines available you wouldn't advocate using them.

I've been looking at local university jobs with a view to going back to work in the university, albeit on the technical side rather than the academic side this time. The engineering department, Cavendish lab and Whittle lab have well equipped workshops with CNC machines, but also considerable manual machining capability. For many of the technician jobs CAD/CAM/CNC is listed as useful but not essential as training would be provided. So Cambridge at least seems to value manual machining skills.

Andrew

I use my KX3 in 1 of 2 ways. Its my only milling machine, I don't have space for a manual one as well and I use it for most drilling operations too. The first is for operations that could be just as easily done on a manual machine such as squaring off stock or cutting slots. For that I use G Code written straight into the MDI interface in Mach3. In that respect its like having an accurate, rigid, manual machine with a powerful spindle (for its size) with DRO and infinitely variable powerfeed on each axis. If you only ever used it like this then you aren't using it to its full potential but you don't lose anything either compared to a manual machine. Yes you have to boot up the PC and Mach3 but that is 30 seconds and it can be left on for hours if needed. It's relatively small so I can't do bigger jobs - thats the biggest drawback.

The 2nd way is designing something with CAD (I have only done simple stuff so far), using CAM to create GCode (or sometimes just writing GCode into a file by hand) and then running that code. That is probably something I do less of.

Regarding leaving it to work and doing something else - I do potter about the workshop when it is working and keep an eye out but I haven't felt confident enough to walk out completely. I made a mistake once and was just in time to jump over and hit the e-stop button before any real damage was done to the machine.

If any of you proud new KX1 owners wants a stand for it, a friend of mine has one from a Chester Champion which needs a new home. The buyer of the milling machine didn't want the stand. As soon as I can get across to see him I'll measure it up and put more info in the classifieds. In the meantime if you want to put your name against it send me a pm

Edited By duncan webster on 21/02/2019 10:01:53

Likewise if anyone wants a stand for the larger KX-3 or that sort of size mill, give Ian a call at ARC as I declined the one with the machine that came to me, I'm sure they will do a good deal on it.

The best recommendation I could make for anyone getting a CNC milling machine (or CNC lathe), is to acquire some good CAM software to go with it.

It'll make life much easier and allow you to tackle jobs that are beyond the average person to code by hand.

Martin.

I agree Martin good CAM software is a must for CNC. When I got the KX1 it came with free full versions of Vectric Cut2D and Mach3, I found Cut2D dead easy to use and intuitive so a few months ago I upgraded to Vectric Vcarve desk top which is even better.

Ian