Finding a good small cnc cad-cam milling machine in NZ.

[Owen_N]

What is a good bed size? 500x x 300y x 300z mm?? 1500w

I cannot find any ads for them in Google nz, only on alibaba or ebay.

Freight is too much from us, uk, or china sources.

Any ideas on brands, models, sizes I should be looking for?

Ex china ones are around 4-5000 nz, or $3500 US.

what are retail prices like for suitable units?

There doesn't seem to be much market in NZ for home hobbyist-sized cam-programmable units.

I would need something like this for making epicycloid shapes for rotary engines.

A sliding surface would require finish sanding, honing, or grinding, with accurate grinding wheel sizing and refinishing tools as well.
Any ideas on rotary stone dressing?
<edit>
This seems odd:

There are tons of manual benchtop mills that look about the right size, are solidly built, and have reasonable torque,
but none have cnc-cam options.

There are some low quality aluminium Chinese ones, but nothing decent.

You wand some substantial chunks of cast iron and and steel.

I have a medium-sized tilting bandsaw here that weight heaps:
- about 50kg-
lots of cast iron and a half-hp motor and only cost $ 310 USD brand new ex NZ, so
the material is not a big issue.

Can you buy CNC-cam retrofit kits?

It wouldn't be too difficult to fit stepper drives to everything!

The hard part is setting axis zeroes, tool location, tool diameter, then working off that.

There are several micro cam-cnc units, but they are way to small- if you want to make something that fits in an 80mm cube?
-underpowered, and frames are too weak and springy.

These are under $1000 US. some under $500 US??

The next step up is a huge jump from $1200 USD to $10,000 USD for professional toolmaker gear, with an enclosure.

<edit>
I have found many conversion articles and kits.
Some kits start around the $500 USD level.

Basic questions:
1) what is the difference between CNC and CAD-CAM?

2) what software do I need for can-cam-cnc on windows?

3) Does the milling machine need its own computer? What type? does it need a keyboard or touch screen?

What level of operator interface is at the machine as opposed to on a laptop?

A "workshop-hardened" computer monitor and keyboard sounds like a good idea.

You don't want coolant spray, swarf, or dust getting in there.

Should I get a dedicated keyboard, or use plastic key covers?
Can I get a ready-made enclosure for the keyboard and monitor?


Example jobs are creating a drawing spline for a epicyclic -generated curved component, then converting that to
mill instructions and tool paths, for rotary engine building.

I will do a little study on the CAD side of things. I am a total non-user at this stage. All my drawings are on paper.
I have a laptop and remote keyboard. Do I need a digitiser keyboard?
What cheap home drafting package or selection to look at, would be appropriate for my home use, and a CAM interface?

I shall need to do some study on available seals.

tip seals could be similar to Wankel ones, with wavy spring backing and carbon-ceramic material.
Side seals probably need to be custom curved and ground metal pieces with wavy spring backing.
Do the side seals use circular slotted joiners, or are there other setups?

I am looking at the "Liquid Piston" layout.
It seems to have a lot of potential.

At present, they are only issuing semi-prototype units to potential user companies, at $30,000 USD each.
A small unit in the 1.5 to 2 kg range, making 5-6 hp at 6-7000 rpm, would be a good one to look at.

As far as I can see, there is no reason to use one of these things unless you need low vibrations, or cannot use a two-stroke for some other reason. power to weight seems comparable, as do applications.

Possibly they will come up with versions with separate oil circuits and catalytic converter and emissions capability.

They don't seem to be there yet.

 

[Jasonb]

Look at Fusion 360 for a free CAD package to design the parts, it also has CAM to produce the toolpaths and code that the CNC will need.

You could contact Ausee tools and see what frieight on a KX3 would be from them. The KX3 is a dedicated CNC machine not a converted mill so castings are a lot more substantial, has a much faster spindle than a similar size manual mill and also far better spindle and bearings.

https://www.ausee.com.au/shop/category.aspx?catid=8355

 

[HenryBanjo]

1. to my knowledge there isn't much difference just different names
2. you will need some software on the computer controlling the machine, and some software to make your G-code. Mach3/Mach4 or linux CNC for the controlling machine, Fusion 360 for CAD/CAM is what ild recomend
3. in most cases, yes. Some machines may have a computer built in
if you don't mind the drive, I'd go checkout chevpac in Auckland I think they sell some CNC machine tools. If not ild say you might want to get a manual machine and CNC it, for this ild recommend machinery house or chevpac or maybe something from trademe. The HM-46B from machinery house or GL-45 from chevpac (Basically the same machine) could be a good option (Its what i use as my mill but i plan to keep it manual unless i get a bigger shed and a Bridgeport or similar), but to change speeds they would need a human to change gears or a VFD on the motor, and I'm not sure if automatic took changing could work well with a MT3 spindle maybe R8 would work better. A variable speed machine could be better for CNC since you can control that with your computer. A CNC conversion would require you to swap the screws for ballscrews, install stepper or servo motors on most/all of the axis (you may not need to CNC both the quill and head/table up down). This old tony did a CNC mill conversion with servo motors which you could try copy, other wise a CNC kit from ebay, aliexpress etc could be good.

 

[Toymaker]

Have you considered a totally DIY machine? You can likely buy all the heavy metal parts you need at local metal suppliers. Use liner bearings for X - Y & Z axis,...multiple sizes are available from China and shipping isn't too bad. You can either buy or build the mill head assembly.

Both my CNC Lathe and CNC Mill are DIY from scratch; if you have access to a few manual machines, it is doable, and be a good option if you can't find what you're looking for locally.

If you haven't done so yet, go over to The CNC Zone forums where you'll find lots of others whom have either modified existing machines or done as I have and built their own DIY.

Below is my DIY CNC Slant Bed Lathe.


My DIY CNC Milling machine with a DIY CNC rotary head mounted to the bed.

 

[peterl95124]

it seems you are the very beginning of a journey into CNC / CAD-CAM, if there is a community college nearby where you can take courses in this topic it would greatly help you up the learning curve. That's how a friend of mine in BAEM-club got started and how I will probably do it if/when I decide to take the leap.

I too want to make some model Wankel engines, I bought one of the O.S. Wankel RC model engines to take measurements from, hopefully using a CNC mill as a "coordinate measuring machine", so I can reproduce it. I'll machine the case out of cast-iron and then polish it by hand (polishing off machining marks usually takes 0.001", so I'll compensate when machining). by starting with a stack of housings and rearranging their order and orientation while polishing I'll end up with perfectly symmetrical and identical housings. I am hoping to make a "two rotor" engine. I will also be able to reverse engineer its design parameters and be able to scale it up if I ever want to (get a copy of "The Wankel RC engine, design and performance" by R.F.Ansdale if you don't already have it (RC doesn't mean Radio Control in this title, I think it means Rotary Combustion)).

HTH, and keep us informed !!!

 

[HenryBanjo]

If you're interested in doing a CNC conversion I've recently watch a series on a CNC conversion of a mill similar to my one from machinery house which I previously mentioned may be a good option for CNC. Here's the video series:


The equivalent available in NZ is the HM48B, you'd probably want one without a DRO but machinery house should be able to provide that. link here:
https://www.machineryhouse.co.nz/m141d
I think you get much more bang for your buck with the HM46 although it doesn't have the stand and coolant, and it would be effectively the same to convert, just smaller X and Y axis. Link here:
https://www.machineryhouse.co.nz/m138
Chevpac has a machine very similar here:
https://www.chevpac.co.nz/catalogue...S141/mill-drill-gl-45-1ph-1-5kw_MD-330290?p=1All of them should be able to ship to you. If you send up going with chevpac, Sid there is really great

 

[MET]

Have you considered a totally DIY machine? You can likely buy all the heavy metal parts you need at local metal suppliers. Use liner bearings for X - Y & Z axis,...multiple sizes are available from China and shipping isn't too bad. You can either buy or build the mill head assembly.

Both my CNC Lathe and CNC Mill are DIY from scratch; if you have access to a few manual machines, it is doable, and be a good option if you can't find what you're looking for locally.

If you haven't done so yet, go over to The CNC Zone forums where you'll find lots of others whom have either modified existing machines or done as I have and built their own DIY.

Below is my DIY CNC Slant Bed Lathe.


My DIY CNC Milling machine with a DIY CNC rotary head mounted to the bed.

I like that multi-tooth countersink bit. I've tried all kinds and still can't find one that gives a chatter-free finish. What is it called, where did you get it?

 

[Toymaker]

I like that multi-tooth countersink bit. I've tried all kinds and still can't find one that gives a chatter-free finish. What is it called, where did you get it?

I purchased the countersink bit some 20 years ago, likely from MSC (Machine Supply Company), but honestly, I don't remember with certainty. However, if you Google, "multi flute countersink bit" or "multi tooth countersink bit" you will find several sources.

I've found the key to chatter-less countersinking is using extremely slow RPM,...under 50 rpm,...I can usually use a standard drill bit without chatter, but the bit does tend to wonder.

 

[timo_gross]

I like that multi-tooth countersink bit. I've tried all kinds and still can't find one that gives a chatter-free finish. What is it called, where did you get it?

I bought a single flute countersink a while ago. The cone seems to prevent chatter. Works well on the medium size drill press. Low rpm and workpiece clamped down.

 

[Jasonb]

As said low speed is the key be it the hole type, single, 3 or multiple flutes.

Mild steel

 

[bluejets]

Had an old HM32 style mill which was originally made in Taiwan as opposed to China, the quality of the former being much better than the latter even though they appeared to be the same thing.
I did a lot of work on this old machine then sold it for pennies to a mate of mine just starting out.
Decided to update to a newer HM46B a few years back, worst move I ever made.
The so called advantages of the newer machine were simply overtaken by the lower quality.
As an example, after using once, the motor shaft (some 15mm diameter ) sheered completely off.
Turned out the motor had been installed with a "location" dowel cast in with nowhere to locate and the motor was trying to drive through a very solid mount with approx. 50 thou "bending moment" to the main motor drive shaft.
Had hell's own job trying to convince the supplier there was a dodgy unit.
Many photos and phone calls finally secured a new motor free of charge which I then had to modify and fit.
The location of the z axis was never on zero as indicated and took some time to get it spot on zero.
It is now doweled for reposition if anyone ever moves it.