Milling Machine

[Anonymous]

Just wondering whether anyone reading these forums uses some sort of CNC device for carving house signs, name plaques and the like? I feel this is an area where a company could see an opportunity and take advantage of it - currently milling machines are quite expensive commodities, and yet I'm not convinced that a milling machine for wood would need the high accuracy (measured in thous of an inch) one expects for serious shop work - I would have thought that a budget level machine for a woodworker could get away with maybe 1/32nd accuracy for example.

Unless someone knows about a budget level milling machine for woodworkers that has escaped my attention!

Andrew

 

[Adam]

A woodrat? Or a modified woodrat with motorised X-Y control?

Adam

 

[johnelliott]

What you need here is a cnc router, and the place where there is plenty of that stuff is the USA. Search Google for CNC router and you will get more info than you need. here's loads of stuff intended for small operations, amateurs even, some people are even using lasers as the cutting implement
As a commercial venture it might be a bit of a near thing

John

 

[Guest]

I bought a ras from a joiner who was retiring and saw some engraved signs in wooden his workshop. I was nosey and asked how he did them and he showed me a pantograph with a router fitted. He did the signs commercially and the quality was very good

 

[Ian Dalziel]

Andrew,
I looked at building a cnc router as a project and nearly built one but after pricing motors, guides and soldering up pcb boards it went ott the expensive bit i found was purchasing the software, i reckoned i could have done it for around £1500 + £500 for the software but it would only do small scale and be very limited, a lot of crinkly backs for not a lot
there are a number available across the pond but still very costly

as for a woodworkers milling machine i would be interested to see if such a thing was available

regards
Ian

 

[Dewy]

Novoserve must be broken Andrew. rofl :twisted:

 

[frank]

andrew look in the trend catalogue prices start from as little as £10,950 to £20.000 8)

frank

 

[norman]

Hi all
The Router june/july has one on page 27 called the" rout a mac" price #1995 (inc vat)
looks interesting,
Regards
Norman

 

[MilkyBarKid]

Just wondering whether anyone reading these forums uses some sort of CNC device for carving house signs, name plaques and the like? I feel this is an area where a company could see an opportunity and take advantage of it - currently milling machines are quite expensive commodities, and yet I'm not convinced that a milling machine for wood would need the high accuracy (measured in thous of an inch) one expects for serious shop work - I would have thought that a budget level machine for a woodworker could get away with maybe 1/32nd accuracy for example.

Unless someone knows about a budget level milling machine for woodworkers that has escaped my attention!

Andrew

Funnily enough I've just bought one of these small milling machines on ebay - it cost about £1k delivered from the states.

http://www.imagestation.com/picture/sraid129/p91f7f426a28c756c0248ace162de1876/f7c7d60c.jpg

It's got a work envelope of about 10" x 5" x 6" (xyz respectively). These can be extended by creative jigging.

When buying in this way - although the components are quality components - it may not be easy to find someone who is using the same combination of driver software, driver hardware, stepper motors and milling machine. This makes working out problems quite difficult.
The taig mill I've bought is very popular so there's lots of help around for taig users.

I've not got mine setup correctly yet - it will take a while but it cuts through wood like butter with small milling cutters. This machine will stay within tolerances of a thousandth of an inch despite using relatively cheap screw threads.

If I was to build a machine - I think I'd buy the same xylotex driver hardware, stepper motors and perhaps try and find a ready made gantry unit where perhaps the electronic hardware was knackered but the sliders and screwthreads were still in reasonable condition and then just drive it with inexpensive software.

The milky bar kid.

 

[Newbie_Neil]

Hi Andrew

I was speaking to the guy at Woodworkers Workshop a few weeks ago and he said that their number one product was the Legacy Ornamental Mill.

He sent me the dvd of the product and it is just amazing. It will allow you to do everything (?) that a lathe can do, but with a router. The router sits on top of the bed, much like the 'rat. In fact, my first thought was that it was a 'rat on steroids. They describe it as somewhere between a lathe and a cnc machine.

The link is here http://www.woodworkersworkshop.co.uk/legacy.htm

http://www.legacywoodworking.com/gallery.cfm

Well worth a look.

Cheers
Neil

 

[Anonymous]

Andrew

This is your lucky day as what you describe fairly very easily made (assuming the size is not too large). My 'area of expertise' is mechatronics (I bet you guessed already that it wasn't woodwork from my posts and projects) and CNC machines are good examples of mechatronic devices. I have designed and built several of these things - mostly for drilling/milling circuit boards and have supervised students that have also built similar devices.

The expensive part of the job is the precision engineering of guides etc but I guess linear bearings (circa £25 each) running on lengths of silver steel (ground straight and even) would do the job nicely. See www.rswww.com for linear bearings and guides.

Control via stepper 3 motors (£20-40 each) would be very straightforward and if you want increased precision, then feedback could easily be derived from cheapish (£35ish each) rotary shaft encoders which would provide resolutions of 0.333 of a degree of shaft rotation.
Other very expensive item will be the actuation device to drive the cutter head - toothed belts fairly cheap and pretty good when tensioned, lead screws are pricey but accurate, ball screws are the top dog but cost £££££'s

Software is free if you can program (C or VB or pascal OK) and costly if not

Interface boards for the motors and sensors are available commercially but they are generally very simple designs and you can probably find some on the web - or I could design them if you are willing to build 'em yourself. These would cost very little for the components.

PROBLEM - if you intend to sell these then production costs are an issue + the price the market would stand + reliability of kit and software needs considerable work + CE marking and testing. Making one for yourself is very different to making a commercial product.

If anyone wants to make one for themselves, then pm me and I will provide all the help I can with hardware/software issues especially with control of motors and reading inputs into a PC or similar.

 

[Anonymous]

Tony, you are a star and you could become very drunk if I happen to meet you in a bar.....

My early career (first 10 years) was Electronics Engineering. Then I did software engineering for 15 years. Moved into the handyman bit only recently (last year). So I think I can probably handle most of what I want to do to create a CNC router/milling machine given the right guidance.

Stepper motors were an integral part of my electronics career as it happens, and if I were doing the job I'd probably err towards a closed loop arrangement so that I count the steps rather than just assume the stepper did what it was told....

Oo-err, now how am I going to break this little idea to the missus....? Is it too early to start suggesting she gets my Chrissie present....?

Andrew

 

[Anonymous]

Tony, you are a star and you could become very drunk if I happen to meet you in a bar.....

Andrew

Consider yourself held to this!! :wink:

If I can help, then feel free to pm

 

[MilkyBarKid]

Tony, you are a star and you could become very drunk if I happen to meet you in a bar.....

My early career (first 10 years) was Electronics Engineering. Then I did software engineering for 15 years. Moved into the handyman bit only recently (last year). So I think I can probably handle most of what I want to do to create a CNC router/milling machine given the right guidance.

Stepper motors were an integral part of my electronics career as it happens, and if I were doing the job I'd probably err towards a closed loop arrangement so that I count the steps rather than just assume the stepper did what it was told....

Oo-err, now how am I going to break this little idea to the missus....? Is it too early to start suggesting she gets my Chrissie present....?

Andrew

Since I got my cnc milling machine - I've been loitering in quite a few CNC newsgroups and there are quite a few examples of people who say that they've had these hobby type mills running for years without missing a step. The general concensus seems to be that its not always necessary to have feedback (always nice tho although it does add extra complications) - one addition I think is very useful is limit switches which
I'll be adding lmit switches to my mill as soon as I can - luckily the three axis control board which I use (xylotex $125) has facilities for adding limit switches as well as things like coolant switches and a fourth axis too.

I'd have thought that it's not really worth building hardware when you can get proven hardware with support for $125, there are loads of suppliers of three/ four axis boards for under £100.

There's quite a bit of relatively inexpensive software out there too.
TurboCNC seems popular and will run under dos on any old dog of a pc.

One thing it's probably worth doing is to learn Gcode programming before you finish your construction - otherwise you're going to be sending your cutting bits to all sorts of places where they shouldn't be because you can't resist learning by experimentation.

Regards
MilkyBarKid

 

[Philly]

Hi All,
Found this linkin my Favorites folder....

http://www.axyz.com/


Take a look-no prices though.
Cheers
philly

 

[Anonymous]

The general concensus seems to be that its not always necessary to have feedback (always nice tho although it does add extra complications) -

board which I use (xylotex $125) has facilities for adding limit switches as well as things like coolant switches and a fourth axis too.

I'd have thought that it's not really worth building hardware when you can get proven hardware with support for $125, there are loads of suppliers of three/ four axis boards for under £100.

Regards
MilkyBarKid

I do not disagree with the open loop comment at all. I do prefer feedback on these devices and usually fit rotary incremental encoders. £100 or less gives you increased accuracy and peace of mind - but no essential by any means as long as the inertia of the cutter head is not too high

As far as drive boards go, the only expensive items are FETs (4 per motor) and 12 of these costs £14.
You could buy all components for a 3-axis stepper driver for £20 and build it in a morning. If driven from the parallel port on a PC (Very easy) then add nothing to that £20.

Encoder input decoding board would cost about the same for 3 encoders.

 

[Anonymous]

Since I got my cnc milling machine - I've been loitering in quite a few CNC newsgroups

Judging by my brief venture into the CNC newsgroup land I reckon that might be a popular extra forum here in the future.

Andrew

 

[Adam]

As far as drive boards go, the only expensive items are FETs (4 per motor) and 12 of these costs £14.
You could buy all components for a 3-axis stepper driver for £20 and build it in a morning. If driven from the parallel port on a PC (Very easy) then add nothing to that £20.

Encoder input decoding board would cost about the same for 3 encoders.

You can get some quite snazzy IC's which contain all the required FET's and some control functionality which takes a lot of the hard work out of the software. It makes it a lot easier to build. Not sure I've got any here at work, otherwise I'd look up the part number for you.

Adam

 

[Anonymous]

Thanks Adam - forgot the more integrated solution, better get the farnell catalogue out. Comes from teaching 'first principles' all the time

However, for encoders this is usually VERY expensive. For example an HCTL2016 or 2020 costs about £12 last time I bought any and only accpets one encoder input.

 

[Adam]

http://www.infineon.com/cgi/ecrm.dll/ec ... ?oid=13859