Advice for CNC buyer

[philbur]

Looks like a pretty big envelope for only 80 kgs. If you are only making small hexapod robots why sacrifice rigidity for such a large envelope.

Phil

[marchantdice]

This is why we talk directly to the customer, anyone can sell a machine but is it the right machine for the job? Our bespoke builds can be produced to customer specifications!

However most customers prefer the larger gantry design as you never know when you have to machine larger components....

Note, we also sell "conventional CNC mills"

[Kipper]

Originally Posted by marchantdice This is why we talk directly to the customer, anyone can sell a machine but is it the right machine for the job? Our bespoke builds can be produced to customer specifications! However most customers prefer the larger gantry design as you never know when you have to machine larger components.... Note, we also sell "conventional CNC mills"

Do you sell those without any cnc controls? Any links to those?

[philbur]

But you have already recommended:

"We would advise purchasing the MDL-3-BSX with the addition of the square Hiwin style profile rails and carriages on all 3 axis, as these have many advantages over the supported rails...."

and you haven't spoken to the guy yet.

A big envelope with 80 kgs might be fine for icing a cake but it's going to struggle with that unexpected V8 engine block recondition. A clear example of biggest is not always best.

Phil

Originally Posted by marchantdice This is why we talk directly to the customer, anyone can sell a machine but is it the right machine for the job? Our bespoke builds can be produced to customer specifications! However most customers prefer the larger gantry design as you never know when you have to machine larger components.... Note, we also sell "conventional CNC mills"

[marchantdice]

Sorry, all our machines are CNC controlled..

Originally Posted by Kipper Do you sell those without any cnc controls? Any links to those?

[Kipper]

Originally Posted by marchantdice Sorry, all our machines are CNC controlled..

Ah...that's OK I'll bin your controls then Any chance of a web link to them?

[JPR428]

I am considering a conventional mill as well. I like the idea of the gantry style because of the potential of larger x-y travel. I've been looking at the Syil X5 which has 400mm of x travel and seems like a good machine. I would prefer more y travel but 160mm is still good.

As well as hexapod robots I've built dozens of other machines over the years and most seem to have a large number of aluminum plates in them, like in these photos of the gearbox from a 1/10 scale tank I'm making.
(By the way, the 3rd picture is of a different gearbox to the first 2)




What I am hoping to do is to cut a sheet of aluminum large enough to make all the parts for the project I'm working on, clamp it to the machine and have all the components drilled and profiled in one operation.

Does anyone use a gantry style machine to mill aluminum and what are the results like?

[Kipper]

Not a gantry machine but....It's a Tank part!.....1:6th Stuart drive sprocket.

Why not plasma or waterjet the parts out of large sheets?




Not found any milling machines on any Marchantdice sites yet.....

[stevespo]

I milled some 6061 blocks recently (center drilled, pocketed, profiled) on my 8020 DIY router and it worked very well. Light passes (.010" DOC), 24K RPM, 90 IPM.

If you want to start with a single piece of aluminum, you'll have to drill all your holes first, then screw through the holes into something solid beneath. Then you'll have to pocket and profile as the last steps. It seems like a reasonable approach.

The downside of a gantry style router is difficulty using coolant/lubricant with an MDF workboard. If you're using a heavy duty gantry with a T-slot table, you'll have more freedom to spray cutting fluid. Or you can cut completely dry, but I found the finish pass was a lot cleaner with a shot of cutting fluid.

http://www.cnczone.com/forums/showth...t=27527&page=5

Even with my initial success, I'd love a dedicated mill for metal projects. The work envelope is smaller, but metal is really what they are designed for.

Steve

[veteq]

Hello JPR428,

been reading the thread and i think youre doing good to
read a lot info before making a choice, for the producht you
would like to make, i think a router is the way to go.
Youre budget is ok and i could imagine you would like
a nice product that last for a long time and makes nice parts
without to much compromisses.

You only would like to mill alu and plastics, the way to go, for that
materials, is a dynamic machine that removes small amounts off material
at a time, the machine moves fast. The result is low forces through the machine
by the milling resultant force, there are also forces in play that result from acceleration
of the gantry etc. So the machine has to be rigid, if it is not rigid the feedrate has to go down.
This type of machines uses a sturdy router spindle with 18 or 24000 rpm,
the advantage is a nice surface finish.
What also help for nice surface finish is a solid machine (Mass) because it dampens
the vibration.

This kind off machines, in my opinion, need products like, linear preloaded bearings,
preloaded ballscrews, preloaded quality HF spindle, preloaded bearing blocks, Solid base.
The reason why my design has stepper and not servos is because the linear bearings and ballscrews
almost dont have friction to overcome. The force generated by the milling proces is also
very low. (small material removal).

The products that are used in this concept for you, are all for sale in the UK.
The products are:

Hiwin HG15 rails incl. blocks 780 euro
Isel ballscrews incl.nut 770 euro
Isel bearingblocks fixed/lose 400 euro
stepmotors+geckodrive g540 incl. 400
Break out board+ Powersupply
Mach3 controller software 100 euro
Ballscrew/stepper couplings 100 euro
elte 0.75kw spindle+drive 760 euro
Vertex measurement plate 600*600mm 300 euro

Total 3340 euro (Incl. taxes etc)

The weight off the aluminium that is used is around 25 kilo,
so around 175 euro, then it has to be milled.
You could take it to a small machine shop, DIY or find
a member in of the cnczone (lokated in the UK) that would help you.
Mill the squere parts and sand the nice small radius and chamfers

Think a shop thats helpfull would mill everything for 1000 euro.
incl material and taxes.

Total cost of all products 4340 euro

A bit above budget, but,
When you have all the products just bolt it together and align.
(aligning is easy with those linear bearings etc.)

The travel in XYZ of the concept machine is: 250/380/120 mm
the base of the machine is a vertex measurement plate (0,007/100mm)
total dimensions are 600/600/100mm.
Max. diameter off mill is 13mm
Think the 120mm in z-axis is no problem, you could use a angle plate to
machine the side of a long part. (look at jpegs)
It is a precise machine, so a long part 500mm, can be clamp in 2 times with
a aligned reference edge.

Look at the videos for the difference in milling.
Look at the different concepts, rigid base etc. , sound, feeling:

YouTube - MDL-0.2-TR CNC Engraving

YouTube - MDL-0.2-TR CNC Engraving

You said you coudn`t find any threads about the MDL machines, here`s some more for you to see:

YouTube - Marchant Dice Ltd CNC Ballscrew Kit

YouTube - Marchant Dice Ltd CNC Ballscrew Kit

YouTube - CNC-Fräsmaschine aus Mineralguss

YouTube - CNC-Fräsmaschine aus Mineralguss

The last machine can be seen at http://www.thomas-zietz.de/ it is the Prototype FS1MG,
Also with a Elte spindle and rigid base. The F2MG is also a very nice machine, but i think around 7.000 euro
with all components.

When buying a router machine like my concept from a company i think you would pay at least 10.000 euro.
So jump in a nice project and DIY, will help if you like.
A machine thats as rigid as the concept machine, but with the travel off the machine you first where interested in: at least 15.000 euro.
It cant be done cheaper then the 4340 euro with the same quality!!!!!

So, the mechanical part is not really hard to do (with help), for the electrical and controller part its
the same way to go. Its good to do!!!
You need a PC and install the mach3 software from artsoft, hook up the geckodrive g540 controller,
(just connecting wires to the right pins off the PC connector) and configure the software.
It is all explained for noobs in the first 4 videos on http://www.machsupport.com/videos
you always can find help by me or the cnczone.

Read more and learn a lot over here, get a machine that suits your application!

There is on all subjects a lot to read over here, i did the same 4 years ago and finally have the budget
for my machine scrambelt together.Have a apointment for milling my machine parts in 2 weeks.

If you have more questions just ask, sorry for the long post.

Kind regards,

Roy Bakker
Automotive student
The netherlands.

P.S. some screenshots about the concept i`m talking about and 1 off my machine.

[veteq]

The last thing is the CADCAM software.

The mach3 machine controller off Artsoft works great, but it needs G-code to know how to turn all the motors.
It uses standard ISO G-code.

This code is coming from a CAM program and is based on the design in CAD.

Every good CAM program has the function to generate ISO G-code.

Thought about a CADCAM package yet?????

Its expensive, you always have to buy it seperate from the machine.