Advice sought on new Mill build

[Boyan Silyavski]

That's good to know. Cause what i hate most is looking at manual in Chinese and nobody to ask for help in English.


Myself and believe others would be very grateful if you continue your build log here with details and so. i would especially appreciate if you share in the future the CAD drawing of the head assembly with the motor, spindle and tool release mechanism. This could save many hours of research and drawing.

[embraced]

Yes, everything will be documented here.

I have found a VMC frame from China that seems to be around my specifications
http://www.alibaba.com/product-detai...904489677.html

The seller I have contacted (not the one above) will sell the frame my itself.
The 'Frame' includes the Spindle, HIWIN guides, P3 ballscrews, auto lubrication system and way covers for 7300USD. the ATC is a 1700USD option.

I have given some thought to either:

• Making a fabricated steel clone of the machine above
• Buying the frame and doing the electronics (not a creative project at all)
• Sticking to my initial idea and doing the entire thing from scratch.

The first option is likely to be the cheapest.
The second option is definitely going to be the easiest and quickest, but the least satisfying.
The last option is one that has the least probability of success, but the most satisfying.


Thoughts?

[Boyan Silyavski]

rails and ball screws at the most will be 1500$
motor , spindle and so 2000$
500-700kg of steel 700$
mig wire, gas and so 200$
epoxy paint and so 200$
additional stuff 1000$
servo motors 1500$

That in worst case scenario, if you are careful with the design it will be more cheaper.

BUT:
-the machine would be exactly as you want it
-better built than the Chinese frame.
-Cheaper
-a lot of small things would be right, that makes a machine GREAT

Dont copy all,use it as guide lines only, build it from scratch and i assure you it will work. It seems you have done quite some research already. Plus one day next time you will like something like this , which you can buy or make your self. So why not from now plan how will fit and be prepared. The Chinese frame will not allow it without sacrificing something.

[JAZZCNC]

No brainer to me buy the frame.!!

You won't make it for less by the time you factor in machine time for grinding surfaces etc. Then you have all the time invested which will be many many weeks. With this you'll be up and working in fraction of time and making money.!

Then you have things like Class 3 ballscrews these shouldn't be confused with the cheap Class7 we buy. If indeed they are Class 3 then they will cost much more and $1500 would just about cover the screws and not rails as well like Boyan suggests.

BUT all this said if your going to this trouble have you thought about buying a second hand VMC. You can often find second hand VMC with dead or absolete Controllers that are perfect for conversion. Even with older ones that have many hours use and worn the structure is still perfectly fine and substantial.
Change the worn parts for new refit with new controller. Often you can reuse servo's and Scales etc even if they are analog drives etc.

You'll get a much better professinal machine for less or same money you'll spend doing this to this level and when done it will be worth double you invested.!!

[Boyan Silyavski]

Unfortunately/or fortunately :-)/ Dean is darn right. Thats why we see so little mill builds from scratch and mostly they are in the smallish range. Moneywise that is Unbeatable, to buy something like Deans VMC and refurbish it. No way that you can do something even similar for the money.

[embraced]

Well that revelation certainly changed my plans...

I had thought of getting a used machine and stripping retrofitting it, but the deals are so few that i would probably be searching forever.

I am strongly considering getting the VMC frame, toolchanger and enclosure (which is offered as a package) and extending the X and Y travels. Also replacing the existing spindle and motor with a single built-in motor spindle (http://www.alibaba.com/product-detai...534965688.html).

I feel that I really don't need the frame to be as rigid as it is given that i'm only doing HSM, and that extending the travels should not be at the machine's detriment.


Thoughts?

[JAZZCNC]

If they do a 40 taper either BT or ISO/CAT then I'd strongly suggest you go for that because you'll find toolholders cheaper and more available as there more common in industry and you'll also have more choice Ie: long nose, collet chuck, mini nose, high speed balance etc.

[AndyGuid]

Don't know if http://www.ebay.com.au/itm/Cnc-mill-...item1c46db7bce would be of interest to you?

[embraced]

I've been watching this one, but it's not quite what I am after. A bit too dilapidated for my taste.

Thanks for the suggestion though.

[Boyan Silyavski]

I've been watching this one, but it's not quite what I am after. A bit too dilapidated for my taste.

Thanks for the suggestion though.

I know what you mean. I also like things that not only do the job but are just great even just looking at them.

So don't despair. If i were you i would go back to the drawing board, draw my best and once ready will start the build. At the end there would always be better choices, but there is nothing that brings more satisfaction than a custom build.

Now i said that you cant beat refurbishing old machine. But that's true that you can not easily waste so much metal in one machine for the same money. Not that you can not do better simpler machine. Look at that link above, 6 tons of a machine , 2.7m high, that's a monster. But imagine that you have to change the linear guides. That could be even more difficult than a new build. You will need a crane, just to see whats going on there and so on. I doubt that it could do HSM.

At the end its up to you, but when i decide to do something i do it. I am in the middle of a build. YES, i could have bought old CNC router and refurbished it and gained ATC and vacuum table.. No, i would not do it, now soon i would have a Ferrari i build to my taste. And i would be very happy every time i walk in the garage.