Canadian brothers make their own CNC

[Mcgyver]

If you are going to be that picky all materials have creep and flow, the real question becomes how much and how fast. Additional all material compress under load, with some rebound, again something that is important. We won't even get into the thermal expansion/contraction differentials in a machine and materials used.

Its not being picky, its about understanding the accuracy a machine tool requires, the techniques and challenges in bringing it about and being able to observe the absence of said techniques.

How accurate, as in specifically what tolerance for flatness, would you have to have in a machine you made to claim it was at all comparable to a commercial cnc mill? Then, what techniques did you see in that video that makes you think they might have achieved that tolerance?

So can they produce an accurate machine, easier than lets say 30 years ago.

Why do you say that, epoxy granite? It's been around for awhile however EG doesn't make achieving accuracy any easier; it makes it possible to make a fabricated machine with better than cast iron vibration damping properties.

The only question becomes are you smart enough?

I don't think smart enters into it. its a matter of knowledge. I have reconditioned machine tools. Its not rocket science, but it does teache one how to create accuracy and the challenges in doing so. So yes I think I have the knowledge. As for smarts, I'm smart enough not to bother when there are paths to a far superior machine for less effort/money. To each their own of course. The point of my posting, as I said, is to discussion machine tool accuracy, what's needed, how you achieve it, whats missing in the video, etc.

I don't question that they are smart enough but they lack knowledge on how to create accuracy, specifically in the realm of flatness. A rather critical part of making a machine tool. Or at least if they have it they're keeping quiet about it.

 

[Former Member]

Its not being picky, its about understanding the accuracy a machine tool requires, the techniques and challenges in bringing it about and being able to observe the absence of said techniques.

How accurate, as in specifically what tolerance for flatness, would you have to have in a machine you made to claim it was at all comparable to a commercial cnc mill? Then, what techniques did you see in that video that makes you think they might have achieved that tolerance?



Why do you say that, epoxy granite? It's been around for awhile however EG doesn't make achieving accuracy any easier; it makes it possible to make a fabricated machine with better than cast iron vibration damping properties.



I don't think smart enters into it. its a matter of knowledge. I have reconditioned machine tools. Its not rocket science, but it does teache one how to create accuracy and the challenges in doing so. So yes I think I have the knowledge. As for smarts, I'm smart enough not to bother when there are paths to a far superior machine for less effort/money. To each their own of course. The point of my posting, as I said, is to discussion machine tool accuracy, what's needed, how you achieve it, whats missing in the video, etc.

I don't question that they are smart enough but they lack knowledge on how to create accuracy, specifically in the realm of flatness. A rather critical part of making a machine tool. Or at least if they have it they're keeping quiet about it.

There is the rub, it comes down to the individuals doing it. And the case what these individuals did, for them it might be simple and obvious, so no documention (video) needed unfortunately for the rest, not so.

Remember the greatest one step advances machinery or otherwise are made be the least knowledgable as they just solve the problems as they arise and are not clouded by standard practice and knowledge (including it can't be done knowledge).

 

[Mcgyver]

There is the rub, it comes down to the individuals doing it. And the case what these individuals did, for them it might be simple and obvious, so no documention (video) needed unfortunately for the rest, not so.

you really think so? Its a possibilty but my money is no just being aware or addressing it given how their (excellent) presentation covered everything else. Even when asked about it they didn't have a answer, not even a "we're not telling" lol

 

[Former Member]

you really think so? Its a possibilty but my money is no just being aware or addressing it given how their (excellent) presentation covered everything else. Even when asked about it they didn't have a answer, not even a "we're not telling" lol

If that's the case, most likely because it's so obvious (to them) why answer

 

[Dabbler]

I hope we haven't strayed too far from the initial point. for a 'modest' sum of money, these guys built a pretty functional piece of machinery. There is no way that it will be as accurate as the Kern (for instance).

This discussion on accuracy is fascinating - it recognizes the balance between theory and the practical.

The big casting facility here in Alberta has a bunch of environmental chambers and will cycle a casting to as refined a point as you are willing to pay for to stabilize the iron. It all goes down to cost and 'accurate enough'...

In the bridgeport casting line, some of the bases were considered 'squirrly' - even after 3 years of aging they still moved too much over a modest temperature range, and were broken up for recasting. No one cared why, they just recycled the iron to try again.

 

[LenVW]

Sometimes the details of the end product are mis-interpreted.
Never overlook the requirement of the application.
If you want more accuracy, quality and options . . .
. . . you are going to have to pay for it.

Managing product development means reaching the requirements that your customers are demanding while controlling you material and manufacturing cost allocations.
I have to give credit to these guys for building their own CNC workcenter. Time will tell if it is accurate enough to complete orders and whether it will last a reasonable lifecycle.
HAAS, MAZAK and others have invested much more then $15k.

 

[Mcgyver]

I hope we haven't strayed too far from the initial point. for a 'modest' sum of money, these guys built a pretty functional piece of machinery. There is no way that it will be as accurate as the Kern (for instance).

How do we know how functional a machine it is? They mill a part, what if its out 50thou? We don't know. If they measured everything and was all with .002" I'd be leading the applause. They said they set out to make a professional cnc mill, what I saw could well make parts out 50 thou or more - or at least I didn't see anything to the contrary. They are not disclosing performance. Too bad they didn't quantify or evaluate it/parts made on it. that imo would be logical end to the story.

I'm not being critical for sport and I do admire the quality of the presentation and their drive and energy. imo a discussion around their methodology's strengths and weaknesses advances the topic.

btw, I'm only speaking up because of practical experience achieving flatness, squareness and alignment with machine tools and with that knowledge, the absence of it in that project (at least as it was presented).