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Homebuilt CNC in Tokyo

With all the 'research' the OP has done he'd know that making a home grown phase converter is easy.

"Easy" if you ignore all the complications I guess. How much will you charge me to deliver a PSE certified 35A phase converter to my door? Spec out the parts and provide links, it's easy right?

Except he's going to tell us used 3 phase motors are uncommon on the used market, and stuff like capacitors etc can't be had cheaply because there's no Jap equivalent of Allied/Newark/mouser/digikey etc etc.

You always resort to putting your own stupid words in my mouth to make your nonsensical points. Neither of these statements are true, you are pathetic.

OP needs to do less research and get off his arse and get building

I'll build this on my timeline and with a well researched understanding of what I'm doing. But you are free to do things your way.
 
3) Practicality. Where am I supposed to put it? My power distribution, like in most Japanese homes, is located inside the residence, in my case in the Kitchen. My wife is a kind and gentle soul, but a massive deadly* box humming ominously on the wall of her kitchen is a non-starter.
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Stop being a drama queen, nobody would be stupid enough to consider mounting a Phase converter on the wall of your (or their) wifes kitchen.

I like my house the way it is, non-industrial. I ran dedicated 30A and 20A circuits to my shop room cleanly and intentionally, no one who didn't have a deep knowledge of electrical sockets would ever even notice them. I do not want to have industrial conduit added everywhere, I do not want to add additional wiring or put big boxes on my walls or outside. I want to be able to relocate the CNC to another location and have no sign it existed here..

If you have 30A and 20A circuits, then you have more then enough power for the Phase converter. Assuming you have sockets at the end of the 20A/30A plug into there.

At my house the phase Converter pluged into the dryer socket.

Why do you need industrial conduit? At the house I used flexible cables for all the connections from the wall to the phase converter, then the Phase converter to the machines. Very flexible. And you can do the wiring yourself.
 
"Easy" if you ignore all the complications I guess. How much will you charge me to deliver a PSE certified 35A phase converter to my door? Spec out the parts and provide links, it's easy right?

What complications?

And why 35A? There's zero chance your going to be needing more than 10A I would venture to speculate.
 
I'll build this on my timeline and with a well researched understanding of what I'm doing. But you are free to do things your way.

Your researching yourself into a corner. You seem to over analyze every aspect of the machine. Your analysis will likely go out of the window when you start building this machine. What your doing doesn't have to be an exact science.

You'll probably learn more from building the machine then from your research to date.

Maybe you like the research, but I'd like to think your going to enjoy building the machine more
 
You brought up noise, I'm wondering if you have an estimate for the "average" sound this thing will leak from its enclosure while running (say, cutting an Al plate).

I've never been to Japan, but my understanding is that excess noise is frowned on, unless you're a Kaijū.
 
You brought up noise, I'm wondering if you have an estimate for the "average" sound this thing will leak from its enclosure while running (say, cutting an Al plate).

I've never been to Japan, but my understanding is that excess noise is frowned on, unless you're a Kaijū.

Funny enough, the machine's name is actually "Kaiju." Not that creative, but I felt it appropriate. But I've no idea how loud it's going to get, especially with undamped Aluminum as it will start out with. It will be in the most optimal room as far as noise leakage and proximity to neighbors. During working hours it likely won't be an issue, and the spindle was very quiet when I tested it. A lot of the work on it will be with softer materials as well. I just hope to be able to work on steel when it is really required, It won't be working 24x7 so presumably noisier work can be planned accordingly.
 
Your researching yourself into a corner. You seem to over analyze every aspect of the machine. Your analysis will likely go out of the window when you start building this machine. What your doing doesn't have to be an exact science.

You'll probably learn more from building the machine then from your research to date.

Maybe you like the research, but I'd like to think your going to enjoy building the machine more

This feels like civil and honest advice, so let's agree to start from this. I'm not a young man, and although this is my first CNC build, this is not my first rodeo. I have a process, it may not be to some people's liking, but it has proven its worth, to me. "You'll probably learn more from building the machine then from your research to date.", is something we both agree, but I do not think it precludes careful consideration before action. The two things are not exclusive and I have avoided a lot of (but not all) costly mistakes doing things after exhaustive contemplation.

That being said, most of that design process is done and the last few components will be ordered this week. So for the people already impatient with desire to see progress (thankfully you are just hearing about this now instead of a year ago when this process started), you will have ample opportunity to critique my actual work rather than my thoughts, lucky me.
 
I don't think the material being cut (or the frame material) will have much bearing on how noisy the machine is. high speed spindles are loud, cutting anything with high speed spindles is loud (wood, metal etc, maybe foam would be quieter) non-air cooled spindles are going to be slightly quieter but I find the cutting noises, the rail noises from rapids with preloaded carriages and even just the nut spinning in air at 30k rpm with a water cooled spindle is loud. (as in well over 80db, probably over 90db at peak, I wear hearing protection 100% of the time)

To keep it from bothering neighbors is going to be a study in sound absorbing and decoupling vibrations. For the noise I suggest the rather expensive but highly effective products that use acoustic mirrors (alternating bonded layers of foam and dense materials) and careful air sealing of the enclosure.

Most of the people on PM have no idea what it is like to have a workshop in dense built up area, at least in Europe power isn't such a pain but noise is concern and there are rules, either formal or customary about when you can make noise (such as nothing on Sunday). Most Americans would loose their sh#t if they couldn't mow the lawn on Sundays :)

Luke
 
I don't think the material being cut (or the frame material) will have much bearing on how noisy the machine is. high speed spindles are loud, cutting anything with high speed spindles is loud (wood, metal etc, maybe foam would be quieter) non-air cooled spindles are going to be slightly quieter but I find the cutting noises, the rail noises from rapids with preloaded carriages and even just the nut spinning in air at 30k rpm with a water cooled spindle is loud. (as in well over 80db, probably over 90db at peak, I wear hearing protection 100% of the time)

To keep it from bothering neighbors is going to be a study in sound absorbing and decoupling vibrations. For the noise I suggest the rather expensive but highly effective products that use acoustic mirrors (alternating bonded layers of foam and dense materials) and careful air sealing of the enclosure.

Most of the people on PM have no idea what it is like to have a workshop in dense built up area, at least in Europe power isn't such a pain but noise is concern and there are rules, either formal or customary about when you can make noise (such as nothing on Sunday). Most Americans would loose their sh#t if they couldn't mow the lawn on Sundays :)

Luke

It's an oddball Japanese low speed ~2700RPM, passively air cooled spindle running off of a VFD. Most of the noise will be directly generated by the cutting tool, and secondary vibrations and harmonics of the machine, which I think we all expect the big aluminum extrusions will factor in largest. I'm going to assume that the higher loads generated by harder materials will have a direct correlation with the amount of vibration generated, hence the increase in noise. But you may well be right that it will all be equally bad.

Acoustic treatment is something I have experience with as I used to build recording studios and other acoustical construction and design work. I'm not saying this is a low priority, just that I will focus on it more once it is something I actually have to worry about. As many here have noted, the only noise being generated so far is in this thread :) So even though I have plans to address these issues, noise abatement, chip handling and part cooling are all getting kicked down the road.
 
With home-built RPC's the trick is getting good phase balance. I did a 5 hp that had about 15-20 v difference between legs. My commercial 30 hp achieves about 1-2 v.
Inrush current is pretty serious but only until the motor gets up to speed. The 240 legs are fused with 75 A motor starting fuses. Startup is achieved by adjusting capacitors. Probably a set to give you appropriate phase offset (relay controlled) and a run set. I have a 100' run of #6 Cu to the shop and the relay for startup is controlled by alexa si U cab remotely start and stop the RPC. The RPC is right next to my service entrance.
 
What sort of tolerances and material removal rates are you trying to hit? Assuming you have realistic expectations your aluminum extrusions are unlikely to be an issue. Just make sure that you're using a good method to join them together. Assuming you're not going to weld them, you'll need lots of fasteners to keep the joints rigid. Cast iron is a great material for machine frames particularly because of it damping capacity. It is 100x more capable of damping vibrations compared with aluminum. However that's fairly easily mitigated by keeping forces low, as well as filling the extrusions sand/epoxy.whatever.

I bought low-preload for an earlier iteration of my CNC as well. They worked well enough though, just required a reduction in cutting forces. I ended up replacing the linear bearings with some lightly used ones that came off a HAAS that was being rebuilt. I'm on like iteration 8 of my machine though.

I look forward to seeing some more pics of your machine and parts!
 
If I were the OP, I would just punt on the machine shop in my really small, no electricity, no noise house, and just rent a small industrial space with 3-phase power, and buy a used professional CNC machine and get to work.
 
Whats wrong with a phase converter in the kitchen? No louder then a dishwasher?

I kinda wish my kitchen had 3 phase now that you mention it. lol
 
If I were the OP, I would just punt on the machine shop in my really small, no electricity, no noise house, and just rent a small industrial space with 3-phase power, and buy a used professional CNC machine and get to work.

Wow, a year of toiling on this and you walk right in and solve it! Like startups should just skip that step and go straight to full production. Genius! It all makes so much sense when you can just say things as if they are: Super easy, barely an inconvenience! I mean there must be hundreds of cheap industrial spaces with 3-phase in Shibuya, you looked right? I mean you got my back and did all the research before posting this, right?

If by cheap you mean several thousand a month with a first and last deposit, 3 year minimum lease and the wonderful "key money" we have where you pay an additional several months rent up front as a 'gift' to the owner. And by Shibuya you mean an hour or more away by train in Kawasaki or some other dingy industrial area. Add the cost of the machine (as you clearly didn't read anything, probably cheaper over the amount of time you've committed with the lease to just buy new), and professional installation (since no landlord is going to allow you to touch anything yourself) you've spent an awful lot of the OP's hard earned money.

Easy to spend other people's money though, I get that.

When I have a complete business plan and viable product that can potentially pay for these things, then it will make sense to have a real facility and equipment. For now I think I'll stick with my plan and wish you luck with yours.
 
Wow, a year of toiling on this and you walk right in and solve it! Like startups should just skip that step and go straight to full production. Genius! It all makes so much sense when you can just say things as if they are: Super easy, barely an inconvenience! I mean there must be hundreds of cheap industrial spaces with 3-phase in Shibuya, you looked right? I mean you got my back and did all the research before posting this, right?

If by cheap you mean several thousand a month with a first and last deposit, 3 year minimum lease and the wonderful "key money" we have where you pay an additional several months rent up front as a 'gift' to the owner. And by Shibuya you mean an hour or more away by train in Kawasaki or some other dingy industrial area. Add the cost of the machine (as you clearly didn't read anything, probably cheaper over the amount of time you've committed with the lease to just buy new), and professional installation (since no landlord is going to allow you to touch anything yourself) you've spent an awful lot of the OP's hard earned money.

Easy to spend other people's money though, I get that.

When I have a complete business plan and viable product that can potentially pay for these things, then it will make sense to have a real facility and equipment. For now I think I'll stick with my plan and wish you luck with yours.

I started EXACTLY at the place you are a number of years ago. End result: I ultimately rejected the home brew machine, and bought a commercial machine....after I had spent a huge amount of money learning what I didn't know prior to the start of the adventure.

My prediction: you will spend more money building your home machine and get poorer results than if you followed my suggestion. Let us know what you actually spend on your machine and how well it works out in the next 3 years.

Now, if you are really wanting to just learn how to build machines, and just doing this project for the fun of it, then I TOTALLY encourage you to proceed...you will indeed learn a huge amount in the process. But, IMHO, you will still end up with an inferior solution to even a very old professional CNC machine. Ultimately what is your goal: learn a lot on a fun project, or have a working machine to build other stuff....

Also, be a little careful about believing you are the only person on this forum that knows and understands Japan. I myself have spent a lot of time in Japan and know the culture and country well.
 
I started EXACTLY at the place you are a number of years ago. End result: I ultimately rejected the home brew machine, and bought a commercial machine....after I had spent a huge amount of money learning what I didn't know prior to the start of the adventure.

My prediction: you will spend more money building your home machine and get poorer results than if you followed my suggestion. Let us know what you actually spend on your machine and how well it works out in the next 3 years.

So you learned a lot and that's a bad outcome? No details at all about the 'mistakes' I'm making that are presumably the same as yours, lots of assumptions about what I've paid. Maybe I'll be more successful than you? Would that make you sad? Maybe sharing the mistakes you made instead of 'solving' my problems with a ill informed hand wave would have been more constructive.

Now, if you are really wanting to just learn how to build machines, and just doing this project for the fun of it, then I TOTALLY encourage you to proceed...you will indeed learn a huge amount in the process. But, IMHO, you will still end up with an inferior solution to even a very old professional CNC machine. Ultimately what is your goal: learn a lot on a fun project, or have a working machine to build other stuff....

Read what I've actually said about the project and my goals. Why would someone build this if not partially for the learning experience itself? Have I ever implied that I expect this to have higher accuracy (or really be better on any performance metric) than a professional machine? No, I haven't. Better than a Shapeoko, sure, not an audacious goal I think we can all agree. It is being built to accommodate the many constraints I have, that I've documented and discussed, that a professional machine wouldn't be expected to meet.

Also, be a little careful about believing you are the only person on this forum that knows and understands Japan. I myself have spent a lot of time in Japan and know the culture and country well.

LOL, people on this forum are always projecting what I 'believe' so that it fits their narrative. I don't assume that I'm alone in my understanding, but I do question your understanding for making the original suggestion. If you know so much about Japan then you'd easily be able to back it up with facts and be able to document where I'm wrong. Show me the cheap industrial real estate listing in Shabuya-ku you found. Put me in contact with your best friend at Tepco who can get a 200A 3-phase drop to my place.

Otherwise, get with the program and be constructive or keep your misguided solutions to yourself.
 
So you learned a lot and that's a bad outcome? No details at all about the 'mistakes' I'm making that are presumably the same as yours, lots of assumptions about what I've paid. Maybe I'll be more successful than you? Would that make you sad? Maybe sharing the mistakes you made instead of 'solving' my problems with a ill informed hand wave would have been more constructive.



Read what I've actually said about the project and my goals. Why would someone build this if not partially for the learning experience itself? Have I ever implied that I expect this to have higher accuracy (or really be better on any performance metric) than a professional machine? No, I haven't. Better than a Shapeoko, sure, not an audacious goal I think we can all agree. It is being built to accommodate the many constraints I have, that I've documented and discussed, that a professional machine wouldn't be expected to meet.



LOL, people on this forum are always projecting what I 'believe' so that it fits their narrative. I don't assume that I'm alone in my understanding, but I do question your understanding for making the original suggestion. If you know so much about Japan then you'd easily be able to back it up with facts and be able to document where I'm wrong. Show me the cheap industrial real estate listing in Shabuya-ku you found. Put me in contact with your best friend at Tepco who can get a 200A 3-phase drop to my place.

Otherwise, get with the program and be constructive or keep your misguided solutions to yourself.

To the OP: you are making many many mistakes in the the design of your machine, already mentioned by others:
- you think that having a cast iron base plate (which isn't really solid if I understand from your most recent post on the scraping forum) that you scrape to some level of flatness is a good place to start your machine. You completely discard the issues related to building the rest of your machine out of aluminum. All that effort making your cast iron flat will have no value when the different temperature differentials between your cast iron and your aluminum start working against each other.
- in addition, I suspect most folks viewing this discussion assumed that the base plate was solid iron, but again based on your recent post in the scraping discussion, the base plates appears to have a relatively small amount of mass because it's mostly empty. This completely defeats any benefit that might have been gotten from having substantial mass in the machine to reduce vibration,etc...thus this machine is looking to be a very flimsy machine which will have great difficulty holding tolerance under load.
- your machine will have way too much flex due to the aluminum. Multiple people on this forum have said so, but you just stick with your ideas and reject what you are hearing here
- IF you are building a hobby class machine, you are on the wrong forum here. Folks here are concerned with professional level work and professional level machines. If you are building a professional quality machine, you will get lots of help from folks here. So far, I'm inclined to believe you are building a hobby class machine. You seem to be hugely concerned about money and the cost of your efforts. That combined with the severe constraints about electrical, noise, and size of the machine just leads one to believe this is not a professional level effort.
- I read over your postings in Garage Journal. My impression is that the choice of components you are using have been decided mainly by how cheaply you can aquire them, not based on any careful engineering design.

Finally, you need to be more respectful, you are a very green novice asking hugely experienced folks for their advice. Don't attack folks you don't agree with. Accept inputs as the gifts they are from folks that have decades more experience than you will ever have.
 
To the OP: you are making many many mistakes in the the design of your machine, already mentioned by others:
- you think that having a cast iron base plate (which isn't really solid if I understand from your most recent post on the scraping forum) that you scrape to some level of flatness is a good place to start your machine. You completely discard the issues related to building the rest of your machine out of aluminum. All that effort making your cast iron flat will have no value when the different temperature differentials between your cast iron and your aluminum start working against each other.

No, I explain why I chose Aluminum despite being better aware of its shortcomings than you seem to grasp. Temperature differentials are a problem in a fluctuating environment, not a temperature controlled one like my workshop. I do not expect this to be a large contributing factor. We've discussed other potential drawbacks earlier in the thread, it isn't exhaustive, but anyone would conclude in fairness that I know this material isn't ideal. That said, you've not brought any actual numbers to show this isn't going to work.

- in addition, I suspect most folks viewing this discussion assumed that the base plate was solid iron, but again based on your recent post in the scraping discussion, the base plates appears to have a relatively small amount of mass because it's mostly empty. This completely defeats any benefit that might have been gotten from having substantial mass in the machine to reduce vibration,etc...thus this machine is looking to be a very flimsy machine which will have great difficulty holding tolerance under load.

Wow, I suspect you are wrong that most people thought that. They've probably seen that cast iron surface plates are not a monolithic slab of metal. You're not convincing me you are really as knowledgeable or experienced as your tone would suggest. They are hardly flimsy, nor are they lacking in mass. My machine may turn out to be spaghetti, but the base plate won't be the cause...

- your machine will have way too much flex due to the aluminum. Multiple people on this forum have said so, but you just stick with your ideas and reject what you are hearing here

Because, like you, they are just parroting 'common wisdom' without doing any actual analysis about the strength and dimensions of the materials I've chosen. Can you make something out of aluminum as strong as steel? Of course you can. You just need more of it. My machine has a lot and many methods to augment it if it isn't enough.

- IF you are building a hobby class machine, you are on the wrong forum here. Folks here are concerned with professional level work and professional level machines. If you are building a professional quality machine, you will get lots of help from folks here. So far, I'm inclined to believe you are building a hobby class machine. You seem to be hugely concerned about money and the cost of your efforts. That combined with the severe constraints about electrical, noise, and size of the machine just leads one to believe this is not a professional level effort.

I didn't realize you were the one here responsible for machine categorization. That changes everything! Kind sir, please don't damn my poor efforts as mere hobbyist, I beg of thee to bequeath it with your most honored "professional" stamp of approval!

In all seriousness, some people will call this project amateur and hobbyist no matter what I do, the moderators and interested parties will ultimately decide if this thread gets locked. And although I've had some really thoughtful and helpful advice, a lot of the conversation here has been from people that have very little to contribute and are more fixated in virtue signaling that they're "real machinists" than actually saying anything useful. Maybe think about what group you want to belong to.

- I read over your postings in Garage Journal. My impression is that the choice of components you are using have been decided mainly by how cheaply you can aquire them, not based on any careful engineering design.

Why not criticize the component choices then? Are 28mm NTK precision ground ball screws junk? Are the 25mm Hiwin rails garbage? Are the Oriental Motors Alpha series closed loop steppers and NEMA 34 motors underpowered yak's vomit? Maybe the $2000 TAC spindle should be tossed in the sea and used as an anchor? Seriously, does the idea that I can select good components and at the same time try to control the costs so offend you that it is an intractable contradiction of possibilities in your head?

Finally, you need to be more respectful, you are a very green novice asking hugely experienced folks for their advice. Don't attack folks you don't agree with. Accept inputs as the gifts they are from folks that have decades more experience than you will ever have.

I honestly don't think you are in any position to judge my ability or experience level. I have asked exactly ZERO people for their advice (although I happily receive it when it is constructive and thoughtful), as I keep pointing out, it is in the first sentence of this thread, so you are wrong on that count as well.

And if I don't seem 'respectful' maybe it is because you came into my thread and started saying dumb stuff, maybe it's a you thing and not a me thing. I'm happy to have a dialogue with you about any aspect of the build based on facts, but when you walk into my thread assuming I'm an idiot and talking shite, you are not going to get a friendly reception and I'm going to call you out on it.
 
Otherwise, get with the program and be constructive or keep your misguided solutions to yourself.

Well.

Doc's someone with a breadth of experience, and to take his well meaning advice and twist it such that you need to reply in full-snark has told me I can go to lurk-mode on this thread.

Maybe useful information will be found later.

Maybe you'll actually make something.

Maybe you'll realize that trying to fight everyone who walks through the bar's doors unless they're of "you're right, boss!" mindset isn't productive.

Whatever.

But you chose your name poorly.

It's Bakaraba...
 








 
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