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Homebuilt CNC in Tokyo

Bakafish

Aluminum
Joined
Feb 21, 2022
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.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
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.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
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.
 

Milland

Diamond
Joined
Jul 6, 2006
Location
Hillsboro, New Hampshire
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...
 

Bakafish

Aluminum
Joined
Feb 21, 2022
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.

Fair enough. I think his doubling down didn't help my attitude. Telling someone to abandon all their work and just buy a machine and get a shop isn't really helpful, even if well intentioned.

Maybe useful information will be found later.

Maybe you'll actually make something.

I appreciate your suggestions, I'm working to implement some of them in the final design. Still can't find any rails with higher preload, but will likely upgrade the gantry rails to a stronger pair of 30mm that are a bit longer so I can space out the blocks a bit more.

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...

That's pretty funny! Thanks again.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Fair enough. I think his doubling down didn't help my attitude. Telling someone to abandon all their work and just buy a machine and get a shop isn't really helpful, even if well intentioned.

Bakafish, HONESTLY, I did EXACTLY that, after futzing around with trying to build a machine, I ended up establishing some space (1.5 hour drive away from home one way, FYI) and bought a commercial machine shown here:
AG0P1327.jpg
This machine has a SMALLER work envelope than you are trying to handle, and weighs 4500 lb...this is what a professional machine looks like.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Bakafish, HONESTLY, I did EXACTLY that, after futzing around with trying to build a machine, I ended up establishing some space (1.5 hour drive away from home one way, FYI) and bought a commercial machine shown here:
View attachment 345212
This machine has a SMALLER work envelope than you are trying to handle, and weighs 4500 lb...this is what a professional machine looks like.

Okay, I hear that you're being sincere about it, and I came down pretty hard on you. But I hope my points, despite being exceptionally pointy, were understood. I'm not actively looking to fight people, despite the appearances, I'm just not used to this level of S/N, as the GJ is so much more supportive.

Keeping the costs low until I can find utility from the experiment seems the most prudent course for me at this time. I have already solved all the problems in implementing this plan, I've got all the specialized parts, just waited to order the extrusions as that's when I have the design as locked in as possible.

I readily agree the machine may turn out to be crap, but there's no reason not to find out at this point. I have a full time engineering role at a giant company (fortunately from home) and want to have something to pivot to when I retire in the next few years, this is the best way I can see getting up to speed. I want the machine close for now, if it becomes a business, I have the finances to do it the official way and the Kaiju will be unceremoniously kicked to the curb.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Okay, I hear that you're being sincere about it, and I came down pretty hard on you. But I hope my points, despite being exceptionally pointy, were understood. I'm not actively looking to fight people, despite the appearances, I'm just not used to this level of S/N, as the GJ is so much more supportive.

Keeping the costs low until I can find utility from the experiment seems the most prudent course for me at this time. I have already solved all the problems in implementing this plan, I've got all the specialized parts, just waited to order the extrusions as that's when I have the design as locked in as possible.

I readily agree the machine may turn out to be crap, but there's no reason not to find out at this point. I have a full time engineering role at a giant company (fortunately from home) and want to have something to pivot to when I retire in the next few years, this is the best way I can see getting up to speed. I want the machine close for now, if it becomes a business, I have the finances to do it the official way and the Kaiju will be unceremoniously kicked to the curb.

I could be wrong, but my prediction is that you will have a lot of vibration in your machine due to insufficient mass, and this will seriously affect your accuracy. In addition, I predict that you'll be unable to cut anything more than aluminum without torquing the machine.

In a side-bar, I had a discussion with another machinist on this forum, and we both agreed that if we were trying to build a very small high precision machine, we would build it out of granite...not just the base, but possibly an entire box. His suggestion was something akin to an Hermle, possibly hanging the grantry from the bottom of the upper slab of granite. This kind of design could rival any modern commercial machine, albeit for very small parts.

Anyway, good luck with your project.

FYI, I was impressed with the remodelling you have done on your house.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Just to add, those Speedio's are sweet, as are the little Datron's... and my wife would be supportive if I bought one. We don't have kids and we own a successful business, the money is there. I just come from a background where you don't spend that much money (to be fair we didn't have money) in the hope it will be useful. And I want to get my crash experience on something cheaper and easier to repair or replace...
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Just to add, those Speedio's are sweet, as are the little Datron's... and my wife would be supportive if I bought one. We don't have kids and we own a successful business, the money is there. I just come from a background where you don't spend that much money (to be fair we didn't have money) in the hope it will be useful. And I want to get my crash experience on something cheaper and easier to repair or replace...

Speedio is in a different class from Datron, Datron Neos are effectively a 2D machine and quite limited, speedios are full out production machines....mine has 4th axis as well.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
I could be wrong, but my prediction is that you will have a lot of vibration in your machine due to insufficient mass, and this will seriously affect your accuracy. In addition, I predict that you'll be unable to cut anything more than aluminum without torquing the machine.

I can't say I'd be super disappointed if I could only cut Aluminum. I understand and agree that would put this in the hobby category, but let's see what it will do.

In a side-bar, I had a discussion with another machinist on this forum, and we both agreed that if we were trying to build a very small high precision machine, we would build it out of granite...not just the base, but possibly an entire box. His suggestion was something akin to an Hermle, possibly hanging the grantry from the bottom of the upper slab of granite. This kind of design could rival any modern commercial machine, albeit for very small parts.

I totally agree, I actually pointed at two projects that did exactly that. My concerns over weight were sincere, this house has wood floors, and while it is better built than most, it would be a mistake to put that much weight on anything but cement and steel.

I've also kept a close eye on granite parts and although big surface plates are often very inexpensive, smaller components are typically quite dear. One of the exceptions in this market, most of these metrological tools are dirt cheap. I don't know why, likely just rarity.

So all those parts would need to be custom ordered, or I'd need to slice up a couple of smaller plates.[/QUOTE]

Anyway, good luck with your project.

FYI, I was impressed with the remodelling you have done on your house.

I appreciate that, it was way more stressful puzzle than this simple machine build :)
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Speedio is in a different class from Datron, Datron Neos are effectively a 2D machine and quite limited, speedios are full out production machines....mine has 4th axis as well.

You have my interest! In what way are the Neo's 2D? I've seen the videos of them running (and with a 4th axis), what was I missing? I'm a Brother fan as that's the 'home' team, but I've never heard that the Datron's were limited.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
You have my interest! In what way are the Neo's 2D? I've seen the videos of them running (and with a 4th axis), what was I missing? I'm a Brother fan as that's the 'home' team, but I've never heard that the Datron's were limited.

I found your original shopping thread on it, good info there. I guess I bought the Datron hype :) I didn't want to deep dive these machines because I worried I will sell myself an expensive box before I needed it.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
You have my interest! In what way are the Neo's 2D? I've seen the videos of them running (and with a 4th axis), what was I missing? I'm a Brother fan as that's the 'home' team, but I've never heard that the Datron's were limited.

Just look at the z limits. In general, folks that buy these machines are doing stuff that has very little z, and from talking to folks that have bought the machine they view these as targeting products that are more 2D in nature. Also, the neo has similar work envelope (other than z) as the Speedio S300X1 but weighs 1500 lb versus 4500 lb, its just not in the same category. Also, in terms of speed, Speedio knocks the socks off Datron, and is I believe the fastest CNC in the market currently.

Plus, Speedio is made in Japan, where you live !!!
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Just look at the z limits. In general, folks that buy these machines are doing stuff that has very little z, and from talking to folks that have bought the machine they view these as targeting products that are more 2D in nature. Also, the neo has similar work envelope (other than z) as the Speedio S300X1 but weighs 1500 lb versus 4500 lb, its just not in the same category. Also, in terms of speed, Speedio knocks the socks off Datron, and is I believe the fastest CNC in the market currently.

Plus, Speedio is made in Japan, where you live !!!

Yep, the Speedio will be the first on my list to check out when I'm ready to pull the trigger. You have some other nice looking machines too. Those 400v 3-phase cutoff boxes were just taunting me. :(
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Yep, the Speedio will be the first on my list to check out when I'm ready to pull the trigger. You have some other nice looking machines too. Those 400v 3-phase cutoff boxes were just taunting me. :(

My machines are built in Japan, Germany, and Switzerland....thus 400V transformer....also a 208V transformer for the Speedio as it didn't like the 230V from utility. And yes, lucky to have 3-phase service. Do a search on Studer S20, thats my most recent and most prized machine.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
My machines are built in Japan, Germany, and Switzerland....thus 400V transformer....also a 208V transformer for the Speedio as it didn't like the 230V from utility. And yes, lucky to have 3-phase service. Do a search on Studer S20, thats my most recent and most prized machine.

Yes, I know it, would love something like that someday. You have great taste in machines! ;-)
 

memphisjed

Stainless
Joined
Jan 21, 2019
Location
Memphis
Back to the concept- building better machine with locally grown organic free range product. Aluminum is obviously not first choice, but not bad choice. Bolted connections and always in flexed tension under load is bad, very poor for material choice. Aluminum does transfer load in compression (shock) fairly well, use that to an advantage and run arch shaped bridge (like two dams back to back). Bolted connections need beefy wing plates, and lots of bolts to get compression to near welded stiffness.
To bad japan doesn’t have native controllers other than brother, Fanuc, Okuma, Sony, toshiba, and I know I missing some others... I run a Slovenian controller- no need to reinvent the wheel on a mill control unless you have some very unique improvement/concept.

If you are making a tool it is either a quick and dirty one to work, or an elegant product. Even if it doesn’t work try for the second- you are not on the clock for this job.
 

mmurray70

Hot Rolled
Joined
Jan 11, 2003
Are the Oriental Motors Alpha series closed loop steppers and NEMA 34 motors underpowered yak's vomit?

You can put all those fancy names in front of it, but at the end of the day its still just a stepper motor. Which is still garbage for any kind of serious CNC. Im aware the closed loop steppers are much better then normal steppers, but they are still garbage.

Have a look online and see what type of "steppers" are used on Okuma, Mazak, Doosan, even Haas machines...
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Back to the concept- building better machine with locally grown organic free range product. Aluminum is obviously not first choice, but not bad choice. Bolted connections and always in flexed tension under load is bad, very poor for material choice. Aluminum does transfer load in compression (shock) fairly well, use that to an advantage and run arch shaped bridge (like two dams back to back).

I just don't have the equipment to get this creative with the structure, one of the reasons I chose the Al profile that can be drop shipped to my door. I suspect that additional damping will mollify some of the worst of these spars behavior, but the bolted connections will certainly be a weak point.

Bolted connections need beefy wing plates, and lots of bolts to get compression to near welded stiffness.

I will be trying to integrate as much steel as possible in this way. I hope to make all the wing plates and backing plates out of steel.

To bad japan doesn’t have native controllers other than brother, Fanuc, Okuma, Sony, toshiba, and I know I missing some others... I run a Slovenian controller- no need to reinvent the wheel on a mill control unless you have some very unique improvement/concept.

I've seen some used domestic controllers sold pretty cheaply, but trying to understand and adapt a full enterprise controller with what I have would massively complicate this project (although would be really useful knowledge.)

If you are making a tool it is either a quick and dirty one to work, or an elegant product. Even if it doesn’t work try for the second- you are not on the clock for this job.

Yes, you get it. This is obviously a bit of a hack, but I take pride in my work and I'm trying to make it as best I can.

You can put all those fancy names in front of it, but at the end of the day its still just a stepper motor. Which is still garbage for any kind of serious CNC. Im aware the closed loop steppers are much better then normal steppers, but they are still garbage.

Have a look online and see what type of "steppers" are used on Okuma, Mazak, Doosan, even Haas machines...

This smacks of, "How many small block chevy V8's do you see in Porsches, Ferraris and Lamborghinis?"

They may be crude, we all know Servos are better, but these steppers will do the job I am asking them to do. I don't think it makes it any less serious, the parts this machine will generate would be identical, irrespective of the motors used. Their biggest practical drawback is speed, which has little impact on someone making parts for himself with a low speed spindle on a timeline of his choosing.
 








 
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