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.