[peteeng]

Hi Gecko et al - My journey with UHPC has sort of ended, It does not offer the stiffness it had promised so has sort of faded a bit for a bespoke machine. It makes sense to commit to moulds for a production machine and I would consider it for that application. Since my interest is in production machines this is still being pursued. Just need to find the outlet for many machines vs single builds.

My next choice is aluminium because I can deal with that in my workshop. The ply machines I have built have exceeded my expectations and I can see I could make ply machines, plasticise the surfaces with epoxy and they would then be suitable for flood/mist cooling. But timber does move (due to environmental conditions) so it would be another stepping stone to a metal machine. So therefore billet AL or laminated aluminium is the material of choice at the moment. Gecko originally want a machine of 300x400x350mm envelope to machine aluminium (with a wish for steel and ti) I think Al is totally doable so stay in that space. Steel and Ti require a different spindle and we cover that in Milli as well. So Gecko make a high rail design or a moving column design. That's my recommendation. A bolted together design can be adequately stiff and its portable. Two configs examples are attached. I prefer that the part stays still this allows optimisation of the mechanics and gets the mechanics up out of the muck. A bolted machine does take patience as there are lots of holes and threads or holes and nuts to deal with (if you do it yourself) but its a step by step approach that gets you to a known place. Welding is hit and miss unless stress relief is available and its a step forward, step back approach. If you have access to a mill and can make the parts to the design spec then everything bolts together as expected (just like a plane does, unless someone forgets to tighten the door plug bolts). The assembles can be epoxied together if permanent connections are OK. You will place a stake deeper in the ground at some point... when you do, carry that philosophy right through in CAD and resolve your design. Even if you do not use it its done. Partial designs litter the hard drives & sketch books of us all.... At 300x400x350mm I'd be looking at the moving column. Less drives to get square and keep square and the spindle is better aligned to the bearing footprints. So my vote is for the M1 arrangement in your case. Peter

edit - I also prefer the rails to be on top of the gantry and the saddle to be an angled bracket. This separates the X&Z bearings allowing a narrower saddle plus allows access to all bearings. A narrower saddle does affect the footprint of the machine considerably (if you go with a gantry design). I also think it helps with reducing the spindle overhang.

[catahoula]

Gecko-

If you have the opportunity to buy machine that fits your needs at a good price (not sure if the shipping is), and your desire is to use a CNC machine, by all means, buy it. I know it doesn't feel like it, but where you are at right now in the process is just getting started and there is a long ways to go before a full custom build is operational. Why not buy the machine then sell it when it's time to move? Being in the middle of a still unfinished build that is now almost 4 years old, this is my advice.


Regarding the machine geometry: most simply put, the reason a fixed gantry machine is usually stiffer is that there is no constraint on the mass of the gantry and support legs. They can be massive while not affecting acceleration. My gantry is steel, 225mm x 180mm and 50mm thick in most places. It is absolutely massive, which is largely why the stiffness looks promising in FEA. A moving gantry can be just as stiff but takes a little more design and engineering (and likely larger motors) for the same stiffness and acceleration.

Also, fixed gantry machines only require one ballscrew per axis, so alignment can be done entirely mechanically.

Lastly, if the ability to move the machine around is important, I would agree with the others that a tubular steel frame is the most appropriate. I'm sure you could figure out a way to fill the tubes with loose sand for vibration damping, but allow the tubes to be emptied when it's time to move.

[GeckoSub]

Hi all,
Just a quick note to say thanks to you all. This is exactly what I was hoping - your thoughts really do help me sort my own out.

Will set aside time over the next few days to make a decision on what the next step will be.

[peteeng]

Hi Gecko and others on the point of vibration and filling tubes with stuff.
1) The commercial builders of machines that fabricate out of sections do not fill their members with stuff. They do stress relieve and this is very important but this has to do with making a machine to the required accuracy not to do with vibrations
2) If you do have to fill your tubes with stuff it means you missed the basic rigidity requirement of that machine and it is a bandaid measure. It may sound damper but is it? No one has done correct dynamic vibration testing of their machine in this forum to find out
3) Std sections push you down the path to non optimum results. They limit your thickness selection at critical points, they are bowed, they are cupped or crowned. They are not the shape you designed them in CAD and they have round corners. So you have immediately compromised your "design" for several reasons
4) Vibration is a second order issue, if the machine is stiff enough it will not vibrate badly in a way that affects the cut. There is chatter in all machines even multi million dollar machines chatter at various times
5) You cannot solve the vibration issue with materials all of them are not damp enough to solve this. Even the best cast iron or composite cast machines still vibrate. The professionals go to a lot of trouble once built to do dynamic vibration tests that determine bearing vibration, structural vibration etc etc to establish working relationships of go no go zones in the spindle vs DOC vs other factors to minimise chatter. At our level we do not have a chance to do this yet. I say yet, because input shaping and some tap testing procedures will become available soon to us "hobby" CNCers that will solve a significant amount of this issue
6) I consul not to use std hollow sections, use thick plate bolted construction. Plate construction allows you to design exactly what you want. It assembles precisely. The plates are thick therefore do not vibrate (significantly) as thin tubes and extrusions do. I'm not sure why bolted construction is overlooked at the maker, hobby, diy level. We are welded to welding for some reason. Strain levels at bolted connections are tiny and friction produces damp connections. Were happy to bolt our rail onto something and that's a critical connection but we seem to be very reluctant to bolt the rest of the machine together.
7) I started researching vibration a long time ago and have come to conclusions as above and I'm actively trying to solve this area of machine design in a sensible manner, hopefully this year I will have some contribution that cause. Peter

[GeckoSub]

Apologies Up Front - Changing Tacks
OK, so… I did a lot of thinking today and the results are in: I will try to make a deal on the used (half) machine.
Before going into my reasonings, I do need to tell you this:
I am super thankful for all your effort, all of you! I learned lessons that I promise won't be forgotten. So, huge, huge thanks and please, please don't feel like you wasted your time helping me out so far!

Granted, this is not the path I set out to follow at the beginning, but right now, it’s the one that makes the most sense - for me. It will get me making parts faster and I will learn a ton from it. And honestly, actually using a machine and getting some real info on what I need from it is a step I have naively been skipping this whole time. It's a bit like trying to design a car without ever having driven one... This and the fact I need to get going are the main reasons for the change in approach.

All that said, please do - if you have it in you - read the rest below for some more elaborate reasoning - and the usual verbose repeating I tend to do..;-(

I will, of course, continue the build log here and I won't, at all in fact, rule out that I will actually build my own machine once I actually know what capabilities I really need and what I like and dislike in a machine. These are lessons I can only learn by getting a machine. Sooner rather than later, as I also do need and want to get parts into the world.



(My) Pros and Cons List:

Cast Iron Castings, Used or New
Off the shelf. Can’t find anything in China I can trust in the smaller sizes and don’t have the skills to correct it if for example the ways are out of whack. And they are actually not even cheap.
Custom castings - same challenges as with my own design for a granite machine:

Own Design - High Rails Moving Gantry Granite Router (Or Other DIY Designs)
The pros are amazing: I’ll get it as I want, size-wise and in many other ways and it will have the best inherent “containment of muck”. Also, not to be overlooked; it would give me an immense sense of pride to say I designed my own machine. Not doing so is a bit of a pill to swallow.
But it will take longer to get going as it’s clear I would need a whole lot more design work and honestly, it will have more uncertainty and a lot of stress come with it.

Bolted-Together Design
I like the idea a lot. But again, it will take a whole lot of design work and without really having any real world experience to base my decisions on.
That said… I just realized a few days ag0 that one of the guys in my Chinese circle of freediving friends has a mold making factory. Well, his family does... So, I could likely call in some very handy favors. But they may be better spent when I have some real experience (see more below). Meaning, I’d rather call upon him to make parts for a machine once I am truly sure of what I want.

Buying Ready-made Ready To Go Mill/Router
Most good ones are way too big. Once in a while a Chinese Mikoni 430 (a 300x400x150ish Fixed Gantry cast iron machine) comes up on the used market. They are supposedly higher end, finished to good accuracy but I only saw one that was even a little bit close to my budget and it went fast. The rest are way over.

Buying Used Granite Machine - My Preferred Choice Now
If I can still get the top part of the machine I mentioned earlier (Granite with seemingly OK motion hardware, 300x400x200), I save some headaches and time, too. The machine may or may not be able to cut titanium and will definitely need more enclosing but it will get me started sooner than finalizing the design of my own with a lot less work and stress.

I am almost certain it will suffice for my aluminum needs for now. And while I still love the idea of a high rail machine of my own design - here’s the real kicker: Even with all your help, I am honestly still flying quite a bit blind. Remember, this would be my first ever machine and I have done a lot of thinking about how to get it right for me and your help have been amazing but I have zero real experience. So, I may get it right with weeks more design work, weeks more of tapping into your knowledge. Or even with all that, I might miss the target, as I can’t really set the target.

The Conclusion - Next Step
So, I have decided to go with the used machine (with a new base) to get started faster and use it as a learner that will still make me the parts I need.
I am also almost certain it will pay for itself within a year, maybe less - so there’s hardly any monetary risk involved in this approach.
And if I need to upgrade/make my own machine next, I will either sell this, strip it for parts or use it as second machine.

Big, big apologies if any of you felt you wasted your time offering your advice. From my end, you didn’t. You helped so much, even though this is not the path I wanted to take, your advice helped firm up that it’s the best one right now.IF the used machine is off the market tomorrow when I reach back out to the dealer, I am back to the drawing board and will then just have to commit to designing within a fairly tight deadline, stress, lack of knowledge and all, haha.

[catahoula]

Hi pete-

I agree completely about the primacy of rigidity over other considerations. This is the reason I suggest heavy wall steel construction- without a doubt the most bang for your buck in terms of N/um.

But, at the end of the day, we're talking mostly about hobby machines. In that case, we can agree that stiffer machine is better than less stiff, and that more damping is better than less damping, assuming it's not too difficult or too expensive or doesn't impact other aspects of design. Adding loose sand is trivially easy and cheap to do, whereas adding epoxy granite, which is also commonly done, is expensive, somewhat time consuming and messy, and also puts constraints on the assembly process regarding when holes need to be drilled, etc. I recently built a large, heavy wall steel base, which was ringing like a bell upon every slight touch or movement, obnoxiously so, until I put sand in it. In no way am I arguing loose sand is an optimal material and will necessarily damp the correct frequencies for machining. People read about vibration damping and it gets stuck in their head, I'm just throwing this out as a thing that can be done to check that box mentally, for essentially free and without much effort, while focusing on rigidity and the million other things one needs to think about.

Overall I think we don't need to be too dogmatic about any of it. The corner radius of RHS/SHS is simple to account for in CAD. Making a convenient combination of heavy plate and heavy tube, where each is most approproate, is efficient. And post-weld thermal stress relief, for all the talk about it, just isn't that big of a deal forost people. You drive it to a place, pay your $250 or whatever, and it's a drop in the bucket compared the the rest of the build.

It's one thing that I've learned in my build: it mostly comes down to the execution.

There are great examples of machines from steel, EG, granite, aluminum plate, in all the various formats of moving tables and columns and gantries (as long as it's not made of t-slot extrusion or plywood ).

Early on in my project I spent too much time worrying about vibration, optimal layouts, hyper precision of various motion components, full closed loop linear scale movement that I don't have the precision to meet in my build process to benefit from anyway, whether or not my rails needed shoulders to mount against, etc etc. That's all part of the learning process, but if I'd just built one of my earlier designs based on a granite surface plate and a steel gantry of a smaller size that I could have machined myself, it would've been pretty much done by the time I finished just the research and design of the "too big to fail" ultimate machine. And it still would've been plenty adequate, with more opportunity to fix or change things later because i woukdnt be stuck in such a sunk cost trap of perfection.

I think I'll sign off here, I'm afraid we're ruining Gecko's thread

[peteeng]

Hi Gecko - Good news on the decision & direction. Look fwd to the build.
Hi Cat - I did contemplate a mill from plywood but aluminium is my choice After a couple of builds, various things become obvious and sensible so all the design anxiety sort of melts and you get on with it... But designers do seek perfection and the Grail is out there... Onward to big things in 2024!! Peter

[joeavaerage]

Hi,

Big, big apologies if any of you felt you wasted your time offering your advice. From my end, you didn’t. You helped so much, even though this is not the path I wanted to take,

I certainly do not feel that the time has been wasted. One of the biggest learning challenges with DIY CNC is to be very clear eyed about your goals and what can and cannot be achieved
with regards skill, cost, availability etc. The hardest thing to do is having dreamed up some solution that you think would be just the best....and almost imagine it built and using it.......but then to analyse
the reality of the design and the various reasons that it unrealisable and change your mind.

It will get me making parts faster and I will learn a ton from it. And honestly, actually using a machine and getting some real info on what I need from it is a step I have naively been skipping this whole time. It's a bit like trying to design a car without ever having driven one..

100% agree, nothing teaches you more than standing in front of a machine and making parts. Things which you'd never consider come to the fore while other things that you thought vital are not at all.
It is highly probable that you will build your own machine one day and the more real world experience you have the better the result will be. It may be that whatever cost you sink into a ready made machine
will be recouped simply by doing the 'right' things on your own design/build rather than expensive 'wrong' things.

Early on in my project I spent too much time worrying about vibration, optimal layouts, hyper precision of various motion components, full closed loop linear scale movement that I don't have the precision to meet in my build process to benefit from anyway, whether or not my rails needed shoulders to mount against, etc etc. That's all part of the learning process, but if I'd just built one of my earlier designs based on a granite surface plate and a steel gantry of a smaller size that I could have machined myself, it would've been pretty much done by the time I finished just the research and design of the "too big to fail" ultimate machine. And it still would've been plenty adequate, with more opportunity to fix or change things later because i woukdnt be stuck in such a sunk cost trap of perfection.

100% agree. I have done just exactly that. Trying for 'perfection' is a trap.....it costs more than you can afford, requires skills, machines, equipment that you don't have. In the end it prevents you from building anything.

'Perfection is the deadly enemy of Good Enough'.

Quite some years ago now when I was designing and building my servo driven spindle, I had all the major parts, the servo and drive, the eye wateringly expensive Swiss made cylindrical tool holder (perfectionist BS),
expensive matched P4 angular contact bearings, and the seals that I had to get from the UK. Then I needed to make the bearing housing, but I felt it was beyond my skill and probably beyond the capacity of the lathe
I had access to at work. Then I thought it would have to be precision ground to be any good. I was under a mortgage constraint at that time so I had all these parts sitting around without me being able to afford to
complete the project for lack of money to do it perfectly. Eventually I decided that the situation was ridiculous, so I bought a piece of 4140 steel and made the bearing housing as best I possibly could on the lathe at work.
It turned out not too bad. Sure in lots of ways its imperfect, but its not actually faulty. I've been using it for six years now.

This is an example of perfectionist thinking preventing you from making progress. I have had several bouts of that....but I'm getting better at building the 'best I can' rather than perfect. Surprise, surprise it usually turns out
pretty good. A more recent example is my trunnion table and fifth axis. Is it perfect?; ie rigid enough not to compromise the machine.......well no, it is not, but neither is it too bad. If I wanted perfect I'd be waiting for years and still not
be able to afford what I wanted....but instead I designed and built the best I could with parts and materials I could afford, if barely, still something like $5000NZD. Useable equipment, albeit imperfect, is still better than no equipment.

Craig

[GeckoSub]

Deposit Made
Thanks so much for the well wishes and continued support despite the sudden turn

My girlfriend who hails from the "Factory of The World" has been instrumental in this whole endeavor and we just put down a small deposit on the fixed gantry granite machine. I can personally order from the more established new goods shops via google translate or sometimes in English but no way, I could have communicated with (m)any of the sellers on the secondhand platform. I am lucky in that she likes the haggling part and I feel like I have been pretty good at vetting the potential deals, so we haven't actually had to communicate much with many sellers before committing.

The seller will start taking it apart tomorrow and once done, ship it to the freight forwarder in a wooden box. Basically, I am getting everything in the pic below except for the base stand and the enclosure.
The wooden box will cost USD 10 and we were told, it would be made "to order by the guy next door", so I will play Big Boss Spender and ask them to make an even sturdier one for a bit more cash - I think that's within the budget and a wise upgrade



Then once the gantry and motion parts arrive here, in 4-6 weeks, I will take some careful measurements, adjust my custom base design accordingly and send that file off to be made in granite. I have an affordable quote on that already. And then another 4-6 weeks wait until the base would be delivered and it will be all about assembly and squaring it all back up.

In the meantime:
- Keep mocking up the base in Fusion
- Buy more stuff. Though, all of a sudden, I don't need much in terms of mechanical motion parts but I do need couplings. And I can start shopping for all the electrical parts I still need and an enclosure
- Think of a stand for this thing. Might have one fabbed here or buy a used PLC table from China as they are sturdy and come in sizes that would be a good match - and some of them have electrical cabinets built in already
- Commit to a controller and software and order. LinuxCNC is slowly back on the table, but it will be between that and UCCNC
- Oh, since I mentioned "squaring" - I do have a granite straight edge and square in the shopping cart. I'll get those ordered. And I will need a Noga style arm and a dial test indicator, too.

I think that's it for now. Feels surprisingly nice swallowing some pride in exchange for actually making a decision on an easier approach

[catahoula]

This is an example of perfectionist thinking preventing you from making progress.

It's a lifelong struggle, isn't it


Nice move, gecko, hope you're making chips soon

[GeckoSub]

Deal Off...


So... turns out the dealer was either over confident or more likely, he set out to run a sort of "lazy scam" on me the whole time.

We had a clear deal where he was supposed to separate the machine from the +500kg base and ship me just the gantry and the motion hardware. I'd still pay for the whole machine as the base is worthless on its own.
He was all:
"No problem, we do this all the time, trust me".
We handed over the USD 150 deposit.

And today, it was:
"Oh, I can't get it disassembled. Why don't you just take the whole thing, boss?".
I politely reminded him that taking it apart was the very premise of the deal and that I was disappointed that he couldn't do it but to please just transfer the deposit back. Which he didn't want to.
So, we stepped it up, gradually - stressfully - to me saying I would devote all the time it would take to get him booted off the used platform. That did get him to offer a partial refund saying he had put hours into trying (utter BS).
At that point, I guess I could have cut my losses, but by then it was about principle.
So... I got in touch with a Chinese spearfishing friend who just so happens to be a police lawyer. She gave him a call... And then soon after the full deposit was returned. No threats, I am sure. Probably just that way, bright people with authority can explain to you when you are wrong. She might even made him think he was doing us a favor... The settlement was that I wouldn't complain about him - which of course hurts the Scandinavian in me. I wanted my money and I wanted to complain, haha.

I now realize, his plan was "only" a scam to be lazy; he would have sent me the whole machine, I am sure of it, but he never wanted to take it apart. I know because he sent a video pointing to some tiny screw inserts at the top of the gantry saying that those couldn't be turned so the stand couldn't come off. Also, not a single other screw had been loosened, no other hardware taken off. And once again told me he could just put the whole machine on a truck bed. This kinda ties in with what he said when I first asked if it was possible to disassemble it and he said if I came to the salvage yard, I could do it myself.

Anyhow, was this fight worth the hours of back and forth and swearing and not getting other stuff done? Nah, not in terms of stress and money. But hey, it really pisses me off when people don't just play it honest from the get go. So, yeah, it was worth it.

Oh, I do need to say that in ten years of living in China and literally buying 1000s of items online, I never once got scammed. Not once. I had vendors accidentally ship me the wrong stuff but it was always corrected at no loss to me.

Anyhow, I do feel bummed about losing this deal. It was a time, headache and money saver. Even now, I think about if I could have taken the whole machine as today's videos also showed the gantry legs being even beefier than I thought. But it would be a huge hassle, shipping it, dealing with it here. And he wouldn't have crated it up, either.

Well, back to the drawing board...

[joeavaerage]

Hi,
bugger!....that looked like a good deal to get you underway.

Oh, I do need to say that in ten years of living in China and literally buying 1000s of items online, I never once got scammed. Not once.

I've not bought thousands of items, but certainly dozens, and my experience is exactly as your is, never been ripped once. I will say I am fairly cautious, others might even call it
skeptical, about how an item is presented and claims made about it. I have come to the conclusion that Chinese suppliers of engineering products are no more interested in
scamming a customer than anyone else. What is true is that should a deal go sour that I have no leverage at all. If there is a complaint about Chinese suppliers is that they can and often
do leave a customer high and dry, but they are no worse at that than any other nationality....even Australians.

Do not be discouraged. Eventually you'll get a machine, be it one you built yourself from scratch or whether you have bought an existing machine or part thereof. If it is a good machine
you will use it time and again for many years even decades to come. The only question is 'Is it a good machine?' That will take time and patience to findf. Any time and effort you put
into getting a 'good machine' will be repaid many many times over.

Craig

PS: I don't really dislike Autralians, it is a Kiwi tradition to give them hell. We used to chop them up and bury them in the garden as fertiliser....until the authorities got squeamish
about it. Say what you like about the Aussies but 'Aussie Fert' sure does grow the best spuds!

[Cadlach]

Hello i have mazak qtn250 M
I looking order
Please contakt [email protected]

[GeckoSub]

Hi,
bugger!....that looked like a good deal to get you underway.



I've not bought thousands of items, but certainly dozens, and my experience is exactly as your is, never been ripped once. I will say I am fairly cautious, others might even call it
skeptical, about how an item is presented and claims made about it. I have come to the conclusion that Chinese suppliers of engineering products are no more interested in
scamming a customer than anyone else. What is true is that should a deal go sour that I have no leverage at all. If there is a complaint about Chinese suppliers is that they can and often
do leave a customer high and dry, but they are no worse at that than any other nationality....even Australians.

Do not be discouraged. Eventually you'll get a machine, be it one you built yourself from scratch or whether you have bought an existing machine or part thereof. If it is a good machine
you will use it time and again for many years even decades to come. The only question is 'Is it a good machine?' That will take time and patience to findf. Any time and effort you put
into getting a 'good machine' will be repaid many many times over.

Craig

PS: I don't really dislike Autralians, it is a Kiwi tradition to give them hell. We used to chop them up and bury them in the garden as fertiliser....until the authorities got squeamish
about it. Say what you like about the Aussies but 'Aussie Fert' sure does grow the best spuds!

Yep, it was literally only 400 bucks for what you saw on those pics. So, yeah, it hurts. Had I had any way to take the whole machine, I would have.
Well...

Maybe after all my first machine will be my own design, haha.
Plan now is to work away at design but get V1 done. Maybe not with perfect, perfect Z design. But make travels long enough in Y that it can make new Z-assembly parts for itself down the road if need be. Actually, it's already very close to being long enough (400mm). Reason being, I can easily stiffen up the base and gantry by speccing thicker walls but the Z will likely be the weaker spot. But I can I can get started with a simpler Z-assembly to get me going. Unless, I figure out a stiffer design faster than I think I will right now.

And then keep an eye out for other deals which I CAD away.

Anyways, I'm off to the beach for a few days. Mate's 40th coming up.

[catahoula]

Yep, it was literally only 400 bucks for what you saw on those pics. So, yeah, it hurts. Had I had any way to take the whole machine, I would have.
Well...

Maybe after all my first machine will be my own design, haha.
Plan now is to work away at design but get V1 done. Maybe not with perfect, perfect Z design. But make travels long enough in Y that it can make new Z-assembly parts for itself down the road if need be. Actually, it's already very close to being long enough (400mm). Reason being, I can easily stiffen up the base and gantry by speccing thicker walls but the Z will likely be the weaker spot. But I can I can get started with a simpler Z-assembly to get me going. Unless, I figure out a stiffer design faster than I think I will right now.

And then keep an eye out for other deals which I CAD away.

Anyways, I'm off to the beach for a few days. Mate's 40th coming up.

What was the shipping charge? Could it really be more than the cost of a custom granite base and the shipping of that? I thought you had decided to buy the whole machine

[GeckoSub]

What was the shipping charge? Could it really be more than the cost of a custom granite base and the shipping of that? I thought you had decided to buy the whole machine

Shipping would have been affordable - especially if he had taken it apart as he agreed to do. The cost of that wasn't the issue, the sheer bulk of the machine was. I don't have a way to deal with a 600kg machine here. I don't have a truck, I don't have an engine lift/crane, not even sure if the local shipping agent here does - the seem to offload everything by hand...
It transpired, that the seller wanted only to lift it onto a flatbed truck and send it on its way. That's clear to me now. Even IF I was ok with that, it would have freaked me out not to have it crated up. I have no idea about how well the freight forwarder would have handled it, how secure it would be standing inside a container on the ocean for weeks. And the issue would still have been how to handle it once it arrived.

The deal I made with the seller was clear, take the machine apart, send me the granite gantry, table and motion hardware. After taking my deposit, he decided he couldn't be bothered to do that despite agreeing to it. Hence why the deal didn't happen.

Maybe if I spent a long time calling in favors, I could figure a way to get it out of the island warehouse where it would end up and take it apart myself. But there wasn't time to do that.

All that said, of course, I have been racking my brain. Maybe I could have shipped it to someone in China who could have pulled it apart for me since the seller gave up after one look - or never really wanted to.

[joeavaerage]

Hi,
I have a granite surface plate 900mm x 600mm x 100mm and it weighs about 150kg. I would presume that if you want a granite machine base you'd need 150mm thickness, maybe more,
even if the base is about the same size. How were you planning to handle the machine base weighing 200kg or more?

Craig

[GeckoSub]

Parts Coming In
I got slammed with some other work so not much traction on the base and tomorrow I am leaving for a three week trip to Indonesia during Chinese New Year. I was really hoping to have the base ordered right about now so it would be on its way once my trip was over. But it wasn't to be.

That's alright.

At least parts are beginning to come in:


As you may remember, I jumped the gun a bit early on the first VFD and then ended up buying a spindle that needed higher frequencies. Hence, why you see two. It's ok, the "low speed" one was cheap as.
The servos are all 400w and I got one with a brake for the Z.

I was surprised how beefy and heavy that spindle is. But then again, it's the first time I have actually handled one.

Besides that, not much to say - from just looking at the VFDs and servos and drives, they all look cosmetically great - though the regular frequency VFD the high speed one and all the servo drives look super clean.

No pics, but the servos seem to have come with most of the cables, might need to splice a bit but time will tell.
Also, I got the 3rd party servo drive programmer cable, some chunky spindle cables, one EFI (will order some more) and I have signal cables come in the next shipment.

I have also found a guy on my island that besides having a vacant workshop slot next to him also has a big CNC for plywood. He is super geeky in the best sense of the word and when I told him I was considering LinuxCNC for the controller but was afraid of the learning curve and setting it up he said:
"Go for it, I will help you!".
So, that's one on the plus side for Linux...

[GeckoSub]

Simple Testing and A Good Find On Readymade Control Cables (?)
Just back from a half work/half leisure trip to Indonesia - guiding a group of Chinese spearfishing freedivers.
Good fun but need to get back on this train.

Sadly, I blew quite a lot of money on other stuff so can't make any big purchases for about a month until the next assignment money come in.

Anyhow, yesterday I hooked up three of the four servos to one of the drives just to see that they spin in jog mode and they all did - one was ever so slightly noisy, though. Why did I only check three and not all four? Well, I need a 24V power supply before I can disengage the brake on the fourth servo but I just ordered one and it should be here in a few days.
I will also check the remaining three drives and sets of cables - just to check that none of them are DOA. Keep in mind, all these were bought used. Happy I got the motor cables, though.

Speaking of cables, in regards to the CN1 control cables from the controller to the servo drives, I have no idea how many signal wires are actually needed on that 44pin connector. I guess at least four. But I also see something about feeding 24V to the controller, not sure why though, so maybe at least six? And then there are various ins and outs that might be worth having at some point in the future.

Four of those 44pin connectors were actually shipped with the drives but the cables were snipped off right at the connector by the salvager so can't be used. Interestingly, two of them have six wires and the other two have ten wires.
I am not half bad at soldering so thought about buying some good signal cable with enough wires in it to be future proof and making my own cables out of those four connectors. But again, no idea how many wires I'd need. But I did find a post by someone who has about seven ins and outs on top of the basic four. And a few of his made sense for me, too. An alarm out, and perhaps I need the brake signal, too to engage/disengage the Z-brake via the controller (not sure how this works, yet). He also has an alarm reset which sounds worthwhile and also has e-stop go to each of his drives, too which may be overkill for me. Oh, also Z-pulse if I end up with Linux and want to give homing to Z-pulse a go.

Anyhow, long story short. Instead of having to add signal wires as the need comes up in the future I found that you can buy ready made "breakout cables" for USD 5 each. They are shielded so I think I will spend the 25 bucks getting five of these and call it done with:

[pippin88]

Buy the ready made cables!

Usually:
Step pulse, ideally differential, therefore 2 wires
Direction pulse, ideally differential, therefore 2 wires
24v or 0v (depending on preference/wiring) common for inputs and outputs
Estop signal into an input - estop should ideally physically cut motor power input, but drive can actually actively stop motor (when told to do so) faster than cutting the drive motor power input will (large capacitors in the drive)
You can also feed in limit switches