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Thor, or should that be Zeus?
So previously, I built a CNC router that was, frankly, a waste of money. JazzCNC kindly referred to it as 'made from spaghetti'.
Since that time, I have bought and retrofitted my Denford VMC which I still have but will sell once Thor, or Zeus is created. I want to have a machine that can move quick, cut Alu with ease and potential a bit more too. I dont generally work with steel but Id like the option to cut some at times.
Ive been itching to do a new build for a while and pulled the trigger recently on some parts. I kinda started a thread looking at some design ideas a few months ago however I wasnt sure that the design I was showing would work. I found some bits online and am now designing around some parts that I have.
If there is one thing to achieve, is a machine a bit more rigid than spaghetti. I am hoping that when you look at the selected parts, this may be achievable.
Let's discuss design first.
Thor, fixed gantry design, the base and gantry designs are not complete, there is a lot of optimisation that can be done. I wanted to get an idea of machine size, weight and design options with the specific rails and ballscrews I have. I have also spent a lot of time reading different whitepapers on machine design and whilst I certainly dont know a lot, I understand a lot more about some of the design criteria, materials and rigidity.
Thor is a fixed gantry system. I originally wanted to do moving gantry (like the Datron machines) however I was dissuaded on this on the basis of getting good rigidity is difficult and I dont want to run two ballscrews / motors for Y. The availability of the bits I bought have also contributed to this.
https://c2.staticflickr.com/2/1524/2...6d704a95_b.jpg
Subsequent to this design, a number of concerns came up. Some of them are around how to make the structure and get the surfaces flat. I intend using either UHPC or some variant or some form of Epoxy Granite or similar.
I then spent some time over the weekend going back to a fixed head design. I watched many videos where a lot of modern machines use this tried and tested method and the design below, suitably called Zeus, was born.
https://c2.staticflickr.com/2/1701/2...e336bf78_b.jpg
Whilst I was coming up with the design, I really struggled with getting the Y table size larger than 65% of what the fixed gantry offers. The 'overhang' of the Z Axis is also concerning however I kept at it.
I then spoke to the person that has sold me all the mechanical bits (my pimp) and his advice is to go with the fixed gantry design. We discussed this at length and currently, my plan is to build Thor (top design).
So, parts.
X Rails - Bosch Rexroth 45mm rails, 1180mm long using high preload roller bearing carts.
Y Rails - as above.
Z Rails - INA 25mm rails, 346mm long (I'm trying to source 500mm rails) with roller bearing carts.
Ballscrews, well, I have a selection. For X and Y I have 6 leadscrews, all 40mm with dual preloaded ballnuts and different pitch options from 10 to 20 mm.
For Z, I have some Eisenmann screws, 32mm, 5mm Lead, dual preload ballnut.
Motorwise, I may have jumped the gun a bit but I am hoping that with all the different options of screws (all use 3080 mounting bearing) that Ill find something that works well in terms of pulley ratios.
I have gone for Panasonic Servos, A4 range. 1.5KW for Y, 750W for X and Z. All of this will be controlled with the CS Labs IP-A unit.
All in all, I am looking forward to this build. I'd love to be testing already but still very far from that.
No more spaghetti and aiming to get speeds of around 20m/min with acc rates of 5m^2.
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Re: Thor, or should that be Zeus?
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Re: Thor, or should that be Zeus?
Omg! The names seems appropriate, or maybe tankbuster! ;) will follow this!
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Re: Thor, or should that be Zeus?
Great! Now even i am surprised. I will be following with great interest. OMG :encouragement:
Charl, now i see what your are up to. Would you like to see the drawing of my Z on mine big machine? It would be very appropriate if you decide on using 3kw-5kw high speed spindle. The overhang i achieved is ridiculously low. Unfortunately still not in proper cad but Sketchup. But you could draw some ideas from it.
Or you will go the BT30 way?
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Boyan Silyavski
Great! Now even i am surprised. I will be following with great interest. OMG :encouragement:
Charl, now i see what your are up to. Would you like to see the drawing of my Z on mine big machine? It would be very appropriate if you decide on using 3kw-5kw high speed spindle. The overhang i achieved is ridiculously low. Unfortunately still not in proper cad but Sketchup. But you could draw some ideas from it.
Or you will go the BT30 way?
Hi, yes, please. Any inspiration, ideas, comments, feedback appreciated. Feel free to email to me, Ill convert it.
At the moment, I am looking at options for spindles. Current view is to either have 4KW Chinese spindle or perhaps something more expensive (if budget allows) something better.
Id love to go to BT30 but not designing around this at present.
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Re: Thor, or should that be Zeus?
Theoretically the bearing blocks should be bolted to the gantry and the rails to the bottom of the bed. If you put the blocks on the bed you introduce unnecessary overhangs and add a lot of metal supporting rails that does nothing. It should be more A frame and less triangular. OTOH, what do I know? -freaking smileys don't work-
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
Theoretically the bearing blocks should be bolted to the gantry and the rails to the bottom of the bed. If you put the blocks on the bed you introduce unnecessary overhangs and add a lot of metal supporting rails that does nothing. It should be more A frame and less triangular. OTOH, what do I know? -freaking smileys don't work-
Thanks. Point taken. This was pointed out too (off this thread) in the design. Ill make the changes.
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Re: Thor, or should that be Zeus?
Wow Chaz - excellent thread. Great to see someone putting a bit of thought in and going for it!
I would lean towards Thor, the top design, although both would do well.
In my new mk4 design I had to go with moving gantry because I still need to cut large wooden sheets, but with your brief these designs are excellent.
If the granite epoxy is too difficult to make/cast then it looks like it could be done with say 150x50mm sections all welded together. Then backfilled with epoxy granite. Weld on some flat 10mm bar where each rail will go, get it skimmed flat, and there you are.
For the spindle I wonder if you could have a bolt-on high speed spindle for aluminium (router mode), then bolt on a heavily geared down spindle for steel (mill mode). Or have both in place so you can choose.
Good luck with however you choose to develop this - watching with interest.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
routercnc
Wow Chaz - excellent thread. Great to see someone putting a bit of thought in and going for it!
I would lean towards Thor, the top design, although both would do well.
In my new mk4 design I had to go with moving gantry because I still need to cut large wooden sheets, but with your brief these designs are excellent.
If the granite epoxy is too difficult to make/cast then it looks like it could be done with say 150x50mm sections all welded together. Then backfilled with epoxy granite. Weld on some flat 10mm bar where each rail will go, get it skimmed flat, and there you are.
For the spindle I wonder if you could have a bolt-on high speed spindle for aluminium (router mode), then bolt on a heavily geared down spindle for steel (mill mode). Or have both in place so you can choose.
Good luck with however you choose to develop this - watching with interest.
Thanks. We have discussed a dual spindle setup. I might want to stick a grinding spindle in there too somehow :-)
I'm looking at rail options for the Z at present, I have some other options to consider although already spent a small fortune on the parts thus far. I will have leftovers, will likely be put into a DIY CNC Lathe.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
Theoretically the bearing blocks should be bolted to the gantry and the rails to the bottom of the bed. If you put the blocks on the bed you introduce unnecessary overhangs and add a lot of metal supporting rails that does nothing. It should be more A frame and less triangular. OTOH, what do I know? -freaking smileys don't work-
Just to confirm you are referring to swapping the rail and cart here on the Z Axis?
https://c2.staticflickr.com/2/1708/2...45d9570f_b.jpg
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Chaz
Just to confirm you are referring to swapping the rail and cart here on the Z Axis?
I was actually referring to the X. At the bottom you have two linear rails bolted to an enormous structure, most of which is superfluous, you only really need the bit under the gantry.
If you fit the linear blocks to the bit under the gantry and the rails to the table then the support will always be under the tool.
You lose an unnecessary overhang.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
I was actually referring to the X. At the bottom you have two linear rails bolted to an enormous structure, most of which is superfluous, you only really need the bit under the gantry.
If you fit the linear blocks to the bit under the gantry and the rails to the table then the support will always be under the tool.
You lose an unnecessary overhang.
Ah, ok, understood.
I'm just trying to find the reference design / document that I used. I did note that this is not final but the shape (with more support) is basically a triangle.
I am however more than happy to make changes based on experience, one of the reasons why I have started this thread.
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Re: Thor, or should that be Zeus?
The way i see it, if you go with high speed spindle, fixed gantry would be better, if you go with servo motor and Bt30, the VMC shape will be better. So at the end there is not so much to consider which shape you go.
With that size bearings and rails length, overhang will be irrelevant. You could try to make it small, just for a designers satisfaction though, but its not necessary.
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Re: Thor, or should that be Zeus?
I cannot claim any "experience" making super routers, but I have made a few tables and converted a couple of milling machines. But enough of the X, here are my thoughts on the Z.
With a knee mill you have 2 controls for the Z, you can lift the table of lower the quill. A round column mill is similarly adjustable. When you CNC it you probably motorise the quill and use the other, heavy duty adjustment, to optimise the quill travel and get maximum support on a job by job basis. You would be lost without this double control of the Z and yet nobody puts it in a home build.
I suggest you make the entire gantry moveable in the Z with some big bolts so you can lock it in the optimum position. I do have expertise in this because when the locking bolts went on my mill everything went to hell in a hand basket PDQ :disillusionment:
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Re: Thor, or should that be Zeus?
That's quite a neat idea there Robin, have never seen that applied yet.
I guess it depends on the intended use of the monster mill, spindle power and speed could dictate smaller (<10mm) cutters which would then indicate that smaller workpieces would be used - no use tickling a 300kg lump with a 3mm end mill I think.
That being said, a dual position gantry maybe offering the tool a 0 - 150mm and 150 - 300mm range could be useful, would need an assisted method of raising/lowering the gantry though - two trapezoidal leadscrews might work along with some heavy clamping method when in position.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
I was actually referring to the X. At the bottom you have two linear rails bolted to an enormous structure, most of which is superfluous, you only really need the bit under the gantry.
If you fit the linear blocks to the bit under the gantry and the rails to the table then the support will always be under the tool.
You lose an unnecessary overhang.
This is the document I was referring to.
http://www.mech.utah.edu/~bamberg/re...e%20Design.pdf
Page 176 onwards discusses Gantry designs. Mine was going to be a copy of their reference design. I agree, it looks wrong, however there is good data in this whitepaper .... did I misunderstand something?
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Re: Thor, or should that be Zeus?
Don't let me stop you, we are all agog at that amazing pile of linear slides and waiting to see what you can make with them. Perhaps not Thor or Zeus, maybe Croesus :friendly_wink:
Lots of pictures please :beer:
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
Don't let me stop you, we are all agog at that amazing pile of linear slides and waiting to see what you can make with them. Perhaps not Thor or Zeus, maybe Croesus :friendly_wink:
Lots of pictures please :beer:
Thanks. I am keen to ensure I dont waste what I have so open to all discussions around the design. If you have a few mins, please read the few pages in that whitepaper .... would love to know your (and others') feedback on the design. Originally, it started with an 'A' frame design. I changed it to suit the whitepaper design.
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Re: Thor, or should that be Zeus?
I don't think I should comment on that white paper, it would be most unfair because I am an opinionated old git. Quite happy to comment on your design though, if you want me to :beer:
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
I don't think I should comment on that white paper, it would be most unfair because I am an opinionated old git. Quite happy to comment on your design though, if you want me to :beer:
You are free to do both.
Ive learnt, with age comes experience, so you are more than welcome to comment. If I didnt want comments, I wouldnt have started the thread.
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Re: Thor, or should that be Zeus?
Guys, what grade of steel should I look at for components that will be machined and used for the Z plates etc? My German friend providing the parts does not know the UK equivalent but in Germany its called 'Automation Steel' Supposedly its easy to machine and works well for this.
I assume its something like 4140 but I'm not sure.
This will be for machining the bearing holders and any plates for the Axis as well as any ribbing that might be used to reinforce the structure.
Any thoughts?
Thanks
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Re: Thor, or should that be Zeus?
Steel? Mild cold rolled steel plate or plain hot rolled iron plate. Using carbon steel is nonsense, except if you want to ring lie a bell later.
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Re: Thor, or should that be Zeus?
More interesting is the table/bed. Are you going to make it or buy it? You might start a permanent search on ebay and see what it trawls up while you are figuring the rest out. The bed from a toolroom mill could be neat.
How about suds, you must have suds to get the heat out of the tool tip, lube it when cutting steel, block the oxide build up when cutting aluminium, stop the melt when cutting perspex and generally wash the cuttings away before they get dragged back in between tool and work piece.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
More interesting is the table/bed. Are you going to make it or buy it? You might start a permanent search on ebay and see what it trawls up while you are figuring the rest out. The bed from a toolroom mill could be neat.
How about suds, you must have suds to get the heat out of the tool tip, lube it when cutting steel, block the oxide build up when cutting aluminium, stop the melt when cutting perspex and generally wash the cuttings away before they get dragged back in between tool and work piece.
I am looking on ebay regularly but I may try and machine something from cast iron.
In terms of cooling, different options, will look at a misting type setup and potentially higher pressure flood coolant.
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Re: Thor, or should that be Zeus?
From what I've been reading on coolant, the 'FogBuster' style of air blast and minimal coolant/lubricant is the way forward. Seems to work well on the youtube videos, very easy to make as well.
I'm collecting the parts for one only mini-mill.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Davek0974
From what I've been reading on coolant, the 'FogBuster' style of air blast and minimal coolant/lubricant is the way forward.
Some things are popular because when the machine is finished desperate work rounds are required for all the things that were never thought of, put of for another day or simply forgotten in the excitement of near completion.
This may or may not be one of those things.
I always want a good flow of suds. I like a variable speed pump so I can adjust the flow. You can filter most of the guck out but some will get through making flow control with a tap tricky.
Suds requires side curtains to catch the spray and two nozzles are better than one because clamps, fittings and stuff can so easily get in the way. I return suds to the tank using Koi carp filtration bags. A good long nozzle on the air duster keeps the pipework clear.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Davek0974
From what I've been reading on coolant, the 'FogBuster' style of air blast and minimal coolant/lubricant is the way forward. Seems to work well on the youtube videos, very easy to make as well.
Only if you want to breath that shit in all day
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
John S
Only if you want to breath that shit in all day
That was my main concern as well, but the fog buster style units are more of a air-blast with a splattering of fluid - no mist or fog (hence the name) looking at them work they do seem to function well, at least on aluminium which is my main target.
I was going for flood (love the smell of suds) but it gets messy, you have, grows germs if not maintained, and i'm still not convinced a mini-mill needs that much when so many seem very happy with air-blast and the odd drip of lube.
I think my build will cater for all options so i'm still open to changes.
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Re: Thor, or should that be Zeus?
There are also people standing over their machines with a can of WD40 who swear it is the greatest thing since sliced bread :hysterical:
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Re: Thor, or should that be Zeus?
Yes, one of them is me :)
I've used three cans so far making the parts on my bridgeport, works perfectly and easy to apply on manual mill.
I have also seen systems filled WD or paraffin on aluminium.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Robin Hewitt
There are also people standing over their machines with a can of WD40 who swear it is the greatest thing since sliced bread :hysterical:
Why would you laugh at something that works perfectly well and with minimal mess.?
Same goes for Odourless mist there's a Clue in the Name "Odour LESS" true while not exactly odour less it certainly isn't unpleasant and gives perfect results with hardly any mess. Unlike conventional Mist system which I think John is refering which choke you to death.
Flood is only any good if it's got plenty of flow and can wash away the chips which isn't easy in deep narrow slots without high rate of flood. Then it gets messy quickly.!!
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Re: Thor, or should that be Zeus?
Exactly, even with manual WD squirt, it only needs applying every few inches or more, just enough to keep the cutter flutes wet i guess.
Whats the best thing to put in a mistless system though??
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Re: Thor, or should that be Zeus?
Just for fun, here's the safety data sheet :acne:
http://www.wd40.co.uk/Files/WD40%20M...07-2015_EN.pdf
Curiously drying out of the HT circuits when your car won't start is no longer one of it's uses.
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Re: Thor, or should that be Zeus?
Have updated the design somewhat taking numerous feedback into consideration. Lots more to do before I start to make castings. I bought a lathe today, oldish Boxford Model A, should help with some round stuff I need for this build.
https://c2.staticflickr.com/2/1446/2...b2a19d20_b.jpghttps://c2.staticflickr.com/2/1494/2...c9c3df0e_b.jpg
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Re: Thor, or should that be Zeus?
Guys,
Where can I buy cold rolled mild steel plate. I need pieces of metal of around 150mm x 150mm x 80mm (QTY 3). I dont really want to buy a full plate at 80mm size, struggling to find anywhere that will supply in small volume. Alu plate, easily source in this size, but not for mild steel.
Thanks
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Re: Thor, or should that be Zeus?
Just a quick question - Why so much mass in this design? Looking at the likes of production mills like Tormach etc, there is nowhere near as much mass in them and they are proven designs.
I like the ideas but over designing is surely as bad as under designing something ??
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Davek0974
Just a quick question - Why so much mass in this design? Looking at the likes of production mills like Tormach etc, there is nowhere near as much mass in them and they are proven designs.
I like the ideas but over designing is surely as bad as under designing something ??
The idea is to allow for absorption of vibration etc. The hollows in the base structures improve strength and keep the weight bit more palatable. I need to check what the final weight estimate will be, I have had some issues with the files in Fusion, so redrawing some of the machine.
The idea here too is that this machine could be running a lot quicker (velocity and acceleration) than a Tormach. Considering the cost of a Tormach (ignore shipment / import duties, just the raw buy price), Thor should be a better machine.
The Tormach 1100 specs are below:-
Feed Rate: |
110 IPM (X,Y)
90 IPM (Z) |
110 IPM is 2800 mm/min. I am aiming for upwards of 10 000mm/min at least. The rails, ballscrews and motors that I am using cost more than the entire Tormach machine if I paid full new price (which I did not). This is before adding the controller, electronics, structure costs, spindle etc.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Davek0974
Just a quick question - Why so much mass in this design? Looking at the likes of production mills like Tormach etc, there is nowhere near as much mass in them and they are proven designs.
I like the ideas but over designing is surely as bad as under designing something ??
More mass=Less vibration=Perfect finish /while using perfect tools, perfect toolpaths, etc./
The big traps here being:
more mass=more mistakes during design=more money spend=same result or better with less mass
or
all perfect, but cheap tools, not adequately changing tools where needed, bad programming, so result is mediocre
Clearly if not for the sake of perfection itself, perfect finish, hard materials mostly or a production machine, there is no point going this way. I can not speak for him, but i made mine machine as it is OTT for 3 reasons:
-will machine mainly aluminum
-will machine long pieces like gantries of smaller machines, etc.
-the extra effort was not so expensive looking at the total of it and will pay off on first big job
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Chaz
The idea is to allow for absorption of vibration etc. The hollows in the base structures improve strength and keep the weight bit more palatable. I need to check what the final weight estimate will be, I have had some issues with the files in Fusion, so redrawing some of the machine.
The idea here too is that this machine could be running a lot quicker (velocity and acceleration) than a Tormach. Considering the cost of a Tormach (ignore shipment / import duties, just the raw buy price), Thor should be a better machine.
The Tormach 1100 specs are below:-
Feed Rate: |
110 IPM (X,Y)
90 IPM (Z) |
110 IPM is 2800 mm/min. I am aiming for upwards of 10 000mm/min at least. The rails, ballscrews and motors that I am using cost more than the entire Tormach machine if I paid full new price (which I did not). This is before adding the controller, electronics, structure costs, spindle etc.
Interesting, thanks.
I was only using Torch as an example really but those feed specs are interesting, any idea of the spindle HP rating? It's obviously designed for normal mill usage - bigger tooling, more cut depth, more radial cut depth so I guess 2800mm/min would be in that area.
I guess you will be running fairly high power motors to gain decent acceleration in small distances or it may never reach your high feeds??
Following your build with interest.
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Re: Thor, or should that be Zeus?
Quote:
Originally Posted by
Boyan Silyavski
More mass=Less vibration=Perfect finish /while using perfect tools, perfect toolpaths, etc./
The big traps here being:
more mass=more mistakes during design=more money spend=same result or better with less mass
or
all perfect, but cheap tools, not adequately changing tools where needed, bad programming, so result is mediocre
Clearly if not for the sake of perfection itself, perfect finish, hard materials mostly or a production machine, there is no point going this way. I can not speak for him, but i made mine machine as it is OTT for 3 reasons:
-will machine mainly aluminum
-will machine long pieces like gantries of smaller machines, etc.
-the extra effort was not so expensive looking at the total of it and will pay off on first big job
Yes, I can grasp the mass effect but surely there is a slope of diminishing gains here - it may work perfectly with a mass of say 1000kg but work no better with a mass of say 5000kg??
The sweet spot is getting the balance right;)