Router Build number 2

**charlieuk** · 28-03-2017

what is your definition of strong dean? steel with servos???? like the vertical machine you posted a picture of ???

which design would be better to go for if built strong??

I will happily build it however just not sure at the moment at what level it needs to be at.

many thanks

**JAZZCNC** · 28-03-2017

Originally Posted by charlieuk

what is your definition of strong dean? steel with servos???? like the vertical machine you posted a picture of ???

which design would be better to go for if built strong??

I will happily build it however just not sure at the moment at what level it needs to be at.

many thanks

The materials it's built from are important but far more important is the design. The vertical machine I've shown isn't design I'd suggest for high quality cutting of Aluminium. It's designed for cutting woods and sign material which it is more than strong enough to do without being over built as to rob it of acceleration/speed.

The problem you have is that to cut woods correctly requires higher feed rates. To produce high quality finish in aluminium required for moulds requires very ridged design and this by it's nature means having to be built from dense often heavy materials. It also needs certain amount of speed/acceleration for 3D surfaces moulds use. This weight conflicts with high feeds unless the rest of the components match up and this unfortunatly means taking the servo route and everything that goes with it.

This dilemma then gets componded by size. Small/Med machines are managable but when you get into 8x4 or even 4x4 it up's the game to another level.
If you want high quality finish in aluminium then you really really need to look long hard at design and what components your going to put with it. Any weak area will be magnified when it comes to surface finish in aluminium.

**charlieuk** · 28-03-2017

ok so sounding like the thing to do for now is to scrap the idea of being able to feed a full sheet of ply through and just focus on the aluminium thing and try and make it as compact as possible while keeping a 650 x 1270 table area Then to dream about a 3rd 8 x 4 machine in the distant future.

Any pictures of a 'strong' 600 x 900 size machine I should be using for inspiration?

**Boyan Silyavski** · 29-03-2017

Originally Posted by charlieuk

Any pictures of a 'strong' 600 x 900 size machine I should be using for inspiration?

My first build from signature, that i did for a friend. Free plans in Sketchup are somewhere in the build. if you are not happy with gantry you could do that from alulminum L shaped or box shaped, though i dont see a reason. that machine is 400x1000x180 but you can widen it without changing anything. all else stay same. It can support up to 5-7kw spindle without any problem. but put a 2.2kw or 3kw spindle there and you have it.

I dont know what exactly you are looking at, Charlie? Why the indecision? The above said is easy to do and i could send you the plans for free if you dont find them in the thread. I could send you for free also the plans of my second machine, but you have to shorten it yourself for half sheet and figure how to put it together, cause i simply dont have a time to support that plans on every step of the way. Each of them will result in a machine that is tested, proven and without any weak spots

As Dean said my designs could not be the greatest innovations, but both machines a build, tested and have no faults.

PS. I have not cut aluminum lately but here is a short video i made once. 6mm bit, full depth i believe at ~2000mm/min. Perfect cut and perfect mirror like finish, though can not be well seen on video. listen to the sound of the machine, then go youtube and compare. Did i say Z fully extended...

**charlieuk** · 08-05-2017

Right well I have finally moved back to the uk, I thought it was best to wait until I was back so I could have a bit of time to re asses, think and deside what I had room for and also take a look at the steel that I was given. It is 100x100 x5mm wall so a little heavier than what people have said so hope that is ok and I have nearly 20m in total so should be plenty there although was thinking of making the legs of something a little lighter weigh?

I have decided on a work area that will allow a max 1220 x 600 to be cut but with the focus on aluminium and forget full sheets for the moment.

I don't really want to do the hole epoxy level thing so will need to figure the best place to build the adjustment in to the axis's

If it is easier and up for the job I will use aluminium extrushion for the gantry.

So back to the drawing board and to start planing how to do the frame.

**Neale** · 08-05-2017

Originally Posted by charlieuk

I have decided on a work area that will allow a max 1220 x 600 to be cut but with the focus on aluminium and forget full sheets for the moment.

I don't really want to do the hole epoxy level thing so will need to figure the best place to build the adjustment in to the axis's

My machine uses 100x50x3 steel box for the long X rails supports, giving around 1550mm travel so not that different to your plan. I also added steel strip inside to give me something to drill and tap for rail hold-down bolts, which is why I could manage with 3mm. However, my rails dip around 1.5mm in the centre. I don't know if the steel was bent to start with, or if it's welding distortion, or something else. The moral is, though, that unless you can really measure and control the materials and the build methods, you have to allow some way to correct the inevitable errors that creep in. I ended up using a mixture of epoxy and shimming, but I'm not saying that that's the best method, just one that worked in this case. Good luck with the build, and don't take anything (like steel box section being straight!) for granted...

**charlieuk** · 08-05-2017

once I have selected the best lengths to use my plan was depending how much they are out to get two of the faces machined flat or if to far out weld a strip to the top and get that machined instead.

I'm thinking doing the same raised rail design but then have flat plates on the verticals to bolt the long rails to so I can shim them or what ever is needed.

**charlieuk** · 08-05-2017

Quick question.. If I build a square frame for the bed is it better to cut the corners at 45deg and then weld them like that or just butt joint them. I'm thinking if I do it at 45 there less likely to distort and I will get a tighter joint. I will be tig welding rather than mig.

**Nickhofen** · 09-05-2017

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That video, showing the machine cutting aluminum like that is very impressive I must say!

**charlieuk** · 10-05-2017

just trying to get the basics down see what you think.

the frame is the 100 x 100 x 5 steel tube i was given

I have the two top rails mounted on plates on top of the short verticals to allow for shimming. I will see get the top rails machined flat before so and maybe one with a straight edge down it for the linear rail to butt up to.

I need to obviously put some diagonals in somewhere I guess

at the moment I have the 3 cross members at 50 x 50 x 4mm with 330mm centers ?