New Machine Build- Started but not finished

[hemsworthlad]

Hello Everybody, This is my first build and first post on cnczone so here go`s.
Although i,ve started and are well along the way i,m still far from finished as the following pics will show.
This obsession/desease first got hold by a chance stumble across a video on youtube of a homemade cnc router, which caused the fatal reaction. . . "I could make that". . . now I managed to resist the urge`s for a while untill one day a friend offered me a 3.6mtr (141") Aluminium extrusion and that was IT. . . . The day i became infected.!!
So I spent meny months lurking around cnczone and other places, watching and learning, planning and trying to work out the best design around this for my needs.
I also spent hundreds of hours designing cad drawings for my machine, I drew just about every combination of design and style there probably has ever been made all based around this extrusion i,d been given.
The choices were mind blowing. . . 1st Size. . . 2nd Material: wood, metal, plastic, paper(mdf). . . .3th Drive: screws, rack, belt. . . . 4th Power: servo, stepper or elastic band etc. . .the choices and variables were endless.
Well after months of this it started to cloud my mind and vision which ultimatley made me frustrated. . . . . . So the only thing to do was get stuck in!!
This is what i finally settled upon:
Style: Moving gantry
Size 1500 x 1300mm( 59"x 51")
Material: steel/alu
Drive: 5mm pitch ballscrews
Power: Steppers
Motion: Profiled linear rails
I say finally because although the size and material where desided easlly the drive and power where not and orginally it was going to be belt driven, mainly due to cost and ease of availabilty.
Then it changed to rack n pinion because i found a cheap source. . . . . But from the beginning i pritty much knew that really i wanted ballscrews, but they were out of my price range so it was looking like R&P was going to be the best i could afford.. . . . . Then i found a cheap source of ballscrews on ebay (linearmotionbearings) so that decided it ballscrews it was.
So the build began and i will show you where i,m upto so far, ask any Qs you want and give any critism you feel all welcome.
Cheers
Dean
(pics will follow)

[hemsworthlad]

The cause of all the trouble!!

[hemsworthlad]

The frame work made from 2x2 box section with a adjustable bed.
The reason for adjustable bed is so i can keep Zaxis as short as possible because i would like to cut some alu parts from time to time also gives a bit more flexability for large objects.
The intention is not for it to be moved often, just as and when required and only if absolutley neccesary due to setup time and trouble of trueing of bed each time.
Maybe more trouble than it,s worth.? . . but if you dont try you never know!!

[FandZ]

Wow, that's going to be one sturdy machine. I like the idea of having the adjustable table and I like how you have those cross support beams. Looking good.

[hemsworthlad]

The gantry is made from a piece of the aluminium extrusion which came of a stair lift, very strong and very light, with more 30/60 extrusion inserted in the top channel for the linear rails to fasten onto.
The endplates and braces are made from 16mm alu and are bolted to more alu extrusion inserted and bolted to the gantry extrusion which in turn along with the braces bolts onto more 30/60 thats bolts onto the rail carrages.

The braces and endplates were cut on a friends mill and mdf templates were made first which helped greatly with checking clearences etc before the final alu parts were cut.
If you look you can see that the shape of the end plate templates are differant to the final parts, they caught the ballscrew end mounts so needed shapeing to miss, also the motor mount was made a separate piece to allow for adjustment and to save some money because it could be madeout of a smaller piece of alu that i already had so didnt need to buy another.

[Hdale85]

Wow, that's looking fantastic! Would love to know why kind of tolerances you get with this machine as I was just thinking about how good a steel framed machine would be with an aluminum gantry.

[hemsworthlad]

Erm. . not a lot to say just a standard Zaxis 190mm travel 4mm pitch with a class 1 ballscrew 3.5Nm Nema 34 stepper.
I have a 2.2kw water cooled spindle to go on this and i,m just waiting for a bracket to arrrive from David da costa which should arrive any day soon.

[Mr.Chips]

You have one solid looking machine going there, and I like the fact that the X and Y axis are very clost together, this will make it even sturdier.

I am building a machine along the same lines as far as the X-Y areas are concerned.

Hager

[hemsworthlad]

Originally Posted by Hdale85 Wow, that's looking fantastic! Would love to know why kind of tolerances you get with this machine as I was just thinking about how good a steel framed machine would be with an aluminum gantry.

Thanks, I dont know what sort of tolerances i,ll be able to hold but the gantry is solid as rock and super stiff so i,m hoping for something decent. Will post when i,m up and running properly.
I do have movement of the x and y axis but i,m not fully happy with the lay out of the x axis belts turning the twin screws, still needs tweaking and refining.
Will post pics soon.

[hemsworthlad]

Originally Posted by Mr.Chips You have one solid looking machine going there, and I like the fact that the X and Y axis are very clost together, this will make it even sturdier. I am building a machine along the same lines as far as the X-Y areas are concerned. Hager

Thanks Mr chips, yes that was a very deliberate design feature. I wanted it as stubby and strong as possible to be able to mill Ali and give me as much flexability as possible.

[rlwoodjr]

Nice looking machine.

I had to laugh at the first post. Once I get into a hobby I find good deals, better designs. I always end up with a lot more parts than I need.

I have built several already but I am not finished yet...

I building a small 3 axis, then a small 5 axis, then I will build my larger 5 axis.

[hemsworthlad]

Not happy with the way I,ve got the X axis setup.
It was never my plan to have the belts setup this way.
I,ve umm'd and arr'd about which way to turn these screws from the begining, the easy route would be to just put steppers on each screw but coudnt live with the thought of racking due to missed steps.
my origanal plan was to put a stepper on 1 screw and run a belt over to the other but i couldn't get a belt that long without going to very wide and expensive belts with large pitch's, so plan B was too put the stepper in the middle with 2 shorter belts.
Again I run into belt length issues, this time couldnt get the right length. needed 1640mm and nearst sizes were 1520 or 1790 which as forced me into arranging the belts in a V shape setup with the longer belts.
Also because i,ve had to use 2 belts i had issues with the screws, the design wasn't for twin belts so the screws where machined for the belts to be inline and i couldnt move them on the frame because of the mounts on the gantry sides, so i had to machine an extension for 1 side to offset the pulley.
The way it is setup at the minute works but it's not how it's going to stay, I dont know how it's going to change but i do know that is going too change, I cant live with it they way it is!!
Probably just refine it for the minute with some idlers and guides untill i figure a better solution.
Also the motor mounts are just temparery untill i can come across some more Aluminium, it,s quite expensive stuff here in uk and not the easiest thing to get hold of in small quantitys.

I do have the y axis part connected and working but havent got any pics of it yet and theres still a lot of work to do on both axis, but i just had to see a little movement because i was starting to get stalled and a little deflated so needed a boost. . . . . . . It worked. . . . It's amazing how a little movement can give you kick up the Arse!!