Well I've been told to start a build log for a Cheap n Easy CNC with cutting area of 900mm x 900mm.
As I would like to turn this into a kit a some point I'll stick up what Ii can for criticism.
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Well I've been told to start a build log for a Cheap n Easy CNC with cutting area of 900mm x 900mm.
As I would like to turn this into a kit a some point I'll stick up what Ii can for criticism.
No hard feelings fella, it was a little blunt . I'd love to know what the problem you see me encountering. as i may be able to pre plan away the issue before it arises.
I've just been giving the DL on past posts which makes everything clear now.
I'm not planning on disapearing but to produce. hopefully i'll have something to show you sketch wise shortly.
Attachment 20178
Real Crap Basic idea of what i'm looking to do.
In regards to general shape and approx motor placements, bearing guides etc.
Don't worry about the criticism. Of course start building one. It is great fun, and you learn a lot. I started off with the same ambitions also, building a cheap one, which in theory is easy.
I started with buying an infamous blue card + three NEM23 motors and a PSU and a DC spindle motor. I bought that blue card because I knew I could make it work (I am an electronics engineer by trade), if it is really as crappy as it's rumour says. After cutting a few meters of aluminium profiles, drilling some holes and bolting all together I realized that it is going to be too weak... and my project stalled because I was not sure I wanted to pay what it costs to buy better material, mainly because I was a bit unsure about being able to finish it.
...then one day I decided to continue, bought better material, and after a few months managed to finish a working version one. It was not something to write home about, but it worked and it proved my own abilities. Used "curtain rods" i.e. unsupported rods as linear slide, used M12 stainless steel screw rods and made my own nut to get zero backlash. I knew it's weaknesses already when I decided to make it, but I accepted them because I just wanted to know if I can make it work.
I realized that it was great fun both to use and to make the CNC, so I continued, decided to upgrade and basically converted the whole machine. New electronics, new spindle, new linear rails, ball screws, PSU as well as a considerably more rigid frame. So, basically now I am on my version three and now I am happy with it. It is not a beauty, but it does what I intend to use it for and it does it very well.
Costs? Well, I stopped counting a long time ago. It's a hobby, so costs doesn't matter as long as it is not tearing on the family economy. Never the less, it did definitely cost more than £1800 so far, I am very sure of that.
BTW, mine is a fixed gantry type, the table moves in Y direction and the Z slides across the table in X direction. I chose this type of design because it gives better rigidity and is easier to build a high quality machine this way.
Thanks for the kind words!
My end goal is to have a vertical sheet sized machine (not any time soon)
I'm prototyping with ply (had plenty) but have seen them seemingly made from MDF and sold?
So i'm aiming for some sort of inner repeating pattern to establish rigidity without excess weight.
I'll keep every comment in mind as i muddle through.
Thanks Again!
Whoopie today my first set of u groove bearing's turned up. Also by a stroke of cheeky luck I scored 4 1.2m mild steel equal angles for free. After 10mins of tinkering I'm now rolling x and y. Still wait for my couplings and sprocket's.
Hmm, kit, 900x900? What made you choose that working area? Thats something new.
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Bad pictures yes. 2nd x axis rail not in use atm.
But it will have one. Y axis both rails in place.
Well its different, it will be interesting to see it cut :applause:
From the look of your sprockets and chain you'll not be doing anymore cycling...😁
Sent from my HUAWEI VNS-L31 using Tapatalk
Rofl
4x free wheel sprocket £2 or free of you have shed load of spare bits like I do. As for bike rides here's a pic of my little bike. Also the results of stupid tinkering.
Attachment 20280
The tricky thing with chain drives is that the smaller sprockets give you terrible cogging and the larger sprockets give you enormous travel per rev requiring expensive low backlash gear boxes to get any king of resolution.
Totally get that! Been doing countless searches on Sprockets and sizes to see what method would be best to resolve travel distance to rotation. Thinking i'd use some sort of gearing to compensate.
small drive cog on stepper to a large cog attached to my "control bar" which would equal a zeroing out of the exterior cogs that connect to the chain.
Attachment 20285
OK so i'm real crap at using sketch up.
If you are serious at this you could design in Fusion360 it is free for hobby use, a big learning curve but it has CAM built in so you could use for generating the gcode later on.
There are plenty of tutorials on it. like https://www.youtube.com/playlist?lis...Alt9yzBIp84sD8
Attachment 20305
Something like this
Is there a particular reason you've chosen chain and not toothed belt?
- Nick
It's just what I had laying about. To be honest may end up using timing belt. If I have too many issues getting cogs for the chain.
Didn't like the price of the correct screws and had problems finding in the final size I want.
As for the belts I could find plenty but already had plenty of chain. I'll have to gear down the ratio between the stepper and the x axis cog control arm. Which as far as I can tell will be easy enough and provide even more torque.
Yep I'm still here. Just been debating and waiting on parts.
so i've been dicking about with my moch up as i learn better in the physical.
So then i had my Y Axis working. I used a toothed belt after someone asking why not.
Now i know why not. Me! I'm soooo lazy. A chain can be a length or a loop real easy. Belt not so much.
Then I worked on my X axis movement.
Had to get creative as no coupling have turned up so far! Annoyed YES!
But i had hit the weight limit for the cheapy motors i had. :(
No drama
All is not lost.
Yes brother. I spotted that. Turns out my gantry is a little heavy with the rails I aquire.
Put a shirt tty Lil dremel style tool on it as a "let's see" . Getting a first eye on the forces and how/what they do and where.
What do you think of the flat rails and the supported bar rails which being best.
OK so where am I.
After the weight limit issue. Rather than buy more powerful motors I scaled down.
Now have a rag tag machine with all 3 working axis.
No spindle as of yet, not even my test tool.
Videos and photos to come soon.
Brace yourselves as she's proper ugly.
A belt can be used as a cut length as easily as chain, if you need a continuous loop then you will need to use an off the shelf size which can mean you need to make your mounts to allow adjustment of pulley spacing, but smooth drive, lower energy losses, and reduced wear and maintenance really can make the effort worthwhile,
Regards,
Nick
Yeah I hear the looped belt i know you can by them presized. That's my issue right there as i would have need to buy several due to how i don't plan most things. Hey it's how i work!
The chain however i can shorten, lengthen, loop or otherwise with ease. the CON being finding sprockets for the Stepper.
OK so over the weekend, I had my mate (kids in tow) come round and we tinkered with the CNC mockups.
After which i had one quick upgrade and now i have an almost fit for purpose machine.
I still want to replace 80% of the parts (as i'm a bad carpenter)
Photos and Video to follow.
The Test
Attachment 20689
Attachment 20688
First Upgrade
Attachment 20690
Not the best photo I know. But she's ugly and I didn't want to break me camera even more. Had me a sticky x axis, turns out that my base was slightly bowed. Will make a table for it to have all straight and on the level. Yes it cuts and more than cake.
Well it certainly ain't pretty....but looks like it cuts and if it does what you want it to do then fair play to you :wink:
Well its good that the kids are leaning something instead of watching telly and it isn't costing too much. It will be interesting to see how you evolve it.:thumsup:Quote:
OK so over the weekend, I had my mate (kids in tow) come round and we tinkered with the CNC mockups.
Thank you bro!
She so UGLY the bag i put over it up and ran away, leaving me a note stating it was cruel and unusual punishment.
I had to agree!
She's going to get upgraded slowly.
Then i'm going to refine a few parts, re cost and send a kit version to my friend in Scotland.
If that goes together and works out the box then i'll think about offering to others.
But they won't be ugly things like this is now.
Shes that ugly due to she costing £100
The kids thought it was amazing! but they are 4 and 7!
Wassssson JR!
I'm not convincing anyone i don't work like that. You will or you won't is my level of sales, lol.
As for my cost
The Spindle is a POO! one that i have on it ATM. Came with a 80mm bracket. - £50
Controlling Motors (Arduino, Board, Stepper Drivers) £20
Ball Screws, bearings and nut £18
Steppers £30
2nd Hand Rails £2
So i'm sorry i under stated! by £20
£120 In total
wood, screws, bearing n bolts (free)
:thumsup:
I'm still alive.
Okay so I've built, destroyed, re-built over and over.
This is where i am now.
Attachment 21656
Attachment 21657
Attachment 21658
Attachment 21659 Combine Shot!
Nah bro, Spindle Mount and Controller £50