02/12/2017 at 23:32 •
today I got the belt for the second axis mounted, i cut some aluminium extrusions to a carefully guessed length and put some legs on the machine and all of a sudden it looks a lot more serious, mostly because it just looks huge....
I flashed the Arduino with GRBL and started feeding the machine with gcode, I haven't made any tweaks to the max acceleration or anything yet, just fired up a gcode sender and made the thing move, it works but the stepper struggles with the x axis, after trying things at random it seems like the gears aren't meshing properly, most likely due to some inaccuracies with the printing, i'm not sure my design regarding driving this axis is the best... But i think the gears might wear down and thus mesh better if I let them run for a while, i disconnected the belts and hooked a drill right onto the driveshaft and ran it for a minute and there was a positive change, i'll also most likely need to get some better controllers for the steppers(or at least adjust the ones I found in a random box).
On the positive side i've now reached a stage where I can parallelize tasks and print and fiddle with software at the same time instead of printing and drinking beer and/or play pinball while I wait.
02/08/2017 at 23:30 •
Not to much to write home about today, at least not in the way of failures and complications..
I got the mounting plate for the nozzle mounted onto the bearings and rails, i am for sure using enough bolts!
One more quick session of printing and i'll have the brackets to attach the belt onto it and i'll have movement in both directions and i can start fidling with some code.
Very little labor today but visually it looks a lot more complete so all in all a great success!
02/07/2017 at 20:00 •
I'm working my way towards the business end of the machine, yesterday my friend and fellow Hackerspace member Runar(https://hackaday.io/runborg) cut out some plexi glass pieces for the carriage that will carry the nozzle, I don't think the plastic I picked up in a rush was the kind you should use in a laser cutter, there was a lot of smoke even with the extractor fan on, it smelled absolutely dreadful and I'm pretty sure I'd get a DUI if a police officer pulled me over when I drove home, the result looks sick though, can't wait until we've scraped together some more funds to get one at Hackheim.
Hopefully I'll get the little pieces needed to mount this on the bearings done tomorrow, then I can start figuring out how to control this machine and if it works as it is supposed to at all
02/06/2017 at 13:27 •
As yesterdays post was mostly just me being extatic of something working I thought I'd add a bit more content today, I'm not the best when it comes to taking pics underway but here are some:
Gear mounted on the drive shaft and the ball bearing is pushed in place so that I can simply slide the whole thing into the mount, also, spot the set-screw in the gear, pretty pleased with how neat this turned out.
And here the drive shaft is mounted in place, it doesn't come out too well in this picture but the clearance between the gear and the adjacent wall is absolutely marginal, I wish I could lie and say it is me being incredibly accurate but that would just be pure BS and you'd all see through that after all the stupid fails I've done in this project.
And here the whole gear assembly is in place, spot the washers on the drive shaft used as spacers just so that everything stays in place, classy mechanics all the way here.
And as a bonus:
THE BOX OF FAILURES!
As a memory of every stupid decision I have made and every failed print that has happened I have collected the pieces in a box, its a nice demonstration on how much work it has been making this thing if I ever bring this to a Maker Faire or similar and it reminds me to measure twice, print once, of course I don't think enough and thus the pile will most likely keep on growing.
02/05/2017 at 23:39 •
I did it! After a lot of reiterations that flimsy belt drive is gone.
I printed before measuring, I ran out of filament at 97% og the print and I designed stuff that turned out to be stupid.
I also got rid of those small blocks to hold the belt axle and made new components combining adjacent parts to one sturdy piece.
The gears are a litte inaccurate but running it for a few moments helped out a lot grinding down the inaccuracies from the printing and I suspect they'll be a lot smoother after some more running time.
Check out the video(I deeply apologize for filming in vertical mode)
01/23/2017 at 22:27 •
So, I figured out how to do gears in Fusion 360 and I made a prototype of a new mechanism to transfer power from the stepper motor to the axle and combined it with the mount for the x axis rail.
I've still got a few more bits left to sort out, I have not made space in the green part for the ball bearing and I need to do some little tweaks here and there just to make everything look and work nicely.
I'm not sure how well these gears will work, the teeth on them are rather chunky but on the other hand splattering pancake batter onto a hot iron plate isn't something that should require that much accuracy, I bet I'll have to do a reprint as always...
01/23/2017 at 16:07 •
So last night I got the new rod mount / belt pulley assembly printed and assembled, it seems to work great, the belts are nicely tensioned now and applying further tension is as easy as tensioning a nut, I'm not sure of the long term durability of it but strengthening it shouldn't be too hard if it turns out to be a bit weak for long term usage.
Of course solving one issue reveals another, my mechanism for transferring power from the motor to the belts is a bit sketchy, a lot of it comes from me gluing the short loop belt and thus making the joint rather stiff that again makes it slip over the pulleys when the joint moves across it, having mounted the belt on the middle of the axle has also resulted in it getting a little bit bent and I've come to realize it might not be the sexiest solution, I am going to redo the rod/pulley mount on this end in the same fashion as the other and I am strongly considering designing a gearbox while I'm at it, I don't know if it is better or not but gears are cool.
01/21/2017 at 21:25 •
So these floppy belts need a sexy solution so I redesigned the component holding the sliding rail in place and the part to hold the pulley for the belt into one component with a tensioning mechanism and it will also add some more stability to the whole rig, I haven't printed it yet but I made a prototype and it seems to work well.
The idea is that a block will be placed inside the slot running along the side, this block will hold the pulley and a threaded rod will run out the back through another block I will glue in place and a nut at the back will allow me to tighten the belt, below I have added a rendering of the prototype I made as I forgot to take a picture of the working prototype.
01/17/2017 at 21:19 •
lLong time no proper update, between now and the previous update I've done loads and only documented me buying enough M4 screws to sink a ship, sorry about that....
Well what have I done?
- Done some more poor design decisions
- Fixed my poor design decisions
- GOTO 1
Love or hate my methodology but I've reached a stage where the machine looks like a machine and it also behaves like a machine, at least along one axis, I want to make the first axis work decently before I move on to fiddling with the next one.
Also, RS components == GREAT, i've used them a lot as they have OK prices, especially if you factor in delivery time vs ordering something from china.... oh and they use the only international courier that actually bothers about customer service around here as UPS and fedex ship all their stuff within Norway with the national postal service, and well, it is easy to see that they are ran by the state....
I have honestly lost track of what I did since last time but these pics should show it off fairly well:
So next steps:
- Get those long belts running along the sides properly tight and not flimsy and wobbly like they are now
- pray that the glue joining the ends of the short belt loop holds up
- Get started on the mechanics for the second axis
And if I get fed up with this I'll start looking into peristaltic pumps for the batter.
I did get the thing to move in a somewhat orderly matter so I guess I have to show that off too, I threw a pair of adafruit h-bridge stepper controllers and an arduino nano onto a breadboard and fired up one stepper, no end stops or anything here, I just tweaked the code until it ran about more or less the full length of the axis.
12/27/2016 at 14:31 •
well.. there's a limit to how many posts I can make about failed and successful prints, lets just say that my poor planning is catching up with me... I have made some decent progress but nothing to exiting yet, i'll post a larger update soon.
On the other hand the mailman turned up with an assortment of 1500 M4 bolts, 2000 nuts, 4000 washers and 6 meters of aluminium extrusions.
I'm waiting for another 500 bolts that are in backorder.