Tonight i printed templates for the sides, and cut one with a scroll saw. took forever.. gonna goto school tomorrow to cut the other 3 with a bandsaw, and use their sanders to clean up the cuts and make all 4 side panels identical. to do this, i am going to put bolts through the axel holes, and bolt them all together before sanding down to size.. gotta read about polishing the edges of acrylic.... heres some photos.

this photo shows an old part for another machine with the wheels laid up next to it.

I thought you guys might wanna see more of this gantry assembly. i decided not to use it because i want something a bit different for this. i will stick to my plans. i put lots of work into it though. its made of john Ks window channel, but used totaly different. i riveted a bunch of it together to for this structure, then painted it.. took an evening... then i mounted a bunch of poorly machined aluminum bearing blocks.. TAKE time when seting up your drills and cuts! its worth it.

Heres 1 part cut, 1 part patterned.. The cut is SOO rough with the scroll saw... gotta have patience and wait till i can use a bandsaw for this... gonna sand all the parts true...

heres 1 side laid on a bench

Wow Vac, I envy your speed. Looking good at this point.
By day 5 you'll have your own billboard on Madison avenue:)

By day 5 you'll have your own billboard on Madison avenue
And vacpress will rest on the seventh day.


He he. Nice work there.
Realy impressive.



Konstantin

Did you ever find anything out about polishing the cut sides of acrylic?

i didnt get nearly as much as i wanted done. i had to stop cuz it was 2am and my roomies were like "why are you sawing?"

kcoaks- no. im gonna ask today at the school shop, maybe the shop leader guy knows.. if not, im sure its just a buffer wheel... i hate my buffer wheel though - it makes a very scary noise.

Vacpress - when I was about your age (seems a while) in the sign shop we used a hooked knife to round over the edge of plex - but that was scary too! Also a wheel (sanding disk) hand held on a drill or belt sander - but then again on a sign 40 feet++ in the air you never notice the small imperfections.
I have seen flame-ploished and "melted edges" on some plastics - but control of the heat is important so you don't "flame" the project. (flame2)
Maybe a beat up iron from goodwill/sallys?
Progress is amazing! Keep it up!
cheers - Jim

Originally posted by vacpress
I thought you guys might wanna see more of this gantry assembly.

...just wanna see MORE!:D

vac

Whene you need parts in plexi ore something i will mill theme for you.
I have made a big cnc milling machine.

At this moment i didn't found a way for cnc color controlling.
Did you found something yet?

publi - i think i did find something out. basically a mix of image processing software to get the pics ready and in a basic "Raw" format. then a program that takes that data and reads it.. it turns out we dont have to "mix" paint.. not really. gotta get the dots small enough that the colors are made up of small dots - like a page in a magazine

as for getting parts machined - that would be great if i didnt have access to a very good AXYZZ machine at school. i cut some parts with a bandsaw and think they suck. so i am gonna get a new piece of plexi and use the CNC here to do it on wed.

if you want the 3D files to build along - that would be very cool.

vac

I will mill the part at my cnc.
I can mill large format parts on it.

cool that you found a way to get the photo in a xy z grid.
How does it work?
for the printhead we can use airbruch nozzels i think.
An other way would be using a piezo cristal and making ower own painthead.

publi -

i like the idea of using airbrush nozzles in a grid and some sort of wire, or hoop, or other system that is "metered". i have decided on the following development path:

1-build a sturdy scale prototype per design. the design i have been posting is 48" wide.. i have my eye on 10' square steel tube from home depot that is $13.00 a piece for a "full size"
2-get the thing working with some GCode interpreter software. i am pretty sure i like the looks of "Cstep" from www.luberth.com. gotta love luberth.. he is as responsible as anyone for all of us being here.
3-write my own software to do some fun algorithmic patterns and stuff with the machine
4-deign and develop some sort of 4-color painthead - maybe a pixation adaptation, maybe something new
5-develop the raster control software to use the 4-color printhead.

as i said - i have access to this at school:
http://www.axyz.com/Images/table_mill_lrg.jpg

so tomorrow or wed. i am going to get all the main parts cut on it. i will post the dxfs and gcode. if you want access to my 3d data - goto solidworks.com and get "edrawings viewer" and i will post the cad data.

I am building with acrylic "plexiglass" but MDF would be fine for a prototype so you can have fun with the idea. if you want help with finding parts, i can give suggestions, also i posted that partial parts list with some guidance in it...
also, this thing could be built in 1/2 scale or 2/1 scale probably.

i plan on using a marker or a single spray-gun for the first round of testing. i want to finish that part fast!

Vac,

Here's how to polish the edges of the plex:
Sand smooth and straight with sandpaper on a block of wood. Bear in mind the heavier the grit the deeper the scratches. 80# isn't too bad. Then sand smooth using 100#, 180# and 220#. Finish with about 320# or 400# depending on how perfect you want it.
Then use the buffing wheel and rouge to polish it out. Don't sit too long in any one spot with the buffer. You don't want to heat up the plex and cause it to flow. It is amazing how soft it is.
I wouldn't recommend flame polishing. If you do any thinner, cleaners or spirits that will come in contact will likely cause the plex to craze.
Nice job so far.

Chris

cbcnc - ah thanks... when i tried my oldskool nastyazz buffing wheel here at home, it started to flow right away - plus that thing is tooo scary to use. i think it might not be exactly the right thing..

a guy at the school shop showed me scraping the edes with a piece of sheet metal to get it clean enough to begin to polish it. i am unhappy with my sloppy cutting though. im sure the machined edges will be closer to ready.. i want to put a 45deg bevel on the outside edge also, with a router - to give it that "special look"

Vac,

If you can make an MDF pattern then you can cut the plex a little big and use a router with a carbide flush cutter to route up to the pattern. That way you will get identical sides and the routed edge is easier to polish.

Chris

hmmm. i keep feeling like if i cant make these simple flat pieces by hand - i cant make anything.. but 1/2" acrylic is sorta difficult to work with... gotta have alot of patience.. its not like wood where you can go fast if your "warmed up". and it smells so caustic.

so - with a router? would it have to have the ball bearing on it? i havent used the router much at all.. not for tracing any templates at least. at home here ive got a porter cable router and table.. i was thinking about just clamping 4 imperfect pieces together and taking them to a big rotary sander st school... i did that briefly today though, and even with the dustcollector going it was way too stinky..

maybe if i opened the windows and got a fan.... OR. ill jsut let the cnc machine cut 4 perfect parts in 30minutes and do it with way less waste... maybe faster than 30 minutes? shop guy at school says we can cut .5 acrylic in 3 passes, but i didnt ask how fast we can run....

ill search the archive for that info... its prolly here..

Sorry, I don't mean to way ahead of you and your skills. I am an old Tradeshow and Exhibit Builder and working with various materials is second nature to me.
Pattern work with a router or router table is how alot of parts are made consistantly. Once you have the pattern (I like 1/2" MDF) then you can cut your pieces flush with that. Nowadays with CNC machines this is almost "Old School".
Your router should be set up with a cutter that, yes, has a bearing on it. I prefer to work on a router table. Your pattern can be double face taped to the plex or screwed down. The pattern is on top and the bearing rides on that. The material should be cut to about 1/16" bigger.
If you are not comfortable using a router or haven't done it before I suggest that you get someone to help you out.

Good luck,
Chris

cbcnc - no i have done similar tasks with a rputer though. ive used mine to make decorative trim and to trim small parts.. i got it anticipating using it mainly as a spindle motor.

thanks for the advice... i will keep it in mind next time.. instead of making a ****e plexi cut, i will make a nice MDF pattern and then do the router trimming. at least give it a shot. when i have a decent machine here at home this will all be a moot point. i am pretty able with the software so setups and modeling can be done faster than carefully cutting...

im not trying to be a "real" machinist.. i just need prototype parts...

thanks

i work all day with plexi for signmaking.
To polish the sites there is no problem.
You just have to know that there are two different plexis.
Just look for acrylox on the net.
Acrylox is a plexi that is made specialy for milling.
Its not a extruded plexi but he is littel softer.
For polishing the sites heat wil be the best way.
Second important thing i use the right milling tools.
For more information you can see at
www.ketele.com
Yes vac post the 3D data
Is the data on a server ?
Can i open theme in mastercam to?

publitime - think there is a mastercam\solidworks translator - if not. check and see if mastercam can load Vrml, STL, or IGS

i can format it to those.

vacpress

solidworks files are ok.
You don't have to format to a other file.

jurgen
publitime@pandora.be

publitime - your gonna start building one? sweet. i will put the files on my server and send you the links.

some of the thigns about the design are not going to be the same on any setup. i do sometuff in SW jsut as a design guide, so i have at least 1 idea illustrated. i dont usually do all the final design in 3D. Its more of a reference. The only parts i used templates to cut on my current build are the 2 sides. I didnt even use the 2 inside panels, just the outsides, this is because i figured i might want to change the design.

So i would CNC 4 of the main outside Panels.. I am still not sure if i want to drive the motor directly, or if i need reduction. I am probably gonna try and do 8x multistepping and a direct drive.

vacpress

I really want to build a cnc color painter.
Whene i have all the parts i need i start building.
I still have some parts at this moment like slides from SKF, belts,weels.
The only thing we need is to findout a way to control the whole thing.
Thene i will see to bought the geckodrives.
In past i have worked with the nc-step drivers but for the colorpainter i will try the gecko's.
In the next day's i will look for some good stuff to spray the paint.
So i will take a injector to see wath is possible to rebuild it.
I also want look for other systems who can make a small droplet because small dropplets i what we need.
I think we can't made a small and scharp dropplet with a airflow.
Air will spray paint out on a big earya.

publitime- consider xylotex drivers. they are much cheper, and depending on your motors, will ork just as well. also, consider just plain rebuilding the pixation idea.. their idea works by running along wire through a paint can, and blowing the paint off when it is at the point where its jsut the finest film of paint on the wire. the wire sort a"whicks" the paint upto the nozzles, which blow the paint dropplets off the wire and ontothe workpiece. these use 3-5 nozzles for each color. the nozzles are aranged in a pattern to make the proplets as predictable as possible?

you can read the patents related to the wirejet. they are interesting, but difficult to read.

http://www.cnczone.com/forums/showthread.php?s=&threadid=3816


has more build pictures and documentation

An easier way to get a semi-polished edge on acrylic. After sanding, as described above, just use 0000 steel wool on the edge. Not a full polish, but close enough. If you make a wood template and flush trim it with a router, you can skip most of the sanding. Just a quick once over with 320-400 and steel wool. If you want to try the flaming, just run a propane torch down the edge. Don't stop moving, and start fast and slow down 'ti; you find the right speed.

Craftics makes cutting and polishing equipment. They have a hand scaper that will give you a pretty smooth finish and will debur the edges. They also have buffing and polishing kits if you need a glossy edge. Anything beyond buffing or flame polishing, would require diamond polishing. These machines are very expensive.

http://www.craftics.com/linedrawings/5edge.jpg