Actually, they are opposite. The trim pot goes toward the mosfets and usb plug with the 8825s.

 

Glad I asked before trying to put them in. Was going to try playing with them some this weekend.

 

Carl,

Have you had a chance to test out the modified version of Marlin firmware that I posted earlier?

Brian

 

Right now the Ramp isn't connected to a printer so the steps won't matter at this point. Now once my C-Bot is built... Actually I will have to decide which board to use. I have both the Ramps and a Smoothie board available.

 

Thanks Carl, hopefully I can get the rest printed without issue.

I picked up a 10" Ryobi miter saw today and plan to make my cuts this weekend. While I was at Home Depot I found this cheap 10" blade:

http://www.homedepot.com/p/Diablo-1...in-Metal-Cut-Off-Disc-DBD100093L01F/202831056

I know it's not what is normally suggested here on the forums but it has great reviews for cutting much harder metals(60-80 stainless steel cuts without wearing out) so if it makes the 20-30 hopefully clean cuts I need for $5 I'll be satisfied.

My plan for cuts with multiples of the same length is to line the extrusion ends up against a flat surface and tape 2-4 of them together so I can cut them all together. I'm hoping that as long as I get those even with each other it wouldn't matter if my cut lengths are off by a mm or so due to inaccuracy in my marking method, cutting blade width ect. It also looks like I'll have about 350mm left over(looking back wish I had ordered 8 1000mm 20x40s) for blade width and overshoot on cut lengths ect. Do you have any suggestions on how to break down the cuts for minimal scraps? assuming stock build size of course.

Thanks again,
Chris

 

I'm so spoiled by Smoothieware's config file vs modifying header files it would be really hard for me to consider a Ramps again if I had both in front of me. I wonder if there is a large performance benefit between the two like there is on the Delta rigs?

 

Yeah even if I have to buy a second blade it will be worth the savings. If I eventually end up building more extrusion based machines in the future I may go with the SBNF-100100 that has been suggested on the forums here before.

Has anyone else successfully built a standard size C-Bot from 7 20x40 extrusions? I have glanced at the numbers and looked at a few combinations to use as much material from each meter of extrusion as possible but so far it seems like I will end up buying another piece of extrusion or two which isn't a really big deal but might be worth making note on exactly how much extra is needed for others considering the build.

 

Well after a lot of trial and error, I've come to the conclusion that dual extruders just don't work.

It's almost impossible to get them at the at the same height.

When I try to use both extruders, one will ooze plastic when it's not meant to, and ruin the job.

If I'm only using one extruder I generally have to heat up the other one as well, any cool dag left on it will snag the job and remove it from the bed. Hot dags wipe off and cause unwanted colour specs in the job.

The hot non printing extruder and also cut through the layer that has just been printed, spreading it around a bit.

I think I'll go back to a single extruder and save my pennies for a Cyclops.

Although I am rather happy with my spring mounted extruders. There must be some reason why everybody isn't mounting their extruders this way, but I haven't figured out what it is yet.

 

What's the concerns with smokepoints and oil breaking down?

I use a few drops to lubricate the trip through the Bowden tube, but I've also noticed that oozing is slightly better, and the finish on the plastic looks different, not really better just different.

I experimented with a high smokepoint oil like olive oil, but it would accumulate in the hot end this caused it to either drop as oil onto the build plate which stopped plastic from sticking, or it filled up the Bowden tube. I switched

I switched canola oil so that the hot end could burn it off, and it's been fine since.

 

So, in fact the smoke point of olive oil is considerably less then canola. Olive oil does actually contain small particulate matter ( olives ). I don't personally cook with it. I only use it as a raw ingredient, in salad dressings, or added in the final stages as a finishing flavor. According to CIA ( culinary institute of america ) olive oil smokes at 175C, canola at 205C. Thanks though, I did learn somethings that I might want to test, I had always thought the grapeseed oil was a much higher smoking point then canola.

I had put my culinary concerns into the 3dP and I think that that was wrong. I can taste the difference between food sauteed in olive or canola, to me olive oil tastes burned. I would say that I have a fairly well calibrated taste, I have 25 years experience in a professional kitchen and Michelin stars on my resume. I am still on the fence whether to oil or not. I have been experimenting with oiling PETG @ 245

 

I'll have to take your word for the smoke points, when I researched it Canola oil smoked at about 200 Celsius which is slightly less than what I'm cooking my PLA at. Olive oil had a smoke point of 240 Celsius, which is much higher than the PLA. Both these smoke points agree with what I was experiencing in practice. Canola works for me and Olive oil doesn't.

I guess I could try extra virgin olive oil, which I think has a smoke point lower than Canola oil, but I brought a litre of canola and I'm only using a few drops per real of plastic, so it maybe a few years before I'm tempted to try something else.

 

What about using Safflower Oil? It has a smoke point of 265C.

When I first got started and read about using oil, what I was reading just said to use light machine oil, which is what I have been using with no problems.

 

@hax0red holy crap, was that you flying that 3DD Heli? little OT, Have you seen Steve Johnstone's videos on ABS printing for making molds. could be a good use for making some fun shaped fuselage for fancy heli flying.

the best explanation of oiling was recently given to me. Oil acts as a thermal conductor, and mainly stays just above the melt zone, helps to shed the heat a touch, cooling evenly will lead to less filament sticking in the cold end, just above the heat break. Kind of similar to the function of the stepped bore thermal barrier.

 

Yeah that's me flying at IRCHA 2008 which one of the biggest RC helicopter events in the world. In recent years the hobby has been swarmed by quad rotors now being called "drones" or quad copters although most require a pilot. The mold making looks awesome and quality is great too. I wonder how much work he had to do to get the molds that smooth? Since it's foam it wouldn't work too well on a 90 size helicopter as they are mainly fiberglass/carbon fiber but I fly smaller 180 sized machines that would work really well with foam, until you crash that is.

 

He prints them vertical, then fills with beeswax. He said that there somewhere. There's a whole series. He's doing some great work with heated chambers these days.

 

G'day Carl, Firstly, Congratulations on a great design! I want to build one. Thank you so much for making it available & extra thanks for theBOM & the instructions. I wouldn't be game enough to try to build it without them! I hope you & the gang won't mind all the questions I will have. I have a Mendelmax 2 which is operational & have printed most of the parts already. I have the bed, glass & heater from another one, which I wanr to use in this one. It measures 250 x 320 mm overall. Looking at your original photo, it looks like it would fit in without mods. Which measurements are critical? I have quit a few pieces of 20x40 and 20x80 that I'd like to use if possible. Maybe I could use the wide stuff on the bottom? I have the Rambo card as well as the 24v supply. Also I have a pair of Robotdigg threaded rod steppers 250 mm long that I will try to fit in! I was collecting bits for a different printer, when I saw yours. Regards, George

 

On the second page of the BOM, there is a frame calculator, you can input the size of you parts, heated bed and lead screw, it will calculate the lengths of the cuts.

 

Sure, I know this & have calculated the new measurements, but I would like to know which measurements ate critical, as I'm sure they all aren't, given the range of dimensions in the various XY designs published. I want to use what I have if possible, but don't want to end up trying a square bit in a round hole, so to speak!

 

Thanks, they actually have become much more powerful today(video was from 2008). Quad looks great! I have a Nano QX which I printed a frame for right away but the design is still a little too heavy so I plan to revisit that project once I'm done with my printers

Still haven't really had a chance to make the extrusion cuts but hopefully tomorrow. Got most of the parts printed except little stuff like end stop mounts although I'm not really sure which end stops to use. I used standard Omron ones on my Mini Kossel with Azteeg X5(smoothieboard basically) and from what I have read in this thread is that the Makerbot style only work with Ramps? Worst case I can design some mounts for normal end stops but I'd love to try the fancier looking ones suggested for the C-Bot.

 

Thaanks for that. I think I'll bite the bullet & either buy the exxtra extrusion &/or get a new hotplate etc. I don't want to mess up the design. Back to the calculator. The Aussie $ has dropped over 22% since I bought the first lot, so it's bloody expensive!

 

Carl, awesome build, thanks for sharing your hard work. I have parts in the mail to build this beauty.

Some notes on the BOM:

1. 25 pk Tee nuts needed are M5. The OPBS stocks them in two different sizes and it's not noted in the BOM if you need M3 or M5.

2. Endstop wires: It may be good to note that you will need jumper wires for the endstop since many of the ebay auctions do not include wires and connectors

One more question:

I can't seem to find the Core XY rear corner STL files, are they still linked on the download page? I see all the other printed pieces, but not the rear corners that hold the belt idler bearings.

 

Amazing design Carl ! I've had a thought : what do you think about using 20x60 profiles, instead of 20x40, for the CoreXY system ?