I went to the Midwest RepRap Fest (#MRRF) in Goshen Indiana this year

I was asked to go by a friend last year, but couldn't afford a hotel at the time. 

Work found out (I have a big mouth) and offered to be a sponsor! A big bonus to this, I got to bring one of our very expensive ROMER arms with a  laser scanner. 

The show was a blast! I am still recuperating.

Considering I own nearly half of the 3d printers I'd seen running in person, the show was EPIC. So many machines! So many people.  The people there listed like my version of a hollywood blockbuster movie!   Prusa, Tonokip, Logxen, Seward, Os1r1s, and more!

I brought my 2 printers. Each has something a bit unique. One has a water cooled hot end, which is rare. The other uses both belts and fishing line on the save drive line, which I have not seen done before.

I didn't even get a chance to take many photos. Disappointing, but an excuse to go again next year.

There was  a local who had lost his hands to bacterial meningitis a few years ago. A last minute project was to have the people who brought printers there print out a pair of robot hands for him. I had the scanner, so I scanned in his arms. By the time the show was over, there was half of one arm printed. It was just SO crazy busy that we just couldn't get it done at the show. The project is getting finished after the show.

In album MRRF2014

This is my portable robot building fastener set. It has many of the the important bits besides structural components. The most important tool is the brain-juice!

Yeah, that’s right, I had lunch with the guy with the reddit Up Vote Orange Challenger.  Crazy cool!

The first Makergear M2 I’ve seen in person. I like it.

Packing up for the show. My Mendal 3D printer fits into a plastic case I’d rescued from a dumpster. It fits perfectly, like they where designed for each other.

All loaded up and ready to go. Two 3D printers, a laser scanner, a couple of computers & tablets, My robot building kit, some stools & a case of Mt Dew.

Here I am scanning a print to see how accurately the printer was able to hit the design. It did pretty darn good. There is a little bit of ‘shrink’ as the ABS plastic cools, and we can see that.

This came off of one of the printers at the show. I compared the file to the print and it came out quite nicely. Undersized, but the profile matched really nicely.

This printer is just wild! It’s made from really common bolts, fishing line, guitar tuners and massive amounts of creativity.

The Simpson printer really looks like a spider, spinning a web. I just love this thing.

This is another pretty cool printer.

I can’t imagine writing the gcode for this, to push out the coordinates as the bed raises.

This is a twisty machine. The linear rods are also the drive. The math makes my brain hurt!

I like this plastic bowden capture.

I got my printer working off of a cheap tablet. This is going to be SO nice!

I got ALL the nylons…

I finally got a chance to give this a try at the Midwest RepRap Fest

I'd bought the app Thursday night so I could us it this weekend.

I used a $50 black Friday special RCA 7" tablet. Plugged it into my Makergear Prusa Mendal running a fairly current marlin on ramps 1.4.

It just worked.

I love it when things just work.

It took me a minute to figure out that there is a tab on the right side to toggle to the printer controls.

I loaded a gcode file I'd sliced and printed on my laptop. It worked just as well as my laptop.

I tried making a water block for water cooling my MakerGear hot end this weekend…

I tried making a water block for water cooling my MakerGear hot end this weekend.

I failed.

A bit of background as to WHY I would want to do such a project can be found at http://mike.creuzer.com/2013/01/watercooling-my-makergear-prusa-reprap.html I wanted to improve over the coil of copper being that I am about to re-install my 1.75mm hot end for a few lbs of plastic. Going to try ABS for the first time at this size. Not sure if I am going to have problems with that or not.

My fail is I was too lazy to go out into the cold to drill a hole on the drill press. I managed to salvage my stupid hole with a bit of tubing. Hopefully it doesn't cost me too much in efficiency.

I really have no idea what I am doing when it comes to using a lathe. Learning from YouTube is difficult as many of the videos posted are by people with as much experience as me (about 3 hours at this point).

Well, the next iteration should be better, right? I enjoyed making this enough I wouldn't mind making it again. But with a drill press. I think I will drill that hole first so I know it's right.

In album Machining a water block FAIL

Using my UNiMAT lathe to fix my lousy hack saw cut and bring the aluminum block down to the right dimensions.

I turned down the black insulator a bit as I don’t have metric drill bits. The bigger tube is to couple airline tubing together on the OUTSIDE so I don’t get even more restrictions of water flow.

THERE I FIXED IT. I ran a bit of aquarium air hose through the buggered up hole. I am going to lose a lot of heat removal capability, but it lets me temporarily salvage this part. The water going through is in it’s mid 60s, so there is going to be a big difference, so it should pull heat well.

Until I make a new one.

I cut a piece of aluminium in half with a hack saw. The tray did a decent job of collecting the aluminum dust. Terrible surface finish on the cut. I did not do a good job of making the cut straight.

I tried drilling the hole using a hand drill because it’s COLD out in the garage where my drill press is.

I FAILED. I totally didn’t get things where they wanted to go. I’ve a hole on the inside, and a double hole on one end.

I can JUST snap the wooden clip in place with the water block installed. It’s going to be a royal pain to un-clip it.

The water block is small and light. It should work well I hope.

I rebuilt my RepRap, and used a CMM and a spreadsheet to help me square the Mendal…

I rebuilt my RepRap, and used a CMM and a spreadsheet to help me square the Mendal Frame using 12 data points.

A Coordinate Measuring Machine (CMM) captures XYZ measurements of differing points taken in 3d space. The one I am using is old, retired, out of calibration certification, and at it's outside edge of accuracy and repeatibility specifications. It still is a useful tool though.

I used it to take a dozen points of my printer's print bed and X carriage at their extremes of movement.

I captured the same 4 spots on the print bed both all the way forward, and all the way back by using the laser cut bed mounting holes on the Y sled. This tells me if there is any lift or fall or twist in the print bed's travel.

I also took points on the X carriage's nut captures at the four extremes of it's travel. Bottom left, bottom right, top right, top left. When compared to the Y, I can see if the X is level and square to the Y but also if the Z is square to the Y. 

My spreadsheet, 
https://docs.google.com/spreadsheet/ccc?key=0Asb6Jfk9hsyhdHVHcmZvMFFjYUI0WHFuZVdjbXZZX2c&usp=sharing does an alignment of the captured points to the print bed. This gives meaningful measurement of the motion of the machine. You can look at the numbers and it makes sense because the front left corner of the print bed – where you home the printer, is assigned 0,0,0 and all points are a meaningful distance from 'home'. The CMM captures the points based on It's idea of 'home' and looking at the numbers is basically meaningless.

I then calculate some correction values at certain points of the printer frame knowing what's easy to adjust and what's hard to adjust.

I assume that the frame is assembled fairly square (I used a jig and measured it with the CMM so this is a reasonable assumption on my printer), so I adjust the moving bits within the frame. The Y sled is given a rotation movement distance, and the Z tower bottom ends are given movement distances as well.

A half dozen adjustments at the bottom of the printer drastically improved the squareness of the printer. 

While +Jerry Rodberg helped me immensely on the spreadsheet, I am still validating my assumptions, the spreadsheet's correctness and the validity of it's recommended moves. It is currently provided suggested corrections that are based off of the RepRap Prusa Mendal frame and how that style of printer can be adjusted.

I don't know that these are actually indeed the best way to correct squareness, and I am sure I will iterate the spreadsheet as I gain experience with it and people's suggestions. Printers of similar axis arrangement should also work with the spreadsheet with a bit of thought on alternate ways to get the desired corrections into the frame. Any Cartesian printer frame likely can be figured out using the same 12 points, and I plan on adding suggestions for different styles, such as gantry frames e.g printrbots.

I am also looking into using the CMM to square a Rostock style printer and verifying dimensions such as the 120 degree, equidistant towers, and that there is no twist going up the printer. But I expect that will require a different spreadsheet.

In album Squaring of my RepRap’s motion

The tweaks suggested in the spreadsheet using the data captured on this CMM improved the printing accuracy dramatically. It’s not perfect yet, but I am iterating the process as I am figuring out the steps that need to be taken.

Here you can see the whole of the ROMER portable CMM I used to measure the RepRap. It’s about all the arm wanted to do to fit in and around the printer. Being able to work off the surface plate – a very flat surface – sure did help a lot.

Assuming the jaws of my mic are square, you can see how bad this first print is by the light gap.

The first and 2nd print after the RepRap rebuild. The 2nd one is after tweaks suggested by my spreadsheet. It measures much more square and is visually better as well.

This is a whiteboard plan for measuring 12 points on a RepRap Mendal Prusa and calculating frame corrections to square up the XYZ in relation to each other.

This one isn’t perfect, but you can see it is a vast improvement.