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Re: SAM4S MINI board - 4 years ago
Would it be possible to use a MCP2518FD daughterboard on the SPI header? It's a full CAN-FD implementation in a 2 dollar chip. looks pretty neat. If that works I'd love to add it to the duet 2 in my toolchanger as well. I'd be willing to do dev work on the firmware to support it if needed. Hmm.. I can't see if the SPI port is broken out on the MINI board though.by John Meacham - Experimental and Hobby
Re: SAM4S MINI board - 4 years ago
This looks awesome and is exactly what I'd want to ressurect some old printers. I have one request, can you break out the CAN bus lines of the CPU onto a header? It would be great if one could talk to the duet CAN expansion boards. Are the paneldue tx/rx lines broken out somewhere too? they are handy for hacking. If you have extra PCBs I would be happy to build one up and test it in a corexy orby John Meacham - Experimental and Hobby
Re: Bed flattening option - 4 years ago
For very large format printers a somewhat related practice is used since there is pretty much no chance of a large bed being flat. A sacrificial piece of polystyrene foam is placed on the build plate and the z axis is set with zero being a few millimeters below the surface of the sheet. The print head just melts into the foam and makes its own flat surface as it gos. The foam is single use of couby John Meacham - Mechanics
Re: Better PEI build surface - 7 years ago
Has anyone tried UV curing adhesive. It would be quite easy to apply and place the pei perfectly squeezing out all the bubbles and then blast with UV. PEI probably doesn't let much through, but a longer exposure might do the trick. Even if 99% is blocked, you are looking at only a couple hours.by John Meacham - Mechanics
Re: Timing belt Vs fishing line - 7 years ago
Quoteleadinglights Is this a contest for the shortest and most ambiguous reply Mike Maybe.by John Meacham - General
Re: New Z-Probe uses Load Cell - 8 years ago
Nice, i am attempting to integrate load cells directly into the arms of my Gus Simpson design to allow z probing and general force feedback for other payloads.by John Meacham - Mechanics
[US-Los Angeles] Free prusa mendel hardware, printed parts, j-head hot ends, filament. local pickup only - 8 years ago
Everything in picture is free for local pickup in santa monica except the motor attached to the extruder which is $10 if you want it. (but the extruder and hot end is free.) whoever takes it _must_ take everything, my only request is if you don't use it all, give what you don't a good home rather than dumping it. This is NOT a complete printer and is missing a few hardware bits, but has what iby John Meacham - For Sale
Re: FuseBox ~$300 CoreXY Printer - 8 years ago
Got a first print out of my FuseBox, it was quite painless. It took a week of fiddling to get results this good from my mendel. after some speed tweaking, this thing flys. may need that volcano hot end. Johnby John Meacham - CoreXY Machines
Re: FuseBox ~$300 CoreXY Printer - 8 years ago
Made an IEC mains fuse box adapter for the FuseBox. A fuse box for your FuseBox. thingiverse http://www.thingiverse.com/thing:1719087by John Meacham - CoreXY Machines
Re: FuseBox ~$300 CoreXY Printer - 8 years ago
Started my FuseBox build, All the parts were printed on a Monoprice select mini printer. It only has a few modifications from the standard build so far, I am using a trapezoidal 300mm Z axis and have changed up the frame to greatly reduce the number of unique aluminum cuts needed to build it. I lengthened the legs (to accomodate the extra 50mm of Z and utilize the same size cuttings as theby John Meacham - CoreXY Machines
Re: New print surface material? - 9 years ago
Quotesimspeed QuoteJohn Meacham Out of curiosity, has anyone tried UV curing glue to hold their print surface to glass? The glue is generally good to 180C so should be okay at printbed temperatures. It would be very easy to apply because you can spend all the time you want squeezing the air bubbles out and getting things aligned since it is a liquid before zapping it. I ordered some cheap noby John Meacham - General
Re: New print surface material? - 9 years ago
Out of curiosity, has anyone tried UV curing glue to hold their print surface to glass? The glue is generally good to 180C so should be okay at printbed temperatures. It would be very easy to apply because you can spend all the time you want squeezing the air bubbles out and getting things aligned since it is a liquid before zapping it. I ordered some cheap no name UV glue and will try it witby John Meacham - General
Re: All-plastic 'Snappy' printer - 9 years ago
Although the motion goes on the gantry, with CoreXZ both motors are grounded at the bottom and do not move So not a lot of mass will be added. And printed pullyes and spools are much easier to make perfect than gears in terms of artifacts they introduce, you just attach it to your stepper or drill at full speed and hold sandpaper to the side and it will become perfectly round pretty quickly. Soby John Meacham - Developers
Re: All-plastic 'Snappy' printer - 9 years ago
Have you considered the CoreXZ mechanism? That would allow you to get rid of both threaded rods and one motor. A substantial savings. I am in the process of converting my prusa mendel to coreXZ (via ).by John Meacham - Developers
Re: plastic (composite) frame for reprap printers? - 9 years ago
Have you seen the GUS simpson? no precision linear guides. no belts, everything but the print bed and head is reprapped plastic, and It's precision puts many cartesian bots to shame. The nice thing is its precision is based on geometry, linkages to control the motion paths and tensile strength of the fishing line, you are not limited by the quality of linear rail or leadscrew you can get. EDby John Meacham - General
Re: extra power to mega2560 - 9 years ago
Resistive voltage dividers won't work for actually powering anything. They only work for driving constant impedance loads and even then are not great unless the load is very high impedance (draws negligable current) You in theory should be safe putting 12V into the DC jack technically, however, you are dropping a whole lot of heat with the on board regulator and it is likely already stuck underby John Meacham - Safety & Best Practices
Re: Installing safety system on my printer - 9 years ago
A big thing one can do for reliability is use thermocouples instead of thermistors, they can be bolted right onto the hot end, no tape needed. the controller has detection of disconnection built in, and if you hit em with a hammer they just become a better thermocouple rather than shattering. Not to mention you can always trust the temperature is the 'true' one since they give absolute readingsby John Meacham - Safety & Best Practices
Re: M Prime One, an open and simple 3D printer - 9 years ago
Very clean looking design, do you have some video of it running? It is not immediately obvious to me how the X (or is it Y..) moves. Do the bars themselves move, like a rack-and-pinon style movement? That is neat, not something that has been popular, but printable, unlike pully belts.by John Meacham - General New Machines Topics
Re: A 'real' robot arm? Where to get it? - 9 years ago
I have a scorbot III, they can be found cheaply on ebay every now and again, perfect desktop size. I have not tried mounting a print head on it yet though, but shouldn't be hard to adapt some of the rotary firmwares to it (like morgan) as you can easily constrain it to just rotate and extend like the morgan.by John Meacham - Polar Machines, SCARA, Robot Arms
Re: OB1 Prism - 12 years ago
Nice. I was actually working on a design using openbeam or hfs-1515 from misumi (they are both 15x15 and can use m3 nuts). Though, I was doing something similar to the 'aluminum mendel. The prism shape isn't really needed when using precise aluminum extrusion. At least, that seems to be the consensus.by John Meacham - General Mendel Topics
Acetone : ABS as ? : PLA - 12 years ago
One of the nice things about printing with ABS was that ABS dissolves pretty much completely and easily in acetone, which is cheap and easy to get anywhere. It made things like cleaning a jammed nozzle trivial. Just drop the hot end in acetone and you are done. Plus, the ability to create "ABS glue", a mixture of ABS and acetone is just so handy. It will bond ABS to ABS as if they were a single pby John Meacham - Polymer Working Group
Re: Differences in PLA vs. layer evenness - 12 years ago
Could it be that the bad filament absorbed more water from the air? Once you break the seal on PLA it "goes bad" pretty quickly in humid climates. You could try baking it in an oven for 4 hours or so and see if it helps. I was able to revitalize some PLA I had that way, but it may have been a different issue than you have. When it absorbs water you can sometimes hear it pop and fizzle as the watby John Meacham - General
Re: Autotune problem - 12 years ago
You could be overheating your power MOSFET. try pointing a fan at it or adding a heatsink or both.by John Meacham - RAMPS Electronics
Re: Filament diameter feedback - 12 years ago
A bigger problem is determining if your filament is even round. If your filament isn't perfectly round, just measuring diameter is not enough and it becomes a much harder problem to solve. Are you sure your diameter discrepencies are not because your filament is slightly oval thus causing different measurements depending on the orientation of the calipers? If we can't count on a consistent widtby John Meacham - Controllers
Re: Very cheap RAMPS compatible hall sensor - 12 years ago
It should be fine, it will just trigger closer and you will have to make sure it is aligned. Seeing as how it can sense the really weak rubberized refrigerator magnets. For a reference, it triggers at about 15mm away for my strong rare earth magnets. What it actually senses is the amount of magnetic flux perpendicular to the face of the sensor, meaning the iron bars are going to affect it someby John Meacham - RAMPS Electronics
Very cheap RAMPS compatible hall sensor - 12 years ago
I found a very cheap (19 cents) hall effect sensor that literally perfectly meshes with ramps. You just stick the sensor in one end of a servo cable and plug the other end into the ramps board as is, and it works perfectly. much cheaper than switches or optos and very reliable. I wrote it up on my blog. The only issue I found is that there is a slight hysteresis in the sensor, meaning that thby John Meacham - RAMPS Electronics
Simple fix to keep boards from getting fried... - 12 years ago
Judging from experience, and the forums, there is a particularly troublesome failure mode for the extruder that people tend to run into which has a tendancy to destroy motherboards/power supplies. That issue is that eventually the insulation around the thermistor will wear through, causing one side to come in contact with the nozzle, said nozzle may actually already be shorted to one of the railby John Meacham - Controllers
Great alternative to kapton tape for holding hot end electronics together. - 12 years ago
Something I have found to be a pain is the kapton taping up the heater and thermistor to the nozzle of the extruder, Even though the kapton can take the temperature, it is annoying to undo when I need to clean the head and it is difficult to make tight enough that the thermistor leads don't abrade and eventually short, plus it just takes a few tries to get everything taped up. Happily, I have foby John Meacham - Plastic Extruder Working Group
Re: First Solar Powered 3D printer - 13 years ago
I run one off batteries on occasion, since I use XT60 connectors for power, I already had some batteries that just plugged right in. handy when I was moving things around and didn't have a good path to run a power cord to the wall. Johnby John Meacham - General
Re: Upgrade your bed springs –> improve your print quality - 13 years ago
I have done the same thing. In fact, I have switched my prusa to have only a single type of spring throughout, I bought the 9657K155 springs from mcmaster to remove the z backlash by pretensioning the nuts. It came as a pack of 12 so I figured id use the extra. Also, for some reason I felt guilty gutting perfectly good pens. I'm just weird like that sometimes though. In any case, I think usinby John Meacham - General Mendel Topics