Mar24

Print fans and hotend heaters

by OhmEye on March 24, 2015 at 2:53 pm
Posted In: 3D Printing

A recurring issue that I see often for many reprap 3D printers that have carriage-mounted fans is seeing the hotend temperature plummet when the fans turn on. The common scenario is printing PLA, which benefits from having strong fans cool the plastic as it prints to prevent curling and improve perimeter print quality. Typically the fan is off for the first layer which prints at a slower speed, then turns on when the second layer starts, and the hotend loses temperature quickly due to the increased extruder feedrate and fan airflow, and can take tens of seconds or longer for the PID function to recover and return hotend temperature properly. What’s happening is the PID function is getting caught off guard since plastic is suddenly feeding faster and removing heat from the hotend more quickly, as well as fan airflow kicking in to increase the rate the hotend is dissipating heat and once the temperature falls it struggles to return temp to normal. In the worst case scenario, the hotend loses enough temperature that the hotend stops extruding and/or the MINTEMP cold extrusion protection kicks in on Marlin firmware. ↓ Read more…

Mar11

OhMarlin fork of RepRap Marlin firmware

by OhmEye on March 11, 2015 at 8:47 pm
Posted In: 3D Printing

I’ve merged my Marlin modifications with a newer version of Marlin, in a new github repo.

Status info GLCD screen for DOGM LCDs
display Z coordinates to hundreds, not just tenths
display SD print progress percentage numerically, not just with the bar.
display endstop state by toggling capitalization of X,Y,Z labels in the coordinate line
display 0% instead of — when fan is off.
display long filename when printing from SD instead of short 8.3 filename ↓ Read more…

Mar01

Disabling KILL_PIN in Marlin 3D printer firmware

by OhmEye on March 1, 2015 at 12:56 pm
Posted In: 3D Printing

In rare situations there is an issue that can cause your 3D printer running Marlin firmware to suddenly stop during a print, leaving you to troubleshoot without knowing for sure if you have fixed the cause. One of the first things I look for is something being wired to use the Kill Pin, such as a GLCD panel. Many LCD panels include a switch to press to emergency stop the printer. Most people don’t use it at all and without a panel many printers do not have any kill switch other than the reset switch on the electronics they use. There is no direct danger by not having a kill switch, in my opinion. If you do have a LCD panel with Marlin, there is a Stop Printing menu item on the main menu that works just fine for me. ↓ Read more…

Jun12

Sunset Test Flight on South Maui

by OhmEye on June 12, 2014 at 1:10 pm
Posted In: Fixed Wing, FPV

This was a short impromptu test flight with my CTH Albatross that I flew shortly after sunset at my usual site on South Maui. I was prepping batteries for tomorrow and realized it was almost sunset and perhaps the wind would die down as it often does, so I went out and resulted in this short test flight. ↓ Read more…

Apr24

Building CTH Assassinator

by OhmEye on April 24, 2014 at 10:24 am
Posted In: Fixed Wing

I’ve had a CTH Assassin kit in a box for months, I held off building it while I played with the Albatross and several multirotors, then I wanted to cut my own foam to extend it for more wing area but CTH beat me to it and released an extended version of their own! At first they named it the Assassinator, although if it were up to me I would have named it Sniper. Then they changed the name to Pinata. I know it’s probably because they like bragging about how tough their planes are and pinatas take a lot of whacks. But this plane doesn’t spill candy if it breaks open. đŸ™‚ I didn’t buy the full kit, they sent me just the needed bits for the cost difference, which was nice of Lee to do for me. I’m taking some pics as I build it.

Apr18

My Exodus from GoDaddy

by OhmEye on April 18, 2014 at 11:27 am
Posted In: Random Noise

GoDaddy is domain registrar with high name recognition because of their aggressive advertising and large presence. Every internet service has both fans and haters, and there is no shortage of stories on the web about bad experiences. I moved my domains to GoDaddy a few years ago mainly for the lower costs compared to my previous registrar, and I learned to ignore and work around the confusing website and persistent upsell ads. The bottom level customer service staff seemed helpful enough and things worked ok for those years while nothing out of the ordinary occurred.

Many of the horror stories I had run across involved problems with fraud and theft, and I took them with a grain of salt and also the lack of any expectation that such situations would ever happen to me. Well, they did, and here’s my GoDaddy story. ↓ Read more…

Oct21

DIY lenses for my FPV goggles

by OhmEye on October 21, 2013 at 6:01 pm
Posted In: FPV

I got this cheap pair of glasses from zennioptical.com for my exact prescription for $6.95. Fatshark dipoters cost $19.95 and do not come in my strength and don't correct for astigmatism.

A image walkthrough of how I made my own diopters for my Fatshark Attitude video goggles to use for First Person View (FPV) radio control flight.

Aug23

OhMini iV Quadcopter Prototype

by OhmEye on August 23, 2013 at 10:16 am
Posted In: Multirotor

This is me doing the first flight tests of my OhMini iV Quadcopter and some PID fine tuning to experiment with the flight characteristics. The OhMini iV is a single-piece inverted-V tail frame 3D printed on my MendelMax 2 3D printer. Some pics of the design are at http://smu.gs/1ajpTlp and it uses the same BoM as my OhMini H-Quad which is detailed at http://www.ohmeye.com/2013/ohmini-quadcopter-bill-of-materials-details/ ↓ Read more…

Aug06

OhMini Quadcopter Bill of Materials & Details

by OhmEye on August 6, 2013 at 12:05 pm
Posted In: Multirotor

Here’s the BoM and some details for the components I’m using for the OhMini quadcopters. The big expense is getting all the basic support gear including radios and charger and cables/adapters, but once you have all that you don’t need to buy it again for each multirotor you build. In my case all this stuff is about $160. The quad itself less RX is about $100. I’m using a $18 RX but for this simple quad there are cheaper available, even one for $6. It just has to be compatible with the TX.

Pics of the OhMini Quad and OhMini H-Quad and my nephew’s first time flying a quadcopter. Here’s my fourth flight of the OhMini with an onboard camera. ↓ Read more…