Regular Member Meeting 2014 04 08

From HacDC Wiki

Time and Location

April 8, 2014
Called to order at ____ by _____.
Members present:
Others present:
Quorum met?

Approval of Previous Meeting's Minutes

Annual Meeting 2014


  • Everyone involved in moving the Scanning Electron Microscope!
  • Ben Mendis (sitwon) and haxwithaxe for truck driving!
  • Zach for improving CNC mill, Laser Cutter, and 3D printer functionality.

Director Reports

President's Report

Vice President's Report

Treasurer's Report

Here is the financial summary spreadsheet for March 2014: File:HacDC Financials 2014 03.pdf. We gained two members in the past month: Christopher Hermance and Kevin Cole. We lost one member, Alex Stone. We have 48 dues-paying members in good standing, two permanently dues-waived members, five temporarily dues-waived members, and three members who are behind on dues.

Project Awesome

Here is the Project Awesome spreadsheet for March: File:HacDC PA Projects-2014 03.pdf. We were back to a positive cash flow last month, so I can declare a Project Awesome dividend of $300 while adding the remaining $103.84 to our unearmarked reserves. There were 14 votes, unchanged from the previous month.

Secretary's Report

Director-at-Large Reports


We moved the SEM! It was quite an adventure and I'd like to thank everyone who helped us out with this.


Project Awesome Reports

Project LASER




Still healthy and stable. Pleased to see this month's expenses almost exactly matched income. Plan to spend the SUPPLIES fund as necessary to repair HacDC equipment. So long as we have at least a few hundred dollars reserve, this includes replacement parts for new equipment like the SEM.


  • $57.95 Dial Test Indicator (Used to level the CNC mill.)
  • $20.47 Air dusters (General purpose and SEM cleaning supply.)


  • ~$100 in filament from Microcenter (receipt not yet submitted).
  • ~$10 LetraTag Material for Label Maker (need to order)
  • ~$80 in SEM supplies (projected)
  • ~$80 for EPSON T5646 Light Magenta Ink Cartridge

Some of these may be delayed, due to the $250 spending limit.


There have been no objections raised to purchase of a small vertical bandsaw like this one for less than the existing $145 budget:


This should be at least as usable as the last bandsaw. Given our present financial situation, I think we should just get something suitable for cutting CNC mill/laser cutter stock rather than seek a more expensive machine.

If there are still no objections, will select the best one within the current EXPANSION budget, and direct Katie to order it. Preference will be given to support for cheap, standard blades.


Member Reports


Prusa Mendel

Was on the fence for a while what to do about this beast. After approximately 300 hours of work, there was every reason to expect the last maintenance cycle would be the last. However, multiple spontaneous failures now cast any plans for long-term stability into doubt. Even if we actually did stabilize it, the effort would be sunk into a slow (45mm/s vs. 300mm/s) machine with ever-present alignment issues. First-layer alignment in particular has been particularly difficult to maintain to any reasonable degree. The non-linear surface has been estimated as a 6th order problem.

Current state of the art designs are likely more than an order of magnitude better, using a 'delta-bot' configuration and highly rigid construction from aluminum extrusions. Such designs are not subject to many of the fundamental design flaws our Prusa Mendel suffers:

Recommend we either purchase one of these, or direct our efforts away from 3D printing until we are ready to fully polish off our own designs (eg. Optical Table, Flex Replicator, etc).

Recommend the Kossel mini kit ($600 + shipping). Julia Longtin (aka. juri) has expressed an interest in getting it running, in exchange for taking our Prusa Mendel. That would also give us some hope that it may become an experimental machine for educational purposes.

We also have an opportunity to pick-up one of these high-grade printers for free at USASEF. Efforts are being made to inform HacDC BOD and members participating in USASEF.

Biosignal Amplifier

As a reminder, fully operational and documented:

Photolithography PCB Fab

As a reminder, fully tested, working, and documented:

Need to create a 'photolithography materials' box to keep the equipment organized and available.

SEM Progress

Organized the wiki pages and began research on replacement electronics. Looks like we need an FPGA managing a bunch of I2S ADC/DAC devices typically used on high-end 24bit 192kS/s soundcards. Have already thoroughly investigated the FPGA toolchains, and HacDC should have already have some usable FPGAs to begin experiments.


Nearly there, another HacDC member has the final Giant Fresnel lens. Projector construction can commence once lens has been retrieved.

Imagnus, Flex Replicator, Optical Table

Still in the same state as last meeting. All in progress.

Unnecessary Mess

Spent >3.5 hours cleaning up work benches at HacDC. Some of the more egregious problems included a melted space heater plug, still plugged into a power strip, a messy chemical spill, and misused solder paste left exposed. In all cases, the responsible parties could have cleaned up much more easily before leaving.

We can do better, and for a long time we have done better.

This does not concern any new items showing up at HacDC, nor project SEM, and probably not any other ongoing activity. Looks like someone using the space couldn't bother to put tools back where they came from or clean up after their mess. Seriously, who here feels comfortable leaving the space with a chemical spill on a work table to harden into sticky residue for the next user? Since I don't know, I can only politely request it not happen again.

This also goes for anyone administrating HacDC events - please watch your guests.


Literally just disposing of the sheer quantity of e-waste is a problem, owing to past inability to dispose of junk more frequently. Failing other options, Waste Management 'dumpster in a bag' is a possibility, at a cost of approximately $200 (not recommended).

Old Business

New Business

Allocate at least $750 to purchase and commissioning of a new 3D printer. Authorize Julia Longtin (aka. juri) to take possession of the existing Prusa Mendel 3D printer, in exchange for getting the new 3D printer up and running within a week of delivery. All contingent on not getting a one of the three proposed printers free by April 28th, 2014.


In order to move the SEM I rented a truck and drove it down to Norfolk and back. I would like to get reimbursed the $724.94 for the truck rental.

New Members


Adjourned at ______.