Belts and gears

Here are some resources for belts and gears and other "drive" items:

http://www.sdp-si.com/ - they have an extensive online catalog and technical education material section.
http://www.econobelt.com/
http://www.drillspot.com/



BTW, the info first came from chiefdelphi.com - a robotics related forum.

Goertzel algorithm for tone detection

Came across an interesting algorithm today - the Goeretzel algorithm - which is used to detect specific frequencies in a sample. For example, detecting DTMF presses on the phone. There is a write up in wiki: http://en.wikipedia.org/wiki/Goertzel_algorithm

A SDCC dev list member pointed out that for some applications, it is sufficient to use quadrature square waves to detect/demodulate specific frequencies. I need to look into this more (see sdcc user request list 2009-May-14 from Scott Dattalo). So far, I've come across:

http://en.wikipedia.org/wiki/Detector_(radio)
http://www.commsdesign.com/showArticle.jhtml?articleID=192200456

Administrative / Business Resources

Project Management Resources:

• http://www.projectconnections.com/ - Premium membership includes templates/forms that are useful for gathering requirements, doing statement of work, proposals, et cetra.

Checklist for making and selling a product

Checklist of things to consider when making/selling a product:

Marketing

• Market analysis of pricing and competitive space
  
• Website
• Print and pdf brochures
  
• Print or Broadcast Advertising
• Search Engine Optimization / Online Ads

Sales and Fulfillment

• Customer service via website and telephone.
  
• E-Commerce platform / payment acceptor (credit card, paypal)
  
• Packaging and Shipping

Support

• Product documentation - Installation manual, operation manual / user guide.
• Customer support via website and telephone.
  

Branding

• Brand Style guide
• Design language
• Brand name, logo, tagline

Product Design

• Software
• Electronics - Hardware, firmware
• Mechanical
• Industrial design
• Design documentation - manufacturing documentation, field support documentation. Part number and revision tracking.

Supply Chain

• Manufacturing capacity (lead time, throughput)
  
• Logistics (for production and fulfillment)

Regulatory / Compliance / Standards

• EMC (FCC, CISPR/CE, +much more!)
  
• Safety (UL, CE, +much more!)
• Environmental regulation (WEEE, E-waste fees, RoHS)
  
• Any other applicable industry standards

"Cultural" Factors

• Local regulation (with possible requirement for local representation for market or regulatory reasons)
  
• Language issues

IP

• Are there existing IP conflicts?
• Can you generate new IP that are defensible?
  
• Can you license the IP instead of making/selling the item?
  

Design firms

I'm using this post to collect design firms... This is just a list. I have no experience/endorsements/etc.

http://www.designcatapult.com/ - Offers a "$5,001" "mind jog" service.



Motorola has their own rapid prototyping service now! http://www.1prototype.com/index.html

RoHS and WEEE

The EU rules on RohS/WEEE are 2002/95/EC and 2002/96/EC:

The RoHD directive (http://www.rohs.eu/english/legislation/docs/launchers/launch-2002-95-EC.html) prescribes the elimination of various hazardous substances. The specific limits does not appear in this document. Instead, 2005/618/EC (http://www.rohs.eu/english/legislation/docs/launchers/launch-2005-618-EC.html) amends 2002/95/EC and prescribes the limits:

‘For the purposes of Article 5(1)(a), a maximum concentration
value of 0,1 % by weight in homogeneous
materials for lead, mercury, hexavalent chromium, polybrominated
biphenyls (PBB) and polybrominated diphenyl
ethers (PBDE) and of 0,01 % by weight in homogeneous
materials for cadmium shall be tolerated.’

(0.1% = 1,000 ppm. 0.01% = 100ppm)

The Waste Electrical and Electronic Equipment (WEEE) directive (http://www.rohs.eu/english/legislation/docs/launchers/launch-2002-96-EC.html) prescribes actions to reduce the entry of EEE's into waste-streams with directives for design for easy recovery of materials, and setting up collection programs for spent devices.

Schematic / PCB release checklist

Part Numering

• Part number should be of the form:
• nnnnnnnn-vvv rrr
• Where nnnnnnnn is the base part number
• Where vvv is the variant number
• Where rrr is the revision indicator (Rev. A, Rev. B, Rev. C, Eng. A, Eng. B, Proto A, Proto B, et cetra)
  

Schematics Prep

• On "full" designs, have a cover page with specification. (Not needed for quickie jobs.)
  
• Be sure to have a title block, including part number, revision number, sheet info, etc.
• Don't be afraid of multiple pages and using blocks. Use net-name connections to your advantage.
  

Parts Library

• 
  

Componet Selection

• When choosing the part, verify RoHS / LeadFree, and that there are no other limitations (max temperature, no-water-wash, et cetra). If any special requirements exists, make sure that is noted on the schematic.
  
• Cross check the mfg part number and device footprint between the datasheet and Digikey/Mouser.
• Verify that the mfg. part number corresponds to the desired footprint. Cross check Digikey and the datasheet.
• 
  
• Do a digikey/mouser scrub.
• Confirm that each pcb part has the correct p/n and footprint. Look at a sample of each component type to make sure it "looks right".
• Identify key components for performance/safety reasons -- indicate no-substitution for these items.
  

Connectors

• Make sure connector clearances take into account the Z height as well as PCB footprint.
• Make sure there's plenty of room to route cables, and to connect/disconnect any internal connectors. Make sure your fingers (or tools) can get in there!
• The schematics should have a drawing showing connector pin-order for easy reference. Include the drawing of the mating cable, too.
  

Board Prep

• Define board size. Verify that the board size will fit in the intended enclosure.
• Make sure you define a 3/8" rail (or component clearance) on parallel edges so that the board can sit on the reflow oven conveyor
• Locate the board "origin" 1-inch from the edges of the PCB document.
• Draw the outline of the board on a mechanical layer, and put dimension information.
• Draw the keep-outs of the board.
• Make use of multiple drawing/mechanical layers to write in comments, add mechanical outline information, show tab-routing details, silk-screen notes, et cetra. Enclosure drawing should be in here, too.

Board Design

• Board hardware (PEM nuts) should have location markings.
• The BOM should specify part number, diameter, threaded/non-threaded.
  
• Board hardware holes should be unplated
• Large mounting holes for solder-mounting should have large spacing to traces and vias to prevent bridging. (Hint: create a design rule to enforce this on specific holes/pads)
• Make sure all mounting holes are the right size, have the right annular ring, and that any hardware that come in contact with the PCB will clear components, vias, and traces.
  

Board Footprint Design

• Verify that pin #'s are correct, and that there are no duplicate / overlapped pads
• Verify that the footprint matches the drawing, and that both are drawn with the same orientation (sometimes, mech. drawings show details from the under-side)
• It's helpful to create a separate mechanical layer just to take measurements.

Pre-release scrubbing

• Make a BOM showing component mfg, p/n, digikey p/n and footprint.
• Generate a preliminary BOM to review. Confirm that each schematic part has the correct p/n and library part. Make sure that the library part is non-generic.
• Be sure to specify panelization information in a drawing. If 1-up'ing the board, make sure there is component clearance on parallel edges of at least 1/4" on each side. If N-up'ing, make sure the panelization will fit on a standard panel. (18"x24" panel?)
  

Release Procedure

• Make sure part numbers and revision information is up to date on the schematic & PCB.
• Save a dated copy of the schematic and the PCB.
• Export PCB file in ASCII format acceptable to the board house.
• Generate a final BOM. All relevant info should be generated from the schematics, and not require manual edits.
  
• Print PDF of the schematic, and the board assembly drawings.
• Generate CAM files: create Gerbers, pick-and-place data.
• Put together a "Readme" file, specifying contact info, build notes, board construction details (thickness, layers, plating type, RoHS/NoPb process, UL/NoPB markings as needed, et cetra, water-wash ok). Text file listing filenames and their use.
  
• Add any assembly pictures or drawings.
• Add any mechanical drawings and CAD models if appropriate
• Put together a separate ordering info document specifying turn-around time and quantity
  

Additional Items

• There should be at least a preliminary product documentation.
• There should be a complete board test/checkout procedure for pilot/production runs. (Not needed for initial prototypes).
• Manufacturing fixtures (jigs, wiring harness, testers, etc.) should be designed and documented as well.
• Provide plenty of pictures.
• Maintain a post-release bug list / improvement list / ECO list to be incorporated into the next revision.
  

See also:

http://www.xteradesign.com/xds/panelization.htm