Jeremy Singley’s VTC Electronic Notebook

 

Spring ‘05

 

 

 

This web site is a record of Jeremy Singley’s contributions to collaborative design projects with students and faculty of Vermont Technical College’s Mechanical Engineering Department and with off-campus clients. 

 

 

Sleigh Bed:

 

At a meeting of the Vermont Wood Manufacturers Association in Hardwick last October, Jack Brown of Brown Novelty mentioned he wanted to build a sleigh bed for his wife but was having trouble finding suitable plans.  I suggested I might be able to find something among my sources.  I found only one design, which recurred on all the sites I checked.   Jack bought a set of plans for this design from Furniture Designs, Inc. - Full-Size Professional Woodworking Plans

 

We met to discuss alterations that would make the design more suitable, at which time Jack unveiled a photo his wife had torn from an interior decorating magazine and left suggestively lying around.  Other design versions turned up at www.bedroom-furniture-direct.com.  The bed in the photo was far more attractive than the one we were considering, so we decided to re-work that design, using dimensions from the purchased plans with adjustments to suit Jack’s bedroom.  Since Jack is an amateur wood worker, he also suggested we might simplify the design by eliminating the vertical panel rails and by using straight rather than faired side rails.  This latter would mean that all the curves would be limited to the bed post contours only.  Jack also wanted a sturdier look, so we agreed to use 7/4 D2S stock for the rails and ¾ inch hardwood ply for the panels.  The bed in the photo had contrasting panels, which we agreed made the design more interesting, so I suggested Jack might want to contact our mutual associate, Randy Flint of Fine Lines in Wood in New Haven, to look into having the plywood veneered with a figured wood.  We discussed possible frame materials and Jack said he’d look among his stock.  He called back with the news that a prior Brown Novelty job had left over some suitable mahogany that went well with his bedroom suite, so we decided to use that. 

 

 

I put together a proposed design, sleigh_bed_1, and met with Jack at his office.  Jack expressed concern that the legs might be over-delicate due to short grain.  I agreed with his assessment, changed the leg profile, and faxed him a sturdier revision.  He penciled a still beefier version over mine and faxed it back.  Unfortunately his revision somehow lost an inch or so of height in the translation, which wouldn’t match his original specifications.  I puzzled over the problem and realized we were fighting the fact that I had leaned the leg too far out of plumb in my effort to match the magazine photo.  Our use of straight side rails in place of the photo’s faired ones made this an unworkable idea, so I straightened the legs in my third proposal.  Meanwhile the bed rail fasteners Jack had selected and ordered from my Rockler woodworking hardware catalogue had arrived.

 

The latest improvement follows up on the realization that our design need only be loosely beholden to the magazine photo.  This reverse-leg idea eliminates the visually odd—and structurally questionable—perpendicular grain juxtaposition at the side-rail/post joint.  If  the top edge of the joint is pinned it also eliminates the tendency of sleigh-bed joints to show a gap over time, since the bottom of the joint can float.  I met with Jack once more in February and he enthusiastically approved the idea.  At this point we’re not far from a design that may actually be commercially viable, which makes the project somewhat serendipitous.

 

I turned in the final plans to Jack when he and I crossed paths at the Vermont Wood Manufacturers’ Association’s April meeting.  He approved them overwhelmingly.   Here are the designs and drawings for Jack Brown’s bed:

 

Sleigh Bed as of March 21, 2005:

 

·        Assembled Bed

·        Bed Exploded

·        Left Headboard Post  

·        Left Footboard Post   

·        Bottom Panel Rail

·        Top Panel Rail  

·        Side Rail

·        Panels

 

We won’t know how much torque the top panel rails will withstand until the bed is test assembled, so I added optional dowels to be installed as needed.   The full-scale patterns of the headboard posts and footboard posts have also been completed and these I will transfer to Jack when we next meet.

 

As an illustration of how winding is the road to a done design, here are some past trials and errors:

 

·        Early sleigh bed drawing

·        Reject headboard post pattern (one post backward!)

·        Fiddling with leg contours, only to reject the entire forward-leaning concept.  (The legs in each trial are a little different from one another, though it’s hard to tell.  Rule of thumb:  if you’re tweaking and it’s not getting you there, you’re working with the wrong shape entirely.)

 

A development that certainly makes my job easier was Jack’s revelation at our February meeting that he has a degree in Mechanical Engineering.  Using skills he learned in a course on production sequence planning, he showed me how he had made a cut sequence sketch and rough-cuts list from the top panel rail drawing I had left him previously.  His efforts to come up with his own production plan saves me a tedious job.

 

My last contribution to the project was to find a picture of a crotch-figured mahogany panel on the web and paste it into the model of the bed.  This can be seen at the Sleigh Bed Project Web Site at http://web.vtc.edu/MEC/1012/Spring_05/Projects/Sleigh_bed/Project_page.htm

 

Wood Processor

 

Early in the semester Roger Howes visited our Design Communication class to pitch his wood processor as a project.  After he showed slides of a machine that used a single chainsaw bar to cut logs to length, I suggested using a band mill in place of the chainsaw bar to increase the processor’s yield.   He invited me to submit a concept.  I made a video demonstrating how using a grapple to lift an entire log virtually free of the conveyor would allow the band saw blade to slice off two billets at once without pinching.   The spacing of the blade’s two cutting edges would of course be adjustable using gang-saw technology.   Since this website seems to be evolving into a dissertation on how the path to successful designs are often littered with dead ends, I’ve included a reject grapple design.

 

 

Super Charger

 

Dan Reid and Mike Petry are designing a Roots supercharger.  I shared with them some photos I took at a recent car show:

 

·        Large Roots Blower on a 440 Dodge Charger

·        Another View of 440

·        Small Roots on a hot rod

·        Another small Roots example

·        Small Roots with forced fuel

 

Dan’s and Mike’s interest in the Roots re-kindled my own high-school curiosity as to how one works.  I found two excellent Web sites that I also shared with them:

 

http://www.sdrm.org/roster/diesel/emd/history/roots.html

 

www.cashflo.co.uk/Roots.html

 

 

RC Flying Wing

 

During the semester I had several casual conversations with Eric Hall concerning his camera mount design for the RC Flying Wing project.  I suggested various off-the-shelf hinges and other hardware that might help cut down the number of parts he’d need to model from scratch.  I also discussed modeling shortcuts with Shawn Clemment, which I followed up with an E-mail.

 

 

Surface Modeling

 

As the class was discussing project proposals early in the semester, Shawn Clemment suggested some of us might model auto bodies.  Mr. Johnson’s response was that Autodesk Inventor might not have the brain power.  As an industrial designer I need to be able to create any possible shape, so I had been experimenting with Inventor’s modeling capabilities on my own and finding hidden powers therein. During Spring Break I modeled a collection of car bodies and unveiled them in class.  Mr. Johnson saw potential in my methods, but he also saw where his experience could improve my results.  Between classes we sat down together and he showed me how using symmetric angle-constrained bow ties could result in cleaner models.  Ditto using the conditions tab to loft from existing surfaces; and using “thicken” to add a normal edge to a compound surface feature.  For lack of a better place, we saved our work in a folder he created in the Projects folder.  Throughout the semester Mr. Johnson continued to coach me and I saved much of my work in that folder.

 

At year’s end Mr. Johnson felt it would be a good idea to make what I’d learned available to future classes, so the Modeling files in the Project folder became the Surface Modeling Project Web Site:

 

  http://web.vtc.edu/MEC/1012/Spring_05/Projects/Surface_Modeling/default.htm

 

 

Assignments and Challenges

 

In addition to Projects, there was class work throughout the semester:

 

Assignment 1

·        Piston Assembly

·        Connecting Rod

·        Piston Assembly Drawing

·        Piston

·        Cap

·        Design Guide

·        Concept Sketch

 

Assignment 2

·        Bottom

·        Top

·        Knob

·        Assembly

 

Assignment 3

·        Press

·        Cast Base

·        Press Base Machined

·        Handle

·        Press Block

·        Press Base Check Sections

·        Plug

·        Connector

·        Design Guide

 

Assignment 4

·        Model

·        Check Sections

 

Assignment 5

·        Revised Base

·        Revised Pin

 

Assignment 6

·        Release

 

Challenge 1

·        Bearing Adaptor

·        Mount

 

Challenge 2

·        Base Casting

 

Challenge 3

·        Fork

·        Base

·        Fork Drawing

·        Base Drawing