Category: Blog Posts (Page 13 of 15)

The final edition of the penholder has been completed and nearly approved for commission as one of the shop training projects. In this most likely final blog post, we would like to do a brief review of the purpose of the project as well as go over a further inspection of the penholder and discuss the final outcome.

Purpose

To review, the penholder project concept was birthed as a way to give students more options for fabricating a project that gives them appropriate training with the shop’s power tools. We figured that a project is the best way for students to be trained, but we realized that there were some complaints with the old project, which was a wall hook. The wall hook was impractical as it had to be drilled into a wall for usage. However, drilling in dorm walls goes against residential life policy at Tufts. In addition, the project was also relatively dull and it also existed as the only option available for power tool certification. Therefore, we brainstormed ideas for new project ideas that were practical, creative, but also didn’t sacrifice using all of the power tool equipment, override the budget, and take too much time. Thus, the penholder idea was born.

The final penholder CAD design is shown below:

Build Process

Naturally, it is important to describe the details of the fabrication process.  The project incorporated the use of every power tool in the yellow zone of the shop. Therefore, we succeeded in our main objective – giving students adequate training in all tools. In terms of a time estimate, we didn’t keep a sturdy time count, but it was estimated the project would take about 4 hours to complete. It is also important to recognize time for errors and miscalculations, which are important as part of the learning process. Therefore, the project is a quite a bit long, but not too long to dismay students, we think.

Tool Usage Diagram

Further inspection: hindrances and benefits

We certainly like the design and practicality of the penholder. However, one aspect that gave us some trouble was the number of holes needed for the design. If we had more time to develop a better design, we would try to brainstorm a way to reduce the number on the top support; an attempt is shown below but would not securely fasten the arms with only one hole. Hole reduction would save time needed to fabricate, as well as decreasing the chance of having to redo the most intricate piece. Additionally, the penholder used more material and cost about 2.8x the wall hook.

Previous penholder design

An appealing aspect of the penholder is that there is slightly more margin of tolerance than the wall hook. Since the wall hook worked with such small pieces, it was incredibly easy to make a small error, but small errors would also be overwhelmingly apparent. Since the penholder involves working with bigger pieces, errors can definitely still be noticed, but there is slightly more room for lesser mistakes without affecting its aesthetic or functionality; this is important because most people will be able to make a functional device. We noticed that many people would complete the wall hook and they would look quite crooked and in some cases, unusable. We hope that people will still make mistakes so they can learn, but also be happy with their object at the end of fabrication.

Additionally, it may be worth mentioning that we polled some incoming freshmen about which design they prefer if they had to fabricate a project. We showed them the completed penholder and wall hook and the majority preferred the penholder. Since this was such a small sample size, it doesn’t capture the entire sentiment and tendencies of the student body’s preferences, but we just thought it their preference was reassuring. Also, it is important to understand that the wall hook will still remain a viable project for students to create for their training. They will now just have the option to do either the wall hook, penholder, or picture frame (which will be discussed in a separate blog post).

We have submitted our drawings for final review by the fabrication supervisor. We are excited that the design will hopefully be approved and ready for fabrication by students in the upcoming semester.

Other Media

Part Specifications

This week we moved away from modeling the table with foam, and began working with the wood that we will use to build the final table. At the beginning of the week I continued to practice making finger joints by hand, using a Japanese Z saw, chisels, and a mallet.

The finger joints will connect all sides of the table wrap

Yesterday, we went to Home Depot and back to Nedlam’s Workshop at Malden High School to prepare the wood for the final table. First, we used the jointer to make sure all of the wood was flat and square before we made any exact measurements or cuts.

Using the jointer at Nedlam’s Workshop

Next, we measured the final widths of our boards and drew up some sketches to plan out how to cut the rest of the wood.

Final measurements for the table wrap

With our measurements planned out, we began by cutting all of the wood to the correct width using the table saw. First, we cut the legs of the table, then we cut our side boards. Once the wood was cut to the proper width, we set up the table saw with dado blades. These blades can be stacked together (shown below, right) to produce a thicker cut than the width of just one blade.

http://www.toolstoday.com/images/dado-Saw-Blades-header.jpg

With the dado blades in place, we cut channels in each of the boards that the plywood base will sit in once the wrap is assembled. Once the channels were made, we used the miter saw to cut our boards down to the correct length.

Mickey helped us set up the dado blades and cut the channels

When we returned to Bray, it was time to glue our plywood together and prepare the MDF legs for milling practice. Once we test the Vcarve files on the MDF legs, we can mill the actual legs.

MDF legs clamped down while drying

Next, we will be making the finger joints on our eucalyptus boards to create the table wrap, milling the topography out of plywood, and assembling the table!

Wentworth Institute of Technology

The Bray Lab staff and summer interns visited the Center for Applied Research at Wentworth Institute of Technology in their Department of Architecture. The Center supports bachelors (sophomore year and above) and masters students in Architecture – around 450 students.

Vacuum Forming Process at WIT

The newest edition to the Center – Kuka Robotic Arm

MassART

Lee MacDonald, Studio Manager at MassART gave us a tour of some of the fabrication spaces at MassART.

MFA

Finally, we wrapped up our field trip with a visit to the Museum of Fine Art which offers free admission for Tufts students.

Below is a picture of how Charles and Ray Eames applied the methods they used for designing and making furniture to creating mass-producible leg braces during World War II:

Group photo in the Japanese Garden:

Over the past weeks, I have been working to set up tutorial and reference pages on how to use the Othermill for 2D and 3D pieces. I included information I found on the Othermill support page, other online tutorials, and tips and tricks I found to be useful from my own experience with the machine.

2D Work

This tutorial goes over both the basics of the Othermill and its physical set up, as well as how to use use the relevant pieces of software. By walking through the set up of a sample file, users are reminded of how to properly format it. The tutorial progresses from a pre-made design in illustrator, to the properly formatted file, explains how to set it up using the Otherplan software, and finally describes the steps necessary for the physical set up. Although it is thorough, the tutorial should not be used to learn how to use the tool. Instead, it should be used for students to reference for help after the trainings. Below is an example of what can be done using the 2D capabilities of the Othermill:

Simple 2D file created in illustrator to create a wooden coat hook

Solid wood coat hook milled using the Othermill

3D Work

The 3D tutorial page does not cover as much of the Othermill basics. Since the physical set up is very similar, it assumes that the user would already have a firm grasp on how to use the tool. Instead, it focuses on converting a model into code that the Othermill can understand. To achieve this, I used Fusion 360. It is an extremely powerful CAD software with a CAM environment. Due to the the vast capabilities of the software, the tutorial had to be quite extensive and detailed. I included some screen shots of the more complicated menus along with appropriate labels. I would advise against using this tutorial as a singular resource to learn how to create 3D topographies using the Othermill. Much like the 2D, it is intended to be a reminder of what was taught during trainings. Below is a sample piece that was made using the 3D capabilities of the Othermill:

CAD model of piece to be milled

Final 3D piece created using the Othermill

We have finished modeling the Penholder after several iterations and have fabricated a working prototype.

Assembly of penholder prototype 1.1

Photos of the built prototype:

Drawings of individual Penholder parts

Penholder Baseplate

 Penholder Arm Support

Penholder Top Support

Penholder Main Support

The Penholder successfully holds pens! It has the same number of tap drills as the wall hook but uses more half by quarter inch material and sixteen inch sheet metal.

This week was focused on modeling the coffee table with various practice materials to get an idea of what parts of the building process might be tricky, practice joinery techniques, and  finalize design elements.

Originally, the legs were going to sit on the outside of the table, with the sides of the table resting on them (seen below, far left)

Evolution of table leg design

After practicing with the XPS foam (shown below), we redesigned the leg several times before deciding on a final plan (above, far right). Now, the sides of the table will sit on the outside of the legs.

Examples of the leg with slots

Instead of trying to create perfect right angles on the CNC Router for the side or reinforcement pieces to fit in, the head of the leg will be cut on the CNC and then two holes will be drilled on both sides for wooden dowels.

Yesterday, I took the practice wood to Nedlam’s Workshop at Malden High School to  plane it before we started building.

Using the jointer at Nedlam’s Workshop

Next, I began practicing making finger joints with scrap wood. The joints will connect all four sides of the table.

Throughout next week I will continue to practice the necessary woodworking techniques, finish building the practice table, and plan out the construction of the final coffee table!

This week the Bray Lab staff and summer interns visited Artisan’s Asylum, a non-profit community fabrication center in a 40,000 square foot warehouse located in Somerville.

We got a chance to checkout the setup of their equipment stations:

Artisan’s Asylum – Soldering Station

Artisan’s Asylum – Jewelry Station

Artisan’s Asylum – Casting Room

as well as their storage methods:

Artisan’s Asylum – Vertical Storage

We met the Overhaul robot featured in BattleBots and spoke with one of its makers.

Artisan’s Asylum – Overhaul BattleBot

We checked out some of the builds to gain inspiration for projects in Bray.

Artisan’s Asylum – Coffee Table

Lately, one of the 3D printers in the Design Lab has been acting improperly. Upon extrusion, the filament would not come out straight from the driver. Instead, the material would bend upwards, often times catching itself on the extruder or creating clumps and knots in the filament that wouldn’t stick to the bed.

We originally thought that there was a clog in the extruder screw tip, so our first goal was to replace it. Also, the extruder was covered in plastic and was missing some insulation tape, so we figured that melted plastic was interfering with the path of the filament or that the tip wasn’t heating properly which would impact the state of the material as it extrudes. Either way, we thought that if we replaced the screw tip, cleaned up the melted PLA, and added more tape, the 3D printer would revert to extruding properly. We began this process by removing the extruder from the conveyor track and preheating it so we could chip away the melted plastic. Once the driver was cleaned up we completely took apart the extruder and examined it for any issues but couldn’t find any obvious problems. From there, we removed the screw tip, which was much harder than expected. We then removed the old tape bits and added a fresh layer of tape and reassembled the extruder. However, when we tried printing, the same problem would occur.

We decided to take apart the extruder once again to look for problems with the individual components within the feeding mechanisms. Once we removed the fans and heat exchangers, we could get a better look at the gears and tubing that leads the filament into the tip.

The gear system that clamps to the filament and feeds it through to the tip seemed to be working fine after testing it. And since the tip had just been replaced and cleaned, we figured the problem had to lie in the tubing between the gear system and tip. Surely enough, the plastic tubing (which can’t be seen in the above photos) that exists in the metal frame had been clogged. We replaced this component and put the extruder back together again. When we ran a trial print, it was a success!

Afterwards, we decided to replace the bed in this printer as well. We had replaced the bed already with one of the 3D printers and the new material was much more effective at adhering to prints. Removing the old bed was a long and tedious process but once we stuck the new material to the bed frame our prints came out in much better shape. All in all, the 3D printer is now functioning very well.