Community Calendar: Fundraisers, Star Wars Day, and other events and activities

How to submit your event

Send details (who, what, where, when, cost and contact information) in an email to editor@ramonasentinel.com.

The deadline is noon Friday.

Items run on a space available basis.

Questions? Call 760-789-1350.

THURSDAY, Oct. 12

Ramona Business Network Exchange, 7 a.m., Nuevo Grill, 1413 Main St. Buffet breakfast. 760-788-1770 or www.bneRamona.com.

TOPS, —Ramona Chapter of TOPS (Take Off Pounds Sensibly), Grace Community Church, 1234 Barger Place, 9 a.m. Weigh-in at 8:30 a.m.

Ramona Library, 1275 Main St., 9:30 a.m. to 8 p.m. Tai Chi at 9 a.m., Adult Coloring Club at 10 a.m., Toddler Storytime at 10:30 a.m., Women’s Art at 11 a.m., 3D Printing Demonstrations at 3 p.m., Music Shop at 3 p.m., Family Movie at 4 p.m., Cool Cursive Club at 4 p.m., Teen Movie at 4 p.m. 760-788-5270.

Bingo, 1 p.m., Ramona Senior Center, 434 Aqua Lane. For 18 years and older. Cost: $14; $5 discount for first-time players. 760-789-0440.

Free Flu Shots, 3 to 5 p.m., Ramona Library, 1275 Main St., sponsored by Palomar Health.

Financial Aid Night, 6 to 7 p.m., Ramona High School, 1401 Hanson Lane. Learn about financial aid for college and how to complete FAFSA and Dream Act applications. 760-787-4057.

Free Acoustic Showcase Concert 6 p.m., Ramona Library, 1275 Main St., featuring Nina Francis whose music is laced with undertones of pop, folk, and jazz.

FRIDAY, Oct. 13

Ramona Library, 1275 Main St., 9:30 a.m. to 5 p.m. Zumba at 9:30 a.m., Bouncing Baby Storytime at 10:30 a.m., Family Craft at 3:15 p.m. 760-788-5270.

Ramona Pregnancy Care Clinic Fundraising Banquet, 7 to 9 p.m., Mountain View Community Church, 1191 Meadowlark Way. Free admission. Food, entertainment, fundraising. RSVP at 760-789-7059 or info@friendsof rpcc.net.

SATURDAY, Oct. 14

Kiwanis of Ramona, 7 to 8:30 a.m., Denny’s, 1946 Main St. Breakfast meeting with speaker. 760-522-2625.

Weight Watchers, Ramona Woman’s Club, 524 Main St., 8 a.m.

Ramona Library, 1275 Main St., 9:30 a.m. to 5 p.m. 760-788-5270.

Free Legal Clinic, 10 a.m. to noon, Ramona Library, 1275 Main St. Sponsored by Ramona Bar Association, first come, first served.

The Special Liberty Project fundraiser, 11:30 a.m. to 1:30 p.m., Vineyard Grant James, 25260 E. Old Julian Highway. Wine, farm-to-table lunch and art. Opportunity drawings. Proceeds benefit the liberty project. http://squ.re/2xxe1Ks squareup.com/store/the-special-liberty-project.

Star Wars Day, 1 p.m., Ramona Library, 1275 Main St. Costume contest with special guests, themed crafts, photo booth, and galactic treats. 760-788-5270.

SUNDAY, Oct. 15

Depression and Bipolar Support Group, 10 to 11 a.m., Rose Garden at Collier Park, 626 E St. 760-443-6861 or www.dbsasandiego.org.

Ramona Library, noon to 5 p.m. 760-788-5270.

Childbirth Preparation, second of four classes, 2 to 4:30 p.m., Ramona Pregnancy Care Clinic, 1530 Main St., Suite 6. Free. 760-789-7059.

Simply Sips & Smiles, 4 to 6 p.m., Rotunda, 16911 Gunn Stage Road. Social nonpolitical event for Ramona women to get to know each other and enjoy common ground. Sponsored by Indivisible Ramona. RSVP to ramonawomen.eventbrite.com. sdconrad4@gmail.

Car Show, 4 to 6 p.m., Albertsons parking lot, 1400 block of Main Street. Owners of pre-1974 trucks and cars are welcome to display vehicles.

MONDAY, Oct. 16

Ramona Library, 1275 Main St. 9:30 a.m. to 6 p.m. Mindful Monday at 9 a.m., Adult Chess Club at 10 a.m., Bilingual Storytime at 10:30 a.m., 3D Printer Demonstrations at 3 p.m., Homework Help at 4 p.m., Stretch & Strength at 4:45 p.m. 760-788-5270.

English as a Second Language, 6 to 8:50 p.m., Ramona High School, 1401 Hanson Lane. Free, no sign-up required. ESL 1 in Room I-59, ESL II in Room I-61, and ESL III in Room I-60. 760-613-6767 or 760-271-7630.

Grief Share, 6:15 p.m., Mountain View Community Church at 1191 Meadowlark Way. 760-789-4798 or 760-789-1634. Ends Nov. 13.

TUESDAY, Oct. 1

Backcountry Quilters, 9 a.m., Ramona Community Center, 434 Aqua Lane. pinecastle946@sbcglobal.net.

Ramona Library, 1275 Main St., 9:30 a.m. to 8 p.m. Beginner Country Line Dancing at 10 a.m., Preschool Play at 10:30 a.m., Experienced Country Line Dancing at 11 a.m., Computer Basics at 2 p.m., Tween Chess Club at 3 p.m., Teen Dungeons & Dragons at 4 p.m., Children’s Folklorico Dance at 4:30 p.m., Citizenship Classes at 6 p.m. 760-788-5270.

Ramona Rotary Club, noon to 1:30 p.m., Amici’s restaurant, 1429 Main St. Speakers: Sen. Joel Anderson and Bill Hicks, Sheriff’s Senior Volunteer Patrol Administration. 619-316-4456.

Ramona Parks and Recreation Association, 6:30 p.m., Ramona Community Center, 434 Aqua Lane.

Ramona Community Singers, 7 to 8:45 p.m., Ramona Town Hall West Wing, 729 Main St. Open to all. 760-788-1887 or g.seashore@earthlink.net.

WEDNESDAY, Oct. 18

Free Mammograms for women age 40 and older who meet income guidelines, 8 a.m. to noon, Ramona Health Center, 217 Earlham St. 760-736-6727.

Ramona Library, 1275 Main St., 9:30 a.m. to 6 p.m. Yoga at 9 a.m., Children’s Storybox Theatre at 10:30 a.m., Preschool Craft at 11 a.m., Spanish as a Second Language at 1 p.m., Teen Time: PS4 at 3 p.m., Homework Help at 4 p.m. 760-788-5270.

English as a Second Language, 6 to 8:50 p.m., Ramona High School, 1401 Hanson Lane. Free, no sign-up required. ESL 1 in Room I-59, ESL II in Room I-61, and ESL III in Room I-60. 760-613-6767 or 760-271-7630.

UW merger plan concerns UW-Stout

A plan to merge the University of Wisconsin System’s 13 two-year colleges with the UW’s four-year institutions next summer has the chancellor at the University of Wisconsin-Stout in Menomonie concerned about losing prospective students.

The plan would transform the system’s 13 two-year schools into regional branches of the 13 four-year schools. Students would still be able to earn associate degrees, but they would bear the name of the four-year school. Students would get a wider range of courses to choose from and be able to take third- and fourth-year courses at the branch campus.

For example, two-year school UW-Barron County would cease to exist. Its buildings, faculty and staff would become a branch of UW-Eau Claire. Students who attend the branch campus would earn associate degrees from UW-Eau Claire and could complete four-year degrees through UW-Eau Claire.

“I…will do everything possible to maintain our historical link to UW-Barron County and remain a top choice for students who start their education there and continue to a four-year degree,” UW-Stout Chancellor Bob Meyer said in a press release.

“In 2015-16, for example, more than a quarter of the UW-Barron County students who transferred to UW System institutions chose UW-Stout, and we must preserve that transfer pipeline.”

UW System enrollment figures show UW-Barron County has fallen in full-time equivalent student enrollment from 484 in 2010 to 315 in a preliminary count from fall 2017. That’s a drop of 169 students, or 35 percent.

Cross said the merger would be done effective July 1, 2018. “Essentially, there will be no change this fall or spring, and we look forward to seeing how to best leverage UW-Eau Claire to expand access to higher education by offering more general education and upper-level courses, as well as identify and reduce barriers to transferring credits within the UW System,” Cross said in an email to the UW-Eau Claire.

Chancellor James C. Schmidt said in an email to facility, staff and UW-Eau Claire students: “While it is too soon to identify all the opportunities this new structure could bring to students here and in Barron County, we do know that meeting the needs of students at both campuses will be our highest priority.”

Schmidt continued in the email: “UW-Eau Claire and UW-Barron County long have enjoyed an excellent relationship, with many students beginning their college careers in Rice Lake and completing their degrees in Eau Claire.”

Schmidt said he will talk in future weeks with faculty students and community leaders in the Chippewa Valley and Barron County to find ways to move forward.

Besides pairing UW-Barron County with UW-Eau Claire, the proposal would bring each UW Colleges campus under one of six other four-year public universities:

The Rock County college would join UW-Whitewater

The Baraboo/Sauk County and Richland colleges would join UW-Platteville

The Manitowoc, Marinette and Sheboygan colleges would join UW-Green Bay

The Washington County and Waukesha colleges would join UW-Milwaukee

The Marathon County and Marshfield/Wood County colleges would join UW-Stevens Point

The Fond du Lac and Fox Valley colleges would join UW-Oshkosh

UW-Stout and UW-River Falls would not be linked to a UW college.

Cross said in a statement that the merger will help the UW address declining enrollment at its two-year colleges, make it easier to transfer credits within the UW System and better address the challenge of Wisconsin’s aging population.

UW Extension programs would also come under new administration as part of the sweeping restructuring plan.

UW Extension’s Broadcasting and Media Innovations division — which includes Wisconsin Public Television and Wisconsin Public Radio — would be brought under UW System Administration, along with the Business and Entrepreneurship Division, continuing education, outreach and UW Flexible Option programs. Cooperative Extension and conference centers owned by UW Extension would be merged with UW-Madison.

Cross said in a statement that the merger will help UW address declining enrollment at its two-year colleges, make it easier to transfer credits within the UW System and better address the challenge of Wisconsin’s aging population.

“Change often produces uncertainty, but we cannot be afraid to pursue needed reforms,” he said. “Our goal is to expand access and provide more educational opportunities for more students, while ensuring our faculty are appropriately organized and supported. We are committed to making the transition as smooth as possible for students, faculty, and staff.”

It’s not immediately clear what the restructuring would mean for programs and jobs in the UW Colleges and Extension.

Cross will bring the proposal to the UW Board of Regents for approval in November, officials said.

Introduction to Material Jetting 3D Printing

In this introduction to Material Jetting we cover the basic principles of the technology that are useful to designers and engineers. After reading this article you will understand the fundamental mechanics of this 3D printing process and how these relate to its key benefits and limitations.

What is Material Jetting?

Material Jetting (MJ) is an additive manufacturing process that operates in a similar fashion to 2D printers. In material jetting, a printhead (similar to the printheads used for standard inkjet printing) dispenses droplets of photosensitive material that solidify under ultraviolet (UV) light, building a part layer-by-layer. The materials used in MJ are thermoset photopolymers (acrylics) that come in a liquid form.

MJ creates parts of high dimensional accuracy with a very smooth surface finish. Multi-material printing and a wide range of materials (such as ABS-like, rubber-like and fully transparent materials) are available in Material Jetting. These characteristics make MJ a very attractive option for both visual prototypes and tooling manufacturing. Nevertheless, material jetting has some key limitations that we present in this article.

A variation of the MJ process uses Drop-On-Demand (DOD) printheads to dispense viscous liquids and create wax-like parts. DOD is used almost exclusively for manufacturing investment casting patterns though and for this reason we will not discuss it here further.

The Material Jetting 3D printing process

How does Material Jetting work?

This is how the MJ printing process works:

First, the liquid resin is heated to 30 – 60oC to achieve optimal viscosity for printing.

Then the printhead travels over the build platform and hundreds of tiny droplets of photopolymer are jetted/deposited to the desired locations.

A UV light source that is attached to the printhead cures the deposited material, solidifying it and creating the first layer of the part.

After the layer is complete, the build platform moves downwards one layer height and the process repeats until the whole part is complete.

Unlike most other 3D printing technologies, MJ deposits material in a line-wise fashion. Multiple inkjet printheads are attached to same carrier side-by-side and deposit material on the whole print surface in a single pass. This allows different heads to dispense different material, so multi-material printing, full-color printing and dispensing of dissolvable support structures is straightforward and widely used. Support structures are always required in material jetting and need post processing to be removed.

In Material Jetting, the liquid material is solidified through a process called photopolymerization. This is the same mechanism that is used in SLA. Similarly to SLA, material jetted parts have homogeneous mechanical and thermal properties, but unlike SLA they do not require additional post-curing to achieve their optimal properties, due to the very small layer height used.

Schematic of a Material Jetting 3D printer

Characteristics of Material Jetting

Printer Parameters

In Material Jetting, almost all process parameters are pre-set by the machine manufacturer. Even the layer height is linked to each specific material, due to the complex physics of droplet formation. The typical layer height used in Material Jetting is 16 – 32 microns.

Material Jetting is considered one of the most accurate 3D printing technologies. MJ systems have a dimensional accuracy of ± 0.1% with a typical lower limit of ± 0.1 mm (sometimes as low as ± 0.02 mm). Warping can occur, but it is not as common as in other technologies, such as FDM or SLS, because printing happens at near room temperature. For this reason very big parts can be printed with great accuracy. The typical build size is approximately 380 x 250 x 200 mm, while large industrial systems can be as big as 1000 x 800 x 500 mm.

Multi-material & Full-color printing

A key advantage of Material Jetting is the ability to produce accurate multi-material and multi-color prints that represent end products.

Multi-material and multi-color printing in MJ can be employed in three different levels:

  • At the build area level, different parts can be printed in different materials or colors simultaneously, speeding up the manufacturing process.
  • At the part level, different sections of a part can be designated to be printed in different material or color (for example creating a stiff case with flexible buttons for prototyping with haptic feedback).
  • At the material level, two or more printing resins can be mixed in different ratios before dispensing, creating a “digital material” with specific physical properties, such as hardness, stiffness or hue.

To designate a different material or color to particular areas of the part, the model must be exported as separate STL files. When blending colors or material properties to create a digital material, the design must be exported as an OBJ or VRML file, because these formats allow the designation of special properties (such as texture or full color) on a per face or per vertex basis.

The medical industry often utilizes full color printing to produce educational medical models. Image courtesy of StratasysMulti-material prototype with rigid opaque (white) and flexible rubber (black) sections

Support structure

Support structures are always required in Material Jetting. Supports are always printed in a secondary dissolvable material that can be removed after printing using pressurised water or by immersion in an ultrasonic bath.

Material jetted parts can have very smooth surfaces with little to no indication of support after removal.

Part orientation in MJ is more flexible compared to other 3D printing technologies, like FDM or SLA. It is still important though, as the extensive use of support material also increases the overall cost.

Matte vs. glossy

Material Jetting offers the option of printing parts in either a glossy or matte setting.

In the glossy setting, support material is added only when it is structurally required (i.e. for overhangs). Surfaces not in direct contact with support will have a glossy finish, while supported areas will be matte. In the matte setting, a thin layer of support material is added around all the the whole part, regardless of orientation or structural requirements. This way all surfaces have a matte finish.

The glossy setting should be used when a smooth shiny surface is desired. The cost of printing glossy is lower, as less material is used. The drawbacks of using this setting are the non-uniform finish of the printed parts and the slight rounding of the sharp edges and corners on the top, glossy surfaces.

The matte setting should be used when accuracy and uniform surface finish are a requirement. The cost of the matte setting is slightly higher, as more material is used and additional post-processing time is required. Notably, parts printed in the matte setting also have a relatively lower surface hardness.

A part printed in half glossy, half matte, showing the difference in surface finish

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Common Material Jetting Materials

Material jetting uses thermoset photopolymers that are similar to the those used in SLA in terms of properties and limitations (they are brittle, have a low heat deflection temperature and are susceptible to creep). They come in a less viscous, ink-like form and have a much higher cost per kilogram (approx. $300 – $1000).

Multi-material printing is a key strength of MJ, as it enables the creation of accurate visual and haptic prototypes. Speciality materials optimised for specific industries are also available, such as materials for tooling (injection molding, thermoforming etc) and medical applications.

The following table summarizes the advantages and disadvantages of the most commonly used MJ materials:

Material Characteristics
Standard
  • Rigid opaque plastic
  • Simulates injection molded parts
  • Brittle
Flexible
  • Rubber-like
  • Customizable hardness
  • Poor elongation at break
Simulated Polypropylene
  • Simulates PP parts
  • Good flexural strength
  • Brittle
Simulated ABS
Castable
  • No ash after burnout
  • Optimized for investment casting
High temperature
  • Good temperature stability (up to 80oC)
  • High strength
  • Brittle
Transparent
  • Glass-like appearance
  • Can be post processed to 100% clear
Medical grade
  • Sterilizable
  • Short-term biocompatible
  • Used in dental and medical applications

Post Processing

Various techniques can be employed to improve the visual appearance or functionality of the MJ parts. These include sanding and polishing, painting, dyeing (for translucent parts), spray coating and metal plating.

Benefits & Limitations of Material Jetting

The key advantages and disadvantages of the technology are summarised below:

  • Material jetting can produce smooth parts with surfaces comparable to injection molding and very high dimensional accuracy.
  • Parts created with Material Jetting have homogeneous mechanical and thermal properties.
  • The multi-material capabilities of MJ enables the creation of accurate visual and haptic prototypes.
  • Material jetted parts are mainly suitable for non-functional prototypes, as they have poor mechanical properties (low elongation at break).
  • MJ materials are photosensitive and their mechanical properties degrade over time.
  • The high cost of the technology may make Material Jetting financially not viable for some applications.

Detailed design guidelines of each of the aspects discussed here are given in later articles of this section of the Knowledge Base. The main characteristics of material jetting are summarized in the table below:

Material Jetting
Materials Acrylic photopolymers (thermoset)
Dimensional accuracy ± 0.1% (lower limit of ± 0.05 mm)
Typical build size 380 x 250 x 200 mm
(up to 1000 x 800 x 500 mm)
Common layer thickness 16 – 32 microns
Support Always required (printed using dissolvable material)

Rules of Thumb

  • Material Jetting is ideal for creating realistic visual and haptic prototypes with very smooth surfaces that resemble injection molded parts.
  • Material Jetting offers engineering materials that can be used for tooling and injection molding manufacturing.
  • Material Jetting can produce very large parts (as big as 1000 x 800 x 500 mm) without compromising on accuracy (typically ± 0.1%).
  • For multi-material or multi-color prints, export your designs as multi-part STL files. If gradients are needed use the OBJ or VRML file format.