About rentapen

Susan Straley, aka Queen of Lean Machine Design, is the President of Rentapen Inc. in Waukesha, WI. She helps manufacturers reduce costs through excellence in 3d desing services, RAPid Tooling Components(TM), and Just-in-Time Laser Cutting Services(TM). Susan can be reached directly at 262-542-8891.

Giving College Students An Opportunity

Rentapen Inc. gets recognized for their participation in Waukesha County Technical College’s Co-op/Internship Program.

WCTC awarded Rentapen with the Certificate of Appreciation for their active participation in the Co-op Internship Program.

Rentapen inspires and guides student-trainees for the potential workforce.


For example, Peter Christiansen is a student at WCTC who joined the Rentapen team as an IT Intern. Christiansen started interning at Rentapen in August 2011.

Christiansen is creating a program that will make it easier for jig and weld fixture design engineers to download 3D models of Rentapen’s RAPid Tooling Components™. The design engineers will be able to get 3D models that can be placed in their Computer Aided Designs (CAD). So now engineers who are designing weld fixtures can go onto Rentapen’s website www.rentapen.com and pull down a 3D model of a block, plate, clamp risers, or shim pack. From there, they can put it right into their Pro/E or Solidworks designs.

Christiansen is graduating with high honors from WCTC, with an Associates degree in program analyst and web/software analyst development. He is planning on joining the Rentapen team as a full time employee on December 20, 2011

“I’m excited to be done with the program and happy to contribute to the workforce,” said Christiansen.

Christiansen used to work in the Casting Industry as a quality control inspector, until he was laid off. Christiansen decided to go back to school for his Associates degree as a programmer analyst.

“We are pleased to have Peter join the Rentapen team full time. He is already familiar with the Manufacturing Industry and fixtures so its easy for him to understand our product line,” said Susan Straley, President at Rentapen Inc.

Rentapen is always introducing new product models to fit their customers’ needs. Christiansen will be in charge of making the product models available at Rentapen’s website.

Rentapen Inc. offers internships in design engineering, CNC operating, laser cutting, and information technology.

Jig or Weld Fixture Design — Five Items to Consider in V-Block Design

Five items to consider when designing your V-block

In our last Jig or Weld Fixture Design blog we talked about different ways to locate a round rod or tube.   One of the more common ways is with a v-block.

Today we will discuss some of the questions that help you decide the material, modeling method using Pro/E  4.0, and fastener locations.

1)      MATERIAL  —

First decide what material you will need the v-block to be.

How much will the fixture be used?    That means knowing what the product is made of because we need the v-block to be strong enough not to wear down too quickly.  We want to be able to produce lots of product before we have to replace any of the parts in the fixture.    The more the fixture is going to be used the harder you need to make the v-block relative to the product tube or rod.

Do you need to plan for weld splatter?

If the v-block is located near the weld joint, you will need to consider using a metal that the weld splatter will not stick to as easily, or using a weld splatter shield.  Remember that like metals stick better.  So if you are welding steel, you may want your v-block to be Ampco 18 bronze or a hardened steel such as 4140 PH or A2.   If you are welding aluminum, hardened steel may work just fine.

2)      TOLERANCING –

Is the location of the rod or tube critical?

If the tube or rod needs to be located in just the right spot in order to work or assemble easily to the rest of the product parts, then you will want to design in adjustability with shim packs.  You will need to look at the product drawing and also know your customer’s preferences.

At Rentapen we design for many different customers.  So we have to consider the standards and preferences of each customer when we design.  Some of them love to shim every locator in a fixture.  Some of them don’t like to shim at all.   If you are a CAD drafter, you may be working under more than one designer.  Each designer may have their own preferences.  But it is up to you to look at the product drawing and then advise them when you think shims will be needed to meet the tolerances of the product drawing.   Then do what they say, they are your customer.

If it is a rough location, you may be able to use a purchased V-block from somewhere.  Do you have a favorite model or brand you would like to share?

3)      FASTENERS –

Once you have decided if your v-block will have shims to fine-tune its location before going into production, you can decide about the location of the fasteners.  If the tube or rod location is critical, you will need to use dowels to lock in the location.  If it is rough, you can just fasten the v-block directly to the base plate with screws.

4)      MODELING —

Locating the Vee in the v-block.

Here is how I model in the Vee cut.  Click on the video to see my method using Pro/E  Wildfire 4.0.

In this video I dimensioned the construction hole from the BOTTOM of the block.  However, the v-cut may fail if I make an adjustment too big in one direction or the other.  Some of the project engineers I have worked with prefer that the dimension for the V-cut be from the TOP surface of the block.  That way you can change the size of the block without having problems with the cut.

Some like to create planes that intersect at the center where the the construction circle will be located.  These planes are created before you start the sketch to cut the Vee.  I think your preference depends on your experience and how your brain works when making adjustments to parts while in the assembly.

5)      CLAMPING —

Clamping is a whole topic by itself that we will address in a future blog.  I just wanted to note that it is something that you need to think about.  We always clamp down our parts in weld fixtures, even if it is a table mounted fixture and gravity does its work.  You want to be sure that tube doesn’t move when the heat of the weld hits it.

 

And now I would like to share a couple of things with you.

First, Rentapen’s Holiday Greeting to our customers, vendors, students, and friends.

Second, we are in the news!  Check out the latest news at Rentapen by clicking here.

Till next time!

Susan Straley

The Queen of Lean Machine Design

Does Your Company Encourage Educational Growth?

Manufacturers Utilize Education to Motivate and Retain The Engineering Workforce.

News 2011-12-15

According to the National Science Foundation, Division of Science Resources Statistics, “The majority of individuals in the labor force with Science and Engineering degrees are in their most productive years, (from their late 30s through their early 50s), with the largest group ages 40-44.”

So what keeps these engineers inspired in the work force?

“Education and learning more software is one way to get engineers ready for work force opportunities,” said Susan Straley the President of Rentapen Inc.

As the engineering workforce changes, employers implement retention and training programs. For example, Rentapen Inc., located in Waukesha, Wisconsin recruits and trains engineering interns. Rentapen has also implemented an education reimbursement program to keep their current engineer’s skills updated and their workforce motivated.

One of Rentapen’s design engineers is expanding his knowledge and updating his skills. Curtis K. a CAD Drafter at Rentapen Inc. just finished his Solidworks course at WCTC on Thursday, December 15, 2011.

Curtis has worked for Rentapen for one year and already has furthered his education to keep current with Rentapen’s 3D design services for customers.

“It is very important for a machine design company such as, Rentapen to have their engineers trained in both Solidworks and Pro/Engineer because Rentapen’s customers don’t all use the same software for their machine designs,” said Straley.

Curtis has five years of experience in Pro/Engineer and is beginning to work with Solidworks.

“I felt I needed to take the class because when I start working with Solidworks it will be easier for me to understand the software,” said Curtis K.

Rentapen, a company that specializes in jig and weld fixture design, encourages its employees to take advantage of Rentapen’s education reimbursement programs.   Since Rentapen’s design customers dictate what software they want their machine designs created on.  It is vital for Rentapen’s design engineers to have education in both softwares.

By: Bethany Kratz, Duchess of Cost Reductions

Jig or Weld Fixture Design – Locating Round Tubing

In this lesson on Jig or Weld Fixture Design we are going to discuss round tubing. 

I can think of three ways to locate a round tube off the top of my head.  That doesn’t mean they are the only ways.  You might be able to think of other ways.  So share any ideas you may have down in the comments section, or email me at straley at Rentapen.com and attach pictures or jpgs so I can share them in future blogs.

V-BLOCKS

We often use v-blocks to hold round rods or tubes.  A v-block is simply a block with a v cut into it.

If I need to design in adjustment with shims, I often will sketch on paper a rough plan. 

Sketching an adjustable V-block

If I am able to use purchased products, like RAPid Tooling Components to locate the V-block, I will sit with the catalog next to me and decide which blocks will work so I can pull those models from the library. 

 

A sketch helps me think about which blocks will have the slip fit dowels and the tapped holes and which ones will have the press fit and the counter bores. 

 

This video kind of explains what I have sketched. 

 Another popular way to hold a tube or rod in place in a jig or fixture is with a goal post. 

Consider the material that the tube is made of and how much use the fixture will get when deciding what material the plates should be.  The plates above are RAPid Tooling Components™.   These plates come in hardened steel (4140 PH) and Ampco 18.  Remember that weld splatter sticks to like metal.   Aluminum sticks to aluminum, steel to steel, etc.   So if you are welding steel, the Ampco Bronze may be a better choice for the plates of the goal posts. 

 

Sometimes the best way to hold a tube is with a pin that is inserted into the center of the tube.  The best method depends on the application, the size and length of the tube,  and your customer’s preferences

 Here is a little video that goes over some of the ways to locate a round tube or rod.

What have YOU done in the past that worked that I have not discussed here?

 

 

RENTAPEN BEATS PRICE and DELIVERS MISUMI STYLE REST PADS

 Rentapen Inc’s CNC operating team goes the extra mile to deliver metric rest pads on time.

News-2011-12-07, Waukesha, WI

The Rentapen’s team is fast and accurate when it comes to getting their customer’s orders out.  Their employees will go the extra mile to make sure a customer is satisfied.  John Dinon is the CNC operator at Rentapen, and these past weeks he and his team have put in many hours of overtime to get a customer’s order finished on time.

An order came into Rentapen Inc. on October 17, 2011 for 219 metric rest pads similar to Misumi rest pads.  The due date was November 28, 2011. John Dinon, along with his shop team went straight to work to get the rest pads done correctly and on time.

Then the customer called four days before the order was to be shipped out and ordered 30 more rest pads.  The shipment date remained the same.  The CNC Operating team worked days, evenings, and even weekends on those metric rest pads. The order was shipped out on time and the customer was very satisfied.

"My best reward is when the customer sends us another order"

John Dinon has worked at Rentapen Inc for a little over a year now.  He was presented with Rentapen’s Extra Mile Award for his efforts in getting the order finished.  “The only reward I need is for the customer to give us another order,” said Dinon.

 

 

Dinon’s attitude and dedication to the customer’s needs is what is needed in the highly competitive machine tool industry.  Rentapen’s culture statement encourages ownership, drive, a positive attitude.

Rentapen Inc. is a machine design company specializing in cost reductions for manufacturers. They do this through excellence in machine design. They specialize in jig and weld fixture design; RAPid Tooling Components ™ (a line of standard yet versatile blocks, plates, clamp risers, and shims used to reduce the cost of jigs and weld fixtures); and Just-in-Time Laser Cutting Services ™.  Rentapen has been in business since 1976 and is located in Waukesha, WI.

Custom Cut Metal Parts

What would YOU cut if you could cut through up to 1″ steel?

It’s getting toward the holiday’s so let’s have some fun.  I want to know what metal shape would you cut if you had a 4000 watt laser available to you?

Take a look at slide show and see some ways that we at Rentapen have used the laser to create custom cut metal parts, etched marble and plastic, and made some tools.

Now it is YOUR turn.  What would you have or what have you had custom cut?  If you have a picture, send it to me at news at rentapen dot com.  If it is ok, I would like to share the pictures in a future blog.

When you are done sharing your metal cut parts stories and pictures, then relax with a couple more fun promotional videos I got from Fiverr!

 

RENTAPEN in the NEWS!
Meet Bethany Kratz, Our Lady of the Laser at Rentapen.

Jig or Weld Fixture Design – 12 Questions

What do YOU ask before you begin your Jig or Weld Fixture Design?  Here are some questions to start the discussion.

When you are presented with some product parts and asked to design a fixture or jig so they can be welded together,  what questions do you need answered before you begin?   It is important to get as much information on the project as possible before you even do a rough sketch.

For example:

1) How many parts will be welded together in this one fixture? 

The production planning team will need to figure this out.  The more parts they can fit on one fixture, the less fixtures and operators they will need.  However they need to take into account that if one station in the factory takes longer than the rest of the stations they will be creating a bottle neck that will slow the whole production line.  That could be fixed by having two of the same fixture, or by reducing the number of parts welded together in one fixture.

2) Is there another product line with very similar but different parts that could be welded together in the same fixture with a quick change over?  

Sometimes a fixture can be used for several products.  Just replacing one or two sub assemblies can quickly create a fixture that can run two or more products.    In a future blog we will delve into the different gizmos and tools you can use to make the change over fast and easy.

V-Blocks for two product lines

Designing for two product lines sometimes is easy.

 

 

 

 

 

 

 

 

 

3) Will the fixture be automated or manual? 

Will you be using pneumatic clamps or manual?  What about sensors that will sense if the part is in place before clamping or before beginning the welding procedure?   Will there be forward and back checks?

At Rentapen, our 3D models will show the placement and mounting of the sensors and clamps.  The design must allow for room for the hoses and wires.  At Rentapen we leave the design of the controls and electrical to the experts.  We focus strictly on the mechanical aspect of the fixture.  It is important to you and the team that there is a clear understanding of where your responsibility lies.   Tasks for who is responsible for what parts of the fixture (jig) or robot cell should be clearly laid out before  you begin the design.

4)  Will the fixture be trunion or table mounted? 

Will it be robotically or manually welded?  If it is robotically welded, what are the dimensions within which the fixture must fit?

5)  When is the project due? 

When should the preliminary design be ready for review?  When should the checked drawings be completed?  Is there a set schedule?

6) Where are the welds?

The answers to these question should be on the weld drawings for the product.  Usually, in a well planned out line, there is a product drawing of the sub assembly produced in the fixture that you are going to be designing.  Study the drawing for the location of the welds.   If there is no such drawing, ask!

7) What are the critical dimensions?

Study the drawing and identify those dimensions that are held to a tighter tolerance.   If there are no tight tolerances between welded parts, then the fixture may not require shimming.   It doesn’t hurt to ask to make sure.  Asking before you begin is much more efficient.

8)  Are there parts that could be put on the fixture wrong?

Study the product assembly and see if you may need to error proof the fixture so that the parts can only go into the fixture in the way they are supposed to.  We don’t want them welding something on backwards.

9) Do you have a list of preferred vendors?  Some manufacturers prefer Destaco or Parker for their clamps.  The larger companies always have a list of the vendors they use and the products they like.  For example, Genesis Systems requires all their vendors to use Rentapen’s RAPid Tooling Components (TM) wherever possible to reduce the costs of their weld fixtures.

As a design service company, Rentapen has even more questions to ask.

10) What are your design and detail standards?

We want to match the customer’s standards as best as possible.   We put the drawings on the customers format, and follow their standards.  We ask for samples of good drawings so that we can see how holes are called off and slots and chamfers are dimensioned.

11)  Do you put more than one detail on a drawing?

Some of our customers put everything on the same size format and put as many part details as will fit on D size sheet.   Other customers limit it to four details on a D size sheet.  And some customers like to have each part detailed on its own sheet.  A B C D or E.

12) How often do you want status updates?

For smaller fixtures, you will design it up and only have them look at it once before you start detailing it.  But for larger projects, usually the customer will want to see your progress once a week, or as you complete the design for each section of the fixture.  I use the term customer to mean who you report to, who you are serving, be it your production planning team or your manager … whoever your customer is.   As a fixture designer the best way to reduce costs for your time is to get feedback on your designs before you go too deep.

What questions have I left out?  What else do you ask? 

Please add to the conversation and let me know what you think!

Weld Fixture Design — Product Changes

How do you design a fixture knowing the product may be modified by the product engineers?

When designing a weld fixture, or jig as some people call them, it is important to remember that things can change.  Machine designers need to think ahead and have a standard procedure to follow that will reduce errors and costs in the case of a product change.  Changes can occur during or  after the fixture has been designed.

Often times the product design team is on a tight schedule to begin production of the new product.  They may hand it over to the manufacturing engineers before all the quirks are ironed out of it.  They may still be producing and working with the prototypes, but they need to start getting the factory ready for production.

Click on the picture to watch the weld fixture design video that discusses this further using Pro/E Wildfire 4.0.

 

Manufacturing Engineers,  what standard method of 3D model component location do YOU follow to help you in the event that product changes are made?

Leave a comment, add a question, sign up for future weld fixture education and updates.

Five Pin Pointers

Weld Fixture 101  – Locating Pins

To recap what was said in the video:

Pointer #1 

You can buy your pins from a catalog or you can make your own.  But don’t use the lock screw design for mounting your pin.  We have found they don’t hold up to the hard use they experience in a weld fixture.

Pointer #2

Harden your pins.  This makes it “harder” for the weld splatter to stick to the pin and easier, then, for you to get the part out of the fixture.  In fact, it is good practice to always harden those components that touch the product parts.  You can surface harden, called “case” harden, or you can full harden, which hardens the part all the way through.  Purchased pins are already hardened.

Pointer #3 

If possible, mount  the pin from the bottom with a screw.   If you can’t mount from the bottom, another best practice is to cut a whistle cut (an angle cut) into the base of the pin.  Then use a set screw to hold it in place.

Pointer #4

When using locating pins in two holes in a product part, use a round pin in the first hole and a diamond pin in the second hole.   The diamond pin will allow for some tolerance variations between the holes in the product.

When I say, round pin, it doesn’t mean that you can’t cut off some surfaces of that round pin as discussed in pointer  #5.

Pointer #5

Other cuts in the pin make it easier to remove the product parts from the fixture.  Square cuts or triangular cuts work well and still have sufficient pin surface to locate the product.

That’s it!  If you haven’t already, sign up to be notified when the next blog on Weld Fixture Design is released!

Now for fun, check out the new video we have from Lashy7 singing our shim king song.

The Preliminary Review – Weld Splatter

It’s a jig, it’s a fixture, whatever you call it, it holds the product together while it is being welded or assembled. In this lesson we are going to look at weld splatter and what to do to keep your fixture ( or jig ) functional.

In tip #5 of the previous blog we talked about looking over the fixture design to review efficiency and functionality of the design. You might want to develop a check off list of items you should explore at this stage.

#1 Can you get your part out after it is welded. Remember the splatter!
#2 Can you eliminate any parts?
#3 Can you make any parts with less machining?
#4 To maintain adjustability, what do you need to protect from weld splatter?

Let’s take a look at our simple weld fixture and see if we can improve upon it.

In the short time we have together I tried to be brief and may have skipped over some important stuff. So be sure to sign up for future updates and education on the form at the right. =============>>>

There it is. Now for a bit of light-hearted fun, check out the song video we recently added to our Shims page!

Please feel free to comment or add suggestions for future topics.   I’d love to hear from you!

 

[author][author_info]Susan Straley, aka, Queen of Lean Machine Design, is the President of Rentapen Inc. in Waukesha, WI. She helps manufacturers reduce costs through excellence in 3D Machine Design Services, RAPid Tooling Components(TM), and Just-in-Time Laser Cutting Services(TM). Susan can be reached at 262-542-8891.[/author_info] [/author]