Pentel P209 Teardown

wrTie has begun!

To start off my titanium mechanical pencil build, called wrTie, I decided to teardown a number of different mechanical pencils for inspiration and design ideas.  I find the mechanisms in mechanical pencils very interesting.  I also find the manufacturing processes that are used exceptionally interesting.

Here is a teardown video of my favourite mass produced mechanical pencil: the Pentel P209 (0.9 mm version).  The Pentel P20x series (there are 0.3, 0.5, 0.7 and 0.9 mm models)  has been around for a long time.  It is exceptionally well made given the price point it is hitting and the parts involved.  There are 12 parts in total, including 5 fully machined parts.  A number of the parts require plating.  There are 2 parts that are molded out of plastic.  And then it has to be assembled!  You can buy a Pentel P209 for less than $5 in the United States and less than $7 in Canada.  That’s actually pretty crazy considering this pencil contains machined parts and even more so once you consider that Pentel is probably selling it to it’s retailers for less than half of what they are retailed for.

https://youtu.be/tM4h61_BLKQ

The heart of the Pentel 200 series is a removable fully contained feeding cartridge.  The cartridge features a number of machined components in the feeding mechanism.  The components are probably massed produced on swiss style screw machines (a lathe but instead of the carriage moving the spindle moves in the Z direction – often called sliding headstock machines).   These machines could be cam actuated screw machines or they could be CNC controlled units.  CNC swiss style machines, like the ones produced by Star or Citizen, are really interesting machines.  Here is a video of a Citizen L20, one of the more popular CNC swiss machine that you will find today:

The Pentel P209 cartridge has been used in a number of titanium mechanical pencil builds on Kickstarter.  I can’t confirm it directly as I haven’t purchased one, but check out this project (you have to scroll about half way down and you’ll see a picture of what looks to be the Pentel cartridge: https://www.kickstarter.com/projects/cogent/titanium-mechanical-pencil-and-titanium-pen.  Given the Pentel’s design, you could easily make a new mechanical pencil by machining a new outside body for the Pentel.  I won’t be doing that because I think it is too easy!

 

 

 

DIY Swarf ‘Cyclone’ Separator

I spent 30 minutes on a Friday evening making up something that has been on my project list for awhile.  I made a swarf separator to go in front of the vacuum.  Often these are called dust cyclones, or particulate cyclones, or separators of some sort.  I made a video of how I constructed it (which took longer than actually making the separator):

The design is very simple.  The pail itself was  from someone with a pool – it was used to hold bromine (I love re-purposing stuff!).  I’ve been saving the pail for this for awhile because it has a nice tight fitting lid.  I cut 2 holes in the top for some 1 1/2″ threaded ABS couplings and a 1 1/2″ to 1 1/4″ bushing found at a local hardware store.  One coupling was male threaded and the other was female threaded.  The 1 7/8 Ridgid vacuum hose fit well onto these couplings after I turned them to fit.  A long 1 1/2″ ABS elbow was used to direct the dirty suction flow along the side of the container.  The ‘clean’ air comes out the centre and into the vacuum.

I immediately tried it by cleaning up the lathe.  It worked very well for metal chips.  I’m not sure how well this design would work with saw dust – something I’m bound to try out at some point.  I don’t do that much work with wood, and when I do it generally is general construction – which usually happens outdoors.

I was considering purchasing a Dust Deputy – a purchased cyclone attachment for standard vacuums.  They are $60 for just the cyclone (still requires a pail with a lid) or $135 for a cyclone, pail, lid and hose.  Lee Valley also has their Veritas cyclone lids for larger containers for about $50, but I prefer the 5 gallon pail size.

I have about $30 into the project including the hose (the most expensive part of the project), which isn’t too bad at all.  Now I won’t fill expensive vacuum bags up with metal chips anymore, and I can keep the vacuum bag for filtration of fine particulate like grinding dust.

I didn’t make drawings for this project because I thought it was very simple.  If you really would like something, send me an email and I’ll try to do something up.

 

 

 

Lathe Drawbar

I needed to be able to bore some holes using the lathe as a mill / drill press for a number of upcoming projects.  My 10×18 lathe has a MT4 spindle taper.  MT4 is a bit of an odd ball taper for a lathe.  It’s not quite big enough to accommodate the 5C taper or the R8 taper – both of which plentiful amounts of inexpensive new and used tooling is available.  The X2 mini mill I have uses the MT3 taper – so naturally it made a lot of sense then to make up an adapter to go from MT4 to MT3, as well as a drawbar and associated hardware to go along with it.

Here is a video of the project:

The threaded drawbar itself was made out of some mystery metal in the shop.  It was interesting stuff with a really hard outer layer that through hot chips all over my arm when I was turning it.  It almost made me want a lathe with a carriage wheel on the right side of the lathe.  The drawbar was turned between centres to within .001″ over 10″ – something I was happy with.  It highlighted my need for a travel steady – I’ll have to add that to the project this.

The MT4 – MT3 bushing / adapter was made out of an inexpensive MT4 – MT3 adapter that would be commonly used in a drill press.  I cut the tang off with an angle grinder and cleaned it up on the belt sander.  I was thinking about making it up entirely, but I wanted a hardened bushing.

Here is the drawing for the project:

Lathe Drawbar Rev 01

The video marks my tenth video that I’ve done, and it also incorporates some significant changes in how I put them together.  Going forward I hope to continue to improve the quality as I learn.

The titanium pencil project is also still very much a going concern – I hope start some tear downs over the next few weeks to start the project off.  Many of the projects I’ve been working on in the shop are laying groundwork for the build.  So in short – stay tuned!

 

Height Gauge Depth Arm

In the shop I have a 2 beam dial height gauge that I use a lot for measuring and general layout work.  As far as measuring equipment, it is my favourite tool to use, even though I would want a micrometer and a caliper before a height gauge.  Once you get one you’ll wonder how you got by without one.

Most height gauges come with a tool for measuring flat surfaces, and for scribing.  To get the most out of the gauge you need a depth arm – basically a pin in an arm, for measuring depths.  I needed one to measure up a motor face so I can get a 3 phase motor mounted on my lathe – one of those projects to complete a project sort of deals.  I decided to make one up instead of buying it:

I made most of the arm on the shaper and used a gift from Max over at the Joy of Precision to bore the hole for the pin.  The boring head Max made is the star of this show.  It is the perfect size for the mini mill.  It is one of the best designs for a small boring head I’ve seen, and used.  The adjusting dial is a tad small but once you get a feel for it adjusting it is easy.  It’s also great because you can bore small holes – saving you from buying a lot of reamers.

The pin was turned between centers and was within .0004″ over the length – something I was very happy with.  The deviation was in the centre of the pin.  The pin sprung between centres a bit when I was cutting – aside from using a traveling steady there isn’t much you can do here about that.  The beginning diameter and end diameter were essentially the same within .0001.  I probably didn’t need  that much precision but I wanted to dial in my tailstock anyway.  At the end of the pin you can screw in standard dial indicator ends using a #4-48 thread.

I made the screw out of brass because it looks nice, and doesn’t mar the pin.  I usually don’t turn that much brass so I was reminded how easy it is to work with.

Here is the drawing for the height gauge arm.  I will be sharing all the projects in Fusion at some point and I’ll post a link.

Height Gauge Arm (Revision 01)

If you are looking to get a height gauge, do yourself a favor and go a dial one instead of a digital one.  Even though the dial on mine is graduated to .001″, you can actually measure much closer in the home shop with it.  Notice I didn’t say in the shop – in a professional environment I get that you need hard numbers and ‘guessing’ at the measurement is very poor practice.  Verniers are also good but I find them slow – probably because I don’t have enough practice.

Tool Post Lock Nut and Handle

I decided to start the New Year off by making some small productivity improvements in the shop.  One of the things I find myself constantly doing is reaching for a wrench to tighten the tool post, and also the tailstock (more on this soon!).  I decided to make a tool post lock nut and handle.

From this point on I’m going to try to make drawings for all the projects that I do in Autodesk Fusion.  I’ll also share the CAD data in Fusion once I get that setup.  Below are the drawings for each of the parts:

  1. Tool Post Nut Arm
  2. Tool Post Nut

In the video I talk a little about the taps I primarily purchase and use in the shop.  YG’s spiral flute bottoming machine tap is my go to tap.  The quality on these taps is exceptional, and work well in many materials that you find in the home shop.  They are designed for tapping blind holes, but work equally well in through holes so to keep costs down I try to just purchase these.  Avoid the cheap import sets for thread cutting.  Usually these sets are made from high carbon steel (not high speed steel), and they generally do a poor job in the shop.

If anyone says you can’t tap properly by hand using machine taps, they probably aren’t using good machine taps, or need more practice I guess.  I find that the YG machine taps are easier to use and start than standard hand taps and do a much better job on the thread.  Let them pick out the broken hand tap.

Table Saw Screw

I found some time between exams, work, and recovering from a nasty cold to make a new table saw adjusting screw for a friend of mine.  It saved his table saw from the dump as he couldn’t get any parts for it anymore.  Can you image?  Trash a table saw because of one screw?  I made a quick video of it:

Max and I are working on the next podcast, I’ve been working on few improvements for my lathe and I have a VFD (variable frequency drive) project for the lathe that will be coming up next before I begin wrTie full time.

 

 

 

 

wrTie

Great ideas begin in the simplest forms.  A sketch on a napkin.  A doodle on a scrap piece of paper.  A few words to solidify the idea that has been formed in the mind.  And the sketch or doodle, the short sentence or scribble, all start with a pencil.  That’s why I’ve thought a fitting project for 2017 is WrTie, a titanium mechanical pencil.

This project symbolizes my desire to do things different.  WrTIe will be a product designed to last a lifetime and pass onto your kids (like that pocket watch you received from your grandfather), a project that challenges design and manufacturing skills, and my desire to be an inspiration for everyone working in their garage.  And that’s where great ideas start.

The real question is can a small shop with manual machines and one man design, prototype, and manufacturer something so simple … yet so complicated?  This is a product made with a material that is difficult to manufacturer with even the best equipment.  And I’ve never machined titanium.  Not even once.

What will follow over the year is a series showing my progress on designing, prototyping and manufacturing a mechanical pencil made from titanium.  There will be product tear downs, unique designs, tiny o-rings, CAD software, research, guesswork, calculated risks, material investigation, tool design and selection, deep hole drilling, tiny machining, the help of friends, many failures, frustrations, lessons from craft beer, and I hope in the end success.

I haven’t written or designed anything.  This is not scripted.  This isn’t a Kickstarter campaign.  Through the power of video you will be coming along for the journey, every step of the way, watching ever failure, and every success.  I want to learn and do something productive, and I hope you do as well.

And in the end if it all works, I hope to have something special that I can use every day.  The drawings, the lessons learned, the tricks discovered, will all be here.

To show your support, I ask you to subscribe.  I will start in early 2017.

Now I need to get this VFD put on my lathe.