Free Plans: Jeroen Jonkman's

By , on November 27th, 2011

Jeroen Jonkman built this Gamma type Stirling engine for his father’s 60th birthday.  He also drew a nice set of plans for it and is very generously sharing them.  You can download them here from MachinistBlog (PDF) or from HMEM if you’re registered there and logged in.  I asked, but Jeroen didn’t tell me much about himself.  But I can tell from the videos he uploaded to his YouTube channel that he’s a skilled machinist and prolific builder of model steam and Stirling engines, many of which are of his own design.  Jeroen is also Dutch and I find it interesting that two other Dutchmen, Jan Ridders and Jos De Vink, have built some of the world’s most beautiful and interesting model Stirling engines.  Jeroen has not produced as many engines as those two but I wouldn’t be surprised if he does someday.

Continue reading → Free Plans: Jeroen Jonkman’s “Stirling 60″

November 27th, 2011 | Category: Engines, Plans, Stirling Engines | Leave a comment

Shop Light Upgrade & T12 Phase Out

By , on November 7th, 2011

I have about a dozen 4-foot fluorescent shop lights in my basement and garage.  They’re all hanging from chains and plugged into ceiling-mounted electrical outlets that are controlled by wall-mounted switches.  They frequently have to be replaced because the cheap magnetic T12 ballasts in them go bad.  On my last trip to buy a replacement I learned something I didn’t know and you may not either.  T12 ballasts and some fluorescent bulbs are being phased out in the U.S. next year (2012) because of higher energy efficiency standards, although some exceptions are being made for residential use.

I don’t know if the residential exceptions will allow you to continue buying cheap ($10) shop light fixtures.   I won’t be sorry to see them go because I’m tired of replacing them every 2 to 4 years.   I’d already seen the video above and had decided that I was going to start repairing my shop lights with T8 electronic ballasts.  So I came home from Home Depot with an $18 replacement ballast, a box of ten 32 watt T8 “daylight” bulbs and a new $30 T8 shop light fixture in case my repair failed.

Repair and upgrade was not that difficult

It wasn’t hard to repair my old shop light by replacing its T12 ballast.  But I’m not going to describe how to do it because if you don’t do it right you can turn your shop light into an electrical or fire hazard.  If you want to learn how then do a search for “T12 to T8 conversion” (without the quotes) and you’ll find many helpful web pages and videos.  But I will give you this advice:

  • Make certain you use the proper size wire nuts so there’s no chance your new connections will come apart.  Vibrations and temperature changes can cause poor connections to become loose.
  • Your new ballast will have to be attached and grounded to your light fixture using sheet metal or self-tapping screws.  Make certain they won’t come loose and you scrape the paint off the ballast underneath your screws so they will make a good electrical connection.
  • Make certain your power cord’s ground wire is also properly attached to the fixture.
  • And make certain you unplug your light before you start working on it :-)

T8  Advantages

  • A 32 watt T8 bulb is slightly brighter than a 40 watt T12 bulb of the same kind.  I’ve begun buying “”Daylight” bulbs because they are much brighter than “standard” fluorescent bulbs and they also seem to make colors appear more accurate.  And because they use less power T8 bulbs also produce less heat.  Which can be an advantage in air conditioned environments.
  • Florescent bulbs dim over time and a T8 bulb won’t lose as much of its brightness as a T12 bulb will.    A T12 bulb will lose about 20% of its initial brightness and a T8 will only lose about 10%.
  • T12 lamps can flicker, hum and sometimes create a stroboscopic effect because they operate at low frequencies (120 or 100 Hz).  T8 lamps won’t because their electronic ballasts operate at much higher frequencies (20,000 Hz).
  • T8 ballasts can work at much lower temperatures than most T12 ballasts.

T8 Disadvantages

The only disadvantage I’ve seen so far is cost.  I don’t remember there being much of a difference (if any) in cost between T12 and T8 bulbs.  But T8 light fixtures seem to cost at least twice as much as T12 fixtures.  [Might still be true at Home Depot but Lowes sells a really nice T8 shop light for $15.]  I’m also concerned about how long their ballasts will last.

November 7th, 2011 | Category: Videos, Workshops | 3 comments

Art Dick, Machinist

By , on November 1st, 2011

I really liked the video about Neil Youngberg that I posted a little while ago and I think many of you did too.  This one about Art Dick is similar because it shows another craftsman doing his job and it also has beautiful cinematography.  You almost can’t tell that it’s a commercial.  I recommend watching it full-screen in 720p HD if you can.

November 1st, 2011 | Category: People, Videos | Leave a comment

I’m learning how to TIG weld

By , on October 22nd, 2011

The stringer beads on the left were TIG welded by my instructor. The ones on the right were the made by me after about an hour of practice.

I started taking a 10-night, 30-hour TIG welding course this week at a welding supply company.  I enrolled partly because I enjoy learning new skills and partly because TIG welding is especially useful in a machine shop.  You can use it to weld almost any kind of metal and it can make very small, precise and neat looking welds with very little heat distortion.  It’s also a very clean welding process that you could do in your living room without getting yelled at too much because it doesn’t produce any spatter or sparks and it creates little or no fumes.

Machinists will frequently use TIG to add a new layer of metal to parts that are worn and then they’ll re-machine them.  Mistakes, such as a hole that was drilled in the wrong place, can be repaired in the same way and you probably won’t be able tell they ever existed.

TIG uses electricity to create heat with an electrical arc, which makes it similar to MIG and “stick” welding.  But in those two processes the electrode (a wire or rod) gets melted and deposited in the weld.  But a TIG electrode doesn’t get “consumed.”  It just creates heat and a filler rod is used to add material to the weld puddle if it’s needed.  So it’s very much like oxygen-acetylene gas welding but with some huge advantages.

  • You can almost instantly turn the heat (arc) on or off.
  • You can very easily and precisely control the amount of heat using a foot pedal.  Sometimes a thumb wheel on the welding torch is used instead.
  • It’s much easier to see and control the weld puddle.
  • You can weld almost any kind of metal.
  • It’s safer. Oxygen and acetylene can be very dangerous.  TIG welding is almost always done with argon gas which can’t burn or explode.  You also only have to deal with one tank of compressed gas instead of two.

TIG welding does have some disadvantages

  • TIG welding requires more skill than MIG or stick welding.
  • TIG welding is a slow process.  TIG is to MIG what walking is to running.
  • TIG welding equipment costs more.  If you’re going to buy a TIG welder make certain it can produce AC (alternating current) because you’ll need it if you want to weld aluminum.  Many of the inexpensive/cheap imported TIG welders you see for sale on eBay and the Internet are DC (direct current) only machines.  So beware.

Being able to weld aluminum is one of the best reasons for buying a TIG welder.  You can weld aluminum with a MIG welder but you’ll need to invest in a spool gun and a tank of argon gas.  And you still won’t be to make welds that are as precise and as neat as those made by a TIG welder.

By the way, most TIG welders can be used to do stick welding.  You just replace the torch with a “stinger” to hold a welding rod and go to it.

That’s my real quick overview of TIG welding.  If you want learn more this Wikipedia article is a good place to start.  You can also leave a comment if you would like to hear more details from me.

I didn’t get to spend much time in my workshop this week

I was in my welding class two nights and I worked late (until 8 PM) on two other nights and all day today (Saturday).  Monday night was spent cutting our grass and doing other household chores.  And I went to bed at 8 PM last night because I’ve caught a cold (my first in 2 or 3 years) and I was exhausted.  So I haven’t gotten any work done on my CNC router this week yet, although I am hoping to spend a good part of tomorrow working on it

I did get some work done on my “winter” workshop.  Some of my wall space was taken up by large plastic storage bins that I’d filled and stacked to the ceiling with things that we don’t use very often.  I got rid of some by ruthlessly throwing out (or donating) things we’ll probably never use again. The room also has a really nice big computer desk that’s kind of the modern equivalent of a roll-top desk because all the storage compartments and cubby holes it has.  I was going to keep it but I’ve decided not to so I can have a longer workbench and more room for tools.  So I’m going to have to throw out or find other places for the things that are in it.  I think it’s going to be a tedious chore and some of the storage bins I just emptied will get filled back up.  But it has to be done.

October 22nd, 2011 | Category: Welding & Metal Fab | 2 comments
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