Dial Indicator Sled for Calibrating Table Saw

I own this cheap dial indicator set, and while it is indeed cheap it works fine for calibrating my table saw.  My only complaint is that its versatile base and arm system just doesn’t work that well for this purpose, especially for setting up the fence where sliding the indicator causes the small base to wobble and also scratch the cast iron top.

My solution was to make something a bit like Woodpecker’s Saw Gauge, only about $59 cheaper.

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Enter the dial indicator sled!

As you can see, it’s just a scrap of 1/2″ plywood with a rail glued on, onto which the indicator is bolted.  Because it’s wood it nicely slides on the table saw surface, and because it has a long edge it registers well against the fence.

While the rail should be somewhat squarely attached it (thankfully) doesn’t have to be all that precise.  We’re only interested in relative distances (how much the needle moves), not absolute numbers.

Here are some more photos, including it being used against a Master Plate to calibrate my sliding table and the fence.

Black & Decker Easy Clean Toaster Oven Repair

I’m writing this short post not to brag about my toaster oven repair skills but to hopefully help out someone else looking to fix their appliance.

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I have had this stupid toaster oven since college (18 years as of this writing), and still use it every day.  I even built a custom under-counter mount for it which lets it do double duty as a plate warmer.

So one morning while toasting an English muffin my kitchen was filled with the odor of burnt electrical insulation instead of toasted baked goods.  “No worries” I thought, this oven has served me well and I just buy a new one to take its place.  I was surprised to see that the under-counter toaster oven was merely a phase, with only one on the market right now.  It’s very expensive for a humble toaster oven, and also mounts differently so I’d loose my sweet plate warmer.

So off to the shop I went with it.  Thankfully the problem was simple to both diagnose and fix: one of the conductors on the main power supply line had degraded, causing it to heat up and burn through its insulation.  I simply cut a few inches off of that degraded conductor and then pulled a few extra inches of the power cord through the grommet into the case of the oven.

The two power conductors each have female connectors and clip on the corresponding male connectors.  One connector was in good shape the but the wire leading into the other had burned out.  In the photos, that wire is labeled #1.  Wire #2 heads to one of the heating elements while #3 goes to a control board.

After pulling in another few inches of power cord, I cut away the crispy burned wire, stripped the insulation, and then soldered wires 1, 2, and 3 back into the old female connector.

SS Brewtech 10 Gallon InfuSsion Mash Tun Review

After having done four batches on my SS Brewtech mash tun I can give it a fair review.

I had been using the same 10 gallon orange cooler for a hell of a long time, over ten years! I had the bulkhead super solid and leak free, and a hard-piped false bottom to avoid suction collapse, and it always worked well and retained heat.  It’s kind of dingy and one wall is heat-buckled but considering my brewstand is made out of bed frames aesthetics isn’t a big priority for my homebrewing.

I bought the SS mash tun mostly out of curiosity, to see if an engineered $400 stainless cooler would be any better than a $40 plastic one.  The short answer is that yes, it is better, but not hugely so.  In my opinion there aren’t any clear-cut differences that make this product a clear winner over a much cheaper plastic option; that decision will come down to your and your budget.  I’ll discuss those differences below in order of importance to me.

Lautering – How well does it strain out your wort?

My cooler takes 2 gallons of vorlauf before the runoff is clear enough to start filling the kettle.  The first gallon is pretty chunky with the second having a few bits of grain and murk.

Because the SS’s false bottom has a silicone gasket around its circumference I hoped that my vorlaufing would be reduced; perhaps no grain would make it under the false bottom at all!  Well sadly it still takes about 2 gallons to get clear enough runoff.  And again, the first half is fairly chunky.  I’m not complaining about this, just noting that it behaves the same as my cooler setup.

Otherwise lautering works equally well as in my plastic cooler.  I have not seen any difference in mash efficiency.  I do need to blow into my runoff hose to get it going whereas I’ve never needed to do that with the plastic cooler.

Heat Retention

Heat retention is important to infusion mashers!  When I first got the stainless tun I ran some experiments on it to find its heat capacity and heat loss coefficient using Bjorn Jansson’s mash physics process.

Here are my results, with the jist being that after 40 minutes the plastic and stainless coolers each lost about the same amount of temperature but for different reasons.  Stainless soaks up more initial heat (Heat Capacity) but retains it better over time (Heat Loss Coefficient); plastic is the opposite.  Each lost 7 degrees over 40 minutes.

T0 (F) T5 (F) T40 (F) Delta T (F) Heat Capacity (kJ/K) Time Calibration Heat Loss Coeff. (W/K)
Plastic 148.1 144.7 141.1 -7 2.988 43391.5 1.6123
Stainless 147.7 143.2 140.4 -7.3 3.955 54968.3 1.2903

So again, there is a wash when comparing the two mash tuns.

Cleanability

Finally, a clear winner for the SS product!  I love how the false bottom slips in with no fittings to undo.  And stainless is much easier to clean that porous plastic.

Usability during the mash

As compared to the plastic cooler, the stainless tun is better in these ways:

  • The lid is really easy to use; no threading

And it is worse than the plastic tun in these ways:

  • The rubber feet will pop out if you drag the tun across a surface (SS provides an extra foot with the tun because they know you’ll eventually loose one)
  • It is heavy!  It’s a lot harder to carry a tun full of wet grain when that mash tun is made of metal.  It weighs 33 pounds just by itself!  A 10 gallon cooler weighs about 11 pounds.

I’m not sure if this is the right section to mention this, but the thermometer that comes with the tun is not great.  I did a bunch of boiling water testing with all my various thermometers and the LCD thermometer was consistently 2 degrees Fahrenheit below what it should have been.  My cheap instant-read thermometer was pretty damn close to perfect!  Because the SS thermometer doesn’t offer a calibration option it’s now sitting in my “extra brewing stuff” shoebox, and I’m thinking about how to plug up the thermowell hole in the mash tun.

Overall Value & Conclusion

This product gets a 5/10 from me.  I’m glad that a few manufacturers are offering stainless mash tuns to us homebrewers, but those products aren’t leaps and bounds better than what we’ve historically used.

I think that the stainless tun is a good choice if you don’t already have a plastic tun built and don’t mind spending some money.  You won’t have to mess around with perfecting your bulkhead, and you won’t ever have to worry about plastic leaching into your homebrew.  While this isn’t a big personal concern for me, it’s always raised one of my eyebrows.

Durability and chemical inertness are what make it better than a plastic mash tun, you just need to decide how much money that’s worth to you.

Segment Calculation Google Sheet Document

Who doesn’t enjoy simple geometry and spreadsheets?  I made my own segment calculation spreadsheet just to get a better understanding of segmented turning.  I’m not doing anything particularly complex so it was a fun little undertaking.

Here’s a link to the spreadsheet with some inner and outer radii already filled in.  Feel free to make a copy of it (in the File menu) for your own project!

The inner and outer radii that you determine from your profile drawing go right into the spreadsheet.  I should clarify that the inner radius does not determine the inside face of the segment, it is where the inside wall of your vessel will be.  As you can see from the drawing, there is some extra material between the inside faces of the segments and the vessel.  So you should notice that your calculated segment widths are a touch wider than the vessel wall thickness.

Like many Imperial system users, I can easily “think” in inches but prefer accurate measurements in metric, so I have the spreadsheet inputs in inches and its outputs in both inches and millimeters.

I’ve also included a “Done?” column so that you can track your progress on a printed copy.

Angle Setup Blocks for Making Wedgie Setup Templates

Jerry Bennett’s Wedgie Sled is a wonderfully simple and elegant solution to the problem of cranking out trapezoids for segmented turning.  If you’re not familiar with his idea,  visit his site and watch his video series.

The only hard part is what to do about setting the angle between the two fences; here are a few options:

  • Buy angle setup blocks – Jerry has them available but they are expensive!
  • Use a digital protractor – I tried iGaging’s protractor but it’s not accurate enough for this application.  A resolution of 1/2 degree just isn’t good enough.
  • Make your own – but how??

The problem with making your own is that the angle temple needs to be quite accurate!  The template’s error will be compounded by each segment in your ring; this is the basis for the “5-cut test” for squaring up a table saw miter fence.

IMG_20180306_195140The route I went with was to use machinist’s setup blocks to create my wedgie sled angle templates.  I got this cheap set off of Amazon, whose smallest angle is 0.25°, and biggest is 30°.  One can set up a wide variety of angles by stacking up two or more blocks.

Making the Template

I made my template out of a 3/4″ thick piece of MDF, although in the photos below I have the cut setup demonstrated with a piece of plywood.

The goal is to make a triangle with one angle being 360/n, where n is the number of segments in your ring.  I was doing 16 segment rings so my n was 22.5°.  And if you dust off your High School geometry, a little application of like triangles will show you that the angle between the two wedgie fences equals the included angle of each segment – very simple!

In the photos below I have three stacked angle blocks to get my cut: 20°, 2°, and 0.5°.  It’s very important work off of a clean edge so that no fuzzies throw off your work.  Here was my sequence:

  1. Cut one edge of the board to clean it up
  2. Rotate the board 90° clockwise so that the clean edge is against the miter fence – Take another light cut to clean up that edge
  3. Add the angle blocks, creating as wide of a triangle as you can.
    1. Take your time with setting up this cut!  Be extra sure that your clamping mechanism doesn’t move the work.

Extra credit can be earned by “squaring up” the triangle – making its two short ends parallel so that you can set up your wedgie sled fairly square to the blade.  To do this, I used a half-angle setup, 11.25° and a little square.  If your wedgie sled is skewed a bit, your pieces will still have perfectly accurate sides but the inside and outside faces will be skewed a bit.

Results

Using the template block is pretty easy, just smush your fences against it and tighten them up!  The other photos are my rings, all of which were one-shot affairs: all the segments were cut & glued in one sequence.  No half-rings or sanding needed.

Prototype Turbo Oven Coffee Drum Roaster

IMG_20180204_135918Inspired by my friend Dominick’s attempt at a Turbo Oven-powered Drum Roaster I thought I’d build my own.  While I appreciate the simplicity of my Stir Crazy base I’ve never been happy with the consistency of roasts; by its very nature it just can’t stir the beans around to evenly roast them.

In his version, Dominick talked about a long roast time of about 20 minutes.  I figured that was due to heat loss through the sides of the enamel pot used for the base.  So in my version I’ve made an insulated base which looks to have solved that problem.

Here’s a video I shot going over the roaster, it also includes some clips of it running.

Base

 

The base is made out of two aluminum walls fastened onto a wooden base.  I turned the base on my lathe, making a tenon around the circumference that the two walls seat against.  There is about 1″ is space between the walls.

The inside diameter is about 9.5″, enough to house the drum I’m using.  The height of the walls needs to be high enough to not only house the drum (plus a reasonable gap on the bottom for clearance) but also high enough to clear the “nose” of the turbo oven.  I forgot this second consideration and was only able to use the smaller of the two drums I bought.  The walls are long strips of 0.025″ aluminum riveted to make loops.  I used small #4 wood screws to secure them to the base.

Insulation is provided by glass fiber insulation.  It doesn’t seem to mind the heat from coffee roasting.

Bearings for the drum rod are two flanged bronze sleeve bushings, 3/8″ in inner diameter.  Because I’m using 1/4″ square rod, I needed something with a slightly bigger inner diameter to house the rod.  And nicely enough, 0.25 x 1.414 is roughly equal to 0.325.  I made sure to buy bearings with a flange to make them easier to mount in the walls.  I only then have to secure one end.

Doesn’t the wood catch on fire?

I asked myself the same question!  But no it has not, it has darkened a bit over 5+ roasts and oozed some sap.  And after each roast I can smell pine resin, but that aroma has not made its way to the beans at all.  The aluminum foil cover seems to help because it reflects the radiant heat produced by the Turbo Oven’s halogen light.

But with that said, when it comes time to re-make the base I will attempt an all-metal construction.  And I have moved a fire extinguisher to my coffee roasting station just in case!

Drum and Rod

I bought two coffee drums off of eBay for this prototype because I didn’t know what size would work the best.  Here is the listing, but in case that stops working they are each 18cm long with diameters of 14cm and 12cm.  The 12cm drum is a bit too small for a 1 pound (green weight) batch – larger, puffier beans will eventually crowd up inside and stop tumbling.  The 14cm drum has worked great on all my 1 pound batches.

The drums have a 0.6cm^2 square drive hole, which is pretty darn close to 0.25″ (6.35mm).  The rod fit in there right away without any filing.  However the holes were out of axial alignment so I had to file one of them on the corners to “rotate” it a bit to allow the shaft to slide all the way through.

Speaking of the shaft, it is a 1/4″ square solid stainless steel rod from Home Depot.  I can’t find it on their site right now or I’d provide a link.  Here is a similar product from Speedy Metals.

Motor

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Roaster with old, noisy ice cream maker motor

This prototype has already seen three iterations of the motor!

Ice Cream Maker Motor

The first was off of an ice cream maker.  It worked OK but was quite loud making it difficult to hear the cracks.  (I also have not-great hearing, picking out details from background noise is difficult.)  However, one positive for this motor was that its drive shaft was designed to accept a 1/4″ square rod!  Another good thing about the motor is that it came from a $10 thrift store find so it didn’t require any eBay’ing.

4W Gear Motor

Version two has me using a 4W, 35RPM synchronous gear motor.  These things are all over eBay and about about $10; here’s one listing.  Be sure that the one you’re looking at is rated for 110V or 120V, there are also 12V models out there.

I have two of these little motors, one fixed to go clockwise and another which will randomly choose a direction when started (this is normal).  We’ll call the former CW and the latter CW/CCW, because that’s what their labels have.

In a test run with 16oz of greens the CW/CCW motor had great difficulty starting out and needed a push.  Not much more was needed to stall it, either.  The CW motor worked a lot better, still needing a push to get started but it would not stall out on its own.  As this writing I have a 14W motor on its way and will try that out and update this post when it arrives.

My first real roast with the 4W, CW motor worked really well but I only used 14oz of beans.  It stuttered a bit while starting but once going worked the whole time.  Roast #2 used 16 oz of greens and the motor would not start spinning until given a little help; but it at least ran the whole time without stopping.

14W Gear Motor

The third motor is a lot more powerful and should be the final one for this roaster.  Here’s an eBay link, but if that doesn’t work for you look for a “14W 30RPM 110V synchronous gear motor”.  It should be about $15 shipped.

While the motor’s description said it has a 6mm output shaft it’s actually 7mm so it immediately worked with the flexible coupler mentioned below.

The motor is reversible, so it has three electrical connections.  This video shows a little more detail into how to wire it up, but the gist is that one AC lead goes into the middle and the other lead goes into one of the side connections.  To change rotational direction use the opposite side.  There’s no polarity with AC.

This motor, like the 4W, is close to silent in operation but has tons of power.  It easily turned 16oz of greens, and I was unable to stop the drum with my hand.

It has four threaded bolt holes in its flange, M5-0.8.

Drive Shaft Coupling

While using a square bar for the drive shaft made it easy to mount onto the drum it made it a lot less easy to attach to the motor.

So I gripped the bar in my chuck’s pin jaws and filed the end of the square bar down to round.

 

Now I can couple the shaft to the motor.  The motor has a 7mm shaft, and I now have a 6.35mm shaft, so I used a flexible coupler to join the two.  I went with a flexible one because I know that none of my work is close to perfectly square or aligned.   This lets the motor and shaft rotate in peace with the flexible coupler taking out the slack.

 

The motor is simply screwed to a T-shaped  plywood stand.  The above photos show the 4W motor but I used the same stand for the 14W motor.

Usage

  1. Pre-heat the unit with the drum in place, slid onto the shaft and in the vessel.  Make sure drum door is pointed upward.
  2. Add beans and replace the turbo oven, set for perhaps 460F.
  3. When 1C comes around, lower the heat to around 440 in order to avoid a rolling 2C
  4. The end of the roast is still kind of awkward.  Turn off drum, remove turbo oven, and then pull out the motor and shaft leaving the drum in hand.  Now open the drum door and dump beans into cooling vessel

It’s not too different of a process as compared to my Stir Crazy, but is definitely less user-friendly when it comes to removing the beans from the device.

Results

IMG_20180204_112727I’ve been getting very good, consistent batches out of this machine.  The drum’s agitation of the beans also does a better job of removing chaff than the stir crazy, my beans are very clean.  I did struggle with over-roasting when I used the loud ice cream maker motor because the light 2C snaps were hard to pick out.  But my last batch with the quiet synchronous motor was right on target because those first 2C snaps were easy to hear.

Ryobi 40V Mower Cutout Fix

I’ve had my battery-powered 40V Ryobi mower (model #40108) for a year now and have been pretty happy with it.  However the last time I used it the damn thing would randomly shut off while mowing.  At the time there didn’t seem to be any rhyme or reason to the problem such as heavy grass or a weak battery which was reading 2/4 bars.  I threw the battery into the string trimmer and it worked great.

So I took the lovely slime-green plastic cover off to see if there was anything obviously wrong.  My hopes were low because I figured the mower would consist of a motor and control board.

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Simple mower internals

Sure enough nothing looked wrong such as a leaking capacitor on the control board.  But while putting it back together I noticed a kill switch I had never noticed before!  It’s located by the handle hinge, ensuring that the mower will only run while the handle is in the folded-out position.

This little switch was flopping around in its hole because one of the spring clips on the backside was broken probably while I was removing that slime-green plastic cover.  When the handle is folded out the switch is depressed, closing the circuit allowing the mower to run.

If you take a close look at the interaction between the switch and handle, it is  not a precision operation.  Due to the position of where the switch happens to be, the handle bumps into it, hopefully depressing it.  Here’s the root cause of my problem: The mower’s frame had loosened up over time, allowing the frame to rack from side-to-side during turns.  This racking let that little switch spring back up, opening the circuit and stopping the mower.

And thankfully the solution was to tighten these two T25 frame bolts, located right above the rear wheels.

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Keep these bolts tight

And as a footnote, I bypassed that dumb switch just to avoid this kind of nonsense in the future.  The connection was wrapped up with electrical tape after these photos were taken.

 

I hope this short article helps someone out!

Lathe Sharpening and Tool Cart

I’ve had my grinder on a Harbor Freight tool cart for the past year.  I don’t have any more bench space in my shop so a mobile solution was all I had left.  Plus skinning the sides with tools works pretty well and its nice having some shelf space.

Gouges on the left, scrapers on the right, with skews, parting tools, and a drill on back.  It’s nice being able to put my grinder and tools right where I want them while turning and then tuck them away when doing something else.

However the lower shelves are only moderately useful because they’re short and deep, and they also fill up with chips.  I couldn’t find a cheap (say $100 or less) tool cabinet with drawers all the way down and a solid top, so I was planning on just building a small two-drawer box to sit in the bottom space.

So off I went to Menard’s to get plywood, drawer slides, and pulls.  On a whim I checked out their tool storage area and found a pretty damn good cart!  It’s just wide enough to accommodate the Tormek jig arms and the price was right.

 

I re-used the tool holders but did make a new top from some 2x material.  Some drawer dividers and I was ready to go!  It holds much more than the old cart and should do a better job of keeping the chips out.

Veritas Strking Knife Sharpening Jig

The thin profile of Veritas’ Striking Knife makes it pretty versatile but at the same time hard to sharpen.  It’s very small so there’s little bevel to “feel” for and the blade material is bendy so it’s hard to keep in the exact same orientation while sharpening.

Consequently over time mine will loose its nice pointed end and flat sides and it can’t reach into tight corners.  To help me re-establish a nice flat bevel I use a really simple “jig”, just a scrap of wood with two 25° slots cut into it.

The jig then holds the marking knife up against the flat side of my CBN wheel.  The 220-grit finish from the wheel isn’t great so I then finish up with my usual honing routine.

This slot-in-a-block-of-wood type jig could be used against a normal bench grinder (front of wheel of course), belt sander, or even to hold the knife for hand-sharpening on stones.

Gouge Sharpening Through a Microscope

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Sample image

Using a cheap USB microscope I took some closeup shots of the scratch pattern and burr on a HSS bowl gouge through three sharpening methods.

Here’s the full album of images

For the purpose of woodturning it seems like the fineness of the edge doesn’t matter a whole lot.  While the burr looks very nasty, and would be bad to have on a smoothing plane iron, it will get immediately knocked off in a woodturning project.