Saturday, October 20, 2018

Mountain Bike


Gave my commuter bike an overhaul to make mountain biking a little friendlier. It had fenders and road 28x700c tires before, now it has 40's and knobs and no fenders to tangle with.

To put on the bigger tires, I had to get a new front derailleur and find a way to mount the lights without the fenders. I made little aluminum brackets for the front and rear:




I also got a smaller handlebar bag. I don't know what sort of G-forces a CX bike front end endures on galbraith mountain, but it was enough to really give the bigger handlebar bag a beating. With the smaller one I still don't have to wear a backpack, but I can still carry tube, tools, garlic press, and a few servings of hash browns.


This version of the bike has been named Monty by my sister.


Hurried to go on a ride with her yesterday, and one bar plug short of a full set, I whittled one out of fir in 12.2 seconds.

The bike is still far from a mountain bike, but after riding the 28mm road tires for a year it feels like I can do anything on it :)


Monday, October 15, 2018

Shelf


Courtney asked for a shelf for her dearest plants, as they were all crammed onto a tiny wire nightstand.


I made some of the pieces in a proper shop, and some in the apartment shop with hand tools. Cutting dadoes is a very different experience on the table saw vs. hand saw/chisel/router plane; half of them were cut by each method. As the front uprights angled inwards towards the top, cutting them by hand was actually desirable in ways. For the back ones, I'd take the table saw any day, but would have instead made them dovetails if I did it by hand.


The shelves are aluminum offcuts from a local metal supplier. I had to trim three of them- you can see the bottom two aren't quite deep enough, but I saved a lot of money by not making them cut up a large sheet.


This is how I carried the wooden pieces back from the big shop- it was rainy and 10pm but overall a peaceful and quiet ride


Here was carrying the aluminum back with my groceries- I'm starting to grow attached to this bike. To me they start as inanimate machines, and gradually become more like animals or friends.

Thursday, October 11, 2018

Weighted Blanket


A therapist/healer hired me to make some weighted blankets. Many people like a soft, heavy weight atop them; they find it calming.


The therapist wanted me to make them because I was local, and I could fill them with tiny glass beads instead of the usual polyethylene plastic pellets. So far I have bought all the fabric in Bellingham. The glass beads are very nice and smooth to the touch. It feels a bit like sand, but since each grain is a smooth sphere they flow more easily.



The first blanket I made had a zippered cover; this one has the same number of layers but is sewn as a single piece. It weighs about 10 lb (4.5 kg) and is 54 x 40 in (140 x 100 cm). If you are interested in buying one, one this size costs about $150. A small one would be closer to $80.


Saturday, October 6, 2018

Sprinkler Stand II

The last sprinkler stand I made is still sprinkling, but dad needed a second one. The turned hubs of the first one have cracked from getting wet and drying out so many times.

I made the new one to be more waterproof-



Made of aluminum, delrin, and stainless steel.



I could have made the delrin inserts a press-fit, but I wanted them to be easily replaceable. They are each secured with a sheet-metal screw.

 

Thursday, September 13, 2018

5C Lathe Part II: Power Supply and ESC


450 w 12 v server power supply connected to 25 amp ESC. With this arrangement, I get a very compact 1/2 HP variable speed motor for $100 or so. The parts are all pretty high quality too-

I made the aluminum enclosure from .062" aluminum found in the remnants bin at local metal supplier. The top handle and aluminum for knob came from a dumpster, and the pushbutton switch on the top was recycled from my wooden computer case build.






Servo tester with 'mode' switch and potentiometer breakout.



Wednesday, September 12, 2018

Thin .040" Parting Tool Holder

 


The slot has a dovetail shape to pull the parting blade towards the tool holder. It's really helpful if the blade can go right up next to the chuck. The parting tool holder made by Taig is weak in this department:


I skimmed maybe .075" off the blade clamp, but it still gets in the way all the time. I'm excited to have a holder that can part almost flush with the chuck!

To cut the dovetail on the new holder, I ground a safe edge on a cheap triangular file and finished the slot with it. It might have been faster to grind a single-point cutter, but this worked fine


It takes up half of the AXA tool holder; the other half will get a piece to hold a 1/4" facing tool at matching height to the cutoff tool.


Made for my 5c lathe. Ideally this would be made of 4140 or something like it, but I used the cold-rolled steel I had. I parted a 1/2" stainless rod and it worked a treat. I have never used a parting tool so thin, and it's a good match for small work and light lathes. I can get real stingy with my bar stock now :)


Sunday, September 2, 2018

5C Lathe Part I: Motor Mount


I'm putting together a new manual desktop lathe to replace the one I put together two years ago. The old one has been awesome, despite its weaknesses and size it is the most useful tool I have ever had.

The new one is made with light production in mind, for making drawer pulls and hand tool parts. It has a 5C spindle, quick-change tool post, and slots for mounting five or more tools in a gang arrangement.


Above was boring out the hole for the motor using a fly cutter. I adjusted the cutter with my most precise hammer and ended up with a darn accurate bore, a snug slip fit over the motor. :) The motor is a 450 w brushless DC motor, pretty spicy for a motor that's smaller than the lathe spindle itself...


I wanted the fit to be close so that the pinch bolt wouldn't have to stress the aluminum much to clamp it (it does clamp easily). The outer edge of the plate is pretty sloppy though; I got tired of filing the gummy aluminum. A mill or router would have been nice for that.


I roughed out the plate shape with a wax-lubed coping saw, which was actually pretty quick. The 18" frame saw also cuts through it plenty fast. I made the plate to fit the vee belt I had on hand (standard Taig lathe belt), after I machined both pulleys. It pivots on the bottom mounting screw and locks with the screw on the top to tension the belt. I erred on the long side for the slot travel since the belt is heavily used.


Approx 1:6.5 reduction. Small pulley machined of steel and secured to shaft with setscrew bearing on flat portion. Also managed to bore a tight slip fit on the motor shaft with a little honed carbide boring bar.


Used steel shaft collar to mate the plywood pulley to the spindle--I often grab the pulley and rotate by hand to tap holes and do other high-torque stuff. Setscrew just seems hackish for this.


Stay posted for the base, tooling, electronics, and maybe even an electronic leadscrew-

Monday, August 27, 2018

T-Slot Nuts: Minimum Effort Edition

Kind of humbling to have to make one's own T-slot nuts in this era. I did it once before using this method when I first started machining at home.


Couldn't find Taig-sized nuts from the usual suspects so I decided it would be best to just make them myself. I initially thought the style on the left (above) would be fast to make, but without a square collet and a rigid lathe it's a slog.

Yesterday I started bucking off 1/2" pieces from a bar of 1018. Absolutely unremarkable in every way except for the little fixture I made for drilling and tapping them this morning:


Nope, I think I was right the first time, absolutely unremarkable in every way. You may notice the slightly over-sized aluminum sub-plate there. I intend to use it for other things, have needed one for a while.

I made a dozen of the nuts:


one two three four six seven twelve

Despite being so rough and rushed, they ain't bad. The threads are square to the shoulders, they are steel, they are all nice and deburred, and there's more meat there than the 1/8" thick ones that came with it.

If the last ones are any indication, they'll do just fine for the next eight years.

Sunday, August 26, 2018

Frame Saw for Metal

I have wanted a frame saw something awful bad for a few years, to use for sawing metal. I think I was blessed (or cursed?) at birth to spend my life hacksawing. It's not as bad as people make it out to be; it's a very accurate tool. Accuracy at the saw is worth a pound of cure at the mill, or often in my case, the hand file. It's not difficult to saw +/- .010", and +/- .004" is not out of the question when all my ducks are in a row.

No matter how it's done, sawing steel is kind of a pain in the butt. Be it metal grit in your collar (glowing hot or just hot enough to burn), a mighty physical workout, or funky old coolant that dearly wants to find a way back to the earth, no method is without its drawbacks. I once bought and restored a little power hacksaw, but it was even slower than hacksawing by hand--I think due to the short stroke, wide kerf, and its lack of deductive reasoning ability. Who am I to blame though?

I once nearly bought an Ellis horizontal band saw, but kept the money instead--my favorite saws for metal are dedicated vertical bandsaws. They are relatively peaceful and versatile.

A couple months ago I found the saw design of Blackburn Tools, which struck me as especially pretty--I just sort of memorized the general form and sketched it out on the wood I had. The wood came from the ReStore, I think it might be alder. I got the idea for the pins from Sean Hellman. The whole thing, including making the three blades, took a full day of work and maybe $20 in materials.


I had put it off for a long time because I thought I didn't have the technology for drilling holes in the hardened blade. I really worked it up in my mind that it was a difficult undertaking. Yesterday I took an $8.50 diamond 'stone' to a $2.60 carbide tipped masonry bit to sharpen it. It drilled so easily and quickly, I felt like an idiot for putting it off so long. To cut the blade, I just clamped it in the vise and bent it back and forth.


The whole thing feels absurdly light to me. I used Kevlar thread for the tensioning string. Like a spoked wheel, it's such an elegant design.



Below is the hacksaw it mostly replaces. I finally snapped yesterday while using it because the thick coating of paint on the blade was making the blade steer unpredictably. It also squeals! Whether the blade is loose or tight, wax-lubed or bone-dry, pressed hard or gently, it really can get loud. I work mostly in a shared apartment, and do my best to keep the people around me happy. I often pressed the pinky of my leading hand against the blade to quiet it down, which feels a bit risky; fortunately I haven't slipped yet. I have even clamped large rubber dampers to the frame and blade, which reduces the noise at expense of stroke length. Which brings my to my last gripe, the short stroke! I am a tall and lanky machine, I feel like I'm pedaling a children's bike with a 12" hacksaw.


I must have sewn through logs of solid steel with that hacksaw by now. Below are some recent victims. 1" x 3" 1018 on the top left, .75 x 3" top right, and underneath is a .75" x 6" slice off a plate of hardened (RC 30) 4140 to make a hatchet stake. New ones are expensive, alright?


Today I put ol' faithful head-to-head with the saw I just made. I tested it on these blanks for odd-sized t-slot-nuts, .25" x .75" 1018 steel. I also tested it against my powered jigsaw at its lowest speed (I'm in an apartment, remember).


Frame saw: 1 min 30 sec - 3 min 30 sec
Hacksaw: 2 min - 4 min
Jigsaw: 1 min 30 sec

The slow speeds represent accurate cuts at comfortable pace. The fast speeds represent breaking-a-sweat speed with less attention to accuracy. All new blades, which might actually be a handicap to the hacksaw due to the idiot at the factory that paints them with ten coats of truck bed liner. The jigsaw, while fastest, was not nearly as accurate. All the pieces were within a .015" window in length :)


The frame saw is also quieter than the other two. I can't bear to put the blade in my hacksaw backwards, but the frame saw is quieter and more confident cutting on the pull stroke. I think once I get comfortable with it, I'll be ready to race the 2500 lb hyd-mech bandsaw at the tech school* ;)

I look forward to trying other blade types in it. The blades I made for it are 14 tpi modified-raker set, and it's clear that vibration was the biggest thing holding it back. I wonder if wavy-set or variable pitch blades would cut better. In any case, the Starrett bandsaw blade stock feels a lot sharper and more precise than any hacksaw blade I've used.

*material cut: 1/4" aluminum tube