Pickle Jar

I had a proof-of-concept at one point for bleeding brakes on the car.  It was a simple design, based on a large bulk jar of pickles.  I had drilled two holes in the lid, and used teflon tape and brass fittings to seal the jar.  Then, one of the lines is run to the brake zerk fitting on the brake calipers.  The other line was connected to a vacuum source.  This allowed me to connect it, start the vacuum, open the zerk, and then simply top off the fluid at the master cylinder until I had fluid in the jar.  Functioned pretty good, until I loaned it to someone who broke the jar.  He got me a new jar, but I thought I'd make a better lid for it.

I ordered two things - a chunk of 4.25" aluminum round cut-off, and a rotary table (needed to cut the bayonets in the lid so it would lock down).  I turned it oversized according to the dimensions from the existing lid, drilled a through hole it (so I could thread in a rod and hold it up (hang it).

I then marked a groove (for concentric attachments, drilled 120-degree-apart holes, then tapped them with a pipe thread.  That allowed me to simply thread in the brass pipe inserts.

The hardest part was putting the bayonets on the bottom lip.  There were six of them, so I HAD to have a rotary indexing table.

First, I used a boring bar to cut it to a solid lip on that bottom inside edge.  Next, I had to mill out between the bayonets.  This is what required the rotary table.  I threw a collet into the spindle with an end-mill, positioned it for a cut, then simply milled the lip off to get a bayonet.

Then I assembled it into a functional brake bleeder :

While I was at it, I had a neighbor who needed a thumb screw for a photography gimble.  So, I cut two of them :

Now I can get back to work on the corvette!

South Bend Junior - How To Set Up For Screw Cutting

I have a problem.  My lathe came without quite a few parts.  I've purchased change gears, and those change gears came with a thick idler gear :

(It's the one on the left.)  You can see the gear used to transfer to the lead screw on the upper right.  Obviously, the one on the left won't fit to the small teeth on the gear on the right, so I ordered an 80-tooth one from eBay.  It arrived, and it, too, wouldn't fit :

I don't have one of those forking banjos, either :

I was not sure how I was supposed to set these up, so I looked up the gearing for cutting an 18-pitch thread :

I needed a 32-tooth gear on the stud and a 72-tooth gear on the lead screw.  I reversed the screw gear and bushing so it would line up with the large gear on the idler (the same one connecting to the stud gear).  This turned it from a compound gearing to an idler gear.

Next, I chucked up a small chunk of cheap aluminum, because scoring from a tool cutter would show up easily, and it was soft enough I could rotate the chuck by hand.  Then, I turned it a few times to get enough for a thread pitch gauge :

And measured it :

18 on the pitch!  Success!  Next, cut some actual threads.  Again, I started with aluminum.

Next, I threw on my 25/64 bar I needed for a custom tap (yes, I had to learn all of this for a tap, which was for a stupid brass pen).

I removed it from the chuck and used a dremel to cut some relief in it (some of the reliefs I cut backwards, so beware if you make a tap), heated it up red-hot, and quenched it.  I didn't care how hard it really was, because it had a single purpose - to cut some threads in a plastic insert to finish a brass pen :

For anyone who doesn't know about South Bend Juniors, that's how screw cutting is set up!

A Beautiful Spring Day in the Shop

Today, I finally had some time to spend out in the shop.  So, I tackled a few projects.  I have a neighbor who is a machinist, and a few days ago, he caught me and asked if I'd be interested in any of his cut-offs.  So, I ran over today to go pick them up :

In that pile of great stuff was some 303 and 304 stainless, brass, bronze, aluminum, steel, and even some Delrin.  I had a colleague asking if I'd be able to machine him some shock pistons for his RC cars.  They are supposedly 12mm across, with a 1.6mm hole in the middle.  I measured it up and threw down a quick drawing :

So, that 12mm is actually 11.80mm, or 0.465".  That hole in the middle which should be 1.6mm is actually 2.54mm, or 0.10".  It means I have some really good leeway when it comes to machining them.  I chucked up some Delrin, and cut five pistons (because one was a little too think).  They didn't turn out too badly!

Next up, I dropped the starter.  I needed to know how large of a fly wheel I have on the Corvette.  I couldn't find the receipt, so I had to do it.  But, I was having problems turning the crankshaft and also counting teeth while I was at it.  I remembered I had an old Harbor Freight composite camera system, so I grabbed the camera, build a frame to hold it, and placed it pointing at the hole through the scatter shield where the starter connects to the fly wheel.  That allowed me to count teeth :

I have a 168-tooth flywheel. I ordered a 2.5HP adjustable starter from eBay, so when it comes, I'll get it installed and running.  Then, I thought I'd finish a brass pen while I was at it.  It came out not too badly :

It was a good day today!

Learning the Lathe - Materials

My next lesson was about materials.  I know steel is not as good as brass or aluminum.  Aluminum is easier than brass.  But, my latest venture was worse.  I needed a new idler bushing for the South Bend banjo (gearing).  It turns out the only stuff I had with a 1.25" diameter was a bar of chromoly that was originally intended for a replacement spindle before I found mine was okay.  So, I chucked it up and started to turn :

The lesson?  If you can wait for better stuff, do it.  The swarf was bad, I could only do about 0.002" removal at a time, and the cut-off of 1.25" was absolutely terrible.  But, the pen is looking good :

The pen is a Jr. Gentlemen's Statesman pen kit from craft USA.  Now I can focus again!

Calculating Taper Offset Using Tailstock Method

I am interested in a die holder attachment that fits into the tailstock on the lathe.  I was watching a few different episodes on youtube, and found Halligan142's method to be enlightening.  It looks like a good, solid tool :

https://www.youtube.com/watch?v=GMuZujQ5_8s

Common Taper Sizes for South Bend Lathes

Taper	Major Dia	Minor Dia	Length	Taper/Foot
#0	0.3561	0.2520	2.00	0.6246
#1	0.4750	0.3690	2.13	0.5986
#2	0.7000	0.5720	2.56	0.5994
#3	0.9380	0.7780	3.19	0.6024

For larger taper sizes, visit littlemachineshop.com.

In it, he mentions that you can use the tailstock offset to cut your morse tapers.  This works very well, so I thought I'd post his formula :

Taiolstock_Offset	=	part_len * Taper_Per_Foot
		24

On my South Bend, I should be able to obtain 0.200" offset on the tail stock.  That is about a 0.5" swing from side to side.  So, to cut a taper for my tailstock (a #2 taper), my taper-per-foot is 0.5994.  If I use a 4.5" piece of steel for this, I will get (4.5 * 0.5994) / 24, which comes out to 0.11238750 ".   That means, I can use a 3/4" piece of round bar about 5" long to cut a taper with about 1.5" extra inches to put a flange on.  I only have to offset the tail stock about an eighth of an inch to do it, and I'd have the spindle for the die holder to run on.

Recompile with -fPIC when compiling Samba with ACL

I ran into a problem trying to compile Samba under a Linux From Scratch (LFS) system :

relocation R_X86_64_32 against function can not be used when making a shared object; recompile with -fPIC
/usr/lib/libacl.a: could not read symbols: Bad value

I kept trying to figure out what was up with my Samba ./configure arguments. It took a while to realize the problem wasn't in my Samba methods - it was in the ACL compilation. When the Samba error in the make specified about recompiling with -fPIC, you need to recompile the library that it is trying to link. I had to recompile the libacl.so binary and fix it, and then Samba compiled fine.

FAILED: Has an address record but no DHCID, not mine.

I am running a little DHCPD/DNS/SQUID server, and after enabling logwatch, I started receiving e-mails in the morning about the following errors :

Dec 18 19:58:06 home dhcpd: Forward map from computername.home.silverhawk.net to 10.0.0.6 FAILED: Has an address record but no DHCID, not mine.

The computername is not a generic DHCP client - it is a host with a statically assigned address.  This message is somewhat annoying.  To remediate this, I have now added a "ddns-update-style none;"  to each host with a static address, e.g. :

host computername {
        hardware ethernet       00:25:8c:7f:ef:01;
        fixed-address           10.0.0.6;
        ddns-update-style       none;
}

I may just turn off the dynamic updates all together.  I am not sure they are as important as I initially thought.  We'll see if this will swallow the error first, though.