Saturday, June 10, 2017

Rings and "Rings"

My wife was gone for the weekend.  So, as a matter of distraction (and after someone said "make a ring on the lathe out of a nut), I decided to try it.  I grabbed a 3/4" nut from some place that rhymes with "Dome Hepot", and chucked it up.  I didn't really care about the finish - it was a $0.50 part and a little bit of time "just because".

Turned out not too badly, even with the lack of caring about the finish :




So next, I turned my attention to my mortising attachment.  I bought one on eBay because it was pretty close to my drill press (though my drill press is not a Delta branded press, I thought it would fit).  The reality is it wouldn't lock onto the quill.  My quill was 2.5" in diameter, and the mortising attachment would fit a 2.6" diameter quill.  Yes, that 0.100" would prevent it from binding down on the quill.  I had a piece of 3" diameter C86300 Manganese Bronze I thought I could make an "adapter" out of.  To make it, I did the following :

  1. Put it into the chuck
  2. Faced it off
  3. Drill a small hole 3/4" deep into the center
  4. Step drill that hole until I got to 1/2" in diameter, still at 3/4" deep
  5. Grabbed the boring bar, and bored that 1/2" hole out to 2.5" diameter, 3/4" deep
  6. Turned the outside down to 2.6"
  7. Beveled the inside and outside edges
  8. Cut off the "ring" (I actually had to go to the bandsaw for this because it just didn't want to cut)
  9. Sanded the back side
  10. Cut the ring into halves
  11. Sanded the ends of each half on the inside and the outside so it wouldn't rip up the quill or the attachment

After finishing the last sanding, I had to test it to make sure it fit.  It was like a glove, but not the one tossed from a fleeing white bronco.  That manganese bronze is nice stuff :


Saturday, June 3, 2017

DIY Trammel and Lathe Test Rod

I needed to adjust my drill press - I knew it was out of alignment, but I did not know how far it was out.  I made a trammel about a month ago.  I had to make some adjustments on it today, because the dial gauges would not stay on the drill press table.  That +/- 0.2" on each side of the drill press was bad, but it was still a guess.

I drilled two more holes for the dial gauges, cut some slits with the bandsaw, and re-installed the gauges.  Then, I threw it into the drill chuck and re-measured the drill press table. and that guess was pretty accurate.  So, I put the table at the high point, loosened the underside bolt holding the tilt just a little, grabbed the 3 pound shop hammer, and just gave a couple of light whacks at the table.  I got the drill press table to within 0.0005" (seemed like 0.0002", but I always err on the side of caution) :





So, my drill press is now calibrated and pretty much level.  I'm stoked about that one!  Next, since I had the drill rod left over from doing the trammel tool, I cut a length of 12" off, and faced and center drilled each end.  Then I stuffed it between centers, and used the law of averages to center my tailstock with the headstock.





I was about 0.020" out of alignment, but now I am only about 0.002" off.  Not sure I can get that much better, but I may try as I feel the need to distract myself.

Saturday, May 27, 2017

Making a Gear Cutter Arbor

I had some gear cutters for cutting some 16DP gears.  It was another break I needed away from placing a lot of stupid gears on a piece of paper to get them laid out.  I did not have a way to use them.  So, here is my stab at cutting an arbor down to size, drilling, and tapping the hole.


Now, I can potentially grab a slab of aluminum round large enough for the gear, true it up, then throw it on my rotary table and make custom gears (127 teeth and 100 tooth gears will be needed for a perfect metric thread base).

Truing a Chuck Back Plate

While preparing to create a tap in my last post, and still needing a break from that Cocoa Table project, I needed to put on a new, small chuck.  My two chucks I already had were either a 4-jaw chuck (takes a long time to get the work close), and a 3-jaw chuck that only had outside jaws.  I had ordered a small 3-jaw/4" chuck, and it had arrived.  So, it was time to get it mounted up.


  1. Install the back plate to the lathe, NOT to the chuck.
  2. Once it's on the lathe, use some tooling to face it off, and cut the shoulder you need for the chuck to fit.
  3. Now you can remove the back plate from the lathe and install the chuck to it.
  4. Once done, it is ready to use.
Yes, it is really that simple.  It was a quick task when I had just a little time to spend on it.




Creating a TAP

Hello, I needed to take a break from laying out so many little tiny gears on my dads Cocoa Table Project, and I did need to redo one of my brass pens.  In order to do that, I had to create a tap to cut some internal threads (15/64" 18 threads per inch).  I had a chunk of 1/2" tool steel from building a tramming tool in Calibrating a Drill Press, so I decided to use that.  It was a matter of chucking it up, turn down a section of that to 0.24" (15/64 is 0.235", but I wanted some space after the threads were cut).  Then, throw on the gears for threading, and cut some 18-TPI threads.



At that point, all you have is a screw or bolt.  For a tap to work, you need to cut some relief to allow the material somewhere to go.  I used a Dremel with a cutoff wheel to put in a leading cutting edge, then some stones to put some good relief in there.  I also cut two sides parallel so I could use a wrench to get a grip on it, then heated it up and gave it a good dunking to get it hard.  Worked great!

Friday, May 12, 2017

Calibrating a Drill Press

Remember that second-hand drill press I found that was made in Taiwan?  It was a little rough around the edges.  I had even checked the quill and replaced the bearings and chuck (that little South Bend chuck was worth every penny).  Well, as I've been trying to set up the tooling for building that table for my dad, I knew I needed to make sure the drill press table was level.  If it is not, you never get 90-degree holes.

In order to get it level, you have to "tram" it.  "Tram" is short for "trammel", which is a tool used to calibrate machinery.  A good trammel will give you measurements within 0.0005" - but I don't have that kind of dial indicator, nor will I unless it is a donation.  But, I needed a trammel.

I had seen a video on youtube (by Dale from Metal Tips and Tricks) on making one.  His was gorgeous, but I just needed it to work.  I ordered 1"x1" aluminum stock about 12" long, and a 1/2" chunk of drill rod, and two cheap dial indicators from Harbor Freight.  Do they have to be right on?  No, because it's a relational measurement that you are after anyway.

Once all of the parts arrived, it took me an evening of work to get the block drilled, cut, tapped, and the drill rod cut and faced, then the whole thing assembled (and to learn how to merge videos, convert them upload them and post).  Not a bad job.  Here's my new trial run at doing this - a video on youtube.



The above video was taken using a cheap Chinese "GoPro" knockoff, an SJ7000.  The camera does have its limitations (it won't do high-speed video work), but it is perfect for throwing a $40 camera into the shop and recording 1080 video (not fake 1080p resolution, the real 1920x1080x30FPS) without fear of destroying it or soaking it in cutting fluid or oil.  It's not bad, but I made the video even worse by having light behind everything - it washed it all out, but the video still came out okay (definitely not professional quality because of the way I did things).  Here's the final "product" :




With that, I threw it into the drill press and measured the table.

Forward-aft is pretty accurate (actually 0.005" off - which is phenomenal for a drill press).  Side-to-side was not so good.  It was 0.200" high on the right, and 0.200" low on the left.  That was actually amazing in itself, as all I have to do is loosen the bolt that allows it to tilt, twist the table, and re-tighten.  I'll do that on Saturday, and I should be able to drill some pretty accurate holes!

Saturday, April 29, 2017

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!

Friday, April 21, 2017

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!

Saturday, April 1, 2017

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!

Friday, March 10, 2017

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!

Sunday, February 12, 2017

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
TaperMajor DiaMinor DiaLengthTaper/Foot
#00.35610.25202.00 0.6246
#10.4750 0.3690 2.13 0.5986
#20.7000 0.5720 2.56 0.5994
#30.9380 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.