Shift linkage bushings are mostly complete

Yesterday I snuck over to my friend's place after leaving work early. I managed to knock out the rest of the work on the bushings for the shift linkage and shifter. Well, they aren't 100% done, but they are done with everything I need a lathe for.

I was so focused on things that I didn't bother with taking photos of the process, since I took photos the last time and most lathe work is really pretty similar. Turning, facing, drilling, reaming and parting. I'm not doing anything groudbreaking, here.

Anyway, here is the one pic I took of the mostly finished pieces:

The left bottom set is for the end of the shifter itself. The other two sets are for the yoke. There is one piece I didn't make, but I am going to see how well this works without that one piece and if it works then I won't bother having to make it right away, which is a good thing.

So if you recall, I left off with these:

 As you can see, those were not drilled and the outside of the shoulders were not faced to size. I hadn't even started the bushings for the shifter, as that was the lowest priority. My shift linkage was so bad at the yoke end, that was what I was needing to focus on, but thankfully I had the time to make them, too.

As far as the process, immediately after I showed up, I found a left hand tool holder and ground a facing tool. The tools I grind (I should take a photo of them sometime) are SHARP. This material seems to prefer a very sharp tool with almost no nose radius and not too much relief on any of the angles. Doing that and tweaking the feed speeds, I can get really decent surface finishes and take off a decent amount (at least for the size of the lathe I am using) per pass. A CNC machine could likely make all of these in the time it takes me to just face one of these things. LOL!

After I got the tool set, I faced the shoulders to size. This dimension isn't exactly precise as the yoke is thin sheetmetal that is pretty flexible. Within 5-10 thou is perfectly acceptable, though I manged to get both sides pretty close to the dimensions I calculated.

Looking at the time, I figured I could knock out the shifter bushings, so I slapped in the round stock, switched tools to the turning tool that I probably should have sharped up a bit but it worked well enough for the little bit of turning I had to do. I got the shafts turned to size, cut the bushings off the bar stock, slapped in the facing tool, faced both sides and then got read to drill and ream.

In production or at least time sensitive work, the thing that nearly always takes the most time is tool changes, so if you can eliminate as many tool changes as possible, especially if you only have one kind of tool holder for what you are doing, you can save a LOT of time. In this case, this basically meant that I center drilled all the pieces first. Dave only has one chuck, so changing the tools in the chuck takes a bunch of time. Granted, this isn't super critical work by any means, so changing the pieces out is perfectly acceptable and preferable to taking the time to mount a tool for every operation change.

So, yeah, I center drilled each piece. I then tried to drill one bushing to the just under the reamer size, but that didn't work too well at all. I read that with this bronze, it helps to grind the bit tip flatter than you would normally find on a general purpose split point bit, but since I didn't want to do that, I just pilot drilled them then got them drilled out to just under the .315" reamer size.

By all accounts, the reaming was supposed to be pretty gnarly, but, well, it wasn't. Dave helped by flooding the reamer with WD40 as we went along. We found a good, chatter free speed to turn the lathe (man, that VFD makes things so easy!) and we finished the holes to size.

In case you didn't know, reamers are for forming very precise and round holes. Drill bits actually don't make very precise or even round holes, usually with poor surface finish to boot. A reamer will make the hole very round and if you aren't rough with it, it will leave an very excellent surface finish for the hole.

We finished up and I had to skedaddle. I didn't get to chamfer the edges, which is slightly annoying but not the end of the world. I can take care of the burrs with a file. These don't have the prettiest finish, but, when these go into production on CNC machines (that's planned), they will be quite the handsome parts.

So that about sums it up for this wall of text. I hope you found some of it interesting, even with only one new picture for the whole post. heh

Busted Sub, Part 6: Incompletion and Frustration

After work, I headed over to my friend Dave's place to knock out some lathe work. Everything started well. I got to work by grinding a tool for the bronze (which needs a sharper tip to the tool than many other materials) and started dialing in the machine. If you will excuse my phone being an utter retard and flipping this video, I did take a short video but it got flipped to vertical video. I hate vertical video. Anyway, here's the video:

Edit: The video should be fixed soon. Man, I hate vertical video.

This is a rough cut with the speed actually much too low. Everything smoothed out when I slowed down the feed a tad and cranked the speed up a lot.

I was cutting it dry. I suppose I could have used some oil, but this was cutting so well, and you can see finish here:

Bling, bling:

This is where I ended for the day:

Those are the four bushings for the shift linkage yoke. As you can see, they are not drilled or reamed. The shoulders are also not faced to spec. So why aren't they done? I had to leave the premises in a rush for reasons of irrationality. That's basically all I'm going to say about the situation.

So, I won't be having any cool self-machined parts on my CRX for a while. I'll just be slapping everything together as soon as the weather breaks.

You want to touch my knob, don't you?

I had a lot of fun making a shift knob! I had some really nice stainless round stock for a long while. With my friend's recently acquired lathe, I wanted to try it out! We were both rather skeptical of the machinability of the stainless, especially on a smaller lathe like the South Bend Heavy 10, but after some tweaking, we were both really happy with the results!

Here's my friend Dave getting things dialed in:

Shiny!

I really like this lathe. It works really well, especially with a VFD running the motor. It's nearly silent with the back gears disengaged. It can turn some really smooth cuts!

We actually had to set up the 4 jaw chuck and indicate the bar in. Neither of us had done that before. It went surprisingly well. Once we turned the bar down far enough, we got the three jaw chuck on and got to work tapering one end down:

This would have been easier had we had the taper attachment working, but it isn't and that's another story.

 Final pass complete:

 Look at how shiny that last pass was! That wasn't even with any polishing. Dave has a darn steady hand.

After the tapering was done, we tried parting the piece off at about 4", but the parting tool is honestly horrendously terrible. All we got was nasty chatter:

 Ew. So, we went medieval on things and lopped it off with a hack saw (while it was spinning, and no it isn't as dangerous as it sounds).

I missed some pictures in the processes, but we flipped the knob around and I chamfered the edge by hand then rounded it over with a file.

Then we got a wild hair up our butts and decided to try to knurl the end of the knob. I figured that if we boogered it up, we could just turn off the failed knurls and no one would be the wiser! heh

Here's Dave setting the knurling tool:

He had heard a tip that you set the knurls slightly off of perpendicular, so the knurls will "bite" better and have a better chance of following each other. If you look at he pic above closely, the rollers have a spiral groove pattern, which basically rubs the surface and pushes the material into the grooves. The bottom roller has the opposite pattern on it, and when the gears roll over the same surface, they create the classic diamond knurl pattern:

 We were shocked when we stopped the lathe and the pattern came out perfect! I'd only tried knurling a couple of times before without a huge amount of success. We didn't go too deep, as that can get pretty abrasive, but the patter really shows and gives a really satisfying texture on the top of the knob! AWESOME!

We flipped the knob around again and polished the thing up with some sandpaper. (I think it was 180 grit.)

 Notice the piece of paper wrapped around the knob. That keeps the teeth of the chuck jaws from digging in to the work, and in some cases, keeping the work from digging into the chuck jaws (though that is rare since they are hardened, usually).

LOOK AT THIS THING! IT IS AWESOME!

 It's fairly large. It's about 1.5" diameter. The small end of the taper is about .750".

 It feels AMAZING. I'll try to weigh it some time, but it is pretty heavy.

The last thing left is to drill and thread it:

 I forgot the thread size, didn't have my tape set and want to be sure of what I am doing before I actually possibly ruin all the hard work and fun that went into this thing!

It's so awesome, kitty approves!

 My friend liked mine so much, he mad his own the next day:

Having access to a lathe is frickin' amazing!

An older, unfinished project, but still fun.

This is from 2008 and I don't have access to a lath or mill anymore, so I can't finish the project until I do. 

What happens when you have plenty of 2024 aluminum, bronze, stainless and machine tools? ITBs (Individual Throttle Bodies), that's what! 

First things first: flanges! You need to have flanges as a strong base for the entire project. Right now, I forget if this is 1/2" or 3/8" thick 2024 aluminum (the good stuff).

The single point flycutter (with a tool I ground myself after some trial and error) going to town on 4 pieces of material:

Notice the clamp on the overhanging material to reduce chatter s much as possible. It worked well enough, since the whole block of material was thick enough when clamped together to be pretty stiff.

After a few passes:

Once I got to that point (I ignored the small nicked spot from an oops with the band saw), I flipped the pieces over and leveled the other side. Gotta love the automatic feed! Set the speed and listen for any nasty noises that means your project is ruined and you have to start over. LOL!

Here's the other side: 

I had a Z6 intake manifold phenolic gasket sent to me and I used poor man's machinist dye (blue wide-point Sharpie!) for my layout. 

I don't have pics of the scribe lines, but . . . I hope you can picture the traced gasket on the chunk of metal. LOL! I determined by, measuring carefully and some math, that the bore spacing for the engine (Honda D16) is 84mm. Armed with that information, I made a bunch of these:

What are those? Pretty close tolerance bushings for the throttle plate butter fly shaft. (THANK YOU JANNE!)

You can see the start of the holes for them here:

I got the holes started then realized I should square up the sides better before installing things that are supposed to be fairly exactly parallel. LOL! 

I didn't take pics of drilling boring holes for them (because, well, the process of boring is . . . boring), but you can see how they fit here:

I used the mill vise to press the bushings in place, two at a time to balance the load:

After I got to that point, I started working on the mounting flanges again. Setting things up in a vise takes time. And though. And time. And measuring. And precision. And mostly time. heh

I didn't bother taking pics of the drilling of pilot holes, but the next few pics will give you a sense of what I was doing:

I left myself some room for final porting and shaping, but I think they turned out pretty well!

(I only had to remake one mounting plate because I oops when setting up the hole spacing . . . LOL)

Some of the other things I was working on while all that squaring up was going on was the actual runners themselves!

I totally forget the exact dimensions of this stuff, but, again, it's 2024 probably schedule 40 pipe.

 Each one needed a small lip turned. Yes, I messed one up. Sue me.

One of the hardest parts of this whole job was turning the butterfly shafts. I managed to keep the tolerances to within +/- .001", which is good enough for me!

I ended up making 12 runners because I could and also because I know I would screw something up in the future.

 Now, an astute observer will notice that I really having filled in the whole story yet! Where are the flanges with the bushings pressed in? Well, I am glad that you asked!

They were getting drilled then bored to size then counterbored!

Drilling the pilot hole:

Using the largest dang bit in the shop (1.25", IIRC):

And then the horrifically painful process of manual boring with a boring head. It would have gone a lot faster if we didn't only have the crappiest Chinese boring bars that fit the boring head. *sighs* It took days to size the holes correctly! (Working after hours during deployment (in Iraq) for sometimes 4-5 hours straight.)

Taking the biggest cuts I could at first to just get to near the correct size:

On size and good finish!

To compare, this is what I start from:

Then, after all that painful stuff, I had to counterbore the top of the plates like so:

 In order to fit the runners in place thusly:

I started making throttle plates, but found out too late that the plates need to have a 10-15" angle on the edge . . . and then we started packing up the equipment. Who knows when I am going to get to finish this stuff . . .