Minor update on the shift linkage bushings

 I used a large diameter drill bit to deburr the center holes. It didn't take long and isn't difficult. It's not as pretty as doing it on the lathe, but, eh, the burrs are off.

Then I tool a file and broke the edges on the shoulders so I don't slice my fingers up handling the bushings. Those burrs were SHARP!

Now they are ready for install once I do some cleanup on the linkage itself. And I keep forgetting to measure for hardware. heh I'll get that done shortly. There are a few fastener stores near my work that I can try to find something that will work be long enough to work. These are made for an 8mm through bolt.

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 5: Stitch weldling and taking apart a shift linkage

I accomplished two things after work today. I managed to stitch weld my new subframe and take apart a spare shift linkage. As always, on to pics. I seriously don't think most of you read most of what I actually take the time to write. heh

Okay, since the pics uploaded in sort of reverse order, you get to see how to take apart the yoke on a shift linkage first.

So this is a flap wheel:

 If you don't use these for cleaning and fab work, you are just plain nuts. They are better than the beave's knees. The only time I ever use normal grinding wheels is when I am doing really heavy grinding or cutting stuff (which I don't do much anymore since I have my portable band saw).

This is more of a side view showing how thick this particular disc is:

These things have a really mixed reputation. I can guarantee that the only people who speak badly of these things have used the cheap ones. I generally buy 3M, Norton and a couple of other decent name units.
Why would I spend up to $12 per disc? Two main reasons:
1. Durability. Generally, the thicker the disc, the longer lasting it will be. The problem with going thicker is that the attachment process must be more precise and just better to hold the higher mass together well. A good flap disc will last significantly longer than the cheap, Chinese ones you can get at HF and other low buck stores. You will get more than $12 worth of use out of one of these better discs. If you can catch them on sale on Amazon or eBay, you can score! Another brand to avoid is actually DeWalt, commonly sold at Homey Despot. While entirely better constructed than the HF discs, they last only a little bit longer and are EXTREMELY expensive for the amount of time you can use them. I'd rather you get the HF ones than those, as there is much better value to them.
2. Smoothness. You won't vibrate your hands into nerve damage. These things run smoother than just about anything else, absorb shock better, are balanced better and depending on the grit you use, will remove material almost as fast as a normal grinding wheel, which means less time grinding (also good for you hands and GSD (Getting Stuff DONE)!).

The only limitations to these are they they are not for edge use, unless you get a specific disc for edge use (they make them, I haven't used one yet). But, for anything flat, they rock. They give you unparalleled control so you can just smooth things over or you can honk down on them and really get the material moved. I love them. You should use them, too, IMO.

ANYWAY, here's the end of the shift linkage that causes most shifting headaches:

This is the other end, attached to the stock shift lever:

 As you can see, all the plasticky bits are falling apart:

 That's the bushing that fits into the end of the stock shift lever. The rubber o-rings, meant to dampen vibrations, are shot, and the thing just fell out when I unbolted the lever from the linkage.

Here are a couple of shots showing how rough the plastic sleeve is inside the end of the shift lever:

Just slap that in and call it good, right? No, thank you. 

I missed a few photos, so bear with me while I explain some things. Take your flap disc equipped grinder and take down the pressed ends of the pins holding together the parts of the parts of the yoke like so:

Then pry the tabs apart and pop everything apart! It's really just that simple. Yes, you'll have to bend the tabs flat, but as long as you don't go overboard, that's totally fine. It's good steel, not aluminum.

This is another source of slop:

 Those plastic bushings just plain wear out. The metal pins rust. Icky, icky, icky, and not good for your transmission at all, either!

The other end of the linkage, where it bolts to the bottom of the shift lever was pretty groady, so I took a knotted wire brush (mounted on the grinder) to it, so it went from this:

To this:

 It will be getting painted after it is cleaned thoroughly.

Now, on to the subframe.

I took the aforementioned knotted wire brush and took off the gunk and as much of the paint as I could from strategic locations:

Then I fired up the trusty Lincoln MIG box:

 

And got my stitch weld on:

 

No, I didn't get any closeups. Some of the welds were nasty. What do you want for MIG welding through paint and crap? It's not that big a deal.

Now a word about doing this kind of stitch welding. The goal here isn't to go crazy. It's to tighten up the structure a bit. Avoid stitch welding corners. They are stiff enough and if you do that, you'll make something like this TOO stiff. For a street car that might get curbed again, if you went a little nuts and welded the whole thing, blasting even the corners togethe, your frame will get tweaked, too. This is bad. If you had a race car and wanted maximum stiffness without going to a tube frame unit, then go nuts. This is more than enough for a street car. 

That's it for this evening. I ran out of light. I am satisfied with the progress and having a good subframe to work with. It will get cleaned up and painted. I'm going to ask if I can use the pressure washer at work. That will take care of all the gunk super-quick-fast.