Digital help to precision and the art of being lazy

And now to something completely different.

Well it is still a mix of make shift fabrication and workshop philosophy, but applied to something else. Beware this will take some time to get thru. I'll show you how I took my fabrication possibilities into the space age. Space age was the 60's wasn't it?

I have an old Bridgeport milling machine. Well worn (clapped out is probably the correct thing to say here) but a very useful and flexible machine. But I have been wanting a digital readout DRO for years. So finally I got my thumb out of my ass and bought a kit. Yes I took a chance and bought it from China. Why? Well I did buy a kit from Asia for my old mill and that was absolutely trouble free. Also I wanted a DRO that could show all 4 axis in one unit. When I looked at the brand name DROs they were pretty expensive when it came to the 4-axis units. 

I got the kit and it was quite clear from the beginning that I did not want to use the supplied hardware. I needed to make custom brackets, just as I did on my old milling machine. I looked around on the web to see how others had done. I found some pics of how others had done it and I thought about it and this is my version. It’s not an how-to-DRO your Bridgeport but some pics of on how I did which could give you some ideas and inspiration.

My thinking was of course to mount as much as possible on machined surfaces which should be flat and parallel or square to each other. In the case there was no machined surface I wanted to make the mounting brackets adjustable enough to get the scales mounted straight.

For the quill there was a bracket supplied with the kit. I could never figure out how that was meant to be used and actually it was of a bad design. I had already made a bracket for a magnetic read head mounted on the the quill depth stop. I cut that down a bit and reused it. But it would be just as good to use the stock hole in the quill stop and glue in a piece of metal with a tapped hole for mounting. My bracket for the read head has a radius that matches the quill depth stop diameter and the mounting holes are elongated so it can be adjusted to be parallel with the scale mounting surface. On this bracket there is a second plate that holds the read head and gives some adjustment side to side and for tilting. I mounted the scale on the same surfaces that holds the stock scale since they where already machined. If you do this take out the mechanism for the feed stop when you drill and tap in the lower mounting pad. Also use screws that only go in about 3mm (1/8”) or it will pinch the bushing for the feed stop shaft. The lower mounting block is probably not needed but it will give me a good surface to mount a chip guard in the future.

I tried to get the scale to sit as high and close to the milling head as possible to avoid unnecessary obstruction and hitting it with my head and other parts I don't care some much about.

Unfortunately I will not be able to use the hand wheel for the quill feed without modification. But I don't have the wheel anyway.

The x-axis was straight forward. Just mount it in the back of the table and the read head on the saddle. Some shims and everything was aligned. 

The y-axis was a bit harder but luckily the side of my knee was flat enough to get the scale mounted straight with a few washers as spacers. The bracket for the read head was also something I had made before and could reuse with some modifications. That’s why it looks a bit odd. There was a machined surface on the side of the saddle, so mounting was easy. This bracket just clears my x-axis feed.

Read head mounted to a secondary bracket for adjustment. The mid section gives some height and tilt adjustments.

The most complicated axis was the Z. No machined surfaces and where the scale needed to be it was not even close to flat. I thought about it for bit and considered different solutions. One thing that could work would be some kind of arms mounted on ball joints that could be locked after alignment. But I opted for brackets made of several parts that can slide and swivel in the joints. This way I had a possibility to do small adjustments of the brackets in all directions and all angles. For this axis too I had already made a mount for a magnetic read head which I could modify and reuse. This has 3 mounting screws and 3 jacking screws for alignment. This design works, but if I had redone it I would make the bracket more like the Y-axis bracket since it was easier to align. After the read head was set straight with a test indicator it was easy to align the scale. With all the screw in the brackets a bit snug but not tight I could drive the knee up and down and it almost aligned itself. Some final adjusting using a test indicator and I was done.

Some final thoughts on how I would do it if I did it again. The basic idea for all axis was OK, but I made all parts the fly. Some dimensions proved to be a bit tight and some screws are hard to access. I might change the x-axis scale for a magnetic since it limits my travel by about 15mm. But overall I’m quite happy how it turned out and all parts was easy to make using scrap pieces of aluminium. Now I just need to screw down all cables and make chip guards for the scales.

The display was mounted with the arm in the kit. I will ad a plate that will hold the collets and tools I most often use. Lord Vader is watching.

The table is usually not this clean

As a bonus I can show the modification (hack might be the contemporary term) of my old used and abused Brown and Sharpe horizontal mill. I'm not really sure if it really is a Brown and Sharpe, but looking in the old catalogs dimensions and features indicates it could be a B&S Plain milling machine size 1 or 1-1/2. It does have a B&S no 10 or 11 taper also. But it might be a clone.

I have a shaper head from my old Vilh Pedersen milling machine. I took some scrap metal and made an alignment collar and a shaft so I could mount it. Works great. This is only step one in the bastardization of this old mill. Maybe there will be an update in the future. But this was a nice step in the right direction. I have been wanting the possibility to do internal splines for some time now.

Shaft with key

Lube it up

Looks almost factory... If you turn around and close your eyes.

OK until next time. Wrench and repeat.

Smart storage, when you outgrow your workshop

Disclaimer: You are about to see some pictures from my garage/workshop. This in no way represents good practice nor should the rest of the team be judged by my standards. Do not try this at home. Remember cleanliness is next to godliness. Now let's talk shop saftey and smart storage.

A machined surface is a surface you make using your machine. Hopefully with some degree of precision. A machine surface is a somewhat flat surface on your machine where you can store tools, parts, rags, catalogs, fast food, etc. Preferably under a big pile of metal chips. Sometimes your machined parts can become the storage space for other parts and projects. That's a practical way to save space. The fun part is when you finally dig in to the pile of parts you have and find all the neat things you have been looking for. So really, slacking with the cleaning up is just like giving you a surprice christmas every now and then. If you know what to look for you can see more than a few ongoing, well not completely abandoned, projects.

Oh there's one of my flathead blocks under my soon to be bass cabinet under some Ford Model B engine parts. At least the stack has wheels and can be rolled.

Other Ford parts on my washing machine

In a recent blog entry I showed you some machining of our flywheel. To do that I had to fire up my trusty old Warner & Swasey turret lathe. And by trusty old I mean old... and not that trusty. Make  no mistake, it will turn big chunks of solid metal into tiny chips in a heartbeat. But the clutch drag in neutral and the difficult to stop 50+ kg chuck sometimes worry me. But hey, moving the forward/reverse lever slightly to reverse the chuck is held stationary most of the times.

Poor old Bridgeport

 I really like older machines with all the knobs, wheels and levers. Big heavy castings, functional design, useful damn nice looking and a lot of space to pile up parts. But what really want to say is that I'm in desperate need of a larger workshop. Much much larger.

OK enough of the stupid rant . Enjoy the horror.

Using my MIG weld as a cart for my TIG welder. How's that for weldporn?

What is this neglected machines? Hardly anything stored on them. 

Until next time: Eat, sleep, salt slush, repeat.

Billet not bought

As regular readers will remember we had some problems adapting our Volvo 6-cylinder to the T56 Magnum. But step by step we made them bolt together like a match made in heaven. Or at least a matched made on Ringön where all sorts of strange things can happen, trust me on that. The last thing to finish was the actual flywheel. We made the blank a while back but to make it work with the Tilton triple disc clutch and the cut off ring gear there was some machining to do. The blank was made from a nice shiny, thick, flat stainless steel plate we happened to have. OK the choice of stainless could be questioned, but it was the only thick plate we had on hand.

The final machining was long overdue, so my Warner and Swasey turret lathe had to dig in. The game plan was easy. Take a light skim cut on the face of the flywheel, machine the step for the Tilton pressure plate and machine a step for the ring gear piece.

First I had to make an arbor holding the blank true in my not so true running chuck. Then face off the flywheel. Well that nice, seemingly flat, almost precision ground surface wasn’t flat at all. Nope, but after almost 1 millimeter was shaved off it was OK. After that turn a step for the pressure plate, flip it around facing off the backside and a turn down a step for the ring gear.

Now this wasn’t that hard at all, but machining stainless is tedious. And what was left of our big nice blank? Well a whole lot less. I don’t know what it weighs or what it did weigh before. But let me put it like this, it’s more race than family car now.

Oh scrap! If someone wants to make a wig, I can set you up. Heavy metal style.

In a dark corner of my work shop, a Ford Model B is on the Bridgeport getting milled for a new crankshaft thrust bearing. Maybe I’ll get back to that one day. Both the Bridgeport and the Model B.

I come from a world where billet car parts are frowned upon and for a good reason. But making your own car parts, engine parts, speed parts and so on is always cool. I must say that I’m actually quite proud of what we made here. Made using old machines, still capable of doing a good job. Billet not bought!! But on the other hand there are probably no company out there offering a Volvo flywheel set up for a Tilton clutch.