Making a beam compass

Today was one of those days when in order to do something I say to myself “I need this tool and (especially now) I can not buy nor justify buying it. So let’s build one”.

And that in itself takes more time than the whole project.

I was in the process of fixing an old dentists lamp that was laying around, the fresnel lens was originally held with some tiny and feeble metal strips that were in horrible shape.

Instead of making a replacement with some leftover stock or filler rods I decided to make a proper retention ring with sheet metal from a computer case.

But, my simple compass wasn’t able to make circles as big as I needed. Thus I set to build a beam compass.

I had the hardened points from a couple of broken punches, so it was only a matter of cross drilling some bolts and figuring out how to end up with something that would be useful.

Except from the bolts everything else came from either the rust bucket or the trash.

There are a lot of things that can be improved but as it is, it fulfills its intended purpose just fine:

Pity that it’s already too late to start the plasma cutter and finish this part.

Jacobs chuck polishing

After spending a great part of the other day refurbishing a nice chuck I set out to fix some of the problems on the drill press.

The whole quill tube has a lot of play but turns out there’s a set screw loose that just makes it better.

I chucked a short section of precision ground bar and set up a dial indicator while I ran the pulley with my hand. The run out was around two tenths of millimeter. Tried again after moving the jaws and applying more force but the result was the same.

Some fumbling and a big hit with a punch removed the chuck from the shaft. There were some patches of light corrosion on both surfaces.

Even so, a dial indicator on the drive shaft showed a wobble of a couple of hundredths. That’s more than good for a machine like this.

But looking closer inside the chuck the taper it had machining marks, like concentric ridges. I didn’t know better when I first assembled it and assumed they were for improved grip or something.

I started the motor and lightly kissed the shaft with fine sandpaper, first 800 and then some 1200 grit until it was smooth to the touch.

Then I painted it with a sharpie and installed the chuck again. This time I noticed it was kind of a loose fit and sure enough when pulling it down only some parts were inked.

I held a drill on the vise and with a paperclip and progressively fine sand paper removed the roughness inside the cone. Now there are ink spots more or less evenly distributed and the indicator registered about 15 hundredths.


Repairing an Albrecht chuck

Long time ago I was waiting for my turn to use the weighting scale on a scrapyard when I stepped over something curious.

Inside a sturdy chunk of mud there were the remains of an electric drill but what got my attention was the keyless chuck. I asked at the counter and got it for free.

It slept for some time on a shelf until I found it again cleaning. It resisted a civilized dismantling intent so I bathed it overnight in a mix of gasoline and paint thinner.

The front came out easily and looked good enough given it’s history except for a couple of spots with tool wounds and corrosion with significant missing iron. Seems it had been passivated on the inside.

There’s a two hole pig nut on the back and that one gave more trouble. I first tried with a round nose pliers and then a punch but it only made things worse.

I used a heat gun to clear any remnant of gasoline, hoping that it would loose the threads but no cigar. So I welded a piece of scrap and with that I managed to pry it.

Compared to the rest this part looked much better. I expected a ball bearing but there was only a hardened steel ring instead.

I padded a couple of beads on the body and after a bit of careful grinding it’s like it never spent time buried.

Now I only have to fix the horrible amount of run-out and play of the drill press.

Fixing a bottle jack

Long ago I won a lot of used tools at an auction. Among them there was a small two ton jack.

Overall it was in fair condition but the lever was really hard to move, so I left it with other low priority things to repair.

Upon a closer look the smaller piston was bent. I chucked it into a vise and tried to loose the nuts but they were firmly stuck.

I cleaned the base with a rag and wire brush and then welded it to a piece of iron channel. I love 6010 rods. I also learned that whatever was used as hydraulic oil catches fire with ease.

Laying on the floor with one foot on it I used a big wrench and a hammer, this time succeeding in getting it apart.

Bottle jack in pieces, welded to channel iron

It doesn’t seem like much but this small curvature made it almost impossible to pump:

Bottle jack: bent piston

I decided against straightening because with the tools I have at hand it would be very certain that I’ll scratch the good part of it and thus completely ruining the jack. So I cut the bent parts with an angle grinder.

Just by chance the parts that were badly out of shape are almost the same length as some ground rods I have from a textile machine.

Bottle jack: bent piston cutouts and stock rod

The plan goes like this: drill and tap the remains of the original piston, make the rod hole bigger and use a long bolt to hold them in place.

I used the cutouts and some small welding rods from the trash to make a new cross handle.

I’m very proud of that weld, the ripples and profile are very smooth and consistent. But I had to grind it flush.

This is before the final assembly, now I can operate it with a single finger.

Bottle jack: working again

Wiring progress

In the last couple of days I finished the remaining welds on the steel support and mounted it on the wall with some percussive persuasion.

I made a couple of supports:

To hang this tray from the roof beams (I also made the mess of dust and bricks):

Weekend worklog

This weekend was a bit slow.

A couple of days ago I started to learn FreeCAD, mostly for its FEM analysis mode and to build a couple of construction plans.

I made another part of the cable trays for our comms closet. Initially I wanted to use FreeCAD for that but at the end it was faster to do a bit of trig and sketch the cuts on paper. It’s held in place with a couple of rivets. I also added a layer of pvc to shield the cables from the metal edges. Fits like a glove.

Cable tray bend

I also started to build a steel support for one of the walls. We made a big opening for cables and I’m a bit uneasy about the lack of support.

Fun with a plasma cutter follows:

Continue reading

Name plate and tags

Well the remote control for our transmitter is officially finished. Today as a last detail I built a couple of name tags for the cables and a bigger plate to mount on the front panel.

They are not only for aesthetic purposes but also to keep things where they should be, as sometimes they drift apart with strangers.

I cut some pieces from a scrap lamp and used the alphabet punch on them. They certainly look better with a small touch of permanent marker.

I like how they lay on the cables. All of this gives me an old time vibe feeling.

Metal name tags installed on audio and rf cables

Sunday worklog

Today I started to build the rope guides for the lightning fixture. I have some nice ground rods from a textile machine that are perfect for this.

Rope guide with rollers

On the evening I went to Futura and cleaned up a bit the stage, moving most of it to one place:

The Museum Corner at Futura

Then I started to install real cable trays instead of our improvised version with halves of water pipes. I need to cut a small section with a special bend to accommodate the opening on the wall.

Cable trays

I emptied most of the rack cabinet and installed the patchbay I built earlier. I had to drill and tap another set of holes as the power outlet interfered with the movement.

I also finished that small table:

Lamp fixture: done

At least for now. The next step will be adding another support for the roof frame and rollers to guide the ropes around it to unblock the light path should we want to project from there.

Today I hanged the lower frame and then attached the cable trays with a set of bespoke clamps and self tapping screws.

Lamp fixture, metal version.

Today I started to replace that old wooden fixture with another one made of steel.

Our original plan was to install some cable trays to have a more industrial look.

Yesterday I assembled the frames on the floor:

Lamp fixture: metal frames

Today I spent most of the afternoon drilling the wood trusses on the roof and attaching the hooks. Then came the time to lower the old frame and hang the white on those hooks.

Letting it gently go down was easy:

Lamp fixture: dismantling the old one

I used some wire to attach the new frame to the old pulleys and help me lifting it near the roof. That seemed a lot easier on the planning stage but I managed to pull it off in a couple of hours.

To end this day I wound the new rope on the pulleys. Tomorrow I’ll hang the other frame (the black) and screw the trays to it.