When I returned home I did some research on the little machine. It was a Unimat DB200. Unimat stands for “UNIversal MAchine Tool”, as it can be configured as a lathe, a milling machine, a drill press, and many other tiny power tools. This one had a heavy base of cast iron, which makes this an earlier model. I already had a much larger Grizzly lathe, but I thought that this little Unimat could be useful for tiny work. I thought it would make for a fun restoration project, too. I watched countless videos about the Unimat to become more familiar with its operation and capabilities.

When I returned to California 6 months later, I asked about the lathe’s history, but my cousin had no recollection of it and told me to take it. I shipped the Unimat back to Michigan on September 12, and it arrived September 18. It had both a 3-jaw scroll chuck and a 4-jaw independent chuck, in addition to a face plate and clamps to hold irregular objects. It had a Jacobs chuck and a live center for the tail stock. The original tool holder still had a high-speed steel cutting tool in it. My goal for the project was to return it to as close to original condition as I could. Many hobbyists seem to replace the original motors with larger, more powerful units, but I wanted to retain the original compact size and appearance. The little 90 watt motor would suffice.

On October 10, I completely disassembled the lathe to assess what I had. There were some damaged and worn pieces, which I found replacements for on eBay. I also made a few replacement pieces on my larger lathe. At some point in this tool’s long history, somebody repainted it in a dull tan-gray primer. The cross-slide was previously molested by a drill, and an ugly block of metal was added to it for reasons unknown. The main spindle bearings and races were in surprisingly great condition, but the pair of small ball bearings for the idler pulley were frozen solid, so replacements were ordered. I don’t plan on doing much, if any, milling with this tiny tool, but I ordered a replacement milling table to replace the original that had a chipped corner. The original belt made from braided rope would certainly be replaced. Both the main and cross slide lead screws were slightly bent, so I ordered replacements for each. Every part was ultrasonically cleaned.

I wanted to repaint it using a hammered green paint that was similar to the original finish, but this color was available only in a brush-on paint. I opted for a hammered copper color spray paint instead. The layers of paint were chemically stripped away, then all painted pieces were masked and primed before the hammered copper paint was applied. I made new aluminum rivets for the faceplate.

Reassembly began on October 26 and finished the following day. The Unimat ran again for the first time in decades. I still need to use my dial indicator to ensure that the cross slide tracks true and that the head stock has minimal run-out, but otherwise, the lathe is back together. The wooden box still needs reconditioning, but that will be a project for another time.

I’m quite happy with the results of this project. For fun, I set the tiny Unimat on my Grizzly lathe for a quick picture to compare the size difference. While the Grizzly will get most of the lathe work, the Unimat will be ready for any future micro-machining needs.

The replacement of the seat wood was long overdue. The planks were quite simple, so no fancy cutting was necessary. Fortunately, I had a surplus of 16-foot cedar 1x6s in the barn. I grabbed a can of spar varnish from the local hardware store to seal the wood against the elements, then set out to replace the planks.

Using the original planks as a template, I cut the cedar into 3 sections as needed. The new planks were sanded, then coated with the marine spar varnish. I had new stainless steel screws in the barn, which were an exact match to the original screws.

This tiny bit of maintenance should help keep the paddleboat operational for the near future. The paddle crank bushings and chain were lubricated, and my initial test ride with Enzo went well. Next, I may look into a bimini top for this fun little boat.

I didn’t realize it then, but this was during the rise of the “minicomputer”. Minicomputers were smaller than the room-sized mainframes and cost much less, but were still the size of a refrigerator or two. Minicomputers were made by several companies including IBM, Digital Equipment Corporation (DEC), Prime, Wang, Data General, and many more. Corporate departments, mid-sized companies, and universities all found uses for the cost-effective minicomputers. In 1983, my employer’s financial systems ran on a DEC PDP11. I programmed using the DIBOL language to create sales or financial reports.

Fast-forward to modern times, when I stumbled upon information on the internet about a fellow in Switzerland who sells 6:10 scale reproduction kits of the Digital PDP-11/70 front panel, complete with a row of 1970s-era red and magenta switches and the requisite “blinkenlights” flashing away. The kit runs hardware emulation on an embedded Raspberry Pi computer. This was perfect, since I had an unused Raspberry PI in my stock of spare parts. The kits are built to order, so I ordered one. The kit arrived a few weeks later.

The parts came in several bags, one with switches and the other with everything else. An acrylic panel faithfully replicates the colors and logo of the PDP11/70, along with a display case and rear panel to house the electronics and any interfaces the builder opts to include. Since the Pi includes WiFI, I’ll likely let this computer connect wirelessly, but I still included an RJ-45 ethernet port on the back to allow for a hard-wired network connection.

The kit took about 6 hours to assemble. Included were 30 switches of various types, 64 LEDs, 37 diodes, 2 rotary encoders, 18 resistors, and an 8-channel logic driver integrated circuit. I was pleased that everything worked when I powered up the circuit board the first time. After the PDP11 replica was assembled, I added it to my network and logged in.

I booted into BSD 2.11, an early UNIX variant, and explored the file systems. Under the /usr/games directory were programs called trek and hangman, both of which I used almost 50 years ago. I typed ./trek to start the program and instantly remembered the game’s commands and strategy. It all came back to me – surprising, since I usually can’t remember what I had for breakfast on any given day. The main difference was that I was using a terminal emulator, which instantly displays the text output where the older teletype would take forever to type each character at a blazing 110 baud communication speed, adding to the sense of anticipation.

This PDP11 replica is mainly a novelty, but I’ve enjoyed logging onto it, booting various operating systems, compiling old software, and navigating the file system using commands from the very origins of the UNIX operating system. What a great way to revisit childhood memories from a time when computers were not yet in our homes.

The bike rides on new axles front and rear, although only the rear was in need of replacement. The new parts came with both front and rear axles, which included quick-disconnect mounting hardware, so I replaced both axles so that they would match. Both rear wheel bearings were replaced. Front bearings were cleaned and lubricated. Cables have been lubricated, and the brakes were adjusted.

I took the bike for a short ride in front of the house, shifting through the gears. The new seat is quite comfortable, too. The bike still lacks a kick stand, so I’ll need to determine which type to order. I plan on using this bike for short rides around the neighborhood and for low-impact exercise.

When I picked up the bike, it was missing a seat, so I ordered a nice gel-filled saddle that would be comfortable and look nice too. That was the easy part. I could see that this bike spent some time outdoors, so there was some light rust on the cables and a few screws. I decided to do some research and learn more about this machine.

It’s a Royce Union brand bicycle, which to me, meant nothing. From what I could tell, these machines have been built all over the world, but today are mainly products of Asia. On the plus side, it had an aluminum frame, aluminum wheel rims and both front and rear suspension. It seemed to be a decent enough machine for my occasional use. It has a 21-speed Shimano derailleur, so there will be more sprocket ratios than I’ll ever truly need. The most obvious issue, aside from a missing seat, was that the tires were flat and and were wobbly on the axles. I could see that the derailleur and brake cables would require lubrication, but that’s easy work. I fired up the compressor and filled the tires, which to my surprise, did not leak. The tires seemed like new, too. I had to lean it against the tool chest since it lacked a kick stand.

Moving to the front wheel, I disassembled the axle and removed the bearings and races. After a thorough cleaning and light application of grease, I reassembled the front wheel. It spun smoothly and true, so the front was set. The rear wheel, however, held all the surprises.

The rear wheel came off easily enough, but I could sense that the bearings were crunched inside. Once the axle was removed, the bearing cage was visibly distorted and the 7 ball bearings had become loose. I then noticed that the bearing race was seriously damaged, so this bike experienced some abuse at some point in its past. Perhaps the rear axle bearings were over-tightened? I’ll never know for sure, but I needed to order some parts.

When ordering the bearings, the most common style seemed to have 1/4″ balls, but other sizes were available, too. My digital calipers were at the cottage, so I used an old-school micrometer to confirm the size of the loose ball bearings. Exactly .250 inches, confirmed.

This rear axle is the older freewheeling style, and has an internal spline that requires a special tool to remove. Fortunately, the special tool with shipping was only $10.54, so that was added to the parts list. A new rear axle with new nuts, dust seals and bearing races was $16.95. A pair of new bearings was $12.70. The price of the seat plus shipping was $48.75. At this point, the “free” bike has cost me $88.94, but is worth fixing.

Hopefully the rear wheel issues will be the end of the problems. I’ll post an update once the parts arrive and I’m able to install them. Wish me luck.

• Rebuilt engine top-end with new intake and exhaust valves
• Honed cylinder (it was still within spec)
• Replaced muffler with aftermarket unit
• Replaced original ignition coil and condenser
• Replaced original ignition points
• Replaced starter recoil spring
• Replaced gaskets and O-rings where necessary
• Cleaned and lubricated the drive chain
• Replaced Hand Grips
• Replaced damaged headlight and chrome bezel with new/old stock parts
• Replaced worn kill switch with new/old stock replacement
• Replaced portion of wiring harness where rodent damage existed
• Changed engine oil

Once again, it starts easily. It’s just as fussy on pavement as it ever was, since this machine prefers loose ground. It’s been in the family for four decades and was deserving of some attention.

A tiny wire wheel mounted to a rotary tool took care of the carbon removal from the combustion chamber. Gasket mating surfaces were cleaned too. The original exhaust pipe and muffler were long overdue for replacement. A hole in the bottom of the muffler was visible next to an old “temporary” patch. The original exhaust parts will be discarded since the aftermarket exhaust arrived last week.

Once the new valves arrive I will continue to reassemble the engine. Until then, I’ll clean and re-lubricate the chain and throttle cable. I’d like to see the ATC 90 back in good running condition before the snow flies.

When diagnosing engine issues, the best place to start is with a compression test. I suspected that cylinder compression was not up to spec, so a compression test was the first step. The specification is 142 – 170 psi. I connected the compression tester, opened the throttle completely, and pulled the starter rope several times. The gauge topped out at 80 psi … not great, as expected. The engine would need some top-end attention.

I pulled the engine head and cylinder for closer inspection. A late evening meeting with work put an end to the analysis, but I was able to get the top end disassembled. As expected, the cylinder head combustion chamber had a heavy carbon build-up. The cylinder didn’t look too bad, and the piston rings were not frozen into the grooves. I’ll look at the parts more closely over the next few days and determine what I need to order. I have already ordered a new exhaust pipe and muffler, mounting studs for the exhaust, a gasket set, and a few miscellaneous parts. Not too bad. I have no plans on tearing apart the bottom end of the engine at this time.

I removed the piston and took measurements. Both the piston and the cylinder are within spec, and visually look good. Therefore, I currently plan on reusing the piston. I’ll lightly hone the cylinder prior to assembly. The valves were heavily caked with carbon deposits, but can be cleaned, lapped and used again.

This is a good start toward getting the ATC 90 back in service.

Enough of the excuses … here’s the latest. Over the past few days I’ve completed the truing of the wheels and have mounted the new tires. Once I find my set of balancing weights, I’ll balance the wheels. 2 years ago the hubs were vapor blasted and look like new. Also, the stainless steel spokes are a nice upgrade from stock. The hubs have new bearings pressed in as well. The aluminum rims are from Borrani in Italy and match the flanged style of the original steel rims.

The new old stock (NOS) engine side covers got several coats of ceramic aluminum engine paint, followed by a heat treatment. The original covers had damage and needed replacing. The right side cover is hard to find, too, as it contains a cast-in kick starter shaft bushing, which tended to wear over the decades on these kick start-only bikes.

I’ll focus on completing the frame pieces and panels that will be painted their original light silver. I’ll get the sanding and prep work done next. Since the warm weather is fading, I’ll outsource the painting to the pros, which will allow me to put the engine back together during that time.

My goal is to work on this during the off-season and have it ready to ride when the snow clears in Spring 2021.

On May 13 I stopped at my mom’s for a carry-out dinner from Short’s Brewing Company. She shared with me a photo of her mother on one of those paddle boats in 1968. This photo brought back many memories of summers spent at the lake. Trips to the log cabin were among my fondest childhood memories.

On May 28 I stopped at John’s house with a trailer. I walked into the woods where he pointed, and I found the boat next to an old wheelbarrow and a pile of broken concrete. I was in shorts and the boat was surrounded by poison ivy – wonderful. I found that the boat was not heavy, so I dragged it into a clearing for inspection. It was rough, but in better condition than I had expected. Still, I knew it was dumped for a reason. I noticed that the steering linkage had broken away from the bicycle “fork”. I lifted the boat and noticed a gouge in the front of the right aluminum pontoon. That was likely the reason it was discarded. Still, this appeared to be repairable, so I dragged the boat to the trailer for a ride to its new home.

The boat’s frame was made from simple steel angle bar, which only had light surface corrosion. The pontoons are aluminum, although crudely made. Each pontoon is held to the frame by three stainless steel bands, which were in good condition. The paddle blades are also aluminum, riveted to steel arms. At some point in its life, somebody painted the frame, pontoons and paddles. Most of the paint has flaked away.

This boat’s construction was more like a hand-made prototype than a series production design. The only hint at its origin was a metal plate riveted to the front frame bar that read “Horst Manufacturing Company, Belleville, Michigan”. I couldn’t find any information about this company, so John did some research using a subscription-based newspaper search. He found two old newspaper clippings that mentioned the company. One was a brief mention of Horst Manufacturing Company as a sponsor for an ad in 1951, which also stated that the company was established in 1933. The other was a more ominous classified ad from November 4, 1984, listing the liquidation of the company’s assets.

Through some additional research I found several newspaper advertisements for this exact product, dating from 1955 to 1960. This was a Horst Waterbike, and it was at least 60 years old.

On May 30, I used an angle grinder to cut away the bolts and disassemble the boat. I’ll replace any fasteners with stainless steel. The chain will be replaced with new. I will have to replace the bicycle fork, but it uses a standard piece so that should be easy. The steering linkages and tie rod may be replaced, too, using newer hardware. The aluminum pontoons and paddles will be cleaned, repaired and polished.

I will look for a local shop that does aluminum pontoon repair to fix the damaged pontoon. I’d like this work to be done professionally. I’ll handle the rest of the project myself.

If all goes as planned, the Waterbike will be reborn and see service on our little lake this summer.