Schedule a Meeting · Talk to a real woodworker: +1 937-890-5197 · 8:00AM – 4:30PM ET

Using a Shop Smith Mark V on a Chris Craft Roamer refit

chapmanruss

roamer46,

Having followed your post here for a long time now it is great to see it in the water. Through the delays, your efforts have paid off. A project you can truly be proud of. ENJOY.

edflorence

roamer 46;

That is an impressive rebuild of an impressive boat! Thanks for the video from the helm...looks like its a lot of fun to pilot that beauty! Congratulations on carrying such a large project through to an amazing finish.

JPG

It ain't "finished" yet, but at least it "functions".

Now to make it "livable" for Mrs.Q.

roamer46

Thanks guys!

Yup, JPG, the missus and I were just talking yesterday about current priorities and a functioning toilet topped the list, followed by fully commissioning the air conditioning systems. After an unusually pleasant spring and early summer, Swamp humidity has returned to normal with a vengeance. But after all the exciting posts involved in finally launching the boat and transiting to my new home port, the rest of the refit will probably seem mundane. lol

Since the refit began, mud dauber nests have been a persistent problem. I reckon I could fill a 5-gallon bucket with all of the mud nests I've removed over the years. A favorite point of entry has been the engine room air intake gills on the sides of the hull. I found some 304 stainless wire mesh with eight wires per inch (so ~1/8" square gaps between the wires) that will stop the bugs from entering through the gills without substantially restricting air flow. I used some leftover Bostik 70-08A windshield adhesive because that stuff bonds so well. As of several weeks ago, the engine room is now mud dauber-proof.

1969 Chris Craft Roamer 46 Refit: Mud Dauber Screens

Cheers,

Q

roamer46

Back to mundane refit stuff, I replaced a rotten salon cabinet panel back in 2015 but wanted a better appearance for the inner cabinet than what Chris Craft did. The original mahogany panels were gorgeous, and so were the cabinet doors. But when you opened the cabinets, the interiors were painted flat white or you just saw the bitumastic-coated hull. I made a proper cabinet box using varnished mahogany. It looks a lot better than the original approach.

1969 Chris Craft Roamer 46 Refit: Salon Cabinet Install

Cheers,

Q

Before

After

roamer46

One thing I've been plodding away on for the last two years is the salon sleeper sofa, which Chris Craft called a settee in the sales brochures. The missus liked the original design, and the missus gets what the missus likes. The original panels had rot in them, but they're good enough to use as pattern and to help me remember how it was originally constructed. It's a complex piece of furniture, but I've got a plan and this is a good first step.

1969 Chris Craft Roamer 46 Refit: Remaking the Salon Settee

Cheers,

Q

Before

Step 1

roamer46

I had some leftover scraps of Tricel lightweight panels, so I'm using them to recreate the salon settee. I'm very glad that I kept the original panels as patterns even though they had some rot in them. Between the patterns and different colored primer lines on the salon floor, I've been able to figure out where the new panels need to be. Then I applied mahogany veneers, Pettit stain, and ICA base coat clear before installing the main settee panel in the galley. It's coming along nicely.

1969 Chris Craft Roamer 46 Refit: Remaking the Salon Settee II

Cheers,

Q

Step 2

roamer46

I'm having trouble with my CAPAC impressed current anti-corrosion system controller. The meter swings between 5.5 (barely protected aluminum hull) to 7.5 (fully protected) but spends most of its time around 6-6.5, which is under protected. Turning the set-point adjustment potentiometer doesn't seem to change anything. This blog post has the schematic from the OEM CAPAC manual, and I've noted voltage readings that I took at many components. I also link to the manual, which has an excellent Theory of Operation section. Unfortunately, I don't speak transistor. If anybody with a grasp of electronics can take a peek and let me know what's wrong, I'd be much obliged.

1969 Chris Craft Roamer 46 Refit: Dialing in the CAPAC Anti-Corrosion System

Cheers,

Q

thunderbirdbat

I have not worked with electronics in years so not sure if this will help. While the components age, they change their values most stay within the allowed tolerance. On the resistors the gold band indicated +/- 5% while the silver band indicated +/- 10%. The other problem is that unless you de-solder the resistor, all putting jumpers around it will do is add a parallel path for the current to go. When I was a young Navy Electronics Tech I worked on some old equipment from the 1950's (about 30 years old) that looked similar to your circuit board. The equipment did not work but we removed and tested all the individual components and they were within tolerance. What we finally figured out was that although individually each components tested within their tolerances, together the difference in actual values were great enough for the entire circuit to not work correctly. We had to replace every component on the board to make the equipment work again. Also a problem that frequently occurred, was the adjustable resistor would not want to adjust and over time would return to what it was set at previously. Sometimes adjusting it through it's full range of values several times can help other times, it does not.

roamer46

Thanks thunderbirdbat! That's very useful information.

I only put jumpers on the 2w resistor on the assumption that the smoke had been let out of it and it was an open circuit. But jumping in another one of equal value didn't change anything, so I presumed the resistor got warm but didn't let the smoke out.

If all else fails, I'll start putting together a list of all the components I'd need to rebuild the CAPAC controller.

Thanks again!

Q

thunderbirdbat

Lets see if I can translate simple electronic theory to basic piping theory to give you an idea as to how it works. It is not perfect but gives a general idea of how it works. A resistor is a form of reducer, a diode is similar to a check valve, a transistor an enlarger and a capacitor is like a small holding tank that once it fills, will dump all at once. the wires are basically like the pipes. Heat is the by-product of each change to the energy flow. The warmer it is the harder it is to dissipate the heat, which can cause problems with the equipment operation. This is the reason most electronic spaces are kept at very cool temperatures. It is not really what happens but as an electronics tech that was forced to learn how piping systems work for quality assurance, it is sufficient to give an idea of what is going on to someone familiar with piping. IC chips are just smaller compact versions of resistors, diodes, transistors and the wiring between them. For physical indications, resistors normally break when they go bad, capacitors may leak or split, diodes and transistors do not give an indication.

roamer46

Thanks for that explanation.

The explanation of how the CAPAC controller works (p. 24 of the manual linked from the blog) indicates "When the voltage at the base of Q3 falls below 4volts, Q4 starts to conduct. This increases the voltage on R12 and causes Q3 to cut off. While Q4 is conducting, current can pass from the base of Q5. This causes the voltage across R13 to be nearly equal to the battery voltage appearing at terminal 3. Therefore, no current can pass from the base of Q6 and Q7, and no anode current is available."

That appears to be the state of mine. I posted a picture of the circuit board schematic with voltage readings taken at various places. R13 does, indeed, have 13.31v across it. And I saw 0.129v at the base of Q3.

The manual also states "the difference between the desired hull potential voltage set on R14 and the reference cell voltage appearing at terminal 1is amplified by Q1 and Q2. This voltage appears across R6 and is connected to the base of Q3. If this voltage exceeds approximately 5 volts, Q3 will conduct and because of the coupling to Q4 will cause Q4 to turn off (non-conducting)."

R14 is the set point adjustment potentiometer on the face plate. Cranking it all the way clockwise, and all the way counterclockwise has no apparent effect. The needle doesn't budge.

DLB

roamer46 wrote R14 is the set point adjustment potentiometer on the face plate. Cranking it all the way clockwise, and all the way counterclockwise has no apparent effect. The needle doesn't budge.

If I understand your annotation, you measured 0.000 VDC on the Blue wire going to the potentiometer (R14). The schematic shows the Black wire going from R14 to the common ground, therefore also 0 VDC. The Theory of Ops says that 'Rectifier (diode) DR1 is used to generate a regulated voltage of 0.7 VDC across the potentiometer R14.' You should have approximately 0.7 VDC at the junction of R4 and DR1 and also at the Blue wire going to the pot. Worth double checking. 0 VDC at both locations would tend to indicate DR1 is shorted or R14 open (less likely). To check the diode by itself, you need to lift at least one leg from the board to isolate it from everything else. Does you meter, evidently digital, have a diode test function?

- David

roamer46

Thanks David! It looks like you're reading my annotations correctly.

I've been giving the greasy eyeball to that blue wire for two days, since I suspected it should be seeing .7vdc instead of 0.000. R4 (1kohm) is seeing +11.24vdc on one leg and connects to the DR1 diode on the other (along with the blue wire), while the opposite leg of DR1 connects to -12vdc or battery/hull ground. The blue wire voltage (0.000v) is the same at the junction of R4 and DR1.

I'm curious--if DR1 is shorted, shouldn't the +11.24v still pass through R4 (assuming it's good) and show up on the blue wire, minus whatever portion the resistor blocked?

I've got a Fluke 15b and it's got a never-before-used diode function.

The schematic NOTES box also indicates that DR1 is "IN1692." Searching the internet, I see lots of PDFs from the 1960s that specify that diode, including one from NASA. But I'm not seeing any sellers of that part number or a modern equivalent assuming it's obsolete. I'll focus on testing the diode first and, if it's bad, try to figure out a replacement later.

Thanks again for the help.

Q

thunderbirdbat

Could the notes actually say 1N1692 instead of IN1692? 1N1692 is a recognized rectifier diode part number.

roamer46

I wondered the exact same thing!

I went to a technical high school ages ago, and in drafting class we were taught that 1 and I are not written the same. But I can't tell the difference between the two on the schematic. Can you?

DLB

The 1N prefix is/was commonly used for diodes where 2N is for transistors. I didn't catch that before. I don't recall the reasoning, and it might be old school now. This was extremely common in my time in the service, late 70's. Maybe it is a Mil-Spec number.(?) Because of that, I read all of these as 1N, and am reasonably certain that is correct. I agree regarding 1's and I's in the drawing, they should be clearly differentiated.

roamer46 wrote I'm curious--if DR1 is shorted, shouldn't the +11.24v still pass through R4 (assuming it's good) and show up on the blue wire, minus whatever portion the resistor blocked?

Yes but in this case it would be 100%. Electrical current will still pass through R4 if the diode is shorted, but the ground via the presumed short will result in a 0V reading. So in this case the full 11.24V is being 'dropped' (converted to heat) by the resistor. If this was working correctly it would look similar to the R5 and DR2 combination you also noted, with voltage drops across both DR2 (also 0.7 V) and R5.

- David

jsburger

Well, all the 1/I numbers/letters look the same in the print. Clearly the word "is" on the print is a letter but all the electronic parts also have the same script for the number 1. i.e "Q5 IS 2NI305". That is thirteen oh five not the letter I 305.

Diodes are 1N not IN. similarly the number is 1692 not I692.

1N1692 are readily available.

BuckeyeDennis

FWIW, the number preceding the "N" indicates the number of junctions that the device contains. Diodes have one junction, and bipolar transistors have two.

thunderbirdbat

Actually this is the way many of the schematics were written from the '40's,'50's and '60's that I have seen. I am not sure when the writing was changed to distinguish between an I and a 1 but all of the older schematics I worked with did not.

« Previous Page Next Page »