Sunbeam S7 Deluxe Chronometric Speedometer - Temporary Substitute

The speedometer has not worked reliably on my Sunbeam S7 Deluxe in about two years.  It would work on and off, then finally it quit altogether.  It needs to be properly rebuilt.  With stories of other folks overseas shipments being quarantined or lost in customs, I did not think it was a good idea to send it to England for repair.  Sure there are proper aftermarket replacements but they cost over $300 USD plus shipping and they still need a cable and hall-effect pickup to function.

I had been just dealing with the lack of speedometer, and I wasn't actively looking for another solution.  Fortunately here in the USA if we register as an antique there is no safety inspection or MOT.  Sometimes targeted advertising is actually a good thing.  In my news feed of a popular social media up popped an advertisement for a GPS Speedometer.  Brilliant!  Why didn't I think of that!  It needs no cable, just power and a clear view of the sky.  The antenna could be hidden anywhere on the bike or just strapped on with tyraps in plain view.  It would look plain and not unusual unless you really looked hard at it to find the digital display.

Nobody makes a GPS speedometer for an 80mm diameter speedometer bucket.  They are all 65mm or 85mm.  My grandma used to say "Can't is a coward", meaning if you think you can't then you are already defeated.  There must be a way to fit a 85mm speedometer in a hole for an 80mm unit.  I bought the speedometer for the modest asking price and resolved to figure it out.
ELING MPH GPS Speedometer Odometer 140MPH For Auto Motorycle With Backlight 85mm 12V/24V

Upon arrival like any good engineer, I took it apart to see how it worked.  The mechanism was simple.  The bezel pried off easily exposing the bucket with the speedo unit inside.  Two screws in the back removed, and the speedo pushed out of the bucket releasing the power connector inside.  Another connector went to the GPS receiver hot-glued to the bottom of the bucket.

The plan was to cut the speedo bucket so that half was above the headlamp and half was inside.  I would then contrive a way to join them back up.

Luckily there is just enough room around the edge for some stainless steel sheetmetal.  The sheetmetal was fastened carefully to the inside of the bezel and passed along the inside of the speedo bucket.  It could then be re-attached by drilling a hole through both and allowing the sheet metal to self-tap.

All assembled, but there was naturally another challenge to overcome.  My bike is 6 volt positive ground and the speedo needs at least 9 volts.  No problem.  I bought a boost regulator and set it for about 12 volts.  It gets powered from the original speedo backlight and there you have it.
MT3608 DC-DC Boost Power Converter

 One night's worth of work and I have an operational speedometer.  I can take my time getting the original rebuilt and nothing on the bike was done that couldn't be reversed.  A big fat o-ring from a spin-on oil filter covers the bottom of the bezel which had to be thick enough to support putting four screws in it.  The o-ring could be backed with some RTV if I thought the bike was ever going to get wet... which it usually doesn't.

The maximum speed is a bit optimistic.

Sunbeam S7 - Wheel Bearing Grease Seals

The Sunbeam S7 Deluxe originally used Angus 182 leather grease seals on the wheel bearings.  While surprisingly long-lived (12,000 some odd miles and 66 years of service) everything is prone to  eventual failure.  This weekend while taking a leisurely trip to visit J&B Moto Company, the rear grease seal lost structural integrity.  Grease was all over the rear wheel and caked into the mud guard.

A quick look for a replacement yielded a modern equivalent.  A Precision 476838 Seal was a perfect fit.  It is a double lip seal and should yield adequate protection.  I doubt they will last over 60 years though.

The old seal is easily pushed out with two sockets of appropriate size.  The new seal is pushed just as easily with one socket.  If the seal becomes cocked in the hole it is very difficult to push.  I chose to use my drill press as a light-duty press for this job since it is easy to line up for a perfectly even press job.  (drill motor off of course)

Remember the castle nut of the seal assembly is LEFT-handed, just like the axle.

Sunbeam S7 spit as polish

The brightwork on KYL95 certainly has lots of patina. I thought perhaps too much. Some of the rust on the handlebars is just surface rust. Yes there is pitting, but its not bad. The headlight surround is also ugly, but not really bad.

I was searching for methods of chrome cleaning that won't marr the surface and came across some discussions involving aluminum foil and water. It sounded reasonable. The aluminum is soft and won't scratch steel or chrome. The water provides slight Aluminum Oxide to build up, which provides the slight chemical reaction and mild abrasive action.

Mothers polish is just too abrasive.

I tried it on an inconspicuous spot and was pleased with the results. Working upside-down the water tended to run off, so I spit on it. That worked even better than water.

The photo doesn't do it justice, but it looks so much better maintaining a level of patina without the rust layer.

Sunbeam S7 clutch cable

KYL95 needed a new clutch cable. The original was beginning to fray around the upper ferrule. (I've been stranded with a snapped clutch cable and its not worth the risk.)
I obtained a Venhill universal cable kit.  It came with the following parts and a nice set of directions on how to make up the cable properly. Many of the pieces I didn't plan to use, but everything was there.
Stripping the original cable off showed the poor condition of both the sheath and cable. I was mainly concerned with the fraying, but the bends in the cable were making more slop than needed in the adjustment.
The new sheath was cut to length, and routed with the end cap that came with the kit fitted to the clutch lever.  The ferrule was slid up tight and pulled tightly by hand with the adjustment fully retracted.  The cable was then kinked to one side indicating the correct length. I then manually made a birdcage shape at the end and soldered the ferrule in place.
The cable is now straight and pulls much easier through the nylon-lined sheath.

Vintage Bike Night York

I've been spotted with the guys from Vintage Bike Night York

Fostering a sense of stewardship

After reading the Vintagent's article entitled "Prouve, Ennui, and the Problem of Cash", I began to reflect on my own sense of stewardship and how best to foster this important notion in others.  In our modern culture of the present, where things are pre-disposed to be disposable, what will people be saving for the future?  If we could only know what would be valuable in the future, would we hoard all we could find today?  What will we save, pass on to future generations of our own family or others who share our delight?  We are merely stewards of this world and all the things in it anyway.  We can take none of it with us, why not preserve it for someone else to enjoy!

I look at my friends and acquaintances who have amassed collections of objects that no one at the time would consider even worth saving, and wonder what will my son choose to consider important enough to keep throughout his life.  (He's already been instructed that he must save his Noggin the Nog books for his own children.)  Chet collects early speakers, Ron collects radios, and Dale collects amateur radio gear.  Matt even made his love of antiquities and coffee into a lucrative business.

I look at myself and consider if I have failed in successful stewardship?  I've already sent a few automobiles to the scrapper.  I tried to preserve them with as little ability that I had at the time.  The need for repair and upkeep overwhelmed me and they were of no use any longer, and worth more as recycled material than the wondrous means of freedom and travel that they once were in my youth.  I'm sure my father would be overjoyed if I showed a glimmer of interest in his 1946 Cessna, which he has maintained faithfully as possible since before I was born.  He stored it for more than 20 years in the garage when he had neither time nor money to spend on it.  The times we spent together flying and fixing will always be remembered as great experiences.  Pass the story with the machinery, and it becomes even more of a legend.

How would I feel if the tables were turned, and my own son wanted nothing to do with this 1949 Sunbeam motorcycle?  Everyone takes their own path.  Today he'd sell it in a second for a steam engine.  The act of careful stewardship is never in vain, only the stories can be lost and the objects aged.  Even the elusive Barn Find has a unique and exciting mystery of its own.  If my own son doesn't take an interest, then someone else will be there to pass the torch to.  Hopefully there will be a future steward to honor the story of the past stewards.

I was always told to take care of my things.  I see now that they aren't my things.  They are the things that I've been entrusted the care of.  Some shortsightedly were abused and misused, others were treasured.  The experience of fatherhood deepens the sense that not only am I the steward of things, but of people and attitudes as well.  Not all of us can be like Barney Pollard, even fighting off the government to preserve a collection.  We can be good stewards of what we do have though.  By choosing the right things to save, and the best things to entrust to others we can more effectively further our stewardship.  There's no sense in becoming buried alive.

Stewardship and Experience together bonded in a Story allow these objects to gain value.  Not just in the sense of currency, but as part of our own lives filling us with richer experiences we would never gain otherwise.  These such heroes live on because they acted with good stewardship.  My wife kept her first car... our 1967 Sunbeam Imp.  Eduardo Pallazo made it possible for me to take over the care of a unique 1966 Sunbeam Imp.  Dr. John F. Patt made is possible for me to care for a very original 1949 Sunbeam S7 Deluxe.  Their immortal stories live on through the continued stewardship and the promise that their stories will be passed along too.  Shake their hand, look them in the eye and share the stories when the torch is passed.  I hope I've provided some inspiration.

In the words of Ian Anderson...

"Once I used to join in, every boy and girl was my friend

Now there's revolution but they don't know what they're fighting

Let us close our eyes, outside their lives go on much faster

Oh, we won't give in, we'll keep living in the past"

-- JETHRO TULL

The secret kit under the seat

Forget all those linear voltage regulator designs I posted previously for the Sunbeam Kubota alternator conversion. The error in my thinking is that an unloaded inductor produces high voltages, which must be dealt with by dissipation as heat. My linear design, while still within its design limits, was really overheating cooped up in the box.  It was experiencing too high an input voltage than I planned.  And it was too ugly to mount outside.

So now I know why they use a shunt regulator. It collapses the voltage reducing the power that must be dissipated. Thanks to Electrex World LTD for having model RR-1 in stock, and for the quick shipment.



I made up some clips to go around the seat bolts, and fastened the regulator neatly under the seat out of sight.  With some spare BSW bolts!  It will also get some air flow.

All the original bulbs are back in place, and I'm ready for a test.... as soon as it stops raining.  Initial indications are that the regulator charges strongly.  It doesn't appear to be over the battery rated charge current, and I'm hoping the bulbs will assist in keeping the voltage load regulation in check.

S7 Clutch Release Bearing Mod

The VXB 6x14x5mm Miniature Thrust Bearings arrived today and were easily installed in place of the original balls.  I added some moly grease for extra insurance.  The height gain was only a few thousandths from the worn parts, and easily allowed the clip ring to be replaced with room to spare.

Clutch Release Bearing Worry.

I've been getting an annoying clunk when shifting gears on KYL95.  I adjusted the clutch cold, but when hot it seems not to disengage properly.  Consulting the SOF gurus and Sept/October 2010 issue of On the Beam, I discovered that a modern bearing AKL 6 could be placed between the original release bearing races and maintain the original configuration.  Brilliant, except that I couldn't find that model number locally.

Off to trusty eBay with no results.  So I got the dimensions (6 x 14 x 5mm) and went searching further to discover VXB Bearing selling through Amazon.
http://www.amazon.com/Thrust-Bearing-6x14x5-Miniature-Bearings/dp/B002BBKCAE/ref=sr_1_1?ie=UTF8&qid=1336961575&sr=8-1

They might actually be delivered in two days!

Luckily the clutch release bearing can be removed easily without dismantling the bike.  Pulling it out revealed that there's nothing really wrong with it, except some radial wear inside the bearing holder cup.  Since there really isn't supposed to be any radial load, and I can probably attribute that to some numbskull in the past putting a frapping nail in place of the clutch push rod.

 

The release bearing is easily removed.  Notice my clever Viton o-ring seal "glued" to the outside lip of the gearbox.

 

The locknut is knocked loose, then removed, after that the bolt can be removed. 

 The balls look fine.  There's a little wear on the races, but nowhere near anything catastrophic.  With nothing to keep the balls evenly spaced, I'm sure they're bumping into one another, shifting the load on the races.

 

The whole assembly fits together like this and then drops down into the cup.

 

Sorry for the blurry picture, but the wear inside the cup is evident from some radial load on the bearing.

The next installment will be investigating the installation of the new bearing.

Sunbeam S7 / S8 permanent magnet alternator conversion (recap)

This is a recap of my alternator build.
(as published in the Sunbeam Owners Fellowship club magazine "On The Beam" issue Nov-Dec 2011)

---

I’ve been frustrated with the original Lucas dynamo on my Sunbeam since I’ve been riding it. Neither the MC45O nor the MC45L (that I later purchased) produced enough electricity in a foolproof fashion. I don’t want to have to worry about if there’s enough charge in the battery to get me home anymore, and I want to run the lights all the time. I also don’t want an after-market alternator conversion that does not look exactly like the original. This is why I was determined to create an alternator conversion by myself for a small price. I submit the following to any interested do-it-yourself owners.

I took suggestion from some Douglas and Vincent motorcycle owners who also have problems with dynamos. A few intrepid owners have taken permanent magnet alternators from modern applications and fit them inside the original dynamo cases. One particular application caught my eye while searching online for a suitable solution. There is a simple alternator from a Kubota tractor that measures only 3-1/2” across and a little over 3” high. I bought model APM0001, which was the smallest available. This came as a self-contained belt driven assembly. I tested it briefly before taking it apart to see how easily it produced enough current being turned by hand to light the tail lamp bulb on my bike. Removing the nut and pushing the bolt out easily disassembled the unit, shown in Figure 1. The back housing was discarded.

Figure1

The magnet cup was surprisingly powerful. It all fit nicely into the original dynamo case. There would be two major challenges. Fit the magnet cup to the crankshaft, and then to fit the case back onto the engine block so it all stayed together. I elected to do the reverse of what the Douglas owners had done, and fit the magnet cup onto the shaft first, so that the stator would be accessible from the front of the bike. It sounded wrong at first, but it eliminated so many problems it was worth the effort, in my mind, to machine all the required parts on the lathe. There would have to be an adapter to fit to the end of the crankshaft, which included pins to fix the magnet from rotating independently from the crankshaft. This I spun out of round stock on the lathe to a relatively high degree of precision. I would use the original left-handed bolt so I didn’t have to machine another one. The outside casing would have to be secured to the engine block by means other than the two long bolts originally used, because they interfered with the outside diameter of the magnet. The wires could easily come out the front and affix to the original terminal block. Below is the solution showing the framework cage that was made to hold the outside casing. I could have welded tabs to the casing, but I didn’t want to modify it.

Figure 2

The whole assembly fits together with a specific procedure, it’s not ideal, but it works. (I later discovered that the magnet was so strong, that I needed to fit two of the sealed bearings inside the stator winding assembly to keep it centered with respect to the crankshaft. That isn’t represented in the photographs.)

The cage, at the left of Figure 2, goes on first. The magnet and center bolt (with spacer) then affix to the crankshaft adapter. The spacer holds the sealed bearings from the original Kubota unit, and another outside press-fit spacer makes up the difference between the stator and the outside bearing race.  The fourth arm of the cage assembly encloses the magnet, before the case is slid onto the cage. The pole shoe screws fasten the case to the cage in such a way that it forces the case into the engine block firmly as the countersunk screws are tightened. The stator coil, at the right side of Figure 2, slides into the magnet which is centered by one of the bearings from the original alternator assembly. This took a brass spacer precisely machined out of an old pipe fitting. The wires tuck neatly up against the casing out of the way of the rotating magnet. The outer plate bolts on with 6 screws and then the cast aluminum cover of the dynamo bolts to the outside of the case.

Figure 3

I’m quite pleased that the mechanics of my alternator conversion work well. The next challenge was to rectify and regulate the alternating current into direct current. Normal people would just have converted to 12 volts and put the Kubota tractor regulator in place of the Lucas MCR2 dynamo regulator. I had purchased a Rooster Booster 6 volt positive ground ignition module, and already had my 6 volt battery and lamps, so I was determined to stay with 6 volts for the present time. I know it’s not ideal, but I knew I could make it work fine. The 6 volt scooter rectifier/regulator that I bought was quickly overwhelmed by the 14 amp capacity (and probably the open circuit voltage capability) of the stator coil, and burned out. I ended up with a commercial shunt regulator from Electrex World LTD.

I spent a lot of time on this project, but it met my goals. It looks original from the outside, it is reliable, and it was less expensive than the alternatives, as long as I don't count my massive investment of time.

Keep Shafting

Voltage Regulation

... or lack of voltage regulation as the case is.  The alternator actually works too well.  I bought this cheap regulator/rectifier intended for scooters.  Its voltage stability is horrendous.  Naturally the Permanent Magnet alternator increases in voltage and frequency as I rev the S7 Deluxe engine.  The regulator should compensate for this and keep the voltage around 6.x volts and not too high such as the 7.x volts that I saw this morning.  At highway revs the ammeter was reading nearly full scale of 8 amps!  "That's WAY TOO much current", I said to myself as I sat beside the road this morning.  The voltage kept going up with the revs... its supposed to be regulated to limit the voltage so that the battery won't get overcharged.  Well, the reason I was sitting beside the road this morning was that the battery WAS being overcharged and had blown the 7.5 Amp fuse that I had installed in series with it.  I was trundling along until I dropped the revs and the alternator wouldn't produce enough voltage to keep the ignition going... at which time the bike stopped running at the intersection.

A quick disconnection of the stator leads and a jumper across the fuse, limped KYL95 back home to the workshop.

So, now I need to replace that cheap scooter regulator.  I imagine its just a simple series pass transistor regulator in there, and its not yielding good results.  The correct solution is to use a switching regulator.  Like this one:

http://www.national.com/pf/LM/LM3150.html#Overview

Oh, and I've purchased a resettable circuit breaker too.  I HATE fuses.

Alternator - First Test on bike Unregulated

I finished the construction of the frame that holds the dynamo case to the front of the engine. My buddy Mark was kind enough to do the welding. A few minor adjustments and some precision holes drilled and I was ready to fully assemble the alternator to the bike.

First the cage must be installed with one arm out.

Then the magnet cup can be installed and the center bolt attached to the crankshaft and torqued down.  The fourth arm is then installed.

The casing can be placed over the cage and the screws installed where the pole shoes used to be.  The critical alignment of the stator inside the magnet cup was done with extreme care and precise drilling.  The stator will have some larger screws holding it to the plate in the final assembly, and a spacer to make sure it stays parallel to the plate.

Everything gets tightened.  In the final assembly the wires would go to the stock terminal block, but for this test without the regulator, I'm just going to hook some jumper leads out through the front.

Old KYL95 started on the first kick and we had LIGHT!!!!!  The automobile headlamp provided some visual load.  The voltage was around 6 at tickover.  It increased to 12 if I revved it up a little.  The regulator/rectifier will be installed in the electrical box, after the cage is sandblasted and painted.

Qwiki on Sunbeam S7

View Sunbeam S7 and S8 and over 3,000,000 other topics on Qwiki.

Alternator - The Build

From the last post, I've got pictures of the Kubota alternator all dismantled.  Next comes the modification pieces.

I've made an adapter ring plate to which flat bars will be welded to hold the case of the dynamo to the engine block.  This has the challenge of interference with the side of the case.  The cap screws that I will use will have to be ground down somewhat, and the side of the dynamo case ground down to accommodate the screws.  This should hold the case firmly to the engine block.

The next big item is machining the crankshaft adapter.  This will be a copy of the back of the armature, which will allow the magnet of the alternator to bolt directly to the crankshaft.  Here's a picture of it just started out of a piece of roundstock.  I'll need to get a parting tool for the lathe before I finish the part.

Here are the plans for the finished part.

Alternator - Proof of Concept

I'm fed up with the original Sunbeam S7 Lucas dynamo, and the MC45L dynamo that I bought. Neither one produces enough electricity in a foolproof fashion.
I don't want to have to worry about if there's enough battery to get me home anymore, and I want to run the lights all the time. I also don't want an after-market alternator conversion that does not look like the original.

The plan is to create an alternator conversion that produces 6 volts, is fully encased in the original housing, and works reliably.

I've seen others who have used a Kubota tractor permanent magnet alternator to do the job. Its only 3-1/2" in diameter and shorter than the MC45L dynamo. That means it should fit inside the casing. The trick is to mount it up.



It comes as a flange mount unit for belt drive, with its own bearings.

[edit]  I actually did use the bearings after all to keep the stator assembly centered in the magnet.  The magnetic forces are VERY strong radially, and will pull the stator into the magnet if there is the slightest mis-alignment or looseness.  A spacer piece was machined to hold two of the bearings into the stator and then the bearings were placed on the center bolt with their own machined spacers.

The permanent magnet rotor can attach directly to the S7 engine crankshaft, and the stator can mount to the engine block, or dynamo casing. All that is critical is that it runs centered and true. Should not be a problem for a guy with a lathe in his workshop.

Here's the sample fit up.  The center bolt presses out of the rotor cup easily.  This will allow me to make a bolt (left-handed Whitworth of course) to fit in there and mount to the crankshaft.  The question is whether 'tis better to bolt the stator to the engine block, or to bolt the stator to the outside of the dynamo, and put the rotor cup "upside down" against the crank.  I'll have to make an adapter to provide the seal to the front of the engine regardless.  The stator to the front makes it easier for the wires to come out to the terminal block on the dynamo casing.

The final part is the regulator / rectifier from a scooter.  I've bench-tested the rectifier / regulator up to 6 amps load.  It works fine with 14 vac input, and does not overheat.

Here's a VERY ROUGH sketch of the assembly.  I keep changing the design, so my dimensioned sketch is pretty bad.  I will require a minor modification to the dynamo case.  The cap screws will interfere with the side of case, so the case will need to be ground away in two small spots not visible from the outside.  The cap screws can be modified slightly to reduce the amount of grinding to the case.