Honda RC166 Grand Prix Racer by CDW - FINISHED - Tamiya - 1/12

[Old Collingwood]

I did  that the first few  tries  with  full size  wheels, takes a while  to  get the sequence  correct.

 

OC.

[Old Collingwood]

https://www.bikeradar.com/advice/workshop/workshop-how-to-lace-a-wheel/?image=3&type=gallery&gallery=1&embedded_slideshow=1

 

OC.

[CDW]

2nd time’s a charm

Mea Culpa

The alignment jig has a specific mark (highlighted with black marker). The rim has a hole for the valve stem that must align with the jig mark. Same is true for the hub. Somehow my rim moved off the mark which resulted in failure at the end. 
Lacing the front wheel should go smoothly I hope.

[CDW]

The custom wire wheel detail set is sold separately by Tamiya at a cost I cannot recall. At the present time, everywhere I've checked are out of stock for this set. Now that I've arrived at the end of my wheel set construction, it was fortunate that I did not lose any of the small pieces such as the nipple parts pictured here. Each wheel has 36 spokes and each spoke requires a nipple, a total of 72 of these almost microscopic pieces needed to complete the assembly. After I got all the way to the end, I found that Tamiya included 1 extra nipple part either by accident or as an extra in case of loss. Loss is highly likely as a part can go flying off the tips of your tweezers like you were playing tiddly winks. If you had carpet flooring, forget about it. You'll never find it. My beef is that even though we pay a premium price for sets like this, they can't even supply an extra half dozen or so in case of loss. It's almost shameful IMO.

[CDW]

With the front wheel finished, will next move on to other challenges.

By the way, as it turns out there was no extra nipple. Tamiya supplied the exact number needed with no spares whatsoever. So if you take on this build for yourself, be forewarned. If you lose one it’s going to be a problem.

[DocRob]

These spoked wheels look the part, CDW. Thanks for the warning about the spoke nipple count. I have no carpet in my cave, but don't want to go hunting for these tiny buggers. I may wear an  apron, like jewelers do.

 

Cheers Rob

[CDW]

1 hour ago, DocRob said:

These spoked wheels look the part, CDW. Thanks for the warning about the spoke nipple count. I have no carpet in my cave, but don't want to go hunting for these tiny buggers. I may wear an  apron, like jewelers do.

 

Cheers Rob

It's going to be interesting and tedious building the chain, link by link. Those pins are even smaller than the wheel parts. I hope the count is right.

[CDW]

Tamiya recommends mixing 4 parts Titanium Gold with 1 part Flat Red Brown to achieve the engine color see in the reference photos., Carbs, various engine covers and plates. Looks like a good match to me.

[shipman]

Coming along nicely.

 

One observation ... the various cables and wiring.

The tube Tamiya provide is way over scale in most areas.

My suggestion would be to find some fine electrical insulated wire from a phone line/computer wotsits in suitable colours.

Or use wire or solder (painted).

[CDW]

4 hours ago, shipman said:

Coming along nicely.

 

One observation ... the various cables and wiring.

The tube Tamiya provide is way over scale in most areas.

My suggestion would be to find some fine electrical insulated wire from a phone line/computer wotsits in suitable colours.

Or use wire or solder (painted).

Agree 100%

What makes the tubing useful is to snip off all but about 2mm at each connection point and use that short section as a connection (like a ferrule) for lead wire or other more scale diameter wire. I have a large selection of lead wire in .1mm graduated diameters to use for detailing. That's my intent here. As you said, old telephone wire often has a more scale appearance as well. 

[shipman]

CDW, that 'ferule' idea is brilliant and new to me.

Alternately, the junctions could be micro-drilled to take the replacement wires; a little more labor there, but ultimately more secure and authentic.

Looking forward to more results of your work.

[CDW]

2 hours ago, shipman said:

CDW, that 'ferule' idea is brilliant and new to me.

Alternately, the junctions could be micro-drilled to take the replacement wires; a little more labor there, but ultimately more secure and authentic.

Looking forward to more results of your work.

My thought was to improvise a ferule that would look like a spark plug boot where they attach to each plug and coil. And yes, micro drill will be perfect for the attachment of clutch, brake and throttle cables. My ignition wires are painted .5mm lead wire. They are hard to see but are attached to the number 1 and 6 cylinders now which are energized by the forward coil. 

[shipman]

Splendid detail improvement..... go for it!

[Javlin]

Looking Good and Real Craig!

[CDW]

Break out the optivisor, it’s time to build the chain!

The chain kit provides a plastic assembly jig.

and a whole bunch of 1mm rollers

 

the rollers are placed in each of the holes of the assembly jig

 

then two sets of photo etched links are laid down

 

more to come….

[CDW]

I noticed the chain kit comes with two different sizes of rear sprockets. I'm guessing maybe there were different size sprockets used on the real bike depending on the particular race event/track. 

[yvesvidal]

This is on the border of insanity.... I admire your patience Craig.

 

Yves

[CDW]

Next up the pins are placed inside each roller. You will note the pins have a specific shape on each end and can only slide into the rollers in one direction. A head on the end of each pin holds each link in place.

After all pins are in place, a plastic molded cap is put in place that hold the pins in position.

The jig is then flipped over so the bottom cap of the jig can be removed, exposing the opposite side of the roller pins.

 

[CDW]

After seeing the way Tamiya engineers designed the tools to assemble this small delicate chain, you and I both will agree they are genius.

 

A photo etch plate of links are placed over the roller pins exposed in the preceding steps. Additional smaller sections of chain links are provided, shaped like “c” clips to snap in place over the links and pins that lock it all together. Two plastic tools are provided to hold these small sections in place while they are pulled down, locking them into position. Very ingenious and well engineered.

[yvesvidal]

I have done spokes and chains at the scale of 1/6th. I admire your patience and tenacity, despite the incredible tool that the Tamiya designers created for that purpose.

 

Yves

[shipman]

I remember building a 1:8 Honda race bike back in 1974.

The chain for that was all individual plastic links and rollers which had to be glued together.

My results were sadly predictable!

 

As with all race bikes, each track needed different gearing, requiring a range of sprockets at the gearbox and rear wheel.

Individual riders preferred their own set-up too.

 

Then there were multi jets in each of the 6 carbs, requiring setting up for varying atmospheric conditions, which these engines were ultra sensitive to; as were spark plugs.

Often the quickest way was a complete engine swap.

 

The real jewel from that period was half the capacity.... a 125cc 5 cylinder!

Edited April 26, 2023 by shipman

[CDW]

Next steps with the chain construction involve cutting the links from the photo etch fret. Since the fret is stainless steel rather than brass, it's harder to cut. I typically use a scalpel blade for this but I found it takes too much pressure to cut through, therefore bending (slightly) the links out of shape. As the fit between the links and the pins is so precise and small, Tamiya recommends "pinching" each "c" clip together to tighten-retighten the fit to pin after cutting. I found this to be beyond my capability with the tools I have, much too small for any forceps I own. Next I am going to try cutting the links from the fret using a micro abrasion wheel on my dremel. Hopefully this will prevent the distortion of the c clips and negate the need to pinch them. If that doesn't work, I'm going to need to find a much smaller set of forceps to maybe even tweezers. I could see this task ruining a set of precision tweezers in the process as the tips of tweezers are not generally used as a pinching type of tool. 

[CDW]

20 hours ago, shipman said:

I remember building a 1:8 Honda race bike back in 1974.

The chain for that was all individual plastic links and rollers which had to be glued together.

My results were sadly predictable!

 

As with all race bikes, each track needed different gearing, requiring a range of sprockets at the gearbox and rear wheel.

Individual riders preferred their own set-up too.

 

Then there were multi jets in each of the 6 carbs, requiring setting up for varying atmospheric conditions, which these engines were ultra sensitive to; as were spark plugs.

Often the quickest way was a complete engine swap.

 

The real jewel from that period was half the capacity.... a 125cc 5 cylinder!

It's odd seeing a racing engine like that in the first photo just lying in the grass. Would that be a maintenance photo taken during the course of a race? 

Great photos!

Would have loved hearing that 5 cylinder 125cc engine rev up.

[shipman]

Yep, those were the 'GLORY' days when race paddocks were basically a field.

No motor homes, teams living in tents and utility vans.

Most riders survived on 'start money' and a private sponsor.

The envy was palpable, only the 'works' riders had contracts. And there were only 10-12 of them at best.

Remember, they were all air cooled, double overhead camshaft, four valves per cylinder.

Tool room specials, creative engineering and no computers by modern standards.

Notice none had any flywheel effect and were a nightmare to ride.

Only the lucky few got the chance and earned every penny.

Track safety was straw bales and a bashed up ambulance.

 

Finally the 500 4.

That's Honda playing with its museum GP racers from 1966 in a glorified car park.

 

Hope you don't mind the overload but it may put 1960's bike technology in front of a new audience.

Finally, finally, serious nostalgia.

 

Edited April 27, 2023 by shipman
lots more

[CDW]

Awesome videos. Could not believe how quick that 2 cylinder 50cc bike ran. Never knew there was such a thing. Who was the test rider?

[shipman]

I believe the test rider is Hiraku Miyagi.

Glad you enjoyed the video's.

 

Honda weren't entirely dominant during those years. Both Yamaha and Suzuki fielded their own exotic two strokes.

Suzuki built a 3 cylinder 50cc.

 

At the end of 1967 the governing race organization (FIM) decided things were getting far too much and introduced severe restrictions in all classes in the hope of encouraging closer competition. Much like post war supercharging was banned for the same reasons.

 

At the moment I'm not at liberty to divulge what was sitting on my table last night.

When I can, it will be a real exclusive treat for late 1940's British GP enthusiasts.

 

I'm fortunate to know some fascinating characters who have even more fascinating motorcycles.

 

Edited April 27, 2023 by shipman
more!

[CDW]

After taking a couple of days off from modeling, I'm back to take up where I left off on this photo etch chain building dilemma. 

 

On the left side of the jig are links I cut from the photo etch fret using a XActo blade. It distorted the shape of the links which Tamiya suggests using "something" (not specific) to pinch the links to tighten them against the roller pins. As you can see from the photos, my precision tweezers are no match for this small work. Got to find something to pinch those links and tighten them. To the right of the cut links are links yet to be cut. I will attempt to do this with a micro cutoff wheel in my dremel. I tried using my Xuron photo etch cutting scissors but those mangle the links as well.

 

I am definitely open to suggestions if you have one.

 

 

[CDW]

I may need to try and grind or file down a set of tweezers to a much finer tip to see if that might work. Obviously not the set pictured, as they are ceramic-tipped. 😄

Edited April 30, 2023 by CDW

[realworkingsailor]

Something like these: https://www.amazon.com/Stainless-Plastic-Cutting-Tweezers-Jewelry/dp/B01MZ6621X

 

Only perhaps hardened for metal work? I’ve seen a few pricy ones for jewellery makers, but there’s got to be something “good enough” for hobbyists that won’t empty the wallet.

 

Here’s a set designed for electronics:

https://www.tdiinternational.com/product-category/hand-tools/tweezers/cutting-tweezers/

 

Andy

 

 

Edited April 30, 2023 by realworkingsailor

[VitusBering]

These are so finely tipped that they will cause a bleed if you happen to get poked by them. Definitely the finest metal tipped tweezers I've ever used. They come with protective sleeves and I am glad of it.

 

https://www.amazon.com/dp/B092VT3YVD?ref=ppx_yo2ov_dt_b_product_details&th=1