"Big Tank" Crocker OHV motorcycle by DocRob - Model Factory Hiro - 1/9

[DocRob]

Ladies and Gentlemen, lets start our engines and begin a new adventure.

Some month ago, I received my first MFH kit, after I saw some pictures of the finished model and fell in love with the bike immediately. There she was, all the great ingredients of an American bike classic minus the to my eye ugly mid section, the classic Harley Davidson models have. 

I will not tell a lot about the history of the bike, as I´m not an expert here, but it´s a pretty exclusive one. Hand built, the numbers of production bikes range between 60 and 300. The few surviving beauties are among the highest priced motorcycles of today.
The Crocker was fast, so fast, that the company complied, to give back the full price of the bike, should the driver be overtaken by a Harley or Indian on a strait road.

The kit was bought from MFH in Japan directly for a decent price and the fastest and trouble free shipping, I ever had and reached after six days on my doorstep.



Since then, I bought some more MFH kits, as simply browsing through the boxes, the absolute top quality of the kits has an addictive spell over me. The kits are multi-media, most parts are from cast white metal, some photo etch, rubber parts, different hoses and wires, some chrome plated metal parts, nice decals, ...

I preparation for the build, I read a lot about MFH kits, to get a hold onto the many new adventures, I was expecting with the build and as one result, I invested into a magnetic tumbler polisher for cleaning the white metal parts. It took my month to finally obtain one to my remote place in the world, but finally, it arrived.



After some successful testing, all white metal parts were dumped into the tumbler´s bowl, then, I added water with a drop of detergent and 200 gram of 0,3 mm steel polishing needles. The strong magnet in the base swirls the needles around the non magnetic parts and `hammers´ the surfaces very gingerly. After about an hour of tumbling the water was dark black and the parts looked like this.

 

It was not so easy to remove the tinier parts from the needles and I keep all the bowls with needles and the blackened water until, I made sure, I picked all the parts out.
For now, I rinsed the parts with water again and layed them out onto kitchen paper to dry.







The finish of the tumbled parts is fantastic, but of course, further cleanup will be needed down the road. Some parts will get polished, as the white metal looks perfectly, like steel or even chrome when polished carefully.

Next step will be checking against a copy of the manual, if all parts are there. MFH manuals include only a rudimentary parts list, but on their homepage, they have pictures of the kits parts, which will be helpful for the task.

I will add a few detail pictures from some of the parts, to show the fantastic casting quality. The tumble polishing of the parts effect surface detail only minimal, details remained sharp.

 







Stay tuned for more.

Cheers Rob

[Egilman]

Gorgeous Kit, MFH has been at the top of the kit engineering world for a couple of years now, the only problem for me is the price... Ordering even one tends to deplete the bank account for quite a while....

 

I'm down for this, we seldom see the classic american stuff even scratchbuilt, to have someone actually producing kits... This has to be modeling heaven....

[gsdpic]

Thanks for doing this build log.  I've been curious about the MFH kits but never really looked into them, so will be interesting to see how it goes together.   I am tempted by some of their 1/12th scale F1 cars.

 

[DocRob]

13 hours ago, Egilman said:

Gorgeous Kit, MFH has been at the top of the kit engineering world for a couple of years now, the only problem for me is the price... Ordering even one tends to deplete the bank account for quite a while....

 

I'm down for this, we seldom see the classic american stuff even scratchbuilt, to have someone actually producing kits... This has to be modeling heaven....

Good to have you along, Egilman. I am absolutely no expert when it comes to classic American bikes, except, that I rode some, I borrowed from friends. 
The price tag is daunting, indeed, but you receive a lot of quality for it. I will see, how this build turns out, to figure out, how many of the MFH kits will find their way into my stash. So far it´s three and one in the mail.
Like you said, MFH can´t be praised enough for their portfolio of rare subjects produced as kits. You sure got the feeling, there is a lot of passion involved.

Cheers Rob

[DocRob]

13 hours ago, gsdpic said:

Thanks for doing this build log.  I've been curious about the MFH kits but never really looked into them, so will be interesting to see how it goes together.   I am tempted by some of their 1/12th scale F1 cars.

Same with me for a long time, Gary. I often looked for the MFH kits, watched build logs with fascination and then there was the Crocker, hitting all my buttons.
The F1 cars in large scale are really tempting. I had the luck two weeks ago, to lay my hand on one of the 200 limited Williams FW16 ´Senna ´Edition, which hopefully will arrive next week. They started to sell at 7:00 pm JST on the seventh of May and a quarter of an hour later, there was a message, all have been sold, so I´m overly happy to have scored one.

Cheers Rob

[yvesvidal]

Great kit and great subject. I will follow, if you don't mind.

 

Yves

[DocRob]

7 hours ago, yvesvidal said:

Great kit and great subject. I will follow, if you don't mind.

Good to have you along, Yves. I´m sure, sooner or later, I will have a lot of questions about how to work with this kind of kits, so be prepared .

Cheers Rob

[DocRob]

Today, I spent some exhausting hours to sort the parts, mainly the white metal cast ones, as they are the most numerous.

I made it a two step affair, first using the parts layout prints from the MFH homepage, to check if everything is there. These photos of the parts are especially helpful, as they are scaled and this helps to identify the parts.

In the second step, I sorted the parts into a plastic box with different sized trays, ordered after the steps in the manual. The tiny parts, like screws and bolts, I left out, as they are easier identified separately. Tomorrow, I will add resin and rubber parts along with screws, nuts and bolts.
 

 

 

Cheers Rob

[Canute]

This reminds me of a TV show I used to watch, Orange County Choppers. They did custom build theme bikes. I'll be following along, too, Rob.

[DocRob]

3 hours ago, Canute said:

This reminds me of a TV show I used to watch, Orange County Choppers. They did custom build theme bikes. I'll be following along, too, Rob.

Well, I´m not much into the chopper thing, Ken. Personally, I prefer European bikes for European roads, they just perform better. My last one was a KTM 950 SM, the last one with carburetors. This thing drove like a sharp blade, but with the handling of a bicycle. Perfect for ultra fast city commuting, alpine roads, just everything below 200 km/h, because there was no windshield. Even week trips were no problem with the furious KTM. I loved that beast, but left it in Berlin, when I went to my island and promised my wife not to drive motorcycles anymore. Well, now it´s mountainbiking .
 

Cheers Rob

[DocRob]

Well, first building steps are prepared. Note to myself, test fit often and understand the manual, specially where parts need to be drilled. I don´t know about the MFH car kits, but with the Crocker engine parts there are dozens of holes to be drilled and some are hard to reach in later stages.

The foot pedal and drill stand for my Proxxon mini drill help a lot to make the job faster. The good thing with drilling white metal, there is nearly no burr to be removed.

The engine block, with one cylinder mostly mounted, showing the parts of the other:



Mock assembly for test fitting of one cylinder. The ribs and heads are actually removed and primed and will be sprayed semi matte black later.





Cheers Rob

[CDW]

I love your choice of subject here, a MFH kit in particular. I've had my eye on that same tumbler for a while now but never decided to purchase it. Your show of how well it works has helped me clearly see its value. Trying to clean up all those tiny parts by hand would be a monstrous task. I first got the idea of the tumbler by watching a fellow who builds MFH kits on YouTube. He suggested it in his builds. 

What will you use as a cement for the metal parts of the kit?

 

PS: one other question about that tumbler...how long does it take for the parts to clean up?

Edited May 24 by CDW

[DocRob]

The engine is on it´s way and it is a bit fiddly, but due to great engineering and tight tolerances manageable. Adding all the V-shaped cylinder parts proved tricky, when the rocker came into play and the connecting tube (carburetor) needed to be added at the same time. Unfortunately, I mis-orientated this part and had to pry it loose later, which was no fun at all and caused some spots for later touch ups.





Cheers Rob

[DocRob]

4 hours ago, CDW said:

I love your choice of subject here, a MFH kit in particular. I've had my eye on that same tumbler for a while now but never decided to purchase it. Your show of how well it works has helped me clearly see its value. Trying to clean up all those tiny parts by hand would be a monstrous task. I first got the idea of the tumbler by watching a fellow who builds MFH kits on YouTube. He suggested it in his builds. 

What will you use as a cement for the metal parts of the kit?

 

PS: one other question about that tumbler...how long does it take for the parts to clean up?

Thank you Craig, the tumbler indeed helped a lot, specially for a kit like the Crocker, where many parts will be left without painting or even be polished later for a realistic chrome effect. 
You can toy a bit with the diameter of the steel pins, I bought some with 0,6mm and 0,3 mm diameter and used 200 gram of the latter. The tumbling process needs to be supervised. I tumbled about an hour, but you have to find a balance, between nice surfaces as a result and not losing sharpness in tiny details like boltheads on the other side.
I recommend wearing rubber gloves, while handling the parts after tumbling, you will be astonished, how black the water will be, and I guess, it´s not too healthy either.
I also got the magnetic tumbler suggestion through videos and build logs too.

Cheers Rob

[Canute]

What is the media used in the tumbler. I have an ultrasonic cleaner and a tumbler I use for cleaning cartridge brasses. The ultrasonic uses several liquids depending on the task. The media tumbler uses a variety of cleaning/polishing media, like corncobs and walnut hulls.

[DocRob]

3 hours ago, Canute said:

What is the media used in the tumbler. I have an ultrasonic cleaner and a tumbler I use for cleaning cartridge brasses. The ultrasonic uses several liquids depending on the task. The media tumbler uses a variety of cleaning/polishing media, like corncobs and walnut hulls.

I use only the 0,3 mm steel pins, water and a drop of detergent. There are polishing fluids around, but I haven´t tested these. The non magnetic white metal parts are relatively unmoved in the magnetic tumbler, which helps avoiding scratches due to impact of the parts. Only the steel pins swirl around and do their polishing job.
I tried a simple rotating tumbler as well, filled with water and tiny steel balls. The surfaces were shinier with that treatment, but you loose sharpness of details and the steel balls don´t reach in all the tiny crevices.

Cheers Rob

[CDW]

1 hour ago, DocRob said:

I use only the 0,3 mm steel pins, water and a drop of detergent. There are polishing fluids around, but I haven´t tested these. The non magnetic white metal parts are relatively unmoved in the magnetic tumbler, which helps avoiding scratches due to impact of the parts. Only the steel pins swirl around and do their polishing job.
I tried a simple rotating tumbler as well, filled with water and tiny steel balls. The surfaces were shinier with that treatment, but you loose sharpness of details and the steel balls don´t reach in all the tiny crevices.

Cheers Rob

Did the tumbler come with two sizes of pins, or are those purchased separately? In the ads I've seen for the unit, did not see the options for pin size selection/purchase. it simply says it comes with pins, not stating size.

[DocRob]

1 hour ago, CDW said:

Did the tumbler come with two sizes of pins, or are those purchased separately? In the ads I've seen for the unit, did not see the options for pin size selection/purchase. it simply says it comes with pins, not stating size.

Exactly Craig, most of the polishing tumblers include a bag of non specified steel pins. Mine, the only one which could be shipped to my place after a lot of effort included none and  had to purchase them separately.

Cheers Rob

[DocRob]

I added more details to the engine and also prepared the distributor. Drilling the tiny oil tube connectors proved tricky. They need to be drilled to accept the oil tubing made from solder wire.
Most of the screws shown on the casings are separate parts and also need to be pre drilled and then inserted. The manual suggests to add the oil tubes next, but I will do it later, because handling the still not finished engine would be a nightmare with the soft wiring on. Luckily the places for the tubing should be reachable later.
I also added some dots of black panel wash here and there to enhance contrasts.




 

Cheers Rob

[DocRob]

The last building sequence was a bit fiddly, with wiring the spark plugs with tiny etched parts and micro rivets, followed by the distributor, which consists of about 20 parts, a lot need to be pre drilled for various installments. There are two variants and I chose the more complicated. The magneto has a fewer parts count, but looks odd and the pictures I have of the real bike always have the distributor installed. I prepared the wires, but add them later, when the engine meets the frame.

 



And that´s how tiny the distributor is, you find it on the left side of the engine, lower middle.



Cheers Rob

[DocRob]

I built up the frame from it´s various parts, which again included lots of drilling and leafing through the manual, to see, which diameter is needed for a hole and what´s going in. Luckily the precision of the casting is fantastic and there are only minimal irritations in the parts.

Here is a mock up with the engine mounted into the frame. Meanwhile said frame is primed and the missing carburetor parts got airbrushed.





Cheers Rob

[DocRob]

After airbrushing the frame with Tamiya LP-1 gloss black, I continued with the engine. I added the carburetor and some fuel lines, which are hard to reach later. The engine is more or less finished now and will be mounted into the frame next.


 

Cheers Rob

Edited May 31 by DocRob

[DocRob]

I have one question for the classic bike experts. Which function has the marked wire, which leads from the distributor to the area of the tank. The other two are the ignition wires, but the third cable, I have no idea of the function. The MFH manual doesn´t show either. The cable just ends under/in the tank area.



Cheers Rob

[CDW]

45 minutes ago, DocRob said:

I have one question for the classic bike experts. Which function has the marked wire, which leads from the distributor to the area of the tank. The other two are the ignition wires, but the third cable, I have no idea of the function. The MFH manual doesn´t show either. The cable just ends under/in the tank area.



Cheers Rob

I am not familiar with this particular motorcycle, but I suspect this may be part of the spark advance/retard mechanism as the old bikes used mechanical means to perform this function. On old Harley Davidson bikes, the left hand grip twisted one direction for retard and the opposite for advance.

[DocRob]

Thank you Craig, 

I think, the wire you refer to is shown in the manual in green It ends at the handlebar. The yellow one with the section 7 reference on the lower pic is the one in question, it´s the same like the yellow one in the upper drawing, labeled section 4.

 

Cheers Rob

[CDW]

Maybe the wire 7 lead to the coil under the tank and out of view?

Does the bike have a battery?

Edited May 31 by CDW

[DocRob]

27 minutes ago, CDW said:

Maybe the wire 7 lead to the coil under the tank and out of view?

Does the bike have a battery?

That´s a possibility Craig and yes the Crocker has a battery.

Cheers Rob

[CDW]

If there is a distributor there must be a coil and a coil wire to the distributor.

[Egilman]

It's a Crocker 60cc engine, late model, it carried a point/condenser ignition, the center wire is a coil wire.... The coils of that era were usually a box mounted somewhere on the frame usually above the spark plugs....

 

Up under the wings of the gas tank was a common spot... 

 

And yes the Crocker had a mechanical spark advance on the magneto mounted engines... It was controlled by the left handgrip and needed constant adjustment, ie. there was no "zero" point you kick started it in full retard and adjusted it on the fly... It took some skill to ride a Crocker... But they were the fastest thing on two wheels of that era...

 

Crocker had an open offer to pay anyone that was beat by a Harley or Indian on the race track, he never had to make any payments to anyone....

Edited May 31 by Egilman

[CDW]

22 minutes ago, Egilman said:

It's a Crocker 60cc engine, it carried a point/condenser ignition, the center wire is a coil wire....

You do mean 600cc, I'm guessing? 60cc is minibike size displacement.