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Discussion Starter #1
Background – some time ago I posted this build, in progressions, on another board. I was recently asked if I could post it here in the customs. No problem....

However, I don’t have time to rewrite it and so intend to more or less duplicate what I posted on the other board, editing as required. It’s important to understand that I had a lot of help, suggestions and knowledge contributed from other members along the way. I’m grateful for their contributions and will try to note many of them as I go.


Hi all,

I've been messing around with this for the last few weeks in my spare time. It's very closely based on John Peckham's excellent guide at the HOMTPA site, found here http://slotcar64.freeyellow.com/mt_ctc1.html

I first saw this guide a long while ago and recent mention of it on another board renewed my interest. Prior to starting I have never attempted anything even remotely like this but I have done quite a bit of electronics/electrical soldering. Brass is an entirely new game and offers an extremely enjoyable learning curve.

I've found my Weller 25W iron only just capable of the job and think a 40W iron may be a better choice. Having said that, I'm still developing my technique with brass and as it improves, my 25W iron might be adequate. Remains to be seen..........

The body comes courtesy of a Matchbox (I think?) Chevy Silverado and sits so firmly over the upper chassis that I doubt any additional fixing will be required. The motor is also a perfectly snug fit between the upper rails - a combination of luck and management. Wheels and tyres come courtesy of some toy that came with one of those crappy fast food meals. The tyres are very hard rubber and will do until I find something better.

The pick-up assembly is what will really make or beak the build I suspect. I'm working on a few ideas in conjunction with the plans I have. I'll say here and now that I think it's one thing to get this puppy working ok on the bench, but another all together on the track. If I can get this working even "just ok" on the track I'll be deeply satisfied.

Following are some shots of the very basic chassis frame. I've since made progress on the drive shaft/gear section and will get some photos up soon.

Any and all thoughts and suggestions are welcome. Thanks for looking.

Cheers,
Michael. :thumbsup:







 

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Discussion Starter #7
Hi all. Thank you for the positive comments and feedback. I do hope that this inspires a few people to have a go at a build of some description. That is after all why we post builds and show 'em off a bit. All I can say is grab a few lengths of brass, dust off the old iron and have a go. Following is the second section of progress.

Enjoy,
Michael.
:thumbsup:

I made email contact with John to thank him for the plans/guide. He seems like a pretty good guy and he did stress that it is a guide only. I've followed it pretty closely so far but have made several changes due to materials at hand, tools available etc etc.

Regarding the power of the iron, I can see myself investing in a 40W iron if I do more of this sort of thing. My solder is electrical 60/40, 5 core rosin at .71mm/.028". About half way into my current progress I grabbed some "Baker's" Soldering Fluid. It's zinc chloride acid flux. To be totally honest I found it made no difference at all. Perhaps it's not the right stuff for the job but it's what I was advised to use. Either way, I stopped using it just to save the clean up. The rosin core works for me. Have since been told that rosin core and acid flux don’t work well together.

So........further progress includes the drive shaft and gears. I used additional wire for extra bracing to the drive shaft as I found the method in the guide enabled a little flex in the drive line. This caused some binding with the gears but the extra wire solved that. Having lapped the gears for about an hour I have toothpaste sprayed all over my workbench but the drive line is beautifully smooth. I'm really happy with how this part came out.







BTW, I was having a lot of trouble getting clean, square cuts on smaller parts so made this "slide table" for my rotary tool. Basically the upper table slides to/away from you via a groove in the lower board and shelf support pins fixed in the upper board. It works well but over a long time I can see the grooves wearing so may install an aluminium guide channel at some stage. Note - the side to side groove is not used. Hope this helps someone.





 

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LED Burner Outer
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I've been wanting to try this for a long time, but never got the brass or 4X4 wheels/tires I needed to do it. I'm liking what you got so far!!! :thumbsup::thumbsup:
 

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Robot Elder
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Michael..
Having built many of these,, one thing to help make em work ,, THEY LOVE OIL! do not be afraid to lay it on em..
Continue to follow Johns directions and you will have hours of fun running your MT..

I built a jig out of brass for my chassis when I built em.. If you contact John he might be able to hook you up with some pics of the one he uses.. really a great tool.. and adjustable while still keeping the chassis and down tubes all square to the chassis.
:thumbsup:CJ
 

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Discussion Starter #15
Hi guys,

CJ, testing so far confirms what you said about them with the oil. Lots of it brings out the best in the drive line. I also use silicone grease on the gears as I find it's less prone to being thrown off the gears.

Thanks for the comments. Any further thoughts, comments or suggestions are more than welcome.

Following is the next section of progress, hope it helps someone.

Cheers,
Michael.
:thumbsup:



The motor is a Tomy turbo. The guide I'm using recommends against them but only because they are hard/impossible(?) to solder to. For mine I have soldered brass wire retainers over the motor to hold it in place. The bottom of the can sits hard on the outer drive shaft case and the gears mesh perfectly. That part was complete luck. This photo shows what I did and has an example retainer in the background.



The worm gear is simply soldered to the drive shaft. I messed up a couple of bolts trying to get the hole centred and straight. Using a drill press I put the bolt thread first in the chuck and then centred a stationary drill bit in a press vice below it. I just found this http://vik-olliver.blogspot.com.au/2...wn-middle.html. It's essentially the same but gives a much better method of getting it all centred. Wish I had seen it a couple of weeks back.

This pic shows how well a 1/4" 20-threads-per-inch bolt marries up with an AFX idler gear. Perfect!



Here is a pic of the axle assemblies removed. Hope it explains the set up a little better. The two separate stub axle housings at the rear will be used to support the pick up assembly.



Ok, what next...........
Here are the main components for the pick up system. I taped the shoe strips together to help achieve the same bends in each one. That seemed to work pretty well.



Following, the pick up assembly is pretty well done but I'm sure will require tweaking and adjusting. The shoe on the right (first picture) is isolated from the rest of the assembly by heat shrink tubing and will feed the +ve side of the motor via the red wire. The rest of the brass will carry the -ve to the chassis and then to the motor. The guide I'm using is open to interpretation about how this system works and I've set mine up quite differently to John's. The "shoe plate extension pin" sits freely in the pick up arm and is prevented from sliding out by both +ve wire and the forward momentum of the car. This enables the shoe plate to swivel and I suspect that this is critical to it's operation. If this bad boy is climbing all over cars it will also be swaying side to side radically. If the pick up plate were rigid I'd lose electrical contact each time the car sways. Anyway, that's my theory and I'm sticking to it. When this makes it to the track it may be a very different story........



 

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Robot Elder
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Michael..
One huge problem you will find with the motor choice.. The MT , will run hot.. and those wiper brushes won't live long.. Hence the Guide suggestion on the Tyco/Mabuchi can motor with removable brushes.. you can replace them easier than the whole can or endbell. as needed..

CJ
 

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Model Murdering
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Thanx for dropping into the customizing forum Jisp! ;)

Your scratchbuilt 4x4 project is very inspiring as it shows that small miracles can be created from very little. Just takes determination and a lot of craftsmanship. I especially enjoy the detailed high quality photo work and the play by play narrative. :thumbsup:
 
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