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  #121  
Old 09-06-2013, 09:47 PM
Frederik Frederik is offline
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I might try to do something with these wheels... not sure yet if they just stick out too much or not..

meanwhile here is a nice vid for you escort fans hopefully I get the video embedded correctly in the post...

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  #122  
Old 09-06-2013, 11:41 PM
Frederik Frederik is offline
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I have tried the 31mm wide tires on these 6mm offset wheels. And that makes me want to try harder to fit them on the car lol now that is some meaty rubber! would have to make custom wider rims with them to take the 31mm tires. It looks like the size of the video I just posted.. In this pic, they are on the rims only on the outer edge (rims are too narrow) but it gives an idea:







If I play a bit with the height of the roll center (lowering the mounting point of the watt's linkage on the axle) the wheels will tuck in more when the body leans... But I still need some clearance when the suspension compresses straight, without leaning....

Last edited by Frederik : 12-26-2018 at 06:49 PM.
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  #123  
Old 09-10-2013, 10:53 PM
Frederik Frederik is offline
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Small update, the jun fac drive shaft was not long enough to mount the motor as much forward as I wanted, so I found a solid shaft of appropriate size (it is from an rc plane starter motor) and machined the center out at the correct size to almost fit around the drive shaft smaller diameter D shaped shaft.

Then I cut the driveshaft small D shaped drive shaft half in two:




And I machined the small D part just a bit so it fits into the new tube extention. I then put the other cut half at the other end, hammer and punch them on, and here is the new 1.5 inch longer half shaft!




New complete drive shaft, hopefully it wont wobble too much from the extra lenght:



I have also made a cardboard model of the front frame, it will be the struts towers and motor mount at the same time. It is all one piece, just cut and fold at places, so I dont have too much soldering when I do it in steel. These picture are an approximation of the full droop of the suspension (fully extended). I will make it so the fully compressed state uses all available fender space, so as to maximize usable suspension travel.







Fred

Last edited by Frederik : 12-26-2018 at 06:51 PM. Reason: Typos
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  #124  
Old 09-11-2013, 09:43 AM
Trini2DBone Trini2DBone is offline
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Nice work on the drive shaft Fred ! Starting to come together now!
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  #125  
Old 09-11-2013, 03:51 PM
Frederik Frederik is offline
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Thanks Preston! I do like how the drive shaft turned out.

I was about to work on the rear upper chassis wih tubing to hold the shocks, but I think whatever frame that will be in the rear will need to mate with the front, so I prefer doing some of the front first because it is more complex, so I have something to construct on when I do the rear. It will be easier to adapt the rear to the front than the other way around.
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  #126  
Old 09-11-2013, 09:15 PM
Frederik Frederik is offline
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Couple pics to show better the cardboard structure. Empty beer boxes for modeling FTW

I now feel the engine and tranny sits a bit too high in these pics. I have originally put the motor at this height because it causes almost no sliding of the telescopic driveshaft with suspension travel (the junfac driveshafts binds and kind of stick instead of free sliding). But having the motor lower will look closer to an actual car's engine and driveshaft placement IMO.




Fred

Last edited by Frederik : 12-26-2018 at 06:52 PM.
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  #127  
Old 09-13-2013, 11:10 AM
Frederik Frederik is offline
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Ok I have a question for you guys, I have not experienced a lot with electric motors in RCs and I would appreciate your input. Given my transmission layout and how I mounted the axle, I end up with a reverse rotation of the motor to get a forward movement of the car.

I plan to use the Tamiya Sport Tuned motor (the one in the pictures) but it has that big arrow saying the proper rotation direction. I was thinking the timing adjustment of the tuned motor for forward rotation must have even more importance than say a regular 540 motor ? Will I lose all the benefits of the tuned motor ?

I know I would have the correct rotation by simply flipping the axle upside down but it is not symmetrical (top and bottom) and I will be running into clearance issues, not to mention having to re-engineer everything

Thanks!
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  #128  
Old 09-13-2013, 11:22 AM
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klampykixx klampykixx is offline
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Yep running motor in reverse will end up with negative timing and much reduced power. Is the gearbox output on one side only? Its an aeroplane gearbox yeh?
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  #129  
Old 09-13-2013, 11:30 AM
Frederik Frederik is offline
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Thanks for the information regarding the motor running backwards. Yes it is an airplaine reduction gearbox. IIRC the gearbox can only output from one side, I'll have to check if the shaft can be put the other way around and go out from towards (under) the motor, but from the pictures, it looks like the motor would be in the way of the output shaft.

Is this what you mean by output to one side only?

Last edited by Frederik : 09-13-2013 at 08:10 PM.
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  #130  
Old 09-13-2013, 11:56 AM
Trini2DBone Trini2DBone is offline
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Don't think you will be able to turn the tranny around...the shaft isn't going to clear the motor enough to get the coupling on. This truly sucks! But we have faith in your engineering magic! Just need to stare at it really hard and it will come! Lol that's what I do anyway!

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  #131  
Old 09-13-2013, 12:03 PM
Trini2DBone Trini2DBone is offline
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Maybe a transfer case between the tranny and the drive shaft?
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  #132  
Old 09-13-2013, 12:24 PM
Frederik Frederik is offline
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Quote:
Originally Posted by Trini2DBone View Post
Maybe a transfer case between the tranny and the drive shaft?
mmmm.. yeah might as well make a custom 3 gear reduction box, in the same design as the GD-600 gearbox i.e. the gears sandwitched between two plates...

I'll have a second look at swapping my axle upside down, but I think the reason I made it that way was because there was more room up on the axle where the frame would sit on the axle, so the axle can compress further towards chassis. If I flip it, it will hit the chassis sooner. And also my watt's linkage is slightly off center vertically so it would probably be too close to the ground.

I'll try staring at it harder tonight and see what ideas seem to pop up
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  #133  
Old 09-13-2013, 12:26 PM
Trini2DBone Trini2DBone is offline
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Can't wait!

Lol!
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  #134  
Old 09-13-2013, 12:48 PM
Trini2DBone Trini2DBone is offline
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http://www.ebay.com/itm/transfer-cas...item232e6da247

Maybe something like this?
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  #135  
Old 09-13-2013, 05:14 PM
Frederik Frederik is offline
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Thanks for the ideas Preston! That would be neat. At the same time it would bring the driveshaft down a bit, if I install the transfer case vertically.

Any idea what off the shelf piece I could use to mate the gearbox output shaft with the transfer case input, to make it as short as possible? I'd like to keep the transfer case close to the gearbox so it kind of looks like an actual tranny, proportion-wise.
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