R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 11-01-2012, 12:29 AM   #106
Tech Elite
 
RCknight's Avatar
 
Join Date: Nov 2004
Posts: 2,273
Trader Rating: 5 (100%+)
Default

I see, well, I hope someone comes up with a design that would allow easier spur gear removal. There must be a way to design it to keep the lightest drive train and yet sill change out spurs quickly if needed. It seems silly.

Quote:
Originally Posted by silvalis View Post
Just checked the pdf manual again, I think you're thinking of the sakura.

The 411 has the two bearing holders held by screws onto the spur bulkhead. You can undo these and slide the holder off and the bearing will usually come with it. The spur has a tube that extends into the bearing. If you pull the bearing holders off, the topdeck still traps the whole spur assembly into the U of the spur bulkhead.

When I had mine, I was under the impression that the idea was to be able to undo the topdeck->spur bulkhead screws for more flex without compromising the spur clamping.

The sakura has a screw holding the bearing onto the spur tube. From what I recall the tube slides out of the spur holder/clamp. Pull these through and the spur assembly is free. (Sort of. You still have to deal with the belts)



What's wrong with the bumper and the steering rack? Plastic?
RCknight is offline   Reply With Quote
Old 11-01-2012, 12:33 AM   #107
Tech Elite
 
RCknight's Avatar
 
Join Date: Nov 2004
Posts: 2,273
Trader Rating: 5 (100%+)
Default

I totally agree and at this point all I want to see are refinements.

Quote:
Originally Posted by andrewdoherty View Post
I am happy we're where we are in car design. I think one of the things we need right now is more stability. I can appreciate that new designs are cool looking, and I know advancements wait for no one, but I wouldn't mind seeing us stick with the same motors and battery design for another 5 years. If that means all the cars look the same in the mean time, I figure its a small price to pay for stability that I think will bring more people into racing.
RCknight is offline   Reply With Quote
Old 11-01-2012, 12:51 AM   #108
Tech Elite
 
RCknight's Avatar
 
Join Date: Nov 2004
Posts: 2,273
Trader Rating: 5 (100%+)
Default

The TC6, BD7, T4 are using a separate motor mount. I wonder if you could design a slider style motor mount now so that you could move the motor forward and backwards. I read on the Xray forums where Martin has hinted about creating an optional one that's very adjustable so I'm looking forward to what they have created.
RCknight is offline   Reply With Quote
Old 11-01-2012, 02:13 AM   #109
Tech Addict
 
Luke Hobson's Avatar
 
Join Date: Jul 2005
Location: newark, nottinghamshire, UK
Posts: 526
Send a message via MSN to Luke Hobson
Default

You already can to a certain extent.... Run different pinion/spur combos...
__________________
Luke Hobson
Awesomatix - Xenon - Godzilla Paint - Moorespeed - ToniSport - MBmodels

http://luke-hobson.blogspot.com/
Luke Hobson is offline   Reply With Quote
Old 11-01-2012, 03:04 AM   #110
Tech Champion
 
tc3team's Avatar
 
Join Date: Mar 2006
Location: UK
Posts: 6,151
Default

Is it just me, or do Tamiya cars suffer from a higher wear rate than other brands?

One example are the driveshaft blades, when you look at the thickness of them compared to xray, wow big difference in size and construction.

I really like Tamiya cars, but imo durability is one of their weak points. I wish they would improve in that area.
__________________
Fusion Hobbies / www.horshamrc.org

The wife stops me being sane and the r/c stops me from going insane....
tc3team is offline   Reply With Quote
Old 11-01-2012, 05:38 AM   #111
Tech Initiate
 
Join Date: Nov 2011
Location: Iceland
Posts: 25
Default

Quote:
Originally Posted by RCknight View Post
I see, well, I hope someone comes up with a design that would allow easier spur gear removal. There must be a way to design it to keep the lightest drive train and yet sill change out spurs quickly if needed. It seems silly.
I think most drivers remove their top deck much more often than they change spur gear so I don't really see this as a problem.
halldor is offline   Reply With Quote
Old 11-01-2012, 06:25 AM   #112
Tech Elite
 
EDWARD2003's Avatar
 
Join Date: Jan 2003
Location: Tokyo, Japan
Posts: 2,004
Trader Rating: 6 (100%+)
Default

Okay, this might sound a little crazy but here it goes. Please feel free to add any comments.

I was thinking it would be interesting to have the drive train run in a horizontal plane rather than a vertical plane. Some how position the gear differential so the pulley is running horizontal to the chassis, this could result it lowering bulkheads and overall CG considerably. If I have time I would draw it up and show you. For now, I will explain it best as I can, the main idea would be taking a gear differential and flipping vertical and redesign the bottom side of the gear differential to have the axle outputs coming out the bottom. The bottom half would not move of course, but the pulley would be spinning.This would take some extra gears and some extra engineering to have it work.

Since now the transmission is running on a horizontal plane you can now place the motor (in between the belt) dead centre of the chassis. This would in turn I think eliminate any torque steer issues. You may ask how are you going to mate the spur gear and motor pinion. Well instead of having the conventional method of running the teeth on the outside, why not the inside. This would centralize the motor and spur gear mount in the centre of the chassis. For weight related reasons, the spur gear mount will move while the motor mount is fixed to the chassis. Also, there would be different motor mount locations along the centre of the chassis to move the motor fore and aft along with the spur gear mount.

I still need to think of how to connect the drive train from the spur-lay-shaft-belt. I was thinking using something similar to the KX-1 or the XXX-S. Any suggestions would be great.

Now the battery would be allocated in the centre as well, now since lipos are getting smaller and narrower. You might be able fit the lipo inside the belts given the lipos width.

Also, the servo will be positioned in the centre as well, it would be mounted exactly to what the F1's are running. Using a low profile servo but flipped upside down so the servo saver is close to the lower chassis deck.

I know this is off topic, but I thought I would dish out some of my ideas that I came up with while I was out for a run.
EDWARD2003 is offline   Reply With Quote
Old 11-01-2012, 06:37 AM   #113
Tech Elite
 
EDWARD2003's Avatar
 
Join Date: Jan 2003
Location: Tokyo, Japan
Posts: 2,004
Trader Rating: 6 (100%+)
Default

This is a very rough picture of the layout. You can move the electronics to achieve balance needed for certain track conditions.

You can even move the speed control and receiver to the back and move the battery close to the servo and have the more right in the middle of the chassis.

Options galore!
Attached Files
File Type: doc Edward's Chassis Design..doc (12.0 KB, 212 views)

Last edited by EDWARD2003; 11-01-2012 at 07:13 AM.
EDWARD2003 is offline   Reply With Quote
Old 11-01-2012, 07:50 AM   #114
Tech Elite
 
niznai's Avatar
 
Join Date: Feb 2009
Location: All over the place
Posts: 2,940
Default

I don't think your idea is off topic. On the contrary, I thought that was the intended topic rather than another never ending discussion about how current designs are all alike and such. i am interested in what I would like to see happening, maybe manufacturers will find some inspiration here and come up with some idea or maybe will borrow one.

Personally, seeing how real cars (electric) evolve towards having individual motors for each wheel, I think that is where we'll end up in R/C as well, but that might be some way off. Once there, it all becomes an electronics' game. No more moving parts, driveshafts, diffs, gears, etc. Completely new game.
__________________
Team Greasy Weasel

The best upgrade to any car is some driver skill.
niznai is offline   Reply With Quote
Old 11-01-2012, 09:17 AM   #115
Tech Elite
 
EDWARD2003's Avatar
 
Join Date: Jan 2003
Location: Tokyo, Japan
Posts: 2,004
Trader Rating: 6 (100%+)
Default

Also, I have another idea where its possible to run a shaft drive system down the centre the the car all the whole keeping the electronics in the centre. This would require the shaft to be smaller diameter but tapering to a larger diameter when reaching the differentials. Ill explain it later.
EDWARD2003 is offline   Reply With Quote
Old 11-01-2012, 09:28 AM   #116
Tech Addict
 
Lessen's Avatar
 
Join Date: Jan 2008
Location: Aurora, OH
Posts: 594
Trader Rating: 2 (100%+)
Send a message via MSN to Lessen
Default

The first thing that comes to mind about horizontally position diffs is the gyroscopic effect that may be produced. Would this possibly over-stabilize the car making it lazy? Just hypothesizing.
__________________
"Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. "
Lessen is offline   Reply With Quote
Old 11-01-2012, 09:31 AM   #117
Tech Elite
 
jlfx car audio's Avatar
 
Join Date: Nov 2007
Location: jackson,tn
Posts: 3,365
Trader Rating: 36 (100%+)
Default

I'm thinking ur design will be overly complex to work in a 1/10th scale platform. I could see moving servo and steering components in front of wheels . Maby moving battery and motor inline even this design is in line with the losi and E4 design , which r very stiff chassis designs and depend on the suspention to do all the work, which makes for a very narrow set up window to work its best
__________________
Justin & Matt Lyons
Awesomatix USA, EA motorsports, Sanwa, Protoform, Avid, Gravity Rc , TSR!
a800s sanwa m12s
jlfx car audio is offline   Reply With Quote
Old 11-01-2012, 12:45 PM   #118
Tech Master
 
IndyRC_Racer's Avatar
 
Join Date: Jul 2006
Location: Indianapolis
Posts: 1,820
Trader Rating: 9 (100%+)
Default

Challenge with the horizontal belt design is the same problem with a shaft drive. The diffs will have to be installed opposite of each other in front/back in order to have front/rear wheels turning in the same direction. You may also have to have some type of bevel gear in the gearbox to make it work.

Still, nice thinking outside of the box.
__________________
I'm currently racing VTA. Check here for rules/info: http://www.usvintagetransam.com/
IndyRC_Racer is offline   Reply With Quote
Old 11-01-2012, 03:34 PM   #119
Tech Lord
 
wingracer's Avatar
 
Join Date: Nov 2007
Posts: 12,861
Trader Rating: 24 (100%+)
Default

Anything spinning horizontally will induce a yaw moment on acceleration and braking. Unless they counter-rotate. Just like conventional layouts induce pitch moments. That's how offroad racers control the pitch of the vehicle with airborne stabs of throttle or brake.
__________________
Sean. Certified speed crazed mowron.
Team Shepherd USA
www.ashfordhobby.com
wingracer is offline   Reply With Quote
Old 11-02-2012, 07:41 AM   #120
Tech Elite
 
EDWARD2003's Avatar
 
Join Date: Jan 2003
Location: Tokyo, Japan
Posts: 2,004
Trader Rating: 6 (100%+)
Default

Thanks for all your comments guys.

Here is my second idea with a similar layout using shaft drive.

1. The shaft drive unit will be fairly unique and would make the design possible... I hope... Now, the shaft drive will be comprised of two different diameters. The smallest diameter would be around 3.5-4.0 mm. (See the wordfile drawing provided). Areas of the drive line that will be under load, such as spur gear drive and the differential inputs will taper to a large diameter. This can be up to 7.0-8.0 mm in diameter. Remember these are just rough numbers.The drive gear on the drive shaft would be 32 pitch 10-12 tooth for durability reasons. I think the drive shaft will be made from steel for durability reasons or titanium.

2. The motor will be dead centre of the chassis. The spur gear will have a unique 64 pitch 80 tooth inside and a 32 pitch ????tooth outer. The spur gear mount will not move. In order to adjust the gear ratio, you will adjust one screw that will raise and lower the motor mount. However, you can select several different spur gears to accommodate for any large gear ratio changes that might raise the motor too high. The motor mount will be separate to the spur gear mount/drive shaft connection. Maybe it would be good to use a clamp style motor mount to move the motor slightly fore and aft like the Mi4.

The drive shaft will be supported by 4 small bearing supports. The bottom chassis plate will be 3 mm thick and have a groove CNC'd down the centre to keep the drive shaft low as possible. Not to sure how much this will affect the integrity of the chassis. Say, 1.5 mm deep?? This will lower the shaft a little and will help keep the motor low. There will also be cutouts in the chassis to accommodate for the large diameter sections (32 pitch drive and differential inputs). I think these cutouts will help give the tapered sections of the drive shaft a little more room to breath. Now, the input shafts will be entering at the bottom of half of the drive ring. Do you think its to run the drive gear at the lower portion of the drive ring?

The electronics... The lipo will be a shorty pack with a modified hard case. The case will have a small channelled groove down its centre. This will help clear the drive shaft. However, I was thinking that there would be an aluminum channel running over top the drive shaft and would act as a lipo locator. The battery would not slide from side to side, and all you would have to do is tape it down to prevent it from sliding forward and back. Speedcontrol and receiver will be situated on either side of the drive shaft. The low profile servo will be slightly elevated above the drive shaft similar to an F1.

Any comments would be great! I love coming up with these wild ideas. Any questions about anything, let me know. This is all creative fun!


* Note in the drawing I have the spur and pinion colour coded 64 red and 32 blue. The 9 tooth is related to the drive shaft, but I've omitted this for a slightly larger 32 pitch 10 -12 tooth on the drive line shaft.
Attached Files
File Type: doc Edward's Chassis Design 3.doc (28.0 KB, 129 views)

Last edited by EDWARD2003; 11-02-2012 at 07:59 AM.
EDWARD2003 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
T.R.C.R. ---Pit's Talk--- teambighead Northwest Racers 25141 12-03-2017 10:06 AM
UK Race Talk TryHard Racing Forum 9876 12-05-2010 11:46 AM
NEW TC design....have a look at this! wingman2 Electric On-Road 15 04-16-2009 10:18 AM
HK Talk Version 1.1 fai Hong Kong Racing 18317 05-13-2007 08:22 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:37 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net