R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 02-11-2008, 03:41 AM   #1891
Moderator
 
Pro ten Holland's Avatar
 
Join Date: May 2003
Location: Druten/Holland (Europe)
Posts: 1,677
Trader Rating: 1 (100%+)
Default

Now that would definetively be interesting!
Pro ten Holland is offline   Reply With Quote
Old 02-11-2008, 05:20 PM   #1892
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

No challenges here. I did offer to ship that puppy over there. Just reporting on what seems to work on my track.

Here are a couple of pics of that Short KO servo. I like the package quite a bit better than the Futaba S9154 aileron servo pictured earlier. It has a steel output shaft and metal gears so it should be durable. I am using it to make clearance for this overly long LiPo battery. They may end up running 4 cell on the outdoor oval which limits me to antique NiMH. I pretty much hate these NiMH batteries in August heat. They come off the charger at about 140F. No delta peak is small enough. Then they heat up during a run and puke some electrolyte. A lot of NiMH troubles are caused when this electrolyte solidifies and blocks the output valve under the positive end of the battery. Fortunately the stock motor they might choose will be a little easier on the battery during the run than the 3.5s I have been running.

Optional Front End Parts
Some parts that have been added to the front end.
Associated TiN coated 1.5 inch x 1/8 inch hinge pins for king pins. This lets me run an inverted pivot ball on top and keeps the E clips from limiting movement.
.080 plastic spacers from MurdockRC. These spacers are narrow and allow freer movement of the suspension.
Murdock RC metal spacers, .010 and .020
Murdock RC teflon Coated Pivot balls on the front end.
Murdock long cylindrical springs. I need to order more of these.
Thin Blue Spring Buckets. Gives more clearance on the wheel at the bottom.

Cut on the eyelets and steering block for free motion without the spring. Link back in the thread.

These parts have all been recommended to me back in the thread and I have tested them on the road cars and found them helpful.

The graphite front brace is from an RC10L3T, I believe.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-ko-short-servo.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-ko-short-servo-009.jpg  

Last edited by John Stranahan; 02-12-2008 at 12:19 PM.
John Stranahan is offline   Reply With Quote
Old 02-12-2008, 11:38 AM   #1893
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

McAllister Nascar COT (car of tommorow)

Here is the first oval body I plan to use on the 200 mm oval car. It has an interesting flat splitter just like the fullsize Nascar body.
The car is awaiting Body posts . I need hugely long ones in the back. I saw some very nicely crafted posts at Murdock RC. They have a wasp waisted Aluminum Pedestal mount about 1 inch high and then a plastic post on top of it. The rear was not long enough for me or I might have considered it. I have used a similar arrangement with an Aluminum 1 " 4-40 standoff followed by a standard post.

I have not mounted the wing. A BRP wing is more or less standard but I have not liked the appearance much. I may try a larger touring car wing. I think the McAllister wing may be undersized based on my experience with this asphalt.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-mcallister-nascar-cot-painted-003.jpg  
John Stranahan is offline   Reply With Quote
Old 02-12-2008, 11:43 AM   #1894
Tech Elite
 
trackdesigner71's Avatar
 
Join Date: Sep 2002
Location: Lynchburg/Portsmouth, VA
Posts: 4,979
Trader Rating: 4 (100%+)
Send a message via AIM to trackdesigner71 Send a message via Yahoo to trackdesigner71
Default

I thought that the NASCAR COT for Chevy was the Impala SS?
trackdesigner71 is offline   Reply With Quote
Old 02-12-2008, 11:55 AM   #1895
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

I think it might depend on the team. The car comes with impala and Monte Carlo decals and two sets of tailight decals. I just liked the Monte Carlo Nameplate a little better.
John Stranahan is offline   Reply With Quote
Old 02-12-2008, 09:54 PM   #1896
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

I am four cell ready now. Some tape will be needed. I am hoping the club will choose LiPo, though.

Note Body mount on left rear shock arm. I hope this holds up. It is not resting on the pod but is sprung with the chassis. It is nice to have it far back. There is an extra body post/bumper behind the battery which will be trimmed off. The four cell pack is folded on the center battery bar. This is located by a plastic standoff. The leads will exit from the center of the pack and will be able to be very short due to the proximity of the speed control and motor terminals.

Speed control will go behind cross brace.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-4-cell-ready.jpg   Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-mcallister-nascar-cot-painted-wing-001.jpg  
John Stranahan is offline   Reply With Quote
Old 02-13-2008, 08:54 AM   #1897
Tech Regular
 
JevUK's Avatar
 
Join Date: May 2005
Location: Dover, UK
Posts: 310
Default

John I don't like your chances with those 3000mah sanyo's They didn't perform well even when they were new. Maybe you could borrow some better packs? I'm sure there will be someone who has something much better they don't use anymore.

Ask them if you can demonstrate lipo's

What do you think of my Evo 10?
__________________
MRT, Novak, Spektrum, Sanwa, Tamiya, Alleven RC, Maxamps, CheapBatteryPacks, Duratrax Ice, Pro Peak PSU, Nuova Faor, McLarney Racing, Futaba, KO Propo, Team Associated, Enerland.
JevUK is offline   Reply With Quote
Old 02-13-2008, 11:45 AM   #1898
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

I will be buying new packs when the decision is made. These old packs were just on the shelf still. I used them to set the car up.

JevUK's EVO 10
Nice. I had read your report. Thanks. Thanks for the Kudos on the other thread. I don't like that center pivot ball much. I notice like you that the linkage binds when the chasssis pivots on the center ball. This becomes worse with use as dirt gets into that pivot. I still think you get better traction than a t-plate car on a rough track. Replace that center pivot ball often.
I would switch to pink rears with a 3.5. I have trouble with traction on a Magenta rear. Give us the maker and age of the car. I assume it is not in current production. I tinkered with the pic. Here it is again. Explain the front end. Does it have the tiny springs under that cross plate. I see the camber and caster are adjustable with the top links. From your description the rear is like a typical center pivot link car.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-evo-10-jev-uk.jpg  

Last edited by John Stranahan; 02-13-2008 at 12:05 PM.
John Stranahan is offline   Reply With Quote
Old 02-13-2008, 12:16 PM   #1899
Moderator
 
Pro ten Holland's Avatar
 
Join Date: May 2003
Location: Druten/Holland (Europe)
Posts: 1,677
Trader Rating: 1 (100%+)
Default

My experience is that magenta's are more stable out of the corner than pinks.
Pinks tend to slide more.
Pro ten Holland is offline   Reply With Quote
Old 02-13-2008, 03:58 PM   #1900
V12
Tech Elite
 
V12's Avatar
 
Join Date: Nov 2001
Posts: 2,641
Trader Rating: 1 (100%+)
Default

JevUK's EVO 10 was made by Trinity. The full name is Evolution 10 and I think it was the first Pro10 car Trinity made.
V12 is offline   Reply With Quote
Old 02-13-2008, 05:15 PM   #1901
Tech Regular
 
JevUK's Avatar
 
Join Date: May 2005
Location: Dover, UK
Posts: 310
Default

Quote:
Originally Posted by John Stranahan View Post
I will be buying new packs when the decision is made. These old packs were just on the shelf still. I used them to set the car up.

JevUK's EVO 10
Nice. I had read your report. Thanks. Thanks for the Kudos on the other thread. I don't like that center pivot ball much. I notice like you that the linkage binds when the chasssis pivots on the center ball. This becomes worse with use as dirt gets into that pivot. I still think you get better traction than a t-plate car on a rough track. Replace that center pivot ball often.
I would switch to pink rears with a 3.5. I have trouble with traction on a Magenta rear. Give us the maker and age of the car. I assume it is not in current production. I tinkered with the pic. Here it is again. Explain the front end. Does it have the tiny springs under that cross plate. I see the camber and caster are adjustable with the top links. From your description the rear is like a typical center pivot link car.
John
Full Size picture of my car

Sorry the camera is not good, the normal camera I use is out of town this week .

V12 is correct , it's a Trinity Evolution 10 circa 1996. Recently given to me by a good friend.

I raced it's sequel the Trinity Switchblade in the 97/98 at nationals the last years of pro10 in the UK. David Spashett won the UK and World championships with the switchblade but actually used the front end from the Evo 10 as he thought the switchblade front end too flexible . After rebuilding the evo10 I now realise that the switchblade was a bit of a backward step.

Yes John the front end has a fixed lower arm with spring underneath. Basic but reliable.

Due to the age of all the parts the center pivot already has play in. I am planning to sand down the 2 halves of the ball joint assembly so they clamp on to the ball harder. It's a bit tricky for me to explain what I mean.

The fundemental flaw with having 2 links is that the distance between them changes as the pod pivots on the roll axis. This means the links are fighting each other and the only thing that allows the pod to pivot is either the slop in the ball joints of the flex of them and the whole chassis.

The only big drawback left with the single middle ball pivot is that the motor toque create large up and down force on the pod. This could be reduced if the up and down pivoting of the pod was moved forward or the suspension did not pivot front to rear but with some sort of side to side linkage system. A T-bar system does effectivly have it's up and down pivot more forward than a pivot ball system.

I wish I could get to grips with cad software to get my ideas out there.

Other modifications:

Fitted switchblade plastic servo mounts, orginal servo mounting was taped to the carbon in between front wheels(pointing bakwards)

"3 Racing" mini shocks designed for Hotbodies minizilla. They could be better but are much better than the trinity shocks which were dire. The new Team Associated "neutral volume" shock looks promising(shown at nurnburg toy fair).

Had to dremel a little bit of the front battery holder away to fit in the maxamps 6000 pack in, other than that it fitted perfect .

Using a corally thrust race in the differential. Trinity relied on one of the normal ballraces to take all of the side loads. Tut tut

All the purple parts are factory upgrades.

Thank's for the advise on tyres all. I'm going to order some GRP Pink rears. Do Grey and Whites not work on asphalt at all?

Regards,

Jevon
__________________
MRT, Novak, Spektrum, Sanwa, Tamiya, Alleven RC, Maxamps, CheapBatteryPacks, Duratrax Ice, Pro Peak PSU, Nuova Faor, McLarney Racing, Futaba, KO Propo, Team Associated, Enerland.
JevUK is offline   Reply With Quote
Old 02-13-2008, 06:26 PM   #1902
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

Jevon-Thanks for the details.
I think you will find the white rears to just fall apart with the 3.5 motor. This reduces your grip in the corner and on corner exit. You will get more spins. I notice Mathijs has recently changed his reccomendation to Magenta rears. I can remeber maybe 3 times in this thread alone when he suggested Pinks on the rear. I have a pair of Magentas and even with high traction on our track and the car turning fast laps the Magentas would not hook up quite as well. This I imagine is very track specific.

Grey is a reasonable substitute for pink but does not grip quite as well on my track with my car.

The track was really dusty today. When I hit a bumper a cloud of dust would come off the chassis. This made slow going in the pan car today.
John
John Stranahan is offline   Reply With Quote
Old 02-13-2008, 11:54 PM   #1903
Tech Addict
 
Join Date: Dec 2005
Location: Belgium
Posts: 528
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by JevUK View Post
The fundemental flaw with having 2 links is that the distance between them changes as the pod pivots on the roll axis. This means the links are fighting each other and the only thing that allows the pod to pivot is either the slop in the ball joints of the flex of them and the whole chassis.
I know what you mean and I had a theory on that too. One thing you can do to improve this is putting the front balls of the links on a spacer so it sits higher then the rear, I can hear you all think: Huh???

Imagine 2 circles of movement, the center on the front ball of the link and radius going through the rear ball.
If the balls are on the same height you will indeed see that when the rear rolls both links will "pull" the suspension forward and it will bind (as you say) eventually.
Now imagine the circles whith the front ball set higher! One link will pull and one will push -> less binding and you will get a "steering" rear end and it steers the right way.
I mounted it once on the GenX but never drove it like that (yeah, I know...) but you really see the rear steering when it rolls.

Just think about it
__________________
Make it idiot-proof, and someone will make a better idiot.
Quante is offline   Reply With Quote
Old 02-14-2008, 02:30 AM   #1904
Moderator
 
Pro ten Holland's Avatar
 
Join Date: May 2003
Location: Druten/Holland (Europe)
Posts: 1,677
Trader Rating: 1 (100%+)
Default

Yes, I have changed my opinion about the magenta tires after a race in Bad Breisig last year.
I had serious spinouts coming out of the corner with pink rears and magenta fronts. No steering as well.

Ater a suggestion of a fellow racer I switched to magenta rear and purple fronts and the car improved a wole lot.
Spinouts weren't completely gone, but almost, and I had refound my steering.
I was really surprised that the firmer compound tires actually gripped the track better.

Since then I have found that on all but the really cold days magenta works better than pink.
This goes for any track I have raced on since. (Oberhausen, Velp, Apeldoorn, Walsum)

I have no real explenation for this.
Back when I was using Ufra tires the soter pink-soft rears always wored better than the pink medium (comparable with pin and magenta respectively).
Pro ten Holland is offline   Reply With Quote
Old 02-14-2008, 10:33 AM   #1905
Tech Elite
 
Join Date: Aug 2002
Location: Houston, Texas
Posts: 3,777
Trader Rating: 27 (100%+)
Send a message via AIM to John Stranahan
Default

Thanks for the link discussion. I see where raising the front of the links might work. I would have needed adjustable links. If I end up with a link car in the future I will try that.

Mathijs-Thanks for the tire discussion. I have noted some difference in hardness by manufacturer for the same color rating. Jacos are a bit harder than GRP. I preferred the GRP tires.

Here is a link provided by SKG earlier in the thread on building the Associated front end. This will help those guys just getting into the pan car sport.
Building the front end.

Setting Up for Oval
I am going to be running my 200 mm car first on an asphalt oval. I practiced a little there with the wide pan car yesterday. Many of the setup techniques are similar to road cars but some are peculiar to oval cars. I plan to discuss as well as get help on these oval specific techniques. A couple of the guys I will be running with have years of flat oval experience.

Wedge/Tweak
For road guys this is a simple adjustment. You put the car on the tweak station and eliminate tweak. This lets the car corner the same in the left and right directions.
On the oval we can add wedge (make the car out of tweak) to fine tune the oversteer understeer balance. You hear the Nascar announcers talking about this on some of the pit stops.
On the old leaf spring suspended fullsize oval cars you would drive a wedge between spring and axle with bolts loosened to partially load up that corner of the car. Hence the name. If you do this to the right rear you are adding wedge. On a pan car you can do this with the tweak screws or on my car or an oval touring car by lowering the right rear spring collar.
So what happens. I talked recently about the right front being overloaded. When you add wedge you preload the right rear and the car rocks onto the left front; thus you also preload the left front. This takes weight off that overloaded right front. You get more steering traction. The car will want to oversteer more.
So add wedge (preload on the right rear) to oversteer. Subtract wedge to understeer.

Camber
I noticed on Jason's pan (fresh from the Snowbirds) that the camber on right front is rather normal for a road car, but the left front is reversed camber (top points out). This gives you more oversteer (hook).

Reactive Caster
I noticed also on Jason's car that he used some reactive caster on the right side and none on the left. The 0, 5, and 10 degree upper suspension mounts give you reactive caster. What happens is, as the car rolls, some caster is removed with the 5 degree mount. (The upper suspension arm pin is now angled), This softens the steering and changes it more toward understeer (push). This is what I use on the road car on both sides to prevent oversteer late in the sweeper.
We did have some problems with oversteer on our asphalt oval late in the turn and will have to take some corrective action.

more to come.

Last edited by John Stranahan; 02-28-2008 at 09:41 AM.
John Stranahan is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Associated Factory Team TC5, Brushless, LiPo, Li-ion Nanophosphate, Tips and Tricks John Stranahan Electric On-Road 839 11-01-2011 04:31 PM
Xray T2R, 2100 mah 2c LiPo, and Mabuchi power: Tech tips and Tricks gacjr0 Electric On-Road 46 11-18-2007 10:09 AM
tips and tricks XXX-NT streetstock Electric Off-Road 2 05-13-2005 10:50 AM
Tips & Tricks Steevo Electric On-Road 54 08-08-2003 10:09 PM
Tips And Tricks rctc3 Electric On-Road 36 03-10-2002 10:54 AM



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 07:18 PM.


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