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Old 12-17-2008, 10:11 AM   #421
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I worked a little more on the proto Pro10 i'll be building and testing during the summer.
As pointed out earielr by John, I'll be going with the panhard bar setup in the rear. Because I found it too hard to find enough space to put a damper on the rear lower plate I opted for the system you can see on the picture, Tamiya TRF dampers will be used for the front and rear (there is a small turnbuckle which connects the lower pod plate with the damper assy).
I already cut the damper assy and it is extremely smooth just as its supposed to.
I'll make the car in such a way that I can accomodate a CRC pro-strut fron suspension as well as the custom Front end which I'll be drawing up in the coming months.
I've been compiling G-Code on the other parts this week so I'll be cutting the rest of the graphite and fiberglass next week, pictures to follow ;-)
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-pro10-q-assy_resized.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-p1010100_resized.jpg  
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Old 12-17-2008, 12:36 PM   #422
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Very nice execution of a 3 link with panhard bar system. Some original thinking there with your bellcrank operated rear shocks. I have thought that a very similar system without bellcranks might control our standard pods with only two shocks (It might work better than our three shock system and could be available as an add on kit). Two shocks on your car will control both roll and bump. Nice. Give us a pic when you get those bellcranks attached to the pod. I blew the pic up and hunted around there. I imagine there should be some short ball end links to the pod bottom or top plate to allow side to side movement of the pod in roll. (I see now you discussed this in a parenthesis)

If you can, get some upper links into your front end to control camber. I know you are designing a new front end which may contain them. Very exiting. Any plans for production or is it going to be just a prototype. It truly will be revolutionary if produced.

Thats a great place for rear body mounts. If you can, include a hole for a centered back front body mount option. This does wonders to improve stiffness of the airdam and wheel arches.

Yes it would work great on the oval as well as the road course. An oval car is a car that you run on the oval. There are no templates that have to be fit. Only a direct drive axle is required. Width can be up to 260mm although 200 mm is pretty standard these day.

World GT does have the sliding kingpin clause, so the CRC front suspension interchange would be a desirable feature. Oval does not have this clause.

John

Last edited by John Stranahan; 12-17-2008 at 12:58 PM.
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Old 12-17-2008, 01:08 PM   #423
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Boomer-Yes that rear pod on the Superior Spectre car is connected only to the pivot balls of the T-plate. There are no other links. There is of course the normal 3-shock hookup at top. It is a simple swap to remove the T-plate and rear pivots, and convert it to a standard t-plate that is bolted more solidly to the rear pod. Only a new t-plate and spacers are needed. That said I like the pivots a lot. Here is a slightly bigger lightened view.
john
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-superior-spectre-chassis-t-plate.jpg  

Last edited by John Stranahan; 12-17-2008 at 01:18 PM.
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Old 12-17-2008, 02:42 PM   #424
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Glad you like it John, and the links from the bottom plate to the bellcranks my PC has a hard time with the complete assy (I'm not modeling this on my CAD station at work but rather on my old P4 at home) so I try to not add too much detailwork (which can prove to be bad but I can estimate the space needed pretty well).

The front will be equipped with 2 turnbuckles, I just have to figure out how to work around the shocks

My home milling option is not really production fit but does a great job for what I use it. This kit will not be in full production

I'll keep you updated on the progress
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-p1010102.jpg  
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Old 12-18-2008, 06:59 PM   #425
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Quante-I see numerical readouts on three axis on your router. Do you have computer control of it? Thanks for the post. Good luck with the project. You need a code name now.

Budget Buildup Continued Shocks
Here are a couple of the items that will go into the budget buildup. The first pic shows the Completed Traxxas BX Shock. It came out nice and is really smooth, but it required some handwork to make it so. Here are the details.
The pistons were slightly oversize for the purple bodies. Maybe .0005 inch or so. They could be forced in but had strong friction on the wall. I held the shaft and rolled the piston at an angle to my pull stroke on sand paper, first 220 then 1200 grit. Until it had only very light friction. I then pulled it in an out of the bore untill there was no more friction. When built up it was super smooth. The associated pivot on the front shock mount was just slightly oversize. I put it on a screw in a Dremmel and made it .001 smaller or so untill the shock would rotate free. The shock needed to be extended for these particular types of top pod plates. I used a CRC red hex standoff, drilled and tapped 3 mm on 1/2 its length to extend the shock. I used the yellow plastic Traxxas part to add compression to the spring. Very smooth. Droop came out correctly to about 2 mm. Plenty of adjustment room on the shock ring. It looks nice. Here is a parts list. The shocks were a good fit to the windtunnel center shock springs. The purple spring retainer is an RPM part.
DuraTrax Shock Bushing Yellow Evader ST (4) 1 3.59
DuraTrax Shock Seal Set Evader ST (2) 1 2.89

This is about $19 for two shocks

The second pic shows the RC18 shocks that I used. The CRC red bodies that I linked to previously were for the Mini T not the RC18T. At least those that I received were. The RC18T bodies are considerable larger diameter and hold more oil than the Mini T shocks. They are also a good fit to Windtunnel side springs.

I used a CRC prostrut graphite steering arm option to make little adaptors for this particular Woods Racing Car. The later model Superior car did not need these little adaptors.

The third pic shows a very nice lightened axle from CRC. You don't really want to skimp here on the axle or the left side clamping hub. Get some good quality units to avoid grief. Also use carbide diff balls.

Final price for the budget buildup is approximately 100-115 dollars for each car. I built four up with similar equipment. This includes three graphite rear axles, 1 fiberglass rear axle and 4 left side clamping hubs.

This does not include body wing tires or electronics.

1 x [3241] 3241 - CRC Pro Strut Front End 1/10th = $49.99

1 x [1728] 1728 - Large D-ring Axle - 10th/SS = $24.99

Complete Parts list on request.
john
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-shocks-001.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-shocks-002.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-shocks-004.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-budget-fleet.jpg  

Last edited by John Stranahan; 12-18-2008 at 11:06 PM.
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Old 12-19-2008, 12:39 AM   #426
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Hi John,

The numeric scales are only there for a quick check/ reference.
My mill is a CNC controlled, that makes life a lot easier and more accurate
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Old 12-19-2008, 05:31 PM   #427
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John, excellent info as always.... but why 4 cars? Some sort of RC IROC race?

Quante- can i ask how you went about building the CNC machine? I've priced them out and they are crazy expensive for a turnkey unit.

Thanks guys, great stuff!
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Old 12-19-2008, 08:28 PM   #428
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There is one new pic of the fleet in my post above


Oval Car Ruggedness
Pejota-Well one car is mine-the other three are for sale at Mikes-HobbyShop.com, my home shop for a very reasonable price, two at $140, one at $160 with ballast and battery strap and electronics platform. The price increase over cost covers the sales commission of the shop. Phone orders are welcome. The goal is to grow the oval club by providing an inexpensive rugged car that I will buy back from local owners when the owner is done with it. Guys will usually move up to a premium car if they decide to stay in the sport.

Here is what I noticed. About the time the racer breaks the fourth graphite bumper or expensive graphite crossplate knife, he has decided it is too expensive to race. My cars all have a combination of hard but flexible under bumpers combined with a soft foam or the CRC hard foam bumper which I like a lot. The Manutech Kydex bumper described and tested on the CRC 1/10 pan thread would be ideal here as an under bumper. The Kydex needs that CRC hard foam (CRC 1759) bumper as well to protect its shape.

Instead of a solid aluminum body post which very effectively levers and breaks graphite, breaks the cross-plate knife (which holds the rear body posts), the cars all have soft body posts.

Rear Axle problems are reduced by the use of carbide ball bearings, Aluminum Nylock nut, and double clamping left hubs. Quality where it counts.

Trouble free performance outdoors from the use of 48 pitch spurs and recommended steel pinions. You get many events of use on a single pair of gears with the mild mod 13.5/Lipo compared to one event with 64 pitch gears and aluminum coated pinions.

all the cars will have a good starting setup tuned just for our LiPo/13.5 and our track. They will perform quite well after only a down tweak adjustment on the first day.

Instead of the traditional oval wing, I have a body on display with the much more rugged and from my testing more effective J-concempts 0100 illusion wing. I can't tell you how many cars DNF each race day because of a broken wing after a crash or finish poorly because those oval mounts are so wimpy and the wing moves after a minor crash. The broken wing is an expensive failure that need not occur.

The racer needs a rear side shock with a shaft that does not bend. He needs terminating hardware that does not bend when you lay on the downtweak. 12 ounces seems to be nice.

This is the car that beginners, or guys out of the hobby for a few years, need, to get back up to speed.

We will see if there is any action on the three cars.

John

Last edited by John Stranahan; 12-22-2008 at 05:04 AM.
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Old 12-20-2008, 03:42 AM   #429
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Quote:
Originally Posted by pejota View Post
John, excellent info as always.... but why 4 cars? Some sort of RC IROC race?

Quante- can i ask how you went about building the CNC machine? I've priced them out and they are crazy expensive for a turnkey unit.

Thanks guys, great stuff!
There's a lot of info to find on how to build your own CNC machine.
There's a few websites you can check out, but I'm not at home so I cant paste some links here.
After reading up in these sites, I drew it up in CAD and voila...

I got my linear guides from ebay, the rest is 22mm MDF (pressed wood), why MDF, its extremely well glue-able and screws/ drills go in where you want them to go in.

Electronics and stepper motors arent really expensive, only the leadscrew is a problem. You get a choice, you can take Trapezoid leadscrews (cheap but with backlash) or ballscrew (very expensive, no backlash).
Thats why I have the extra scales on there, to calibrate the play out of the screws -> I use trapezoids (anti-backlash compensation in Mach3).

You gotta think of it lke this: I'm only cutting 2-3 mm graphite with a 1.5mm cutter, its like going with a hot knife through butter!! At first I even used a Dremel, but I got a Kress 800W milling motor instead.
With this, even aluminum isnt a problem, provided that you're cutters are sharp.

The construction cost about 300 (100 linear guides, 50 leadscrews and accessories, 30 wood, 100 electronics and stepmotors (I had a powersupply rack)).

Then you need a good milling motor, another 120.

Cutters are real cheap! I buy used ones but they're resharped, 50 1.5mm cutters fr 12, same for the drills.

And for accuracy: I cut my own CEFX T-Bars and I'm just as quick with these as I am with the original ones....
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Old 12-21-2008, 03:31 PM   #430
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Quante-nice machine. When you finish making that car with it, it will be a real achievement.

Superior Spectre Test and Tune, Offset Pod

This is my first offset pod car, although I have driven other racers cars which often have offset pods. An offset pod has a longer diff hub and is position farther to the left on the car requiring a short left hub. Putting on an offset pod or moving the motor left with spacers will tend to tighten the car (less oversteer). The tuning session was short and sweet. On first drive this is what I noticed:

I started with the car square and 12 ounces of left downtweak. I had super steering traction. I had on the car a CRC based strut suspension, but with associated style kingpins, shortened upper A-arms and outer pivot ball ends. This gave the front end the same geometry as the Pro strut front suspension, but gave me the mildly trailing steel 1/8 inch axle which I like for strength and also, I have always liked the way they drive; Just a bit softer corner entry than an inline axle; no instability 2/3 through a corner. The first pic shows this suspension but with the optional aluminum caster block which I did not use on this budget buildup car. I could effortlessly keep a tight line. Give this geometry a try on the oval.

As I increased power lap by lap I ended up with some late corner exit Looping. This problem is distinctly different from oversteer, in that, you cannot correct it by counter steer. The rear end also does not slide out. You see the car just suddenly head to the inside board. The only driver control you have is to ease off on the power. I think still, that this problem is caused by the car "standing" on the right rear, which torque steers the car inward. Low powered cars (4 cell/17.5) are likely not to have this problem. Full size cars are also not likely to have this problem except high powered dragsters with super rear traction when they experience a difference in traction between the left and right rear tire. They are likely to dart off to the wall, with the driver unable to steer. It is caused by loss of steering and torque steer not loss of rear traction.
On this offset pod car, the problem was small. I had to add huge power on corner exit for it to exhibit. Still, it is better just to tune it all out then you CAN add huge power on corner exit. I increased left down tweak by one full turn clockwise on the right rear shock. This helped a little. I added some left rear positive offset by putting only a thin 1/8 inch spacer behind the left rear hub. This fixed the car right up. I had the best corner exit speed ever. Not doubt my placement of the 3 ounce lead ballast weight resulted in smaller levels of tuning required. See the second pic.

Here is the final important points of the

Setup with 13.5/LiPo on medium high grip asphalt, Offset Pod

6# green Windtunnel front springs. I may try purple to soften corner entrance grip a little.
Pink left front, Purple right front
2 degrees caster right front. 0 degrees left front.
No right front offset is available. None was needed with the offset pod.
Long wheelbase option at the front.

Copper Windtunnel 11lb/in center spring, 35 weight oil.
Blue 7# Windtunnel left side spring, 35 weight oil
Copper 15# Windtunnel right side spring, 35 weight oil
12.4 ounces of left down tweak (measured just after the session body off)

72/28 gear, XXPink/Purple rear tires on both sides. No rear steer was needed.

I was very pleased with the car and felt it would easily win races.

CRC pro Strut Front End Report
I have to note that I assembled one of my budget cars with a complete Pro Strut front end of very recent vintage as it came in the package. I was quite pleased that the kingpins that, on previous early edition cars, were tight in the lower pivot balls now had just the right feel. They would drop through by gravity alone, but had little play. This meant I assembled the whole front end without the tedious hand work neccesary to make an Associated front end free. This saved an hour at least.

Monday work begins on a new track surface.

Third pic, OOP's wrong thread. Things I might be carrying when watching dancing with the stars.

john
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-crc-front-suspension-002.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-ballast-weight-005.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-colt-officers-acp-recoil-spring-guide-kit-010.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-axe-gun-c-004-resized.jpg  

Last edited by John Stranahan; 12-22-2008 at 06:54 AM. Reason: fixed gear ratio
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Old 12-21-2008, 08:30 PM   #431
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hey John could you give me the breakdown on the quality of the g3.iwas talking with my fellow racers about getting one and they said the ksg is jokingly reffered to as K.eep S.ending G.raphite.any words of wisdom on this issue?thanks
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Old 12-21-2008, 08:59 PM   #432
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Jeremy Reed,

I can tell you the KSG G3 is an awesome car on the track especially if you can get some help from a team driver in getting it dialed in.

We've seen several DIE HARD Hyperdrive racers make the switch in the last month or so, and they are freakin DIALED with the new car.

It does look fragile, and that's due in part to some of the cuts made to give the front suspension "FLEX" (If you hit stuff....run a LARGE high density FOAM front bumper....to save parts)

NOTE: I have NO Ties to KSG nor any other Chassis mfg. I'm NOT a "Team Driver" pushing my favorite car...and I currently myself have KSG, HYPERDRIVE, and ASSOCIATED oval cars. (No G3 though -- too rich for MY blood )
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Old 12-22-2008, 05:01 AM   #433
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Jeremy-If you use this Kydex front bumper along with the CRC foam bumper, you will avoid most graphite breakage with any of the cars. We have had no particular problems with KSG. The second thing to avoid is solid aluminum body posts at the back of the car. These will tend to break the graphite they are attached to.
Either use a back window wing mount or my preference the HPI plastic mounts attached to the body. These mounts will work with the traditional oval wing as well as the J Concepts 0100 Illusion wing that I like. If you remove the potential for breakage at the front bumper and at the wing, the rest of our pan cars are very rugged.
I can see where the front of the chassis might be broken using the typical graphite front bumper.

Joe-Thanks for the post and report.

John

Last edited by John Stranahan; 12-22-2008 at 06:48 AM.
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Old 12-22-2008, 08:31 AM   #434
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I started cutting the carbon fibre and fiberglass today and here are the first pictures of something put together!!
Everything falls in place perfectly and I'll be cutting the small parts tomorrow.

Lessons learned:
- The 1.55mm cutter went to 1.52mm after all this CF cutting and was still pretty sharp, I had expected this to be a lot more so this means I'll be using less cutters
- Countersink drills DO NOT like 10.000 rpm (->slowest I can go)..... had to redo most by hand and the countersink drill does not really last long (the countersink drill became blunt after 10 holes or so. I was using a HSS cutter for metal... Oh well, I can still use it, but I'll be countersinking by hand from now on.
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-p1010112_resized.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-p1010113_resized.jpg  
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Old 12-22-2008, 11:00 AM   #435
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WOW!
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