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Old 08-06-2010, 09:38 AM   #1621
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John,

Not to get you more excited but this is only Jason's first cut at it. Just wait until more racers get these into their hands and start experimenting with there own ideas.

A couple more engineering cycles later and not only will the cost per unit go down but also the weight by creating molded parts instead of milled aluminum.
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Old 08-06-2010, 01:23 PM   #1622
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Very good explination john, couldnt say it better myself. It does have a damper tube in the front and uses medium height ballstuds the allow for maximum movement. The damper tube has an oring on the piston to increase resistance as the contact area is much smaller with the shorter lenght.

As for weight, 1st prototype was 8 grams heavier than the L4 strut front end and about the same as the new AE front end. I have made a few small mods to drop a little weight. When i get the final production parts complete i will weigh it again.

I am very pleased with the performance of the front end.
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Old 08-06-2010, 04:02 PM   #1623
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really interesting stuff there. i was wondering how you were going to compensate for the super short stroke of that damper tube.. any chance of this bolting into a standard associated front end patern? really hard to tell what is going on in that yokomo pic.. is that a torsion bar with single damper for both right and left?
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Old 08-06-2010, 04:43 PM   #1624
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Quote:
Originally Posted by tallyrc View Post
really interesting stuff there. i was wondering how you were going to compensate for the super short stroke of that damper tube.. any chance of this bolting into a standard associated front end patern? really hard to tell what is going on in that yokomo pic.. is that a torsion bar with single damper for both right and left?
Our front end bolts right up to standard AE mounting. I will be making it with adapter plates to fit pretty much anything on the market.

From what i have seen, yokomo used small coil spring between the arm and caster block near the hinge pin and also a center shock w/ spring. Looks a bit more complicated than it needs to be but to each there own.
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Old 08-06-2010, 05:06 PM   #1625
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Here is another view of the Yokomo. That coil over shock spring would be the supporting spring , but the cross bar looks more like a sway bar; other wise there would be a set screw to keep the center part of the sway bar from turning. The sway bar is essential here to keep the suspension even left and right when using only a single spring.
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Old 08-07-2010, 05:30 AM   #1626
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I will see if i can find the 1 pic. It shows a small coil spring over the arm. Very different.
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Old 08-07-2010, 05:34 AM   #1627
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It looks like what i thought was a droop screw is actually for adjusting ride height. I know that at the worlds, they removed the spring on the shock and just used it as a dampener. Let me know what you think.

http://www.rctech.net/forum/electric...omo-r12-3.html
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Old 08-07-2010, 05:35 AM   #1628
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ok, that didnt work, i will try this
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Old 08-08-2010, 04:29 PM   #1629
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Thunder Power Batteries
from 7/27/2009
Quote:
Originally Posted by John Stranahan View Post
Periodically I tested some new batteries. Here are the results.

Thunderpower 5000 mA-h 40c hard case ROAR approved
#1 7.46 V average at a 20 A discharge, 5211 mA-h
#2 7.46 V average at a 20 A discharge, 5244 mA-h

The Thunder power packs have the best ever voltage in my tests. In the heat you have to gear down about "1/2 tooth (48 pitch) over the SMC packs as the motors are that much more powerful. In a track test yesterday with track temps at 137 F the Thunderpowers did not swell at all. Temp of the pack was a modest 126 F at 3.5 minutes. I did not get a full 6 minute run though. The SMCs swell badly at this ambient temperature in a high drain car like an open mod wide pan or open mod TC with good traction.

I would not buy a pack that has not been safety tested by a third party. ROAR has provided us this service. Take advantage. Not only you RC car, but your full size car used to transport the pack, and your house are at stake. Use a LIPO sock when charging. Use a LIPO sock to store charged batteries.

Charging at greater than 1.25C dramatically reduces lifetime. Heating reduces lifetime. ROAR requires a 1C charge rate for racing and no pack heating. I suggest you follow suite at your club races.
I thought I would give a followup on these Thunderpower packs. I have been using them ever since this test. They have over a hundred cycles now and are a year old. They still run good in the wide pan car and the touring car and have good punch and run time. Some problems have developed though. They no longer tolerate the heat and swell up after a run. I did a test today by cooling the pack to 88F starting point. (last week they started at the bench temp of 108F) At the end of a 5 minute run the pack had swelled up, but was only 120F on the outside. It is apparently building up more internal heat than before which is causing some of the solvent to evaporate. It recondenses on cooling and the pack works again but still swells up on the next use. I think I have reached the usefully limit for these packs in Houston. 100 cycles is great considering the high amp draw (47 average amps). I plan to retire these 3 packs. I have one newer 5200 pack as well. I have not noticed it swelling.
This has been a difficult problem for us at Mikes-Hobby shop running open mod. A lot of brands puff up when brand new.

John
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Old 08-20-2010, 07:58 PM   #1630
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3-Link Rear Suspension on 1-12 Scale CRC Carpet Knife V 3.2r

Guys have tried this before. Here is my take. Main Chassis down travel is a full 4 mm at the rear. At the moment this is limited by the Panhard bar but a new hole in the bottom plate for the right rear shock mount will fix this. Shocks are about 160 mm wide at top so I am going to think that it will fit in the body and clear the tires. I have neither so I will have to test this later. The body pins are in a hole that was probably used on the previous body. Road test to come. It will be a while as I need a speed control. That rear pod movement is oh so buttery smooth.

It took only some spacers to move the battery braces up and a couple of 4-40 thick Aluminum washers on the Front side link holes to limit side to side movement. I installed the late model longer side links that have adjustable tension. I used Dubro HD rod ends on the top link and Dubro standard rod ends on the Panhard bar for extra clearance.

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Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-3-link-1-12-scale-001.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-3-link-1-12-scale-002.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-3-link-1-12-scale-001.jpg  
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Last edited by John Stranahan; 08-20-2010 at 08:11 PM.
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Old 08-21-2010, 04:31 AM   #1631
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Looks good John.
I am planing on building a multi-link rear based on the one that Quante has built. It uses tubes and side springs to help the weight and complexity down.
I am going to base it around a 12r5 with custom cut chassis and lower pod plate.
Let us know how yours handles I would interested to know if it is worth the effort.
We race on a large outdoor track witch is low-medium grip and a little bumpy.
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Old 08-21-2010, 10:20 PM   #1632
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GWH74-thanks. Will give a track report as soon as possible.

Dual A-arm Front End on 1-12 Scale CRC Carpet Knive V 3.2
Work Continues on the 1-12 scale. I adapted my Dual A-arm suspension to it. Seems to fit fine with a few dimensional changes. The top plate is about .25 lower than the 1/10 scale setup. The big question was whether the shock would fit. It seems to fit fine. I can lower the top plate even more if there is body clearance problems. The shock stroke seems to be long and good. I found better front end performance the closer the shock end was to the wheel (ala late model rear corvette shock).

John
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CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-1-12-scale-dual-arm-front-end-001.jpg  
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Old 08-22-2010, 03:33 AM   #1633
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Looking good.

I was planing on using the 12r5 lower arms and mount shock end onto them. The arms normal mount to the bulkhead using a threaded aluminium bush like the TC5 uses for the lower arm mounting blocks. Screw a long grub screw into the shock end and then this will screw into the threaded bush, simple, easy and cheap.

I notice that you use the 18r shocks on most of your project car. What are your thoughts on them. I was thinking of using 1/12 rear shocks for the rear of mine due to the large range of strings available for them. What is the spring selection like for the 18r shock?

Gareth
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Old 08-22-2010, 04:47 AM   #1634
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Hey John,

Here are a few pics that show a little more detail as i promised. Hope you like it.
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CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-44784_146356055384682_100000308647687_312268_1561059_n.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-45025_146356112051343_100000308647687_312270_1668041_n.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-45418_146356195384668_100000308647687_312271_3653006_n.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-45550_146356258717995_100000308647687_312273_7111004_n.jpg  
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Old 08-22-2010, 12:25 PM   #1635
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Jason Thanks. Sweet. Nice anodizing. Here are a couple of those pictures lightened up a bit.

Gareth-looks good. Give us some more pitures when you are farther along.

RC18T shocks
What is not to like. They wear well on a pan car. They are cheap. Rebuild kits are cheap. They are the right size (small). They are a modern bladder shock design. The shafts don't bend. The ends don't bend like standard Pancar side shocks. The spring comes off easy with a removable lower seat. A side shock spring cut to 3.5 coils will fit. Cut to four coils the end can be flattened with a little torch and pliers and it will fit and look nice.

Note that CRC has come out with an Encore Micro shock now with good ends. It is possible my complaints helped in its development.

2 and 3 lb/in springs don't exist, but I wind these and sell them on my web site. A copper Associated side shock spring makes a good 4 lb spring. The standard Associated RC18T front springs are blue at .5 lb and gold at 1lb
John
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-45025_146356112051343_100000308647687_312270_1668041_n.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-45418_146356195384668_100000308647687_312271_3653006_n.jpg  
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