speedy_w_beans

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Everything posted by speedy_w_beans

  1. speedy_w_beans

    HPI Super Star Monster Truck Wheels help

    Are you talking about these? Front: http://www3.towerhobbies.com/cgi-bin/wti00...=LXM871&P=V Rear: http://www3.towerhobbies.com/cgi-bin/wti00...=LXM875&P=7 I've used both chrome and white on different DT02 and DF02 projects, but it looks like black is fully available as well. -Paul
  2. speedy_w_beans

    How long does a build take you?

    When I built my first kit, a DF03 Dark Impact, it took about 25 hours from opening the box to having a shakedown run without a body. Over time and with a little more experience, I've seen my standard kit build times drop to about 15-20 hours per chassis. I must be really slow, because when I read reviews about kits, invariably the author will say how he built the whole chassis in 4-6 hours before paint/decals. Granted, there are time differences for 2WD vs. 4WD, type of dampers, dogbones vs. CVDs, gear diff vs. ball diff, etc., but I'm wondering how people manage to build running chassis in such short times. How long does it take you to build a standard kit chassis and do a shakedown run before trim/paint/decals, hopups, or modifications? Do you have any best practices to save time? Replies with chassis codes, build times, and general time-saving practices are appreciated. -Paul
  3. speedy_w_beans

    So, What Have You Done Today?

    Trimmed the lexan and applied window masks to a HPI Ford F150 Flareside body to use on my TB03 chassis. This looks like an easy body to paint and decal. -Paul
  4. speedy_w_beans

    How long does a build take you?

    That Mazda 787B is an awesome car. I can understand why you'd spend 40+ hours working on it. I bought some better hex drivers the other day. Flush cutters and some parts trays are next on the list, then we'll see how the next build goes. -Paul
  5. speedy_w_beans

    How long does a build take you?

    So I just finished a HPI Blitz ESE Pro chassis build tonight; with electronics installed and a first shakedown run, it probably took me 15-17 hours in total. All of the plastic flash has been trimmed, all of the link lengths are within .05 mm of book spec, the ball diff has been broken in, the tires are glued, none of the screws are stripped, bullet connectors were installed on the ESC, etc. I'm amazed someone can put together a chassis like this in 4-6 hours. I have another DB01R kit waiting to be built, and I'm pretty sure that's going to take another 15-20 hours as well... It doesn't seem like a few better tools and some parts trays are going to radically cut these build times for me... Painting shells is another matter, as well. Thursday nights are for trimming, sanding edges, and reaming holes. Friday nights are for masking the different paint layers. Saturdays are for painting and using a heat gun between layers. Sundays are for decals. There's probably a good 12-15 hours per Lexan shell for me... -Paul
  6. speedy_w_beans

    Stick or Wheel controler

    It's an easy decision for me -- my right thumb sometimes locks up from an old injury, so stick is a definite no-go. I don't have to worry about losing steering with a pistol controller! -Paul
  7. speedy_w_beans

    How long does a build take you?

    I think taliesin makes a good point about work space and good tools. Generally I keep my work space organized and the tools are laid out in front of me, but I can see some specific tool upgrades -- flush cutters instead of regular cutters and a hobby knife to trim the flash, for example. Another good upgrade for me would be to invest in some better hex drivers. Finally, maybe some trays to pour out the metal parts so I'm not digging in bags so much -- I've been afraid to lose metal parts and have generally pulled parts from bags only as needed. One thing does seem to stand out from the comments above -- it seems like some of you have built multiple copies of the same chassis, which leads to familiarity and less time reading the instructions. For the most part I've been building a different chassis each time. Thanks for the replies. -Paul
  8. speedy_w_beans

    So, What Have You Done Today?

    Finished my Blitz ESE Pro chassis after two days of working on it. I just need to add receiver/ESC/motor, take it for a test run, and paint the shell. It's kind of fun to compare it against my homebrew DF02-based SCT. -Paul
  9. speedy_w_beans

    TL-01 Bowler Build

    That's looking really nice. -Paul
  10. In anticipation of a future TT01R Type E rally conversion project, I've put a few hours into thinking about how to seal the TT01 gear diff so different silicone oils can be used instead of packing the diff with more or less anti-wear grease. The following pictures and description are for a version 1 prototype, but I think it's showing enough promise to share with the community. Feel free to comment back; I'm very open to feedback and suggestions. In the first photo the sealed gear diff components include: - Ring gear with enlarged center hole - Standard TT01 bevel gears and spider shafts - Diff cup with enlarged center hole - Drive cups with machined recesses for O-rings - Gasket for sealing the ring gear, diff cup, and screws The TT01 ring gear and diff cup I had measured 0.312" OD and 0.200" ID where the drive cup shaft is inserted. The drive cup shafts measured 0.195" OD and 0.135" across the flats that key into the bevel gears. This only provides about 0.005" of clearance between the hole and the shaft, not enough for a regular Tamiya damper O-ring. I went on the hunt for some thinner O-rings at my local hobby shop and hardware store, but there wasn't anything readily available. As a compromise, I opted to use the regular Tamiya damper O-rings as shaft seals, but that required removing extra material from the shafts and gear/cup holes so the O-ring could fit reasonably well. The second photo shows a TT01R drive cup with a machined recess for the O-ring. Since the Tamiya O-rings measured about 0.072" in thickness, I needed to create much more than 0.005" of clearance between the shaft and hole. Eventually I settled on a recess that measured 0.135" OD and 0.100" wide, centered between the cups and flats. I figured if the flats measured 0.135" across, then reducing the shaft diameter from 0.195" to 0.135" for the O-ring should be acceptable without compromising too much shear strength (yes, there is less cross sectional shaft area for the O-ring as compared to the flats, but it seemed worth trying like this). The clearance was then 0.0025" + 0.030" per side of the shaft. I tried compressing the O-ring, but it was almost impossible to fit in the gear or cup hole. So, the next step was drilling out the holes with a 15/64" drill bit, increasing the hole diameter from 0.200" to about 0.232" (measured). This added about 0.016" of clearance to each side of the shaft while reducing the wall thickness of the hole from 0.056" to 0.040". This didn't seem like too much material to remove, and it provided an overall clearance of 0.0485" per side between the shaft and hole. I figured if the O-ring compressed from 0.072" to about 0.048", it would probably grow sideways to about 0.096" width, which would fill the recess and cause it to stay centered during operation. My second attempt to install a shaft in a hole was successful, but it took a little pushing with a small hex key and working around the perimeter of the O-ring to get it to slide inside the hole. Lubed with #500 shock oil, the movement seemed smooth. The third photo shows an assembled diff. With a shaft, O-ring, bevel gear, and spider gears installed in the diff cup, I filled it about 3/4 way with #7000 weight gear diff oil. Compared to #400 weight shock oil, this stuff was really sticky and slow to flow. I had cut a crude gasket out of a nitrile glove (measured only 0.0025" thick), but it was difficult to handle and would move out of position each time I tried to put the ring gear/shaft/O-ring/bevel assembly on top of the diff cup assembly. The fingers on the ring gear that mate with the slots on the diff cup would deform the gasket and cause it to move, which meant I wouldn't get a good seal if I installed the screws at that point. After a few attempts I gave up, and decided to make a paper gasket by photocopying another diff cup and then cutting out the detailed image. Since the ring gear was already wet with diff fluid, I stuck the paper gasket to it and pre-positioned the slots so I only had to align the gear to the cup. It all went together much more easily with a detailed paper gasket. A few screws later, and everything was tightly assembled. Right now with #7000 fluid the diff feels like a freshly built standard TT01 diff that's been heavily packed with AW grease. I'm expecting the diff won't loosen up with time, though, since the fluid will continue to flow around the gears instead of getting squeezed and pushed out of the way like the grease. I plan to build another one with #3000 fluid to see if there is a perceivable difference in diff action. I've had the diff sitting in front of me, lying on its side, for a few hours and haven't found any fluid underneath it yet. It probably needs to sit for a few days and then driven hard just to be sure. The final photo shows how I machined the recesses in the shafts. This is a poor man's lathe; I clamped a drill to the workbench, chucked the drive cup, partially clamped the drill trigger, and used a square hobby file that measures 0.097" to 0.100" per side to grind away the material. I'd periodically stop and check with a caliper, adjust pressure, and continue. Even though it was very uncontrolled, I was able to maintain the target OD to within 0.001" to 0.002" across the width. After grinding away the material I'd make a pass with 400 grit sandpaper to semi-polish it. Future improvements: - I'd like to find more appropriate O-rings and adjust the clearances and tolerances to reduce the shaft side play and the friction between the shaft and hole. If I can find some O-rings that are 0.030" in thickness instead of 0.072", I could avoid drilling the gear and cup holes and just focus on machining the shafts with narrower and shallower recesses. - The gasket made from a nitrile glove was too crude and made assembly difficult. I'm not sure if a paper gasket is going to work long term. If it works, I'll just keep photocopying diff cups and cutting out the images carefully. I may need an alternative; it's too early to tell. - While the poor man's lathe worked for now, it sure would be nice to have something more controlled. Thanks for reading; I hope you enjoyed this post. Comments and questions are always welcome. -Paul
  11. speedy_w_beans

    Experimental TT01 Sealed Gear Diff

    Just a quick update. I built version 2 of the diff today and now have it sitting to test for leaks. The shafts have .020" deep by .050" wide recesses cut in them, and the plastic ring gear and diff housing are no longer modified in any way. I reused the same nitrile gasket and gear set inside the diff. The smaller O-rings with less compression have reduced the friction considerably, and now it's easy to tell the effects due to the diff fluid. The side play of the shafts is also reduced, but there is enough compression of the O-rings to continue sealing even under worst case conditions. I used 3 mm ID O-rings with 1 mm cross section. When stretched over the recesses, the cross section reduces a little bit but the shaft is still guaranteed to seal even when pressed to one side. So, standard shafts with .020" deep x 0.050" wide recesses machined into them, 3 mm ID x 1 mm cross section O-rings, .0025" nitrile diff housing gasket, and standard ring gear/diff housing/bevel gear set should yield a usable, sealed gear diff for the TT01. The plan is to build a final set and use them in a TT01R Type E rally conversion project. The only remaining enhancement I can think of right now is to very lightly countersink the ring gear and diff housing holes to make O-ring installation just a little easier. -Paul
  12. speedy_w_beans

    Getting back into it, build advice? :)

    You might want to take a look at: http://dhrc.rchomepage.com/RolloutCalc.htm Plugging in 2S, 7.4 V, 68T spur, 23T pinion, 2.17 transmission ratio, 6400 kV, 70% efficiency, 1500 g weight, and 64 mm tire diameter the estimated top speed of the vehicle is about 62 km/hr or 38 mph. With 3S and 11.1 V the estimated vehicle speed is 93 km/hr or 58 mph. This setup could be quite a handful to drive on unprepared surfaces. With an average ride height of 5 mm between the bottom of the chassis and the pavement, it would be easy to bottom out when hitting a bump at these speeds. You might also want to think about thermal management -- blower fans on the ESC and motor to keep things under control. Investing in an IR thermometer that can measure at least +100C would be a good idea so you can check ESC and motor temps after runs, then adjust gearing accordingly. A few packs of different pinion gears might be helpful. It'll be fun to see this car zip around at these speeds, but I suspect a 10.5T or 13.5T motor is in your future... Don't forget to glue your tires to the rims! -Paul
  13. speedy_w_beans

    Getting back into it, build advice? :)

    For racing normally only 2S (7.4V) is allowed. For playing you could put in a 3S, but with a 4.5T motor you should check the kV rating of the motor, multiply by 11.1V, and see how many RPMs the motor might theoretically spin. There may be a maximum safe RPM spec'd for the motor before the rotor shatters due to centripetal forces. Add in some safety margin, like maybe don't exceed 2/3 of the RPM limit, and that could settle the battery question pretty quickly. -Paul
  14. speedy_w_beans

    Tamiya's that you never wanted

    Rather than identify a list of individual kits I don't want, it's easier to list out the attributes of kits I try to avoid: - Friction dampers - Nylon drivetrain bushings - Nonadjustable suspensions - 380 motors - Plastic dogbones - Plastic propeller shafts - Plastic diff cups and axle cups - Solid rear axles - Single front shocks - Unequal length tie rods - Self-tapping screws - Screw pins - Lots of E-clips Oil dampers, ball bearings, adjustable suspension links, 540 motors, and metal dogbones/prop shafts/cups are essentials for me. I don't like self-tapping screws, self-tapping screw pins, a lot of e-clips, and unequal length tie rods, but I can accept them as part of a design. My son and I mostly have modern Tamiyas in our fleet; the only exceptions are a few Lunch Boxes and a Buggy Champ re-release. -Paul
  15. speedy_w_beans

    Getting back into it, build advice? :)

    Knowing that you're going to play casually at first and then possibly club race later, you might consider the following... - Build the chassis in stock form first and use it as-is. I looked through the TA06PRO manual and saw that it has a lot of nice things already, such as sealed gear diffs, metal drive cups, CV swing shafts, bearings, thread dampers, etc. For playing this is a very nice chassis and you really won't have to change much at all -- you'll be able to focus on your setup and experiment with it. The sealed gear diffs should work very well with higher power motors and won't require the attention ball diffs do. - If you do start racing at the club level, consider getting a few of the optional toe blocks to set the rear toe and possibly the aluminum steering set and aluminum steering bridge if you find there is too much slop in the steering. The stabilizer / anti-roll bar set could be useful as well. A few spring sets, an assortment of damper oils, and an assortment of diff oils will also help you tune for conditions. I'd skip the carbon parts and titanium screws -- you'd likely not feel the difference. I'd also skip the ball diffs, one-way bearings, and front direct coupling -- Just use the diff oils to tune the front and rear. - Something to think about -- Novak's Ballistic motor series has interchangeable stators, so you can buy a single 4.5T motor now and at a later date buy 10.5T, 13.5T, 17.5T, 21.5T, or even 25.5T stators at lower costs and reuse the motor can, rotor, sensor board, and sensor harness. This allows you to have multiple motors without actually having multiple motors. - A nice guide on RC car setup can be found at http://users.telenet.be/elvo/. -Paul
  16. speedy_w_beans

    Getting back into it, build advice? :)

    A few thoughts... I hope some of this is helpful. - TA06PRO: Nice! I have a TA05V2R; the R-level and PRO-level kits have all the nice goodies included. - 4.5T is a pretty hot motor; are you racing, bashing, or doing speed runs? The lower the turns, the faster things wear out or break on the chassis. Watch your belts and ball diffs; we all love doing full-throttle launches at times. Also, a low-turn motor will provide less run time. I'd also consider a 40C or 50C LiPo to keep up with the current drawn under hard acceleration. If it was me I'd be thinking about 13.5T or 10.T, a 30C to 40C LiPo, and changing the gearing to get the top speed. But this depends entirely on what you're trying to do with the setup. - Check your ESC and make sure it has low-voltage cutoff (around 6.2V to 6.4V) to protect the LiPo. If the LiPo's voltage goes too low the cells will be damaged. - Make sure you have a balancing board to correctly charge your LiPo battery. The cells need to stay balanced to minimize the risk of damage. - See if your charger provides a "storage charge" function. If you don't plan on driving the car for a few months, LiPos are happiest when they are about 40-50% charged and stored in a cool, dry environment. - You may want to use Deans plugs, Traxxas plugs, or bullet connectors instead of the usual Tamiya Molex connector between the battery, ESC, and charger to reduce the risk of a meltdown at the connector. - 2.4 GHz is the right decision for running brushless to avoid interference/glitching problems. - Coupled with the question about motor turns, are you racing, bashing, or doing speed runs? For racing, Protoform makes some popular bodies including a Mazdaspeed 6 that is supposed to provide more steering due to aerodynamic effects. Also check out Protoform for a slippery body to do speed runs. For general bashing and playing, the GTR body is perfectly fine. Again, this depends on what you're trying to accomplish. - On my TB-03 Xanaxi Nismo GTR kit, the supplied wheels are +2mm offset; these fill out the wheel wells pretty well. You might want to check wheel offset for the best "look." - What steering servo are you looking at? This could have an impact on the BEC rating of your ESC. If you're running generic low end Futaba S3003/S3004 servos, then there's not a big concern with 1-2A. But if you start running high-speed, high-torque, digital servos then the BEC should probably be rated for 3A or more to avoid glitching the radio receiver. Enjoy your build; it should be a lot of fun! -Paul
  17. speedy_w_beans

    What Did Santa Bring You? Christmas 2011

    @GregM: That's a really nice Lego Technic set (#8070)! My wife gave me #8880 Super Car ( http://www.brickset.com/detail/?Set=8880-1 ) back in the 90s, and it was a fun build. Your car looks more realistic and sleek. -Paul
  18. speedy_w_beans

    Suspension - does anyone take it seriously?

    @smittyvk: You might be interested in this: http://users.telenet.be/elvo/ -Paul
  19. speedy_w_beans

    Suspension - does anyone take it seriously?

    I've gone so far as to measure spring rates with a hobby vise, digital scale, and calipers. I would compress the spring by 10 mm and measure the resulting increase in grams on the scale; this was done for Dark Impact and Sand Viper kits, as well as an aftermarket spring set from Eagle Racing. Once all of the spring rates were measured, I then measured distances from hinge pins to shock attachment points and bearing hubs as well as weight distribution. The distance measurements were important to estimate how much weight each spring was actually seeing due to lever effects. Then I started changing springs either in the front or rear of vehicles to improve jumping response, and then adjusted oil weights to improve damping based on the new springs. This was all done with the kit CVA dampers. In the case of the Sand Viper I think the stock rear springs measured 428g/10mm, which were too soft relative to the front springs. They were replaced with aftermarket 563g/10mm springs, and the car was more neutral through jumps at a local track. With the Dark Impact I think we softened the front springs from 1100g/10mm to something like 900g/10mm. I was happier with the driving behavior; it suited my style more. The CVA oil dampers included in many kits are ok, but not great. The TRF dampers are much better because the piston seals against the wall of the shock body better and the piston thickness/hole sizing provides both "pack" and damping, where the CVAs don't really provide any "pack" for landing jumps. With our TRF201, DB01R, and Associated B4 the dampers are really quite nice. The CVAs on our Sand Viper, Dark Impact, and Durga are ok for fooling around; the Durga springs are more in tune with its chassis than the Sand Viper and Dark Impact. I've never bought a kit with friction dampers; that just doesn't seem like it will do the job properly or consistently. -Paul
  20. speedy_w_beans

    What Did Santa Bring You? Christmas 2011

    My wife really suprised me this morning when I unwrapped a re-release Buggy Champ; I had no idea that was lurking under the tree. @Percymon: Awesome Lego kit! Have you seen this time lapse video of the build? -Paul
  21. speedy_w_beans

    What's the best 2011 re re ?

    I'll vote for the Ford F150 Baja, Blitzer Beetle 2011, and re-re-release Lunch Box Gold Edition. I like the F150's body shell; the box art paint job is great. The Beetle seems like a fun runner for parking lots and streets. As for the Lunch Box, it's probably the one vehicle I have fun with every time I touch it. We need a Lunch Box Racing League! -Paul
  22. speedy_w_beans

    TL-01 Bowler Build

    Hi Percymon, You tried acetone and boiling, but did you try baking? I've heard about this technique as well, but haven't tried it for fear of damaging my wife's oven. -Paul
  23. speedy_w_beans

    Experimental TT01 Sealed Gear Diff

    Hi Mad & Zac, Thanks for the encouragement and ideas. RTV is a good alternative; I went down the nitrile/paper gasket path just to make it easier to disassemble the diff in the future. As a matter of fact, I cut a new nitrile gasket two days ago and installed it, and there hasn't been a leak since then. So, I'm encouraged by the results with a nitrile gasket and O-rings on the shafts. I ordered different O-rings two days ago as well, and much to my surprise they showed up in the mail today (Christmas Eve). Sometime early next week I should have a complete version 2 diff including machined drive cups with smaller recesses, new O-rings, new nitrile gasket, and standard ring gear/diff cup/bevel gears/spider gears. It should have less friction and less side play, and it shouldn't leak based on lessons learned with the version 1 diff. I'll post pics and details when it's complete. -Paul
  24. speedy_w_beans

    M-stick chassis

    I love how lightweight this vehicle is! I didn't quite understand what was going on in the video; was that zero throttle and full steering lock? -Paul
  25. speedy_w_beans

    What Did Santa Bring You? Christmas 2011

    - DB01R kit. - Blitz ESE Pro kit. - Two LiPos, two charging bags, and a charger. - A bag of Deans plugs. - A 1/32 mini Unimog as a stocking stuffer. -Paul