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speedy_w_beans

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Everything posted by speedy_w_beans

  1. Exciting stuff. I wish you lots of commercial success bringing these to market!
  2. I doubt any BMW engine could be tuned to legendary horsepower numbers like the 2JZ from Toyota. Toyota should have refreshed the MkIV drivetrain and put it in this car. I'll stick with Tamiya's MkIV releases.... Heck, I'd even take a MkIII shell...
  3. Oh man, as soon as I read you had a leak with the main shutoff that brought back bad memories of a 1970s house I owned in Pittsburgh years ago. Like you I had to do some repair work on copper plumbing and shut off the main valve. Upon turning on the water again I had a shutoff leak, and it took some tightening on the packing nut and some strategic valve positioning to get it to stop. What a pain! Other than the quick M4 build thread I did on Friday, I've been servicing all my outdoor equipment: mower, weed wacker, leaf blower, generator, snow blower, pressure washer, and chain saw. The mower was the worst; it's 14 years old and things are wearing out. The return springs on the transmission and blade clutch needed replacement, also the blade clutch cable. The handlebar height adjustment is broken, but I have that rigged with some drilled holes and bolts. It was time for a new blade. The tires have about 1/3 of the tread left, and the front ones are toed out some. My wife wants me to get a new mower, but the engine still runs great. I can't let it go until the engine or deck dies. If I can make it last 20-25 years that would make me happy.
  4. Very nice. Grastens and I were chatting about different classic F1s, and I had suggested at one point that a 2-4-0 would look great next to a Tyrrell P34. I had planned to take a F104 and make a custom rear pod for it, and recreate the body from public photos. But, it looks like you're doing all the hard work already, so I might have to consider one of your kits when it comes available.
  5. @Badcrumble, I took some measurements of the battery tray and it can take a pack up to 133 mm x 47 mm x 26 mm. The "fingers" at each end of the tray are below half height, and the mounting posts are inboard. I think the wiring coming out of a regular NiMH pack would fit without a problem.
  6. Thanks for drawing my attention to this; this 761 would be the perfect starting point for a 761C / 2-4-0. Is this officially licensed from Teknacon, the current owner of March's drawings?
  7. If I was measuring torsional stiffness of a chassis at home, I would start with a workbench, lawn mower blade balancer, block of wood the same height as the balancer, clamps, a 1 meter dowel with 1 cm markings, some weights on fishing line loops, and a measuring tape. The setup would be to clamp the rear of the chassis to the block of wood and workbench, creating a reference surface that doesn't move. Then support near the front center of the chassis with the balancer so it can twist freely. Center the dowel rod and clamp it to the front corners of the chassis. Now you can take a measurement from the floor of the garage to the one edge of the dowel using the measuring tape, and start adding weight to the other side of the dowel. After adding weight, measure the change in height of the dowel relative to the garage floor again. The weight applied to one side of the dowel at a known distance from the center line of the chassis is the torque you're applying to the chassis plate. The change in elevation on the other side of the dowel at a known distance from the centerline of the chassis will give you an angle of twist using the arctangent function on a calculator -- arctangent of (change in height / distance to the centerline of the chassis). It won't matter if weight side of the dowel flexes a little while adding weight; it's not the side you're measuring. The other side of the dowel doesn't flex because it doesn't see the change in weight. It's the same principle as a balance-beam torque wrench. The purpose of using such a long dowel is to amplify the small amount of twist the chassis plate might show. In theory you could clamp one side of the chassis plate to the reference wood block and clamp the dowel to the other side of the chassis plate to measure torsional stiffness in a different axis, but in that side-side axis I think the plate is so wide you won't get much meaningful information. The primary measure of torsional stiffness is front vs. rear twist. You could support the ends of the chassis on blocks of wood, apply weight in the center, and measure vertical displacement of the center, but you would need a decent reference surface (like an inspection-grade granite block) and a height gauge. That can tell you something about bending stiffness, but it changes as the chassis plate is built up to include other parts and even a battery clamped into position. So, those are some ideas for you. If you do create a setup and take some measurements, it would be nice to see some photos and hear about any insights you get.
  8. I wasn't ready to install electronics or a body onto the chassis just yet, so I omitted certain parts from bag 8 and bag 9 (servo arm and turnbuckle, antenna tube, servo tape, motor screws and pinion, and body posts). It did seem useful to wrap up the chassis portion of the build installing the battery tray, servo mount, front bumper, and wheels/tires. Here are the battery tray and servo mount parts from bag 8. The battery tray accommodates either standard or shorty LiPos, and has adjustments for length/width/height via fasteners and sliding parts. The servo mount is a modern floating design secured to the center of the chassis. Straightforward installation. Front bumper and tire/wheel parts from bag 9. One thing to note is the front body posts don't line up with Tamiya's M-chassis offerings. Swapping body shells between Tamiya and 3Racing chassis might mean an extra set of holes up front. The axle nuts are nice -- they're serrated and flanged. The tires come glued on the wheels already, and the rubber compound feels slick. They might be good for a test drive, but they don't seem to be a great compound for grip. Parts installed. There's no extra axle stub length beyond the serrated nuts; this means you may not be able to use regular nylon lock nuts. Just something to keep in mind if you're picky about axle nuts. Based on building this chassis to this level, here are my thoughts: Good Interesting, thoughtful, modern design features – single-screw outer suspension mounts, bulkhead-mounted steering, floating servo mount, convenient LiPo tray Intentional damper spring selection? Good materials and fasteners overall Minimal slop in finished assembly, smooth operation, things work as expected Neutral Documentation – print presentation, transition to online Some assembly sequencing – steering bridge and turnbuckles Axle stub threaded length Not much Ackermann Bad Center pulley mounting holes easy to strip if you’re not careful Some aspects of quality control – scuffed chassis plate, roll bar tweak, CVD pins Could use droop screw plates to protect the chassis plate If I had to rank the four 3Racing kits I've built so far, then from best to worst they would be: M4 M-chassis: In general this kit went together very well. D4 drift chassis: Close second to the M4; the black edition is really pretty good. FGX EVO 2018: Cool design and glad I own one, but there are some weaknesses in the execution of the kit. D3 drift chassis: Too many design and quality issues; it took a bit to fix things and make it work. I haven't taken the plunge and bought one of their high-end kits yet (like the Advance 2K18 EVO or the M4 PRO), but I'm getting closer to considering it as the experiences with these entry-level kits continue to improve. When I get around to painting the BMW 2002 shell I'll update the thread appropriately. In the meantime, I'm happy to field questions or take measurements for anyone who wants to know more.
  9. Bag 7 included the damper parts. Probably the most exciting aspect of this bag is how 3Racing provided distinct springs for the front and rear of the chassis; it implies they did some testing and intentionally selected the springs instead of throwing four of the same springs into the kit. Assembly was straightforward. Dampers installed.
  10. Bag 5 is all about building and installing the roll bars for the front and rear of the chassis. I was impressed to see the bars are supported by collars inserted into ball bearings; this is normally a feature found on more expensive touring car kits. I think the first time I came across this feature was with an Associated TC6 Factory Team kit a few years ago. There was something weird about the included roll bars, though. I was careful to position the collars the same distance from each end of the wire, and generally tried to center the bar and orient the collars in the same direction (set screw facing up), but when I went to test the coupling between suspension arms (which were 100% free/unbound), I found one arm would sag lower than the other arm. I played around with offsetting the bar to one side or the other, but what ultimately helped me balance the roll bar effect was to take one collar, loosen it, rotate it, and retighten it in a different orientation. This introduced an elevation change on that side of the bar and helped balance the spring effect. I found I had to do the same adjustment to both the front and the rear bars, although the front bar was less of a problem than the rear one. You may also notice one of the bars has stripes painted on it; the other one does not. There were no instructions or noted differences; I checked them with calipers and found them to be the same diameter wire, but it was still a little concerning there was a visible difference between the two. Ultimately I put the painted bar in the rear and the unpainted bar in the front. Bag 6 included parts for the front and rear uprights, as well as CVDs and turnbuckles. The CVDs came preassembled; I took them apart to check the cross pins for flats. Like the FGX EVO 2018, I had to use a Dremel to grind some flats in the pins to make sure they don't slide out during use. The uprights themselves were a snap to build up. The turnbuckles took a few extra glances at the parts list to confirm which adjuster to use at each end of the turnbuckle shaft; there are different lengths, closed and open cups, some that allow more angle than others, etc. It pays to check this carefully. Also, installing the steering turnbuckles on the center bridge is a little challenging given how close they are to the chassis plate; it may make sense to change the sequence of the instructions and install the turnbuckles on the center bridge before installing the steering assembly to the front bulkheads. Front and rear uprights, CVDs, and turnbuckles installed.
  11. Bag 3 is all about the motor mount, belts, and bulkheads. Everything went together smoothly. Each lower bulkhead is located with a molded-in pin and secured with a pair of countersunk screws. Threaded aluminum spacers add some rigidity between pairs of bulkhead parts at each end of the chassis. The motor mount is actually aluminum. The front spool, rear diff, and center spur/pulley assembly all drop into their respective bulkheads and have some default settings for belt tension. Note the front steering rack is now part of the front bulkhead; this is a modern trend with several manufacturers doing this now. The TB05 and EVO7 do this too. Bag 4 introduces the upper deck and damper stays; the main parts are cut from FRP. In particular, the damper stays are extra thick. Here are the upper bulkheads and stays for the front and rear. The ball connectors get their own plastic mounts that are then attached to the upper bulkheads. The combination fo the FRP stays and aluminum spacers make the overall assemblies very rigid. There's a fair number of button head screws holding the upper bulkheads and top deck in place. I noted in the FGX EVO 2018 build thread that all of the button head screws for that kit were tight on the end of my 2 mm driver; this had been the case in my D3 build as well. In the case of the M4, all the button head screws fit my driver just as well as the countersunk screws. No problems at all.
  12. Like the other 3Racing kits I've built before, the parts are organized into roughly 10 bags representing the major steps of assembly. Some kits have a few more bags; the M4 kit includes 9 bags. Wheels with pre-glued tires are included, but there is no body. This is purely a chassis kit. The first bag covers the front spool, rear gear diff, and center spur and pulleys. The gear diff is clearly not the same as the FGX EVO 2018's gear diff, as there is sufficient clearance to install the cross pin in the deeper case half without grinding any material. The front spool is typical and familiar from their D3/D4 kits. The center pulleys are a little unique in that they clamp the spur in the center. The gear diff went together smoothly, as did the front spool. However, I found assembling the center spur and pulleys to be a little delicate as the small screws and thin flanges on the pulleys made it easy to strip holes. Coming from the previous step of building the spool, my sense of feeling was calibrated for beefy M3 screws threading into plenty of material. Going to M2 screws with minimal mating flange material, I managed to strip the first screw hole but then install the remaining three screws correctly. In the end I backed out the first screw and added some CA to the hole and figured it was good enough. The next bag was for the main chassis plate and suspension arms. You might notice the plate has some scuffing on it, likely from handling in the factory. It's not a huge issue; it's just a detail I noticed after removing the contents of the bag. The arms went together quite easily. In addition to the ball connectors for the shocks, there are ball connectors for roll bars too. The inner split suspension blocks are normal for belt-drive cars these days; one thing I found interesting was the outer blocks only use one screw each to hold them in place. Each outer block has a pair of metal pins pressed into it and these pins in turn mate with holes in the chassis plate. This means it's a little faster/easier to remove the outer suspension blocks than regular 2-screw designs, but they should still be able to take some impact thanks to the pins. All of the suspension arms moved freely and didn't require any filing or fitting.
  13. Six or seven years ago I took one of my TT01s and converted it to a shaft-drive 4WD M-chassis using 3Racing's TT01 Mini conversion kit. At the time I think Tamiya had their TA05 M-Four belt-drive chassis kit available, but it was limited to 380 motors and the unique LiFe battery they had adopted in Japan. So, I went the conversion route, blinged it out, and topped it with a HPI Datsun 510 shell from their Cup Racer series (225 mm wheelbase). Overall I was happy with the result: I've been dabbling with 3Racing builds over the past couple years in addition to Tamiya builds, having completed D3, D4, and more recently FGX EVO 2018 chassis. Some chassis builds have been better than others; I found the D3 had some fundamental problems in materials and design, but the D4 was substantially better. The FGX EVO 2018 was pretty satisfying overall, but it too had some quirks possibly from the original FGX. When I saw the M4 belt-drive 4WD M-chassis offered for $80 USD recently, I jumped on it as an impulse buy to try with a HPI BMW 2002 Cup Racer shell that's been in my stash of bodies for some time. I reported yesterday (Thursday) that the M4 kit arrived in the "postman brought me" thread, and @Badcrumble responded to my offer to do a quick and dirty build thread on the chassis, so here it is. It was raining throughout the day today, so I used it as an opportunity to finish the chassis and collect some thoughts even before this thread is approved. The posts below will have some insights gleaned from building the chassis all at once. First, a quick word about packaging and documentation. There is a sticker on the top left corner of the box announcing 3Racing plans to not include hardcopy manuals in future kits; they include a few QR codes which represent web addresses for the product page and the manual page. The M4 kit I received did have a manual included with it, but it was bound in the same way as the FGX EVO 2018 manual -- essentially photocopied, punched with a few holes, and secured with a binder strap. I moaned about this some in my FGX EVO 2018 build thread, but the reality is it won't make any difference as 3Racing moves to electronic distribution of documentation in future kits.
  14. Gearhead RC did something similar with a central hub and more/less offset depending on how the wheel is flipped. What they didn't do, though, was come up with a spacer to go double wheels on an axle. As usual, you make nice stuff with the machine tools available to you!
  15. I think the DB02 Leonis suffered from too much weight and some early durability issues, at least with the rear prop shaft due to the angle to clear the battery. There was an upgraded rear prop shaft released relatively quickly. There wasn't much chatter or acceptance of the kit from the start. It was a point in history where there was no love from the Tamiya-nati for cab-forward Lexan buggy bodies. It went to closeout pricing relatively quickly in the USA and is discontinued. It was the same situation with the DN01 Zahhak; it seemed like many people didn't like the body or box art scheme. The cost to upgrade it didn't make sense in general when 1st-gen TRF201 kits were being sold at bargain prices. The DB01 proved to be a little more popular with Durga, Baldre, R, RR, and RRR kits released. If any of these three were to become a future classic, the DB01 might simply because there were enough kit iterations; this implies there were enough sales for Tamiya to keep making more of them. Enough people might remember them.
  16. Got a call from the local post office and picked these up today, a F104W and a 3Racing M4 (4WD M-chassis). The F104W is a donor for a custom project; it's in the long-term queue. Happy to do an abbreviated build thread on the M4 chassis if anyone is interested.
  17. @isomer1, I don't care much for step screws either; take a look at my in-progress build for some ideas on how to upgrade away from them.
  18. If the XMaxx is your baseline, then I don't think Tamiya will have anything to offer. It's "models suitable for radio control" vs. "the fastest name in radio control." Choose appropriately.
  19. Will we be getting red, blue, black, gold, and standard editions of this too?
  20. I don't think I've ever had a negative comment or judgment from others, but there is definitely a wide swath of people with whom this hobby does not register. I've learned over time to present the hobby as "detailed scale vehicle building" instead of "driving toy cars." People seem able to imagine sitting at a desk assembling something (much like a stamp collection or butterfly collection), but the notion of driving a "toy" makes it seem childish. By my estimates I'm over half way to the grave; there's not enough time left to really care what others think.
  21. Some TB03 bling to enjoy; I'm not even sure if you can find these carbon conversion sets anymore...
  22. Interesting. I've placed numerous orders with them over the past five years, and with only one minor exception every order turned out well. In that one instance I used live chat and submitted photos of the issue, and they took care of it. They seem fine for basic items like LiPos, chargers, wires, connectors, receivers/servos/ESCs/motors, and tools. The USA warehouse seems to deliver just fine.
  23. Finished this little oscilloscope kit. Total investment was $30 and about 4 hours of soldering. I used to have access to $80,000 oscilloscopes, spectrum analyzers, and other great test and measurement equipment from my employer, but for home hobby use this should work just fine. My neighbor is constantly working on his older cars, and there are times when it's nice to have something like this to monitor crank/cam position sensors, ECU data buses, even spark plug wires (with a coil wrapped around the wire), etc. just to be sure the wiring on the harness is functional. Anything timing related, really. It would also be nice to see waveforms coming from a receiver and going to steering servos and ESCs, or verifying other channels for lights, winches, smoke, etc. The specs are pretty meager with a usable input voltage up to 40V and a frequency up to about 100 kHz; published specs are higher but online reviews have shown its true limitations. It'll be an ok complement to a regular handheld multimeter.
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