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About DesignerDave

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  1. The function of the wastegate valve is like you say, to bleed off pressure when it reaches a certain limit. In that respect you are right, although it is much more like an air pressure regulator in function than any sort of governor. A governor of a lawnmower engine cuts fuel/air if the engine exceeds a certain RPM, at least the one like you described, thus limiting engine speed. The wastegate however isn't limiting boost to slow down the engine. It's limiting boost to keep the stress levels down of all parts exposed to that pressure. If you keep letting the pressure go up, the engine internals will have to withstand high pressure as will the hoses and everything else. If you were to floor the pedal even with the wastegate being actuated to bleed of excessive pressure thus maintaining a set max pressure, the engine could still rev to destruction. The ECU will be what intervenes prior to that, while the wastegate just did it's part to keep the intake from having too much pressure in it. That photo reminds me of how the older two strokes actuate their exhaust valves. Spring preloaded ramps that have ball bearings in them. Scooter CVT's are similar, as are Sleds CVT's... although those are usually pivoting arms instead. The list is endless.
  2. Activity in general with Smarts seems to have dropped considerably, this website included. At least it seems to have anyway. Dave
  3. Thank you very much for your feedback. I agree with you that really the electronic shifting isn't nearly as important as the manual clutch, the only real problem is you can't really have one without the other. Mercedes could easily do it but without the ability to make drastic changes to the ECU software it really isn't practical to keep the entire OEM shifting configuration. I could interface with the electrical motor and add a solenoid to the shift lever assembly, it is important the driver have feedback as to the exact moment the gear is engaged. Even so, to keep the gauges showing the gear is still unlikely. You couldn't have the ECU trying to shift for you on it's own because you need to press the clutch to do this. The ECU still needs to think the car is in neutral or it'll show three bars the second it requests for clutch movement and it doesn't happen. At least this is what I assume it would do if it didn't have clutch movement within a certain time allowance. This first design has an external slave and external cable operated detent/shift unit. We'll see how that works out and if we need to go back to the drawing board that is okay too. I'm trying to make this as cheap as it can be both from a manufacturing and installation standpoint. Hopefully this will not require any sheetmetal cutting, that will be confirmed next. We'll probably build a bunch of other smart widgets along the way. Would anyone find tapered plates to slightly widen the rear wheel spacing and take out the camber angle useful? I could whip those up like hotcakes, better than cutting, welding and painting, especially for the average owner? Thanks again for your helpful perspective! Dave
  4. Would anyone care if we just ditched the carpet around the pedals and put in a vacuum formed thermoplastic mat instead? As you can see in this image of the same pedals with only the sheet metal shown, there is much more room when you ditch the carpet. I'm thinking something similar to a weathertech mat style material. I consult and machine for a plastics company here that uses the same vac forming machine WeatherTech does, it wouldn't be too hard to make a new custom mat for that area. This would not only really help with the space down there, but also make it easier to keep rain and snow away from everything. Also it would be easier to install the clutch master cylinder below the floor and make a new "box" that bolts on from underneath to attach the brake and clutch to. My understanding is that the existing unit isn't perfect anyway. Not sure if people would hate the idea of cutting a hole in the floor if a template was provided? I'll see how far I can get without resorting to any of that. I'm open to feedback as always!
  5. I've been spending a little time getting a feel for what is reasonable in the world of racing pedals, in terms of spacing between them. As I mentioned earlier my racing background is on the motorcycle side so I don't claim to be an expert in what works best in the world of pedals. What you see below is the preferred pedal spacing used by some drivers. The Lotus Elan came from factory with actually a tighter spacing than this, so this isn't actually as bad as it looks, and this is with the carpet still in place. If I ditched the carpet there would be plenty of extra space, but that isn't the plan. (Although the carpet is heavy and I would love to ditch it) The location and width of the throttle is the same as stock. The really wide (ugly) brake pedal tread is gone, instead is a racing setup sized pedal used on all three, which is common. I think the wide brake pedal makes it look impossible to install a clutch pedal with any reasonable amount of leftover space. I'm going to make the pedals adjustable on the arms to adjust as needed once it's together. Also I'm getting rid of that annoying offset between the pedals from the driver, flat across will be much more comfortable I think. Obviously since the dead pedal is also the wheel well, that will still be there.
  6. Yes, can be used not matter how bad the fork is, unless you have made something else and totally messed up the fork. The typical hole left by the actuator is not a problem, this is one of the major advantages to the concept. Worst case: Fork gets hole in it and car is now immobile. Pull actuator, install tip and replace. Other than having to calibrate the actuator, you are good to go, forever (Until something else breaks)
  7. Tolsen: The cost of the fork is irrelevant in this case because of the cost of labor to change it, and the sad fact the new fork will have the same problems the old fork did. It is not a fix, just a consumable at that point. A consumable that is very time consuming to change. Thanks CANMAN for confirmation of the adjustment. Adding the acorn isn't really a fix either because the problem is primarily the relative motion between the tip of the actuator and the fork itself. What really doesn't help things is how low the hole is for the actuator. If you ever go through a puddle or dusty conditions everything will be introduced to that point and just make the "grinding" even worse. The other pivot point doesn't see the wear and tear because of how shielded it is, because it has a spring to keep it fully engaged and lastly because it sees quite a bit less angular displacement due to it's location. Anyway, I spent far too long designing a little replacement tip for the actuator, the profile exactly matches the socket of the clutch arm so you can remove actuator, place tip on actuator, install and the problem is gone for good. The motion and friction is now between the special heat treated and coated insert and the tip of the actuator in a sealed environment with the appropriate grease. The arm only sees the pushing force of the actuator, not the "rubbing" as before:
  8. Very interesting for sure. Thank you for your feedback, I'm certain that if you would prefer the less labor intensive installed unit and you are already capable of doing the more labor intensive install, that easily holds weight with anyone who doesn't actually work on the car themselves. 10 hours worth of labor (likely more by the time it's all said and done) is a lot of money to be saved and easily justifies a little more cost on the kit itself. Dave
  9. No need to guess, I have a low-ish mileage clutch arm right here. Now I can see the exact radius of curvature they used in both sockets, it isn't constant. (Don't worry, eventually I'll stop posting shots of 3D scans and CAD files and start posting pics of actual machined parts, but since this is the start, this is what you see first!) More to follow soon on this little fix. Could save all of you quite a bit of time and money fixing your smarties! By the way, if you are thinking of modifying your actuator, please wait! Dave
  10. I think I have a solution for this problem that can be done in-situ that will last the life of the vehicle. As many of you know, I've been working quite a bit on transmission & clutch actuation related items on this car lately and I didn't want to invest the time in an external clutch actuator until I solved this ball socket wear problem. I'll post pics of the new design shortly. I have a high precision CNC lathe here so I can whip these up like hotcakes. - Quick question, and this is important to my design: Is Anyone's actuator anywhere near the limit of travel in the bolt slots AWAY from the bellhousing? Both of mine here are near the middle. Middle or closer is perfect, further and I need to know. I would think MB can hold close enough tolerances that everyone is in the same ball park. I assume as it needs to be adjusted over time it keeps getting closer to the bell housing right? Please let me know if you know! Dave
  11. Thanks! To answer the question about just swapping transmissions: The transmission the car has now is a manual transmission in every way. No need to change it, it has the right ratios, right clutch, everything. Just need to take the actuators off and put "adapters" on it to allow direct mechanical control, that is what I'm doing. I'm going to finish the shifter and pedals tonight hopefully, but I'm stuck on the shifting actuator. I'm getting prices back on all the purchased parts, the external unit will automatically increase the whole price of the kit by at least $250. I'm trying to keep the cost of such a kit down because I know Smart car owners, especially the cdi group, are very conservative with their pennies (nickels now I guess?) Another question for all of you: Which matters more to you? Lightest and best performing package at the expense of having to drop the transmission, split the cases and install the kit or, Higher cost, bolt on solution at the expense of more inertial resistance while shifting but hopefully much less labor cost to install. To be honest I've never tried to drop just the transmission alone with the engine in the car, I assume you still have to drop the engine/transmission assembly to do this, just to get access to all the bolts around the bell housing? Any time I've worked on my smarts I just drop the subframe. I don't want to assume most owners are comfortable with doing this. Once I finish the pedals and shifter I'll need to decide before cutting metal. I personally don't mind pulling the transmission and going that route, but I want to run with whatever most people would want to go with. Dave
  12. Quick update on this: After designing everything to fit inside the transmission to make the car shift manually I couldn't help but think that no one would want to invest the amount of time and money it would take to install those parts just to have the smart a true manual car. So, set that design aside, here is what I have now. Although mechanically simple and rugged, this is a geometrically complicated unit. It is a cable operated detent unit that bolts on in place of the electric shifting motor, being very similar in both size and weight. To install, you remove the old shifting motor, making note of what gear the car is in. The best would be to leave it in reverse before you take the motor off, but that doesn't really matter. Then you shift this unit in the same gear and bolt it on. Run your cables, install the shifting stick, pedals and external clutch slave (changing so you can do this without dropping the engine), install dummy electrical connectors and your done. The hardest part of the whole job will likely be dealing with the frozen bolts holding on the electric clutch actuator body. At least that will be the last time they need to be touched, as the hydraulic slave is self adjusting. This shifting unit has a very unique detent that changes the rotational output per shifter stroke depending on the gear. To shift into Neutral you just row down to 1st and then it's a half shift, with the shift into R being a difficult tall detent well over half way through the shifter travel, the only shift that is like this. This will be very obvious to the person shifting just by feel, and I don't think anyone will shift into R by accident. The shift from 3rd to 4th is still two shifts offset internally because the drum doesn't get changed, you just perform the action in the same angular displacement of the shifter arm that you do all the other shifts, so it will take a bit more effort to complete that shift, but the transmission is not at risk of any mashing of gears. One thing that is nice about shifting the car manually is not only that can shift hard and fast when you want to, but you can actually take it really easy on the transmission when you like, shifting really slowly when it's cold for example. I really appreciate comments and feedback on this project. I hope I'm not the only one that finds this idea to be worth doing. I've wanted a manual diesel smart since I first was in one! Dave
  13. A Smart car is a great "single owned vehicle" if you were debating between it and a motorcycle. It carries more cargo than a motorcycle and keeps you drier, but it doesn't carry more passengers. When I was a young man all I had was a motorcycle at one point, so this does actually apply to some people. The Cdi also gets better fuel economy than most bikes. When you compare it to other cars, it only makes sense if you have to drive in very tight areas with hard to find parking, or if you want to put decals all over it, they get more looks than many vehicles. If you can't work on it, think hard about whether or not you should just buy a new electric or something. Any German vehicle that is old will cripple you if you don't do the work yourself. Especially a German diesel. Having just said that, I say you should go with a VW Golf TDI (1.9L ALH) with a manual tranny and don't look back. Easy to work on and get better fuel economy than even the cdi does if the speeds are frequently on the highway. I've owned three and I've owned three smart cars and I love my smarts, but for an only vehicle the Golf is a hatch with a ton of versatility and relatively cheap parts for what it is. They also have the best crash test ratings in the business. Dave
  14. Thanks for your feedback! I've almost finished designing the new drum with the pattern just like you suggested. I can make the lockout optional so if people want to add the lock to go into N or R they can. After getting all the geometry input and playing with each syncro and the new detent design I can say you will know just by feel when you shift into N. I'll have a green and red light that come on when you are in N and R, obviously the car needs to know R for the back up lights, so we'll see how I have to go about that, whether I just bypass the existing wiring to the bulbs and just run my own discrete circuit, time will tell. Anyway, when the syncros are disengaged, it takes almost no effort, they practically help you, so the only resistance you have to overcome is my new star detent for half the shift, the original side ball detent no longer does anything. When you shift into gear it takes a little effort to slide the syncro in. You will be able to feel that although you did overcome the detent, you didn't actually engage a syncro, mind you the detent will do some of that work for you. It'll be fine That 3 to 4th shift will be interesting. By using 8 positions (A full shift for N) I can only have 45 degrees of barrel rotation for each shift, so I can't really offset the syncro engagement of the two sets of syncros. The design of the shifting forks prevents you from having too steep of a ramp on the drum. It's actually very clever, those inserts are what allowed them to make the barrel out of aluminum and still have good life.
  15. Ahh typical Tolsen post. Your right, I should look into it. What do your local laws say about you messing with your EGR system, or your wheel bearings, or your alternator pulley... What would your insurance company say if you told them you figured you had a better setup for lubricating the front WHEEL bearings on your smart car? I mean, it's not like a locked wheel could ever be a liability. I think my insurance asks if I have modified the car for performance. I can honestly say no, because as you pointed out earlier the transmission already shifts as fast as possible, so clearly this mod will lower performance. I'm good! Thanks though. Really.