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  • in reply to: 3D printed Indy Roadster chassis #18499
    racer68
    Moderator

    Hi guys

    I thought I’d give a quick update on my Roadster chassis. I scavenged some parts from existing cars so that I could start some testing. Very quickly I found that the shaft bearing would need some additional support as snapping it in had allowed  it to  occasionally pop out at speed and I didn’t want to glue it in until the entire car was finished and ready to race. So I designed a little screw in brace. The 3D printer really has trouble printing tiny parts and holes but after a couple of iterations I came up with this :

    It’s strong enough to accept the small Professor Motor body screws I had on hand and keep the bearing in place, while still being removable for any drive train changes.

    Cheers

    Steve

     

    in reply to: 3D printed Indy Roadster chassis #18508
    racer68
    Moderator

    I added the bracket as the shaft bearing was popping out at speed, the snap fit I had designed was enable to restrain the torque of such a mighty motor!

    All better now, things are starting to slowly pull together.

    Cheers

    Steve

    in reply to: 3D printed Indy Roadster chassis #18507
    racer68
    Moderator

    Bracket for shaft bearing

    Cheers

    Steve

    racer68
    Moderator

    Hi Art

    I’m having some of  the same types of issues as Felix. I made a post to an existing topic yesterday morning(which may have gone over the size limit because of  inadvertently choosing the wrong image) and it has not yet shown up but some of  my posts often take a day or more to be visible and some I’ve had to redo several times despite seeming to fit all the specified parameters.

    Cheers

    Steve

    • This reply was modified 7 months ago by racer68.
    in reply to: 3D printed Indy Roadster chassis #18485
    racer68
    Moderator

    Thanks guys

    At some point I think I’ll try to get a list of the wheelbases and overall chassis lengths of the bodies that people would like to use so that I can modify and  archive the appropriate print files for each body.  I’ll need to finish my testing of the final chassis first. There are also some hard limitations on what can be designed. The chassis at this point is exactly 20 mm wide at its widest point and can not be made any narrower without rotating the motor 90 degrees. The position of the motor in the chassis can not readily be set back without running afoul of it’s front engined intent, as it is already at the base of the windshield on my Eldon Watson Roadster, though other cars may have a little more leeway. The wheelbase which is currently 66.9 mm can be lengthened readily but using a spring coupler for the shaft means there are some real packaging constraints and the current space of about 18 mm between the motor and the support for the rear axle and gears is the only place to shorten the wheelbase. With careful fabrication the most the wheelbase could be shortened would be about 10 mm. If you wanted to use body posts for mounting the body the front post would have to be ahead of the guide and the rear post behind the crown gear. These limitations are not unique to this 3D printed chassis but are based on the provisional rules, scale and packaging constraints. There are many alternate ways to mount a body but they would have to be accounted for in the chassis design. I still have a lot to learn about 3D printing and design but I think it is another tool that can make our Hobby more rewarding.

    Cheers

    Steve

    in reply to: 3D printed Indy Roadster chassis #18446
    racer68
    Moderator

    Good Morning Racers!

    I thought I’d share an update on how the 3D printed chassis project was going.  Unfortunately the adjustable chassis idea was just not workable as in order to have enough strength it meant that it would be too wide for some of the roadster bodies eligible for this class. Luckily, as my fusion 360 design skills slowly improved I found that parametric modelling allowed me to easily change the wheelbase in software for each individual car. My wife, who has been very supportive of my various hobby obsessions even bought me a full size 3D printer ( a Tronxy XY-3 Pro ) so that I could print a chassis in one piece.

    I found a free file on Thingiverse for printing a Dremel chop saw attachment and with only minor modifications I had a way of making precise cuts for the motor shaft, the tubing adapter, the spring connector and the 2mm gear shaft.

     

    I went through several iterations of the chassis design to make sure all the components would fit and align properly and that the chassis would be strong enough to take the abuse that a roll over expert like myself could inflict. Here is the final result in black and another earlier version in orange, for greater visibility, sitting on the 3D printer bed.

     

    There’s some more work to do fitting and testing the components and then trying the whole thing out on my plastic test track. I’ll try to do another update in a couple of weeks. In the meantime you all stay healthy and we will be racing again by the end of the year.

    Cheers

    Steve

     

    in reply to: 3D printed Indy Roadster chassis #18337
    racer68
    Moderator

    Hi Drew

    Thanks for the compliment. I am still developing this chassis and hope to do basic debugging  on my Plastic track. The chassis as it stands is fairly stiff but the space just over my initials is designed to hold some weight, either a piece of brass or some lead in order to move the center of gravity further towards the rear axle.  with  brass glued in it should be extremely stiff, my initials are just a little bit of vanity and are not likely to stay as is. The needs for flexibility in certain planes of a  slot car chassis is very complex in such a small narrow chassis with a front motor but I am experimenting with some webbing reinforcements in  order to keep the flex only where it’s wanted.  3D printing allows me to vary the thickness of the chassis strategically and Fusion 360  even has tools to show where the stresses are, although these are still beyond me. I am trying to modify my design so that I can do a precise wheelbase for those that  already have bodies that they would like to fit. The material I am using is PLA which is very stiff but somewhat brittle and I’m going to experiment with an enhanced PLA, PETG and ABS to see which is the best combination of printability and durability. If I can get my design refined enough to be useful to others I’d certainly consider producing at least a small run. I think the Indy Roadster class is a natural for this type of chassis as between this chassis and Art’s body anyone could build a car to qualify for this class.

    Cheers

    Steve

    in reply to: 2021 Outside Track Optimism #18012
    racer68
    Moderator

    I’m not sure about the details of doing an outdoor race but Luis has very generously mentioned that he has a place where a bathroom would be available and that would go a long way to convincing me to participate . I look forward to when we can race again but the pandemic has been difficult for my family and I think continued caution is warranted. My aunt got very ill with Covid and developed kidney failure and  my cousin Nick died. Tele-funerals are a sad and surreal thing. Scarborough has been particularly hard hit and I think the vaccines are our best hope right now, people don’t seem to have either the personal discipline or the sense of shared fate that would help us out of this before they arrive in bulk.

    I’ve been working a little on the Indy roadster class and inspired by Colin John over at Group 25’s facebook page I’ve even slowly been learning fusion 360 in order to be able to make custom chassis for  my roadsters. My current 3D printer is a malevolent toy that is not large enough to print an entire chassis but I’ve been experimenting with ff050 motor pods and shaft supports and I thought I’d share this picture of my current iteration.

     

    the pod in the foreground should meet the criteria for motor placement, the one behind is a few millimeters too short. They both fit the motor very securely without the need of screws or glue. The parts have been designed to work with standard size Scalextric or Carrera bushings or their bronze equivalents. I’ve been using PLA to print and as it is not as strong as the ABS  or Nylon that a manufacturer might use so I’ve had to make  some compromises in design to make up for its relative fragility. It is stiff and very light. The whole chassis without fittings will weigh just under 6 grams! I hope you are all well and if we can’t race ’em it least we can build ’em!

    Cheers

    Steve

    in reply to: Simple Spray Booth #17854
    racer68
    Moderator

    Looks great Drew, thanks for the pictures, I like the use of the cut down furnace filter. Is that a Ranchero on the turntable ready to be painted tomorrow?

    Cheers

    Steve

    in reply to: Simple Spray Booth #17843
    racer68
    Moderator

    Hi Drew

    Sorry I missed your question until I saw Ken’s recent post. I used a wood working dust port That I found on Amazon : Big Horn 11428 4-Inch Dust Port with 4 Mounting Holes .

    This one is offset to one side as it fit the space that I would usually use the best but there are straight ones available as well. I then used a large hose clamp to attach the ducting to the dust port. I used the box in a box design as it makes it easier to pack up and move around. It is a little easier to seal but it’s probably much of a muchness especially if you don’t move your booth often.  I think your enhancements sound great. More light is always a good thing and the turntable is something that I need to get for mine. Please post your finished booth. I find it fascinating the different ways our club members can solve the same problem.

    Cheers

    Steve

    in reply to: Ford Model T Hot Rod #17722
    racer68
    Moderator

    Thanks Felix

    There is a wealth of experience amongst our friends and I appreciate your sharing yours. Photos are especially helpful. I think that I can use your approach as I’ve had the same issues with off centre holes and wandering. I’ve been trying to work on a low power ff050 front motor chassis in between more pressing projects and precision is important because of all the other potential power losses with such a design.

    Cheers

    Steve

     

    in reply to: Ford Model T Hot Rod #17538
    racer68
    Moderator

    Thanks DB

    I especially appreciate the included photo. I don’t have Ken’s skill either but  I have the drill press and with a couple of drinks to steady my nerves I think it’s worth a try.

    Cheers

    Steve

    in reply to: Ford Model T Hot Rod #17527
    racer68
    Moderator

    Thanks Gary

    It’s great to have more resources . Does anyone have any experience or tips on building scratch built brackets? I’m trying to figure out how to build modular chassis with scratch built parts so that a limited set of modules could be used for both rear and front motored cars( such as Indy Roadsters) of different wheelbases.

    Cheers

    Steve

    in reply to: Ford Model T Hot Rod #17520
    racer68
    Moderator

    Looks great Gary, I love that the motor is fully exposed. It gives it that real “Hot Rod” feel. Would you please give us some details on your rear axle bracket, did you fabricate it yourself ?

    Cheers

    Steve

    in reply to: Simple Spray Booth #17438
    racer68
    Moderator

    Drew the fan looks fine, good specs, good price, good reviews. Using twin or triple fans does need either a custom box or vent but it’s all just bench racing until you actually have to  do it and I haven’t done it yet. If I get around to the upgrade in the next few months I’ll post photos. My original booth was designed  for easy disassembly and storage, that’s why I used the box in a box idea. The rear exhaust assembly is attached with a hose clamp which can be loosened and the whole thing stored inside the tote with it’s lid on. None of us ever have enough room for all our toys!

    Cheers

    Steve

Viewing 15 posts - 16 through 30 (of 68 total)