This is a guide to how I built my 3DP popsicle chassis. It's aimed at the complete beginner to 3D design and Windows 10 users (sorry Apple fans)
This is to show that you don't need lots of drawing or CAD skills to be able to produce useful, but simple, designs for 3D printing and that you shouldn't be put of having a go.
When I bought my first 3D printer, I had no idea what I would do with it and treated the purchase more like buying an expansive man toy. I certainly had no thoughts about designing my own objects for printing, my drawing skills are still very basic and at the time I had no desire to learn to use a CAD program.
Over time I have printed a few things with the printer but never made full use of it. Over time the range of available slot car items that can be down loaded and printed has grown considerably and II started to down load any suitable chassis I could find and the odd body but I had the need for a simple chassis that would be adjustable in wheelbase and also width, I also wanted it to take any motor type and have adjustable mounting points. I have I have a few PCS and MRRC adjustable chassis that meet the first two requirements and even a few Revell Ladder chassis the meet the first one but none of these allow for the other options. While browsing the forum an article was posted that included a popsicle stick chassis and I realised that it should be possible to make a plastic printable version that would be fairly simple to adjust as required and meet all four of the above requirements.
So, let's build a simple chassis. First let me say that this is aimed at Windows 10 users as I don't know if any similar software is available for Apple users, although you should be able to do this using many of the free CAD software.
To follow along you will need Windows 3D Builder.
A basic popsicle stick chassis just two rectangular sticks held apart with cross braises that hold the motor and guide flag in place, so where do we start?
The most important thing to remember, to simplify construction is to keep the centre of the rear axle on 0 for its X axis and the centre line of the chassis and motor on 0 for its Y axis. With this in mind we will start with the rear axle as all other parts are measure front the centre of the rear axle. Insert a cylinder and rotate in to 90º roll, the diameter isn't that important at the moment and can be set to either that of your axle or a bearing. My rear axle is set to a X and Y measurement of 5.2mm, which on my printer gives a good push fit for the bearing.
The next thing we need is two chassis side members, these are mad from a cube so insert a cube or if you want rounded end to the chassis use the custom option. You can adjust any of these measurements to suit your own requirements. If using the custom option, the only change is to set the roundness to two and then add, the starting measurements are X=70, Y=2.8 and Z=10. The under the object menu select settle for the side bar. At this point change the Z position of the rear axle to 5mm so it is in the middle of the side bar.
A couple of points to remember. At the end of each process use the deselect circle in the right-hand selection menu, just to be safe. All changes to position are based on the centre of the object selected. All changes to the size of the object will keep it centred on the same point. If you make a mistake just undo it.
We now need to position the side member in relation to the rear axle and we need a rear overhang of about 10mm, you can adjust this later to suit your crown gear and body. The new X position for the side bar is 35, half the side bar length less the over hang of 10 and less half the axle diameter 2.6 which is 22.4, which we can round down to 22.
I find it easier to colour code parts as I build the chassis to make it easier to know what parts linked and I use red for parts that will later be removed.
The side bar now needs positioning relative to the centre line and for this you need to know the width of you motor. The centre of your motor will be on the Y=0 so the side bar needs to be at Y=0 plus half the motor width plus some clearance, say 0.5mm, plus half the width of the side bar, 1.4, which for me is 11.5mm. Change the side bar Y to 11.5mm. We can now make and position the second side bar, with the side bar only selected from the object menu select duplicate and set the new side bars position to the same X and Z as the first and the Y to the same but negative value, in my case -11.5.
As long as the we have an identical positive and negative value for these parts anything on Z=0 will be in the centre.
Using the required wheelbase, we can place the front axle. I use a diameter of 2.65 for the front axle so it's position will be the wheelbase, say 68mm, less half the rear axle diameter, 2.6mm, less half the front axle diameter 1.32 which is 64.08. You can duplicate the rear axle and change its X and Y dimensions to both be 2.65. then set its X location to 64.08 and here you will notice a problem in that the axle is in front of the chassis, this isn't a problem as we need to duplicate the side bars so we can extend the chassis and at the same time make it wider. Select just the two side bars and duplicate them. Now click so that you can see them paint them a different colour, say black. Then drag them to the right, using the green arrow until the rear is just past the rear axle.
We need top make these bars further apart so select the top bar and add 2.5mm to its Y position and make the front bar thew same negative value. This gives an overlap of about 0.3mm at the join of the bars.
This is to show that you don't need lots of drawing or CAD skills to be able to produce useful, but simple, designs for 3D printing and that you shouldn't be put of having a go.
When I bought my first 3D printer, I had no idea what I would do with it and treated the purchase more like buying an expansive man toy. I certainly had no thoughts about designing my own objects for printing, my drawing skills are still very basic and at the time I had no desire to learn to use a CAD program.
Over time I have printed a few things with the printer but never made full use of it. Over time the range of available slot car items that can be down loaded and printed has grown considerably and II started to down load any suitable chassis I could find and the odd body but I had the need for a simple chassis that would be adjustable in wheelbase and also width, I also wanted it to take any motor type and have adjustable mounting points. I have I have a few PCS and MRRC adjustable chassis that meet the first two requirements and even a few Revell Ladder chassis the meet the first one but none of these allow for the other options. While browsing the forum an article was posted that included a popsicle stick chassis and I realised that it should be possible to make a plastic printable version that would be fairly simple to adjust as required and meet all four of the above requirements.
So, let's build a simple chassis. First let me say that this is aimed at Windows 10 users as I don't know if any similar software is available for Apple users, although you should be able to do this using many of the free CAD software.
To follow along you will need Windows 3D Builder.
A basic popsicle stick chassis just two rectangular sticks held apart with cross braises that hold the motor and guide flag in place, so where do we start?
The most important thing to remember, to simplify construction is to keep the centre of the rear axle on 0 for its X axis and the centre line of the chassis and motor on 0 for its Y axis. With this in mind we will start with the rear axle as all other parts are measure front the centre of the rear axle. Insert a cylinder and rotate in to 90º roll, the diameter isn't that important at the moment and can be set to either that of your axle or a bearing. My rear axle is set to a X and Y measurement of 5.2mm, which on my printer gives a good push fit for the bearing.
The next thing we need is two chassis side members, these are mad from a cube so insert a cube or if you want rounded end to the chassis use the custom option. You can adjust any of these measurements to suit your own requirements. If using the custom option, the only change is to set the roundness to two and then add, the starting measurements are X=70, Y=2.8 and Z=10. The under the object menu select settle for the side bar. At this point change the Z position of the rear axle to 5mm so it is in the middle of the side bar.
A couple of points to remember. At the end of each process use the deselect circle in the right-hand selection menu, just to be safe. All changes to position are based on the centre of the object selected. All changes to the size of the object will keep it centred on the same point. If you make a mistake just undo it.
We now need to position the side member in relation to the rear axle and we need a rear overhang of about 10mm, you can adjust this later to suit your crown gear and body. The new X position for the side bar is 35, half the side bar length less the over hang of 10 and less half the axle diameter 2.6 which is 22.4, which we can round down to 22.
I find it easier to colour code parts as I build the chassis to make it easier to know what parts linked and I use red for parts that will later be removed.
The side bar now needs positioning relative to the centre line and for this you need to know the width of you motor. The centre of your motor will be on the Y=0 so the side bar needs to be at Y=0 plus half the motor width plus some clearance, say 0.5mm, plus half the width of the side bar, 1.4, which for me is 11.5mm. Change the side bar Y to 11.5mm. We can now make and position the second side bar, with the side bar only selected from the object menu select duplicate and set the new side bars position to the same X and Z as the first and the Y to the same but negative value, in my case -11.5.
As long as the we have an identical positive and negative value for these parts anything on Z=0 will be in the centre.
Using the required wheelbase, we can place the front axle. I use a diameter of 2.65 for the front axle so it's position will be the wheelbase, say 68mm, less half the rear axle diameter, 2.6mm, less half the front axle diameter 1.32 which is 64.08. You can duplicate the rear axle and change its X and Y dimensions to both be 2.65. then set its X location to 64.08 and here you will notice a problem in that the axle is in front of the chassis, this isn't a problem as we need to duplicate the side bars so we can extend the chassis and at the same time make it wider. Select just the two side bars and duplicate them. Now click so that you can see them paint them a different colour, say black. Then drag them to the right, using the green arrow until the rear is just past the rear axle.
We need top make these bars further apart so select the top bar and add 2.5mm to its Y position and make the front bar thew same negative value. This gives an overlap of about 0.3mm at the join of the bars.