As you can see in the pictures below the steering is hitting the arm causing it to break easily
Are there any versions where the steering bracket is mounted a bit further away? I seem to be having enough space inside the wheel.
Building instructions, suggestions, questions and everything about this chassis and its related parts
All types has been updated in the suspension system publication.
I have stretched the wide of the C-hubs and Rear Fixed Blocks from 22mm to 21.8mm so it enters easier into the lower arms.
I have done something similar to all the front steering blocks but just in the part that touches the C-hub, so it will enter easier too.
I have added the Botyoyo corrections to TypeC and my own to TypeA and TypeD.
So please, if you have your folder with the files, update them with this new ones please.
Find them here: OBTS Chassis Suspension System Publication
I tryed to make them a little more ressistant, the same way i tryed to follow Botyoyo's advices about it and incorporated the pin lock system from MTC chassis.
You can find them in the OBTS Chassis Suspension System Publication. Look for the "upgraded" files in the file list.
(any correction welcome)
If you follow this instructions and the ones in the related publications you should come from this:
To build this:
The parts in this photos doesn't include the sides of the chassis, so the weight of the printed parts will be bigger.
On-Road, Buggy, Truggy, Short-course would be 4 different types of rc cars. As this OBTS Chassis has been my first one, to try to get to the most people possible I tryed to make a configurable chassis wich would allow to build those types of cars, "more or less"... There are many differences between this types, starting from wheelbase, the wide of the car, the size of wheels, the spected speed, the height to the floor...
But options are not only to build different types of rc cars, also to give more chances to build some parts of the car, as the steering system wich can be build with 3 different sizes of bearings. Something similar happens with the normal Buggy / Truggy CVDs, there are various options so you can choose the one is easier or cheaper for you to find.
I think an interesting start point is the type of car you want to build and its related wheelbase.
Now you must know wheelbase will influence the max. size of battery in length and also the length of the motor can. So for example, for a 255mm wheelbase the max. battery length will be 135mm. For a standard 270mm wheelbase it will be 150mm. Also the length of the needed central dogbones for transmission will change with wheelbase and "partial wheelbases"
New dlb's concept: Partial Wheelbase :S The car chassis, mostly in all its structure, is divided in front and rear parts. This is needed to be able to print them in the most common printer bed size, 200x200mm.
Hey! I almost forget about it. I created my Youtube channel to upload all my videos about MyRCCar and some other future projects. Here you have some links for OBTS chassis related videos:
Related Publication -> MyRCCar OBTS Universal Chassis
If you take a look to the first MyRCCar publication, the OBTS main chassis, i shared the parts in "kits", related to this front or rear partial wheelbase. For your chosen wheelbase, choose a front part kit and rear kit wich sumatory is that wheelbase. So for example, for a 270mm wheelbase you could use the 135mm front part and the 135mm rear part. This "simetry" in the partial wheelbases is the best if you want to use the same central dogbones for front and rear transmission.
Now is time to see wich is the biggest front or rear chassis part you can print. The 135mm partial wheelbase bottom parts of the chassis measures 186mm in their longest direction. So a 145mm partial wheelbase bottom part will measure 196mm, and so on. This ones would be the max. size printable in a 200x200mm. If you have an Anet A8 with a 220x220mm bed you could print the 155 and 165 partial wheelbase bottom parts too...
As you can see in the drawings in the OBTS main chassis publication, there are indications for each partial wheelbase, as the desired dogbone length and others. For total wheelbase under 270 you can only do shorter the rear part of chassis. 135mm is the minimum front partial wheelbase wich can fit the servo and steering system correctly.
The publication files are kits of parts for each front or rear partial wheelbase. Each of this kits includes the bottom part (main part), the top cover (Light type) and the sides (Closed type) for that wheelbase.
All you need to know to start is the partial wheelbases you want to use. Once you know it, download the proper Front Kit, Rear Kit, the Battery Towers, the Servo Holder and the Side Links, needed to join the front and rear part of the sides.
Now it's time to separate the parts in the kits. Start with the front part kit. You will need a slicer as Siplify3D or meshmixer to separate them and use them individually. Open the kit in Meshmixer, clic on edit, and then in "separate shells". The Object Browser will bring up and you will see the four parts. Use the eye at the right of each object text line to identify each part. Select one of the parts (objects, text lines) and clic on File->Export and save the individual part stl file with a proper name.
This was the most complex part of building the chassis, separating the parts in meshmixer. :S
I would start printing Front Bottom part and would continue with the Rear Bottom one. If you chose a 135+135mm wheelbase config, then don't print the sides. You have better "one piece per side" options in the buggy or truggy builds. The sides of the 270buggy can be printed in 200x200 bed easily and they are low and light. The sides for the 270truggy are high (as the closed from the kits) but with a little different shape, wich will allow the truggy shell to fit better and deeper. If you want to use the kit sides, then you will need to print the Side Links too. Go on printing the front and rear top cover parts. Remember to rotate 180º the rear bottom and rear top cover to print them over the right surface. You can also rotate them in meshmixer previous to save them as stl.
I would print them in 0.2 or 0.25 layer height. 2x 0.48mm perimeters for a 0.4mm nozzle, 5 or 4 top and bottom solid layers, and between 15% and 50% infill. I print them im PLA as they don't recieve too much heat, just the part near the motor. I use a negative horizontal expansion of -0.02 to be sure my Anet A8 will print holes in the desired size. I did not break any of this parts printed with similar to the above params.
The Servo Holder is an easy print, just make sure one time you have printed it that your servo fits good inside it. Use 2x M3x16 countersunk screws to join the servo holder to the chassis.
The battery towers will need maybe 0.1 layer height to be well printed and doing 2 at the same time with good retraction parameters can help printing them at better speed. Use 2 M3x8-10 Countersunk screws to put the towers in the chassis.
And now THE BATTERY HOLDER!!! You need to choose from many versions. Use the indications in the drawings to find yours. You should be able to use typical clips fo this battery holder system.
Now is time to put at least the sides and bottom parts of the chassis together!. Overlap the bottom parts and use countersunk screws to screw the bottom to the sides. Use them to have the parts together as one. You will need the F/R and central diffs to add the top covers, so put them apart by now. The M3 countersunk screws can be 8 or 10mm in length, but i think they can be 16mm if you are using the kit sides or truggy ones.
CHASSIS CHAPTER CLOSED! CONGRATULATIONS!!!
Related Publication -> MyRCCar OBTS F/R Differential Housing
This housing is designed to use a HSP 02024 metal differential, with it's paired pinion. There are many compatible ones, as the ones that comes in the "Quanum Vandal" I use as source for parts, including screws.
Remember at the begining the "Caster" concept?¿? You will see many cars wich have some caster in the front axle, for example 6º the top part towards the inside of the car is very common, and a little or 0 caster in the rear axle is also common. I have tried 6º in the front and 0º and -3º in the rear axle. I provided many more options but i did not try them. I'm sure you can find a lot of info about caster, camber and toe, i always make a mess with the names but concepts are there.
First of all you will need the bottom and top parts of the F/R diff. housings. There are two different bottom parts. The interesting one is the 5104 one, to use 5x10x4mm bearings to hold the pinion of the differential in position. Print one each time so if the bearings don't fit you haven't wasted 2x plastic. You will need to add supports to print the bottom diff parts. I hope you know how to add them in your slicer. To join the bottom and top part you will need one M3 nut and M3x8-10 countersunk screw.
IMPORTANT: Each time you print a part, you should test if the printed features are the desired ones. I mean size of holes, specially for the bearings, wich can be hard to fit if you did not use negative horizontal expansion as i always do. So print one and if everything is ok, then the copies.
Now you should have a bottom and a top part of FR diff. Lets imagine is the front one and you want to use 6º caster as i do. Then you must print the related 6º Lower Arm Supports (LAS_6C) and Butterfly Support (BS_6C). If I remember correctly, all this caster parts are RTP (are in a Ready To Print position).
Do the same to have your rear differential housing, but this time use the LAS_0C or LAS_3C and the BS0C or BS-3C, for 0º or -3º rear caster.
I'm quite sure you can't wait more to put those housings on the main chassis!!! Use M3 coutersunk screws with 12-14mm length. You will need 4 for each diff housing. But i recommend you before doing this, to put the part of the LAS that goes in the inner side of the diff housing. Use M3x16 Courtersunk to join LAS parts to the diff. housings. You will need 8 screws for that.
You can also now screw the Butterfly Supports to their diff. housings. Use 8x M3x10 Countersunk screws for this.
There are other parts in this F/R Diff housing publication, the 3d printed pinion for the differential (you need 5mm piano wire and rotary tool for this) and 3d printed vases for this pinions, but if you are expecting something "hobby level", you need to use sourced metal pinions and vases. They are cheap or come in the kit. In a Quanum vandal kit you have two pinions but must cut the rear one with rotary tool (extra long axle). Also it only includes 1 useful vase, so you will need to source another one.
AND THAT'S IT! F/R DIFF. HOUSINGS CHAPTER CLOSED!!!
And now lets go for the Central Differential Housing, you'll find some options here but it will be quick compared to previous chapters.
Related Publication -> MyRCCar OBTS Central Differential Housing
By now we have the universal chassis and the F/R Diff. Housings. You should have tested the 02024 diffs and their pinions fit good in the housings. With the center diff. housing you will be able to test if your sourced center diff fits well and also to test the central transmission, using the proper dogbones for your chosen partial wheelbases.
You have two posibilities for the center diff. housing. You can place it centered in the chassis or displaced to the right side to allow bigger batteries in the left side. This is the option you should choose, as there is no other transmission designed by now for the centered position.
The center diff. housing will allow you to use 2 different 1/8 center diffs, the SST and the Trooper one. Avoid the center diff adaptors for 02024 if you want the car to be reliable. So if you are going to use one of the 1/8 center diffs, go back to the Main Chassis publication, look for the drawings of your chosen partial wheelbases and look for the length of your needed center dogbones for a 1/8 "deviated" center diff.
This housing consists of a bottom part, a cover and two "adaptors" to use the differential you chose. Try to print this parts with a bigger infill, maybe 50%. The rest of the params would be the same for me than the previous ones i told you.
One time you have it printed, you can put it on chassis and screw it from the bottom with 5x M3x30 Countersunk screws. They can be shorter but this way (30mm) they contribute to strength up the chassis structure.
To put the central dogbones in place you can put the adaptors in the diff. align them over their final place, insert the dogbones heads in the F/R diffs vases and then go down with the diff into its housing while you make the other heads of the dogbones enter in center diff vases.
If your chosen central dogbones are too short, you can use some kind of "soft plastic or silicone" tube to cut near 1mm sections to put inside the related vases so the short dogbone can't move to the end of a vase and get out of place in the other side... I think Lijw, one of the makers, has had problems with this "addons", destroying them after some use. That's why you have to find the soft but durable material to put in there.
Ok, let's suppose you found the right ones and they fit well. (I think that was the case for Botyoyo, the first MyRCCar maker). Please Yuran! Tell us your partial wheelbase and chosen dogbones (reference or something).
Now it's time to put the motor in place!!! If you have not screwed the central housing to the chassis you will probably be able to put the motor and its screws easier. Use some M3 washers to secure the motor better in its final place. Very probably, if your motor gets hot, it will transmit its heat to the screws and those to their zone, so the PLA of the housing near the motor zone can get some heat too... that can make the PLA "melt" a little and then the screws of the motor can get a little loose. I'm quite sure you will have some problems with this during some time because the motor pinion will separate from the diff's spur due to one of the screws of the motor to get a little loose.
A last important thing about this is the distance between the motor pinion and the diff's spur. Remember they can not be too far but also too near will be a bad thing. I put them very near and screw very hard one of the 2 motor screws. Then I separate it very very little, so i can hear there is some play when i move the spur of the diff or the pinion. That's when I screw strongly the second motor screw.
And that's it! If you reached this point is time to put the Top Cover to give the car chassis its final strength and maybe do your first transmission tests! You must be sure the center dogbones don't get out of their places. For this you will need 8x M3x16 Countersunk screws. When you are screwing the ones of the F/R diffs, remember that the holes of the bottom and top FR diff. parts are "screwing holes", not "passing holes", so use one of your hands to get both parts and the top cover firmly together while you screw those ones.
YOU DID IT!!! END OF THE CENTER DIFF. HOUSING CHAPTER
Now you can put all the electronics more or less in place, so you can test the transmission and also turn the servo. I'm sure you want it to look as an RC car as soon as posible so you will probably do it:)
Related Publication -> MyRCCar OBTS Steering System
This chapter will be also easy. The steering system consists in two pivots and two "steering towers" over them. Both towers are linked by the steering plate, so if the one with the servo arm rotates, the other will do the same way.
So just 5 parts but... One more time you have to choose. I made the system for 3 different bearing sizes. I recommend you to use 5x10x4 if those are easy to find ones for you. You will need 4. If you can get for the same price 6x12x4 bearings, they will also do the job, maybe better.
When you have chosen your desired bearing size, you can print the related parts named with the proper bearing number, 5104 or 6124.
The towers will need supports to be printed. Take a look to their inside to position them correctly. It will be important too the "negative horizontal expansion" for this towers and pivots, as they have to fit well with the bearings.
When you have the 5 parts printed, start introducing the bearings in the towers and then the towers into the pivots. You could also screw the plate to one of the towers.
To screw the towers on their place you will need 4x M3x8-10 countersunk screws. if you have the rest of the chassis in one piece, you will have to screw the upper and lower screws of a tower the same time. You will probably need some pliers to hold the pivot base while you screw. After puting towers in place, remember to screw the second plate screw.
So that's all by now about the steering system! We will have to link the towers to the front steering blocks and also to the servo. For that i designed some "balljoint" steering pins wich are also valid for the servo link. If you want to use this system to link them, I use 4.7mm balljoints with M3Screws. If you buy a Vandal Kit as i did you will be able to use its steering pins and probably the servo link instead of this 3d printed balljoint steering pins.
HEY! END OF THE STEERING SYSTEM CHAPTER!!!
Related Publication -> MyRCCar OBTS Suspension System
Ok, you are a few steps from being able to do your first run!
This last chapter will be about the suspension arms, the C-hubs, the steering blocks and the rear hubs. Al this parts but the front C-Hubs will be dependent of the CVD you want to use.
So one more time, you have to choose between a lot of options! The cheapest option for me is adquiring the CVDs as part of a car kit.
As i know the "Quanum Vandal Kit", i did parts to use its CVDs, rear wheelvases and dogbones.
As i had the OpenRC Truggy recommended and expensive Reely CVDs, i also did the parts to use them.
As HSP CVDs are some of the cheapest ones and easy to find, i made various versions of parts for various HSP CVDs. This include 102015 and 122015 for short arms, 106015 and 166015 for normal long arms (715 version) and 108015 and 188015 for extra long arms (769 version)
I remember you again that the short arms with short HSP CVDs has not been tested already. So if you want to try those, remember to contact me to talk about possible modifications, including butterflys and their supports to make a less high chassis to acommodate better the normal car bodies.
Ok then! If you know what CVDs are you going to use, then you can start printing. As the four arms will be mostly the same, you must print first one copy and test it completely with your CVD.
Let's start printing the front axle suspension system. Print a Lower arm. This one will require supports but they have been incorporated in the model. If you can, separate shells in your slicer and use the provided support in a separate printing process so you can print it for example with 2 or 3 top/bottom solid layers, 1 perimeter and 0 infill. Fo the arm I would use 50% infill or solid and the first parameters i told you about, 0.2 or 0.25 layer height, 2x0.48mm perims... etc.
Ok you should now have one Lower arm. Let's go printing a front C-Hub and its simetrical. The arm will be swappable for any wheel, but front C-hubs are simetrical. Use the right one for the arm you want to build up.
You will need 3mm piano wire to cut out 4x 56mm long pieces. Insert one of this 3x56mm pins in the long hole of the arm.
You will also need to cut 4x 33mm long pins from 3mm piano wire to link the front C-Hubs or rear FixedHubs to the arms. Maybe in near future i apply to this arms the same "pin locking system" I used in the MTC Chassis arms. You will probably need to use a X-acto knife or cutter to remove part of the plastic in the interior of the place for chubs in the lower arms to let them enter better in place. If it initially gets too tight it will probably get more freedom soon.
Now it's time to put the lower arm with the front C-hub in place. For that, insert the rear part of the 3x56mm pin (already in the lower arm) in the Lower Arm Support hole you screwed to the diff. housing before. Then use the other "LAS" and screw it (remember, 2x16mm countersunk) to the diff. housing.
If you are building the front suspension arms, you will need to print two Front Steering Blocks, the correct type for your CVDs, the same way you will have to print 2 simetrical rear fixed C-hubs of the correct type for the rear axle. I explain next the types of steering blocks and rear fixed c-hubs:
Types A, D and X must be used with 715 arms. 122015 and 102015 with 475 arms. 108015 and 188015 with 769 arms.
Now that you have the front steering blocks printed, put the bearings into them and place one into the front C-hub. To do this, enter the steering block near its final position and then rotate it until holes in the Chub and steering block are aligned. Use 2x M3x14-16mm to secure the steering block in place. This system needs to be improved but it works quite well by now.
Now would be the moment to put one of those CVDs in its place, entering the screw extreme through the bearings of the steering block. Then rotate the C-hub to its final position while you align the other extreme of the CVD to enter into the diff. vase.
If you bought a car in kit, as I did because I think is the cheapest way, you will also have the upper suspension arms, wich can be adjustable as mine are. If this is your case, use them, put them in place and find the proper length adjusting it to your desired camber.
If you don't have them you can print the proper version for your lower arms.
This can be a little tricky, as you can choose for various lengths. This is because the "camber" of the wheel can be adjusted using one or other length for the upper arms. To have 0º camber, use the UAS_XXX with the same number as your lower arms. You can choose a little longer or shorter ones to alter the camber from 0º.
For each of the upper arms, you will need to print some little supports, wich are found in this publication. Use proper length M3 screws to secure the upper arms over their supports and in their place.
OMG!!! You don't have Butterflys!!! Those should be an easy print... but be sure to print them strong. Also, there is a "stronger" version of the butterfly, i suggest you to use this one. You must secure each butterfly in its butterfly holder with two or four M3x16-20mm sockethead or roundhead screws and also use M3 nuts, better if self locking in the back of the butterfly holder
If you tested all the printed parts of an arm to fit well and to acommodate correctly your CVD, then is time to build up the other arms!
Here you have some more photos of the OBTS chassis assembled:
As you can see in all this photos I'm using sourced Upper Arms, Steering Links and Servo Link. If you need the Steering and Servo Links for 4.7mm BallJoints you can find the necessary parts in this publication -> MyRCCar Adjustable Steering pins, Suspension Uplinks and Servo Arm
The cheapest RTR (Ready To Run) rc car kits you can find will probably include a brushed motor and esc, limited torque non metal gearings servo, a very ugly Radio+reciever and a ni-mh battery around 2000mAh with its charger. This can be a very good deal if you are not sure if this "3d printed hobby" will be for you. Anyway you could find other RTR or ARR (Almost Ready to Run) kits wich could have some of this parts and also better components, as the Quanum Vandal ARR kit, a very interesting one for me as it has 1/10 brushless motor with 50A ESC and a standard servo for little more than 36€ respect to the KIT version with no electronics. Remember you need to add a battery+charger and Radio+Reciever to this ARR kit.
If you can afford a little more than the minimum requirements, this is the "sourced parts" chapter I would invest that little extra. I'm sure you will be able to use this same components in many other 1/10 rc car projects if you finally don't like this one.
Oh my RC god!!! That's a really big bunch of things... Wasn't this car 3d printed?¿?¿? :S
If you look for each thing individually and make the sumatory of prices... Also maybe you won't find all of them from same provider...
Many of this mechanical parts will be the same or very similar in many 1/10 cars, but I'm sure now you know than many many of them can be found in a Quanum Vandal Kit for about 60€. Of course I have no relation to the sellers more than I'm one more buyer. I was so sad when i started using this parts as then in Feb2018 Vandal was out of stock and "discontinued"... But last time puting an order with my cousin a few days ago there were more than 100 in stock in EU and i think a lot in UK warehouse. Maybe they knew about my project, but i really doubt it :)
If you know about any other car kit with interesting prices and good stocks please let us now!
Other Useful Sourced Things
Other Useful Tools
You know that, more than all previously mentioned publications there are at least 2 more, one for a Buggy Build and other for a Truggy build. Of course, they are mostly the same. Same Bumper, Wing and lights can be used in both builds, so the only thing changing will be the wheels, the "sides" of the chassis and Shell.
To be able to use this shells you need to build a 135+135 wheelbase car. The shells are designed to be printed in "Vase mode". They have 1mm thickness so 2x0.48mm perimeters should do the work. In this vertical position the are 220mm long so be sure you can print them with your printer. Anet A8 can do it as it can print more than 220mm in height. With 135+135 config you will also be able to use the provided buggy and truggy chassis sides on the publications
If you did not use the 135+135 wheelbase config, then you must adapt this shells to your desired length. You could give it a try just "deforming" the object in the long axle. So you could have a 240mm length shell scaling just the Z axis to 109%. You could also make the smallest 205mm version (for 255 wheelbase) scaling just Z axis to 93%. You can use the chassis sides provided in the kits of the chassis publication but only for the Truggy Shell. Anyway you could also scale the shell in the wide direction something like 16/15 to have a 10mm wider shell wich will help it to be fitted better.
The "pre-made" sides created for the buggy and truggy builds (135+135) can be fitted into 200x200 bed being one part per side. Other bigger ones won't fit easyly, that's why I created the F/R splitted parts. Anyway you want continuity in the side structure and that's why the side-link is needed. If you would like to have other length "one part per side" chassis sides please tell me about it or try modifying existing ones, the stl file, in a program you can move vertex or edges. I think Blender is a free one where you could try that.
If you have read carefully everything you will know your bumper and wind will last a lot more (than one simple hit) if you print their holders in TPU. I know many of you are "trending" to CR-10 and the like printers, wich use to be bowden. I know TPU and bowden are not a good combination.
The rigidity and flexibility but more than all, its form preservatring capabilities make this material very versatile for me. I printed the mentioned holders in TPU and they really do the work, so...
How can you help me? Giving a try to a MyRCCar project would be a good thing, and if you like it, uploading a make and giving likes to the related publications you like. The most important thing you can do is give atributtion, wich for me means explaining people who you show your car to that is a MyRCCar project, and if they are interested maybe facilitating them a way to get into the project, as letting them know about "thingiverse" and/or "dlb5".
What I have done by now is quite enough for me. I don't specially plan to do more and more chassis or updates. I think this project needs some time to see if it's really interesting for the people. If it is, I would like my designs to turn into the seed for up-coming MyRCCar projects and parts. I could also try to organize all my life around this "keyword" and try to get some direct economic benefit selling models or parts, even making personalized bodies for you or others at a good price. This is not my intention, and if you respect my initial philosophy, it should not be yours.
One easy thing you can do is create videos of the build sequence or reviews of your build. Also "in action" videos will be extra well welcomed, that's the best way for us to know what could we expect
You can modify most of the parts and publish remixes of them (look each license of each thing to know about your posibilities for those parts). Try to do not duplicate already done things. Your remixes (they are if you use the original model as a source) must open new posibilities or solve found problems.
If you make your part from the ground, even if it is to replace an existing part to allow something new, I would not consider this a remix. It's your creation and I think you could upload as it. This is the most desirable contribution you can do.
Now, the nearest person you will find who have built a MyRCCar will be at 10.000KM or maybe more. But I dream one day you will find somebody to make a race! Colors are good to distinguish the cars, but more are the different bodies! So if you want to contribute, making compatible bodies and shells would be a very good thing too.
Here you have some other ideas of "things" you can design to contribute to MyRCCar:
I continue my dream being the designer of the 15% of the MyRCCar things. If you (the community) convert all this previous ideas and a few more into free shared things, then the real idea behind all this, empowering final user, you, will success!!!
I have written a lot here in thingiverse. My english is poor and each time I review less my writing than the previous one. I want to apologyze if I'm a little "heavy" or "intense". I don't want to let anything "en el tintero".
I have spent a little time writing up this building instructions and they are incomplete. I hope you find them useful anyway and like them!