hi, I had a 10mm drive shaft and was wondering if the 6mm hub could easily be enlaged (drill pressed) to fit my 10mm shaft and still have a functional set srew…
this is for a school project, i am building a tracked sumo robot.
Is this drive shaft just a shaft? or is it part of something? If it is just a shaft by it’s self, you can go to www.smallparts.com and buy a 6mm shaft and cut it to the length you need.
i wont have room to add a 6 mm hub, i am running a screwdriver motor and it will ideally just have the hub slip over the 10mm crank shaft.
so yes, it is the drive shaft.
I dont know if you can remove that much material out of the hub. You are talking 4mm more material to remove which may leave you with just the rim. I’m not sure how much material is available with the 6mm hole. it would have to be more than 4mm.
yep, thats basically my question, i emailed tech support. but i cant tell from the pictures if i will have a “safe” amount of material left. if anyone has a set they could easily measure it and let me know. this is what im hoping for. Thanks!
I just checked the size of the “shoulder” area (the thick bit in the center of the hub), and the digital caliper says that the outer diameter is 9.42mm.
Drilling it out for a 10mm diameter shaft would remove the thick center section completely, leaving only the thinner body section. This would make it less stable and more prone to rocking on a shaft if it isn’t a perfect fit, but since the setscrew is tapped all the way from the outer edge to the center hole, I would expect that you would still have all of the locking capability that the hub normally provides. You’d have to drill very carefully to enlarge the hole while still providing an exact fit for your shaft, and ensuring that it remained centered and perpendicular to the plane of the hub, or else you’ll wind up with wobble or eccentricity in the final product.
hmmm, i thought the set screw was on the smaller part. I think I can pull it off then. anyone disagree?
As shown in the product photograph:
The setscrew runs through the thick body of the hub.
I think it is doable, but like Seamus said, you will need to be very careful to drill perpendicular or else you will get a wobble. A drill press is the only thing that would work best. I would not try it by hand.
drill press forsure no worries there. thansk guys!
if my shaft enters the track chassis and it will onyl be 22mm from the inner wall of the chassis, will it be long enough for the hub to be correcly positioned? im running a 2" track setup so it should be almost identical to the tack chassis on the lynxmotion robots. if it is too short my option is to fit a hex bit into the shaft (its a screwdriver end as a shaft) and mount the hub to that… any objections???
thanks!
These are hard questions because you are retrofitting everything. Best bet is to take a caliper and measure the components.
the problem is i have no idea where the hub needs to be oriiented, it seems off center in the picture, but i have no idea. i also do not have the exact dimensions of the hub. i would imagine the plastic wheel interface is centered and the hub is offset to the drive side. from what i gather, the gap is 1.5" from wall to wall of the chasis. I would like to know where the center of the hub is located along that 1.5" length. anyone?
thanks again guys!
Mike
That’s correct. The hub is offset the thickness of the two sprocket halves, so the rprocket is centered inbetween the 1.5" panels. I think it’s around 0.20" but I don’t have one available to me right this moment. This will be pretty easy when you have the parts in hand.
my fear is that my shaft may not be long enough, its very close. wouldnt the face of the hub be offset by the thickness of onyl one sprocket face(the wall plastic thickness) as the other sprocket would be located on the other side of the midpoint?
it would seem thhat if i knew how thick the wall of a sprocet is, i could draw the whole thing out accuratly.
The thickness of the plastic in the center of one of the sprocket halves that I have here is 0.0860 to 0.0875, averaged over several readings at various angles and on different surfaces, to account for variances.
The thickness of a HUB-02 is 0.250 inches at the face where the sprocket mounts to it, with the set screw at the halfway point between the faces.
Adding half of the hub’s thickness (0.125) plus the thickness of one sprocket half (0.087), the centerline of the sprocket assembly is offset from the center of the setscrew by 0.0995, or for all intents and purposes, 0.10 inch.
Regardless of the offset, you still want a drive axle to pass all the way through its hub, in order to provide the maximum possible support and stability. If your axle is “just making it” to the point where the setscrew can grab it, then it’s too short.
thanks! very helpful. I think its going to work! on a side note does annyone have experiece with the rubber compound on the lynx tracks, are they very gummy or somewhat hard. i iintednd to use them on a 20x20cm 3 kg sumo robot. my fear is that if they are typically used on much larger bots that the compund will be to hard.
thanks,
With rubber material the industry has created a rating called Shor A Hardness. These tracks are rated for 45 which is somewhere between a pencil eraser and a car tire. I have also considered using them form sumo. 