I'm trying to incorporate two bearings on the ends of same axle into my DIY contraption.
The problem is mounting them in alignment. Currently the main issue is 15mm I.D bearing being used on 14mm axle. Centering is achieved by a strip of metal wound around axle, but the stack of washer, split washer and nut still manages to tilt the bearing.
Another, albeit smaller issue is that the "housing" for 35mm O.D. bearing is made by 32mm hole saw and then expanded by hand using a file.
How do i fix this? Completely different approach or some tweaks to current setup.
One thing i tried out is placing the nuts directly against bearing. But then i'd have to add another set of nuts to lock them in place and this in some places might require to re-do the whole device.
What about housings? I don't think i'd gain much precision with 35mm drill. I was thinking more in the direction of adjustments and rubber elements to allow some controlled play.
>>952630
use two bearings with a spacer between them
you need to increase the distance the rod is held in by
>>952639
Hmm.. good point. Won't i end up with even more "braking"? E.g. if i fail to align those two same end bearings, I'll get +2 drag points.
Maybe just using a longer strip of metal inside the bearing might help? Like pic. related.
But to be honest, if i'm buying more bearings i might just get the correct I.D. ones. AFAIK, getting 15mm thread axle would be more expensive. It's just that i had these laying around.
use self aligning pillow blocks, small ones are like five bux
wrapping shim stock around allthread is janky as fuck tho
>>952649
Yeah, that could happen.
The thing is that your housing is made of wood, which is prone to compressing under load, especially with such a long lever arm.
Can you 3D print your housing? They would likely be less prone to compression and would be dimensionally accurate so there's no need to sand to fit.
>>952658
>Can you 3D print your housing?
Nope.
>>952655
>ones are like five bux
More like 10..20Eur/piece excl. shipping around here. So it's a nono.
I guess my first priority would be getting the bearing straight on axle, then look what can be done about the wooden housings.
I'll try the double nut + thicker shim variant and try to force the shim down the bearing with nuts.
>>952655
*pillar block
>>952753
>literally illiterate
So i tried that double nut / thicker shim thing and it centers the bearing on axle well enough.
Now i'm left with sorting out misalignment caused by dodgy housing. What do you think on filing the hole bigger and making a rubber shim from old bicycle tube? I'm suspecting tightening the C would compress the rubber and force the bearing in odd angle anyway.
>>952837
You need a rigid housing to tightly grip and hold the bearing, NOT something compressible like wood or rubber.
>>952844
Damn. I guess i should start looking for suitable 35mm ID tube then.
>>952630
>Currently the main issue is 15mm I.D bearing being used on 14mm axle.
Get the right size of rod or bearing, whichever would require less work to replace. Why did you need to ask?
>>952655
>use self aligning pillow blocks, small ones are like five bux
well,,, the cast-iron ones usually aren't cheap.
the cheaper ones are the stamped-steel ones, like as shown.
These are really the easiest way to end up with bearings that are aligned. Farm stores sell these from ~3/4" bore up to about 1.5" diameter or so.
The 3/4" ones cost around $10.
There are smaller ones you can find online but they tend to be rather expensive.
-------
When I need little bearings aligned I usually make my own mounts... I gave up trying to align two separate mounts, it's too much trouble for me. It never works.
,,,,
I clamp two thick plates together with a thin spacer in between them, and then bore a hole all the way through big enough for the OD of the bearings. This way I can be CERTAIN that both bearings are held in exact alignment.... Then I drill corner holes and thread one side to allow clamping one side solid to something else, while only lightly tighening the other side enough to hold the bearings. (too tight and they bind). I'll get a pic of this in a moment...
>>952866
>I'll get a pic of this in a moment...
This is the easiest way I've found to make small bearing mounts, AND get the bearings aligned perfectly every time:
1. Get two thick pieces of metal, and put a thin sheet in-between them as a temporary spacer. (in the pic, this was two 3/4" thick pieces of aluminum with a 1/8" sheet in-between)
2. Drill two sacrificial holes in the center, and bolt the stack together. (in the photo, these are the two empty holes left in the centerline of the whole thing)
3. Drill the four corner holes, in the tap size you need for tapping threads. (these holes were using 1/4-20 threaded rod)
4. With the stack still bolted together, drill out the holes in ONE plate, big enough to pass a bolt through. This becomes the "top" plate in the MSPaint diagram.
5. Tap threads in the holes in the other plate. This becomes the "bottom" plate in the MSPaint diagram.
6. Put allthread rod in all four corners and tighten them with nuts, and then take out the two center bolts.
7. Clamp the whole thing on-end, and drill + bore a hole all the way through, big enough to fit your bearings OD in.
8. Take the whole thing apart, and discard the spacer material. It was only temporary.
When you mount this, the base plate nuts (the purple nuts in the diagram) can be tightened as hard as you need to hold the mount stable. The blue nuts need to be only tight enough to hold the bearings in place, and not overtightened.
You cannot just run four long bolts all the way through, that won't work.... The bearings get squished out of round and don't spin freely if there is too much pressure on them.
Oh gee.. at this point my best option seems to be actually finding someone who could 3D print the fixtures. Price wise at least.
>>952881
Thanks. That's a good idea to keep in mind. But in my case there are several problems - space between bearings must be accessible, i don't have the exact diameter cutter, neither facilities for precision metal working (e.g. drill press).
In the meanwhile i'll keep looking for suitable tubing and 3D printer...
