-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
JRP3
Hyperactive Member
Tapped without drilling? In any case, you wouldn't want a hole and thread the size of the lug bolts, that would be overkill. Probably just a 1/4 inch or M6 fine thread socket head bolt to screw into a tapped hole in the lug nut.
My two cents:
1) About drilling into the wheels: Be VERY, VERY, careful! And by careful, I also mean that you should consult with a mechanical engineer who understands the stresses wheels undergo. As Gizmotoy pointed out, fracture points can lead to catastrophic results. Many lives have been lost to microscopic fracture points.
2) About using steel wheels: One of the reasons for using alloy wheels is to lighten the weight to get better fuel efficiency. The weight in a wheel effects fuel efficiency far more than the same weight elsewhere on the car. You might as well not bother trying to get an aero wheel.
1) About drilling into the wheels: Be VERY, VERY, careful! And by careful, I also mean that you should consult with a mechanical engineer who understands the stresses wheels undergo. As Gizmotoy pointed out, fracture points can lead to catastrophic results. Many lives have been lost to microscopic fracture points.
2) About using steel wheels: One of the reasons for using alloy wheels is to lighten the weight to get better fuel efficiency. The weight in a wheel effects fuel efficiency far more than the same weight elsewhere on the car. You might as well not bother trying to get an aero wheel.
@JRP - the pans are way off the lug bolts, centerbore or the central part of the spokes.
@WarpedOne - Have a closeup of those plastic straps or a link? They add a thickness that might fit into the clearance that my pans offer. But the natural tensioning would be lost.
Re Fracture Points: Doubt an 1/8in shallow hole drilled on centerline of spoke at the thickest part of the casting will amount to much. Fondle a rim yourself to appreciate.
Further: the users who entertain this sort of project will probably do mostly non-stop long distance econo-cruising, since they already have come to terms with having 'non-repeatable' brakes.
--
@WarpedOne - Have a closeup of those plastic straps or a link? They add a thickness that might fit into the clearance that my pans offer. But the natural tensioning would be lost.
Re Fracture Points: Doubt an 1/8in shallow hole drilled on centerline of spoke at the thickest part of the casting will amount to much. Fondle a rim yourself to appreciate.
Further: the users who entertain this sort of project will probably do mostly non-stop long distance econo-cruising, since they already have come to terms with having 'non-repeatable' brakes.
--
I've stolen the picture from Aero wheels
What is the weight of a single 19# pizza pan?
Lets agree to disagree. I wouldn't drill, not into rims, not into into lugs, only into the pan.
What is the weight of a single 19# pizza pan?
The point that I'm not sure that you are grasping is this: It's not the raw amount of material lost that is at issue. It is the potential for the hole to be the genesis point for a micro-stress fracture that will grow over time with wheel stresses.
The failure will not be from the lack of material strength due to the hole itself. It will be from a stress failure that sprang from it. Much larger structural members have failed from much smaller material defects.
Yes, stress risers would be the cause of failure. You need to drill correctly. Initial hole drilled undersized using plenty of machine oil to keep things cool, then a reamer to enlarge the hold appropriately, followed by deburring. It's not rocket science, just need to do it correctly. But the real question is what the attachment point should look like. I have no good advice on that topic; I've done airframe fabrication and nut plates just aren't a good solution here.
JRP3
Hyperactive Member
The bolts should still hold the pan tight to the edge of the rim or wherever it contacts, even if it's not touching in the middle. If the pans flex too much and end up dishing in then you might need a spacer. Or instead of bolts use studs screwed into the lug nuts with stop nuts on them.
As has been stated the concern is a stress riser. The edge of the hole needs to be at least smoothly radiused, not just drilled and tapped.
By the way, I have read of a case where a wheel flew off of the car, even though all the lug nuts were still bolted on. Stress fractures, most likely caused by using the wrong tools to tighten the lug nuts, possibly caused by over-tightening the lug nuts with the correct tools, caused all the lug nut heads to shear.
Furthermore, these catastrophic failures are not likely to happen when traveling at low speeds--the higher the speeds, the greater the stresses.
Furthermore, these catastrophic failures are not likely to happen when traveling at low speeds--the higher the speeds, the greater the stresses.
Aircraft is all about minimally THIN materials where stress is palpable and fractures probable. Here we have amply over-sized non-forged material so a different realm entirely. Would I be drilling tiny holes in an 18 pound forged racing rim - not likely! We might reflect here on the excellent 2 year experience of these OEM 19in rims - no known failures to date. Shows that there is an abundance of extra strength designed into them.
The pan edge needs to be held to the rim with some pressure. The nylon straps will just keep loosening, so fail!
The plan is to drill 1/8 in holes and insert tight fitting pins to scratch the inside of the pan. Then attach with self tapping screws.
--
The pan edge needs to be held to the rim with some pressure. The nylon straps will just keep loosening, so fail!
The plan is to drill 1/8 in holes and insert tight fitting pins to scratch the inside of the pan. Then attach with self tapping screws.
--
Here is the Tesla 19in rim with a straightedge across it. The centerbore plane is a few inches below the highpoints of the spokes, which themselves are slightly proud of the tire bulge. The beauty of the pans I happened upon is that they fit perfectly in this scenario, such luck! Hope this clarifies a complex 3D situation. Speaking of 3D, do printers come 20in wide?
--
--
fastener mount cable ties - Google Search :
Pro Tie N8SDSM25 8-Inch Natural Nylon Standard Duty Screw Mount Cable Ties, 25-Pack - Brazing Torches - Amazon.com
Not sure if 8" is long enough to get around rim "spokes" but there is also a 15" version on amazon.
If your worried about it sliding on the spoke you could place a little tape like what is used on wheel weights on inside to keep it locked in place. Some tape & felt on pizza pan where it rubs the raised part of the wheel may also be needed to keep the pans quiet and may even allow for alignment of pan if tape/felt was placed on outer edge where it covers the wheel rim.
jcaspar
Member
I was brainstorming options for this and I thought of this:
Peel and Stick Laminate - Clear | Duck® Brand
It is a giant sheet of peel and stick clear duct tape, essentially.
What if you just cut a 19" circle and stuck it on the face of the rim? I know that it would not last for a really long time, but maybe for just one use or for a road trip.
One problem is that the area that is not in contact with the rim would be sticky and gather crud, but probably not more than a dusting.
There is no danger associated with them falling off or failing, other than litter.
Peel and Stick Laminate - Clear | Duck® Brand
It is a giant sheet of peel and stick clear duct tape, essentially.
What if you just cut a 19" circle and stuck it on the face of the rim? I know that it would not last for a really long time, but maybe for just one use or for a road trip.
One problem is that the area that is not in contact with the rim would be sticky and gather crud, but probably not more than a dusting.
There is no danger associated with them falling off or failing, other than litter.
jgs
Active Member
Could be viewed as a feature. Anything that adhered to the disposable sticky wouldn't end up on the rims.
Similar threads
