Wheel Fab Question

[miniman101]

Is grinding off the chamfer from OEM lug bolts to make them work with a set of adapters a stupid idea for safety reasons, or is it not a big deal?

[DinanS3]

personally i woudnt but thats just me ...could have issues centering up the wheel on the stud

[ShowCar]

It's a stupid idea for safety reasons. <-- DoD Safety Engineer

[DubsMcGee]

Safety is for pussies.

[miniman101]

I am really out of options.

The only other thing that the guys at Adaptec could think of is getting 20mm spacers and then use the OEM bolts without modification.

[DinanS3]

do that

[ShowCar]

Well you haven't described the problem with any detail, so you probably won't get much help here.

[MechE30]

decreasing an effective radius will increase your stress concentrations on that point.

bad.idea.

[BlackVR]

Will tuner bolts not fit?

[ShowCar]

Regardless of whether or not it'll hold, you'll always worry about it. It'll always be an unnecessary risk. You won't enjoy driving your car.

[KeithStone]

What is the problem? The lug bolts dont fit in the holes in the wheels your are trying to run?

take some pictures or something.

Also, when in doubt.......

[ShowCar]

It sounds like the chamfer (seat) on the stock lugs won't allow them to engage deep enough and sit flush with the outside of the spacer. Modifying the lugs isn't the solution, though.

[KeithStone]

but. the lug sits in the wheel, not in the spacer. it is a wheel problem, not a spacer problem.


oh wait. he didnt tell us shit. we dont know.

[ShowCar]

Right, I'm speculating that he's using spacers wide enough to require the two sets of lugs. One to hold the spacers to the wheel and the other to hold the wheel to the spacers. Yuck.

Sounds like you just need lug bolts with the proper seat (tuner vs conical).

[miniman101]

Yeah the OEM bolts have chamfer and therefore aren't quite long enough to get through the adapter and into the hub with a enough threads, so I wanted to get new longer lugs with my size and thread pitch, but 14x1.25 doesn't exist in a longer size than what is stock. So I am looking for options. So far its machining off the chamfer on stock bolts, or buying $300 20mm adapters that will fit the OEM bolts without modification.

[ShowCar]

What adaptors are you trying to use now?

If you've decided that those are your only two options, I'd weight their costs. $300 vs. current adaptors plus whatever the machining will cost on the stock bolts plus repair of the damage that will occur when your lug breaks and your wheel falls off plus medical bills associated with the accident you cause when your lug breaks and your wheel falls off plus damage to your ego.

Color-coded for effect. Just do it the way you know you should.

[BimmerTim]

I think it will be fine.

They are my old adapters which don't use cone or ball-seat bolts. They used standard zinc plated hex-head bolts from any hardware store.

The adapters are hubcentric, so there is no purpose for the lug bolts to also center it.

I bought these adapters from adaptec and ran them with normal hex-head bolts they provided for about 10,000mi with 0 issues.

There is little stress on the bolts themselves. Not to mention they are M14, which is even stronger than the M12 I was running.

[ShowCar]

They are my old adapters which don't use cone or ball-seat bolts. They used standard zinc plated hex-head bolts from any hardware store.
That's a much better description of the problem. Just get the proper hardware and you'll be fine.

I still wouldn't even consider grinding down stock bolts if it were my car.

[BimmerTim]

The problem there, is that it doesn't exist.

There is no such thing as an M14x1.25 Hex Head Cap Screw. There just isn't.

I found them in Titanium, but they were nearly $20 a piece, and had to be special ordered from Ukraine.

That is why he wants to machine the chamfer flat, essentially making a shouldered M14x1.25 HHCS.

[BimmerTim]

This is basically what he wants to do.

From this:

http://i214.photobucket.com/albums/cc127/metall1080/lugcham.jpg


To this:

http://i214.photobucket.com/albums/cc127/metall1080/lugflat.jpg

[ShowCar]

Well then I guess that's your only option.

I was picturing him with a bench grinder and a pair of vise-grips. Done correctly, I'd be more comfortable with it.

[BimmerTim]

I think he's talking about having a machine shop turn them down.

Also, I would prefer to see new bolts made and hardened, but that will cost as much/more than the adapters.

I don't know. I don't love it, and I don't hate it. It's not ideal, that's for sure.

[OptimusGlen]

how about convert from lug bolts to studs?

buy or cut stud to desired length, buy lug bolts that fit. Boom.

[BimmerTim]

That would probably work too. You can even get wheel studs that convert thread size/pitch.

[OptimusGlen]

truth, I have some that I ordered by accident, and are now sitting in the corner of my garage.

[oneunder]

Glen, I think that is a really good ideal :thumbup:

[BimmerTim]

Also can't find studs for that thread. This is ridiculous.

[miniman101]

Yeah, basically I am up the creek in regards to finding non-existent bolt that I need. I am going to try my plan and hope for the best. It makes me slightly nervous, so maybe after a while I'll go by the 20mm spacers and sell the ones I have from Tim.

[miniman101]

I talked to a friend of mine who is a electrical sub-station designer/engineer in Chicago. I gave him all the info about this situation and he is going to talk to his people and run the numbers and find out exactly what rigidity those bolts will have after the chamfer is ground away. This will be the deciding factor once I hear back from them tomorrow. And if it is going to be unsafe to run them like that, I'll buy the 20mm adapters. If it is safe, then I save $300 dollars.

Thanks for all the input everyone. I'll post what I know when I know it.

[ShowCar]

What will the 'rigidity' tell you about their ability to hold your wheel on? I'll be interested in hearing what they say.

[BimmerTim]

PS. 3 of us in this thread are mechanical engineers.

[miniman101]

:redface: Well a fourth opinion doesn't hurt...
No I am sorry. I didn't mean to offend.

[Stumanbmx]

Mechanical Engineer in training checking in...

I wouldn't trust turning down the conical portion of the bolts. Yes it is basically turns it into a hex head cap screw but thats not their original design. A conical seat transfers stress much better then a 90 degree angle. Every time I got in my car I would be afraid of the heads shearing off.

If you can't find proper bolts or studs I would either get the 20mm spacers or just ditch the whole setup and get something else. It's just not worth the risk.

[BimmerTim]

What?

Conical seats are used to center the wheel. When the adapter is hubcentric, there is no reason for a second method of centering. The only thing the bolts need to do is hold the adapter to the hub. I just wish that the bolts were plausible to find.

[DubsMcGee]

This is basically what he wants to do.

From this:

http://i214.photobucket.com/albums/cc127/metall1080/lugcham.jpg


To this:

http://i214.photobucket.com/albums/cc127/metall1080/lugflat.jpg

Shadows? Reflections? Visible Planes? :uberbarf::uberbarf::uberbarf::uberbarf::uberbarf:

[BimmerTim]

hater

it took all of 3 minutes of my lunch break to fake model that.

[Stumanbmx]

What?

Conical seats are used to center the wheel. When the adapter is hubcentric, there is no reason for a second method of centering. The only thing the bolts need to do is hold the adapter to the hub. I just wish that the bolts were plausible to find.

Yes, I know. I'm just saying I would trust the bolts to hold the adapter to the hub after machining off the conical portion.

[ShowCar]

:redface: Well a fourth opinion doesn't hurt...
No I am sorry. I didn't mean to offend.
It's not offensive, it's foolish.

If you're just hunting for somebody to agree with you, ask your mom. Don't bother wasting your time and ours asking for opinions and advice with no intent to actually follow through with anything but your own plan.

Have you spoken with a machine shop that'll actually do this? I don't deal with machinists directly anymore, but I can't imagine you'll get 20 lug bolts turned down for less than $160.

How did 'the numbers' come out?

[OptimusGlen]

I'm thinking it would be much cheaper for a machinist to cut 20 studs out of bar stock then it would be for them to cut down 20 lug bolts.

[ShowCar]

I'm thinking it would be much cheaper for a machinist to cut 20 studs out of bar stock then it would be for them to cut down 20 lug bolts.
Or maybe get a really long shoulder bolt and have a machinist shorten it and cut the proper threads into it. I've done this before for other applications. It's not ideal, but none of your solutions using these adaptors are.
http://farm6.static.flickr.com/5026/5612793959_913fb49bfb_o.jpg

[Die Frau]

Beautiful picture, Matt.

[ShowCar]

I'm an engineer, I swear. I don't boot up my workstation unless I absolutely have to.

[BimmerTim]

Hmm. That's a good thought, Matt. That would probably be easiest, and cheapest. Shit, he could probably do that himself with the proper die.

[toasted]

JB Weld.

/thread.

[Die Frau]

In my non-m.e. opinion - Matt's solution seems like the best and cheapest solution.

[toasted]

Make sure you use washers.

[BimmerTim]

Why? I never did, and had no problems.

[ShowCar]

Shit, he could probably do that himself with the proper die.
Yeah, that'd probably be a real bitch though. I've never done it, but I've broken many, many drill bilts trying to drill bolt heads for safety wire.

[BimmerTim]

Also, here is a pic of the adapters.

http://i214.photobucket.com/albums/cc127/metall1080/22383d14.jpg

[BimmerTim]

Yeah, that'd probably be a real bitch though. I've never done it, but I've broken many, many drill bilts trying to drill bolt heads for safety wire.

The other day I had to drill and tap one of our stainless chambers for some brackets, and I broke 2 drill bits and one tap.

[ShowCar]

Yup, I wouldn't bother trying to do it yourself. A machinist would much rather help you with this though, than to screw around with OEM lug bolts. If I ran a shop, I'd refuse to work on the lug bolts. Before you make any decisions, I'd fully weigh the cost of each option (like I suggest initially). I suspect that the correct adaptors might actually be about the same cost.

Option A: Value of current adapters, shoulder bolts, machining time
Option B: Cost of proper adapters, bolts?

[OptimusGlen]

OP, why don't you have a machine shop cut chamfers (countersinks) into the bolt holes on the spacers so they match the lug bolts?

Or, since it's softer aluminum compared to harder bolts, buy a countersink bit at Home Depot or Menards (ok, might actually have to order one because of the angles...) and cut the countersinks yourself?



one of these, but bigger of course
http://www.vintagepistols.com/images/weldon1.jpg

[ShowCar]

Glen, take a look at the picture, there isn't much material there.

[OptimusGlen]

ah, yes didn't see that.

well, whatever he does, I think that machining down lug bolts should be off the list. I would never trust that.

[ShowCar]

That's what the rest of us said, but his friend in chicago that designs electrical substations is 'running the numbers'.

If you do end up modifying the stock lugs, please don't bother showing up to any motorsports events. I don't need to be the guy on youtube that gets hit by a wheel/tire combo at 60mph.

[Stumanbmx]

That's what the rest of us said, but his friend in chicago that designs electrical substations is 'running the numbers'.

If you do end up modifying the stock lugs, please don't bother showing up to any motorsports events. I don't need to be the guy on youtube that gets hit by a wheel/tire combo at 60mph.

This. Getting hit while running cones is not on my Auto X wish list this summer.

Also, I like the idea you presented Matt. Should be much safer and possibly easier. That was the best engineering drawing I've ever seen.

[VR6GTI]

here you go:
http://cgi.ebay.com/ebaymotors/07-MINI-COOPER-WHEEL-STUD-CONVERSION-14x1-25-12x1-5-/180536984954?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a08d7c57a

[Crispy222]

$2.50ea plus $1.75ea nuts = $85.

http://www.upgrademotoring.com/wheels/whl_acc.htm


Lug Stud Conversion for the New Mini Cooper. Convert your one of a kind Mini Cooper 14x1.25mm lug bolt to a 12x1.5mm lug stud application. With the 12x1.5mm lug nut option you will have a lot more choices for lug nut styles

[BimmerTim]

There you go. Two more options.