I use one like this, but have to re-teach myself how to read it each time!
I use one like this, but have to re-teach myself how to read it each time!
And, as the rotor wears it develops a lip at the circumference (on the non-anti-dive side at least) that makes using a caliper difficult to step over the lip to get the correct measurement on the worn surface. On the anti-dive side the pads extend all the way to the edge of the rotor, so a lip doesn't form on that rotor.Using that type of caliper doesn’t give a true representation of the rotor thickness, since the measuring surface is so long. Next to a proper brake rotor caliper, the next best tool for the job is a micrometer, preferably with a pin for one of the measuring points.
Make a donation to my favorite charity, ME..So, my next BIG question now, is what else can I do whit the $800 I was expecting to spend there.
Thanks for the tip Gabe. Good idea. ; -)
ah-ha ! You remember this one, eh ?Christian:
Whatever happened to your backyard garage/workshop you planning about a year ago. Did you ever build it?
If not- put the money towards that.
That is correct. In fact, it's not possible to easily measure rotor thickness with a caliper, this because the rotors usually have a ridge around the outer edge, and a caliper would measure from the widest point (the ridge), not from the worn surface of the rotor.Using that type of caliper doesn’t give a true representation of the rotor thickness...
+1 above. For my purposes I purchased this one from Amazon and it's accurate enough for what I use it for................ there are cheap micrometers available that are perfectly fine for this application. We're not measuring anything critical, just trying to get a decent estimate on the thickness of the rotor, and comparing it to the 4.00mm minimum thickness spec.
Agree with that, we're not checking an engine build or something like that. There are plenty of inexpensive options to get the job done. (Although, Miyotoyo metrology products are awesome.Just to add a dose of reality to this thread, there are cheap micrometers available that are perfectly fine for this application. We're not measuring anything critical, just trying to get a decent estimate on the thickness of the rotor, and comparing it to the 4.00mm minimum thickness spec.
As you measure different places along the rotor surface, your measurement will vary by a few 0.01mm, so having a micrometer that is accurate to, and reads to 0.001mm is useless, the rotor isn't uniform enough for that to be of any value. Any cheap mic will be good to 0.01mm accuracy, and even that is overkill for this application.
I have a few micrometers, a cheap one that I bought new somewhere I can't remember, a used Mitutoyo that I picked up off Ebay for about $25, and a digital one that I got from Harbor Freight. For this application they're all pretty much the same, so you don't have to spend a lot of money to get something useful, and it can also be used to measure the occasional un-marked valve shim.
This is especially true once the disc has significant wear on it and there is an unworn rim on the outside where the pads didn't contact.Using that type of caliper doesn’t give a true representation of the rotor thickness.
Great fix on the battery door Michael.
Have you checked the guidelines in your area to be sure? I am within the city of Montreal. In my borough, a building permit is not required for a garden shed. Regulations regarding proximity to the property line and the size in relation to the house and the lot are all that is specified and the homeowner is expected to respect them. There is nothing regarding what type of floor. If you can build it on a concrete slab all the better.I would have prefer a concrete floor, but, It is much more simple, with the city's regulation, to have something smaller than 100 square foot with a wooden floor. They then considers it as a removable shed.
If someone doesn't have a micrometer, many, if not most, vernier calipers have stepped jaws that open up at the heel end. The opening is wider there than it is along the measuring portion of the jaws. This step clearly can be seen in both of the verniers pictures in posts 13 & 17. This step allows the vernier to be slid beyond the lip on the edge of the disk while still allowing the measuring jaws to close against the friction zone. This step is there for just such a purpose. The measurement that the vernier would give would be more than accurate enough for measuring a disk unless the disk was badly gouged.This is especially true once the disc has significant wear on it and there is an unworn rim on the outside where the pads didn't contact.
possibly, but when the disk nears its wear limit, you've got a (nominally) 0.5mm lip on each side of the rotor, I'm not sure the caliper can accommodate that much of a lip. I have calipers and micrometers and don't bother with the calipers for this job because the mic is so much easier to use, and move along various parts of the rotor surface.If someone doesn't have a micrometer, many, if not most, vernier calipers have stepped jaws that open up at the heel end. The opening is wider there than it is along the measuring portion of the jaws. This step clearly can be seen in both of the verniers pictures in posts 13 & 17. This step allows the vernier to be slid beyond the lip on the edge of the disk while still allowing the measuring jaws to close against the friction zone. This step is there for just such a purpose. The measurement that the vernier would give would be more than accurate enough for measuring a disk unless the disk was badly gouged.
They use to be expensive, but that is no longer the case.That is correct. In fact, it's not possible to easily measure rotor thickness with a caliper, this because the rotors usually have a ridge around the outer edge, and a caliper would measure from the widest point (the ridge), not from the worn surface of the rotor.
It could be done, I suppose, if one used shims (for example, coins) on either side of the worn surface when taking the measurement, and then measured the shim thickness and deducted it from the gross measurement.
A micrometer such as the one illustrated in your post would be the preferred tool, but micrometers tend to be expensive devices not commonly found in home toolkits. A caliper such as the one I used to measure the coins in post 17 above is less expensive and all around more useful to have. But, it would require that shims be used if someone wanted to measure the thickness worn surface of a brake rotor.
FWIW, I have a micrometer - but only because one was passed down to me by my father-in-law when he retired from his work as a machinist.
Michael