HS22 Machining a car brake disc rotor on the Harrison 140

[@RicktheRecorder]

What happened to the other side of the disk? It is most important that both disk faces are parallel.

[@HaxbyShed]

It's a while ago now, I recall I clocked the other face and it was running ok and in reasonable condition. The disk was not warped. If the other side had needed machining I would have reversed the 4-jaw jaws and held it in the handbrake hub which I'd cleaned up already, or stuck it on a faceplate. Cheers

[@Ник-л9х6ъ]

@@HaxbyShed Глупая работа Позоришь токаиную обработку ты

[@HaxbyShed]

@@Ник-л9х6ъ Это не очень приятный комментарий. 😒

[@stephenweir2003]

I don’t understand why you would clock in two worn surfaces. A brake disc registers on the hub not the wheel. So you should clock the inside face where it’s meets the hub and the inside diameter there it locates on the hub.

[@HaxbyShed]

Well you are right of course. I think I was trusting that the hub face was seated and registered accurately on the chuck jaws. I may be skimming the rear discs on my own car later this year and I will do as you say. Most days are a learning day for me. :-)

[@bernardmauge8613]

Correct

[@Beardmondy67]

.. Good vid,.... What size Multi Fix tool post are you using on the 140 and what make ?.. Cheers in advance,.. Dan,.. SW London.

[@HaxbyShed]

Hi Dan, it was a size A from PWE tools. pewetools.de/en/ I bought pre-Brexit from ebay UK. I have bought some extra holders since Brexit so he will still ship to UK. Cheers Paul

[@Beardmondy67]

@@HaxbyShed .. Howdy there, Paul,.. Thanks for the prompt reply and info,... I'll give PEWE a look,... Keep up the splendid 140 vids ,...Muchly obliged,.. Dan.

[@RRINTHESHOP]

Nicely done Paul. Should work.

[@HaxbyShed]

Thanks Randy. Basic but I was pleased the way it turned out.

[@cdrive5757]

The current crop of today's machinists have totally forgotten how to use a Face- Plate! You have a brake rotor that is "as stated" true and in good shape on its rear face. This same rotor has convenient lug holes for easy mounting on a face plate. Another benefit of the face plate as compared to ANY chuck is minimum overhang that a face plate delivers. Wakodahatchee Chris

[@HaxbyShed]

I like you name C Drive 😁. In video HS151 I skim some big 360mm VW Phaeton rotors with a bit more confidence. Cheers

[@donnykiofetzis5775]

is this a test piece, remember disc have a specified thickens if you take too much off there usless

[@HaxbyShed]

Hi Donny, it was a test piece to see if I could swing it in the lathe with the bed gap in place. Usually discs can be cleaned up taking very little off and there are in fact 'brake lathes' for that purpose. These days discs/rotors for common cars are very cheap so it's often not worth the time to skim them but some years ago I've had car discs skimmed at a main dealer. In my humble opinion discs in the past were made of decent material whereas today they seem to be poor material regarded as a disposable consumable every few years. Once they get a bit of rust on the faces they won't clean themselves up through use and the rust patch just grows. The rear discs on my car are looking a bit that way so I may give them a light skim rather than give VW another chunk of cash.

[@bernardmauge8613]

Hello Paul Bernard here. I turned my front rotor (Audi 100 ) yesterday and it was a disaster. I had sparks, vibrations and deep grooves on the disc and had to admit defeat. The disc was glazed by the pads with no scoring marks and I made it into junk. I had put new discs on the car and this was only for practice on the lathe. I wished I had seen this video before my attempt but I was a day late. On my old French lathe Ernault Battignoles, I have two speeds to choose from (not including thread cutting) one his called "Volee"which means full speed and the other is "Harnais "which is slow. I always use Volee to do all my machining so this is what I used, I think it was a mistake looking at the speed on your video. I also used the cheap Banggood tools that are rought but work ok for me on my other cutting work. What did I do wrong? I even used the automatic carriage thinking my hand at the crank was not steady enough, use cutting fluid, to no avail. Also I am about to invest on better cutting tools and I know you made a video on that. May be you could send me a link. I have had issues with British sales to France since the Brexit, so I may have to look somewhere else. Take care.

[@HaxbyShed]

Hi Bernard, good to hear from you. It's hard to give specific advice but in general I would say use slow speed and a sharp HSS tool to cut through the glaze. The cast iron used for brake rotors is pretty poor quality in my experience. Cheers

[@rogerhutchings5811]

All brakes are cast iron

[@HaxbyShed]

Hi thanks, yes I thought it was cast iron. I have machined a number of cast iron items before and it's usually a pleasure to work with but these discs were really dirty low quality metal. No wonder they don't last long these days.

[@davidellis279]

Obviously this man knows nothing about brake rotors, You Never Ever just machine one side of the disc,these discs are cast iron and should be machined on the inner and outer together to ensure accuracy and eliminate any run out of the disc,the handbrake drums are always corroded like that because basically it’s a parking brake and rarely the shoes come into contact with a rotating drum so rust up because there is no friction between the shoes and the drum. I have a proper brake lathe which is designed for the job and is accurate to better than 2 thousand of an inch and most times spot on. I am considering buying a lathe for commercial roters because they are a lot bigger than car and small vehicle ones,I appreciate that he set up the disc with a dial gauge but it should set up on the hub that bolts up to the vehicle,if he had made a mandrel so the disc could have been secured to the mandrel and then fitted into the lathe for machining ensuring total accuracy.

[@HaxbyShed]

Hi David, thanks for your comments. I have seen brake lathes in operation and yes I understand they machine both sides together. Here I'm machining just for myself making the best of what I've got. That one was a spare disc rotor for practice. However if I needed to machine another disc rotor for myself I think with care I could do it. Cheers.

[@davidellis279]

@@HaxbyShed Hi and thanks for your comments,front brake discs have to be really accurate to eliminate brake judder,you have have the right idea but they really need to be set up for machining on the hub face Not the casting as sometimes the casting are not as accurate as they should be,I just didn’t want people to think they could be resurfaced on one side only because they have to be parallel to each other to work properly and safely.

[@stevecallachor]

The reference face must be the inside face of the drum? Otherwise you’re wasting your time!!! Stavros

[@HaxbyShed]

Hi Steve, .... I think you are saying the datum face must be the face that bolts up to the hub, and yes I would agree. There I was relying on the front face of the jaws being true and clocking the disk friction face was just a double-check. Machining that disk rotor was an exercise to see if I could do it, and it was never actually used. However it looks like I'll be machining a pair of disk rotors on son's car soon and I'll have to be careful to get those right..... but I do have quite a bit more experience now. Cheers

[@Ник-л9х6ъ]

Вы правы и контроль диска должен быть Измерив толщину диска в четырёх точках микрометром Допуск полторы две сотки Тогда будет норма На видео работа сделана не качественно