On the berco brake lath they have a series of cups that you select to fit the flange size, these push on each other with the drum in the middle, then there is a spring loaded cone that helps you centralize the drum , usually all it took was a couple of tightening and loosening and re tightening attempts for it to clock ok , then strap it with the thick rubber de ringer ,the boring bar was very rigid about 50mm, brake lathes are fairly slow , but do a great job .

the patterns on the surface at 6:34 are a result of the brake drum vibrating during turning resulting in an unconsistent cut. i encountered this problem too. my solution was to slow down the lathe to an minimum (usually around 200rpm) and going for a rigid tool holder. when it stops screaming and singing during turning the surface turns out fine, usually...

how lots of old shops did it ..they couldn't afford a machine that just did brakes...takes more time because of the set up but the finished product is just as good

That's like, effort, and stuff.

I turned a drum with just the three-jaw chuck holding. Selected the lowest speed on the lathe, used a boring bar with a carbide tip, and ran the travel at the slowest speed. About seven passes and it was smooth. Since I have a brake lathe, I used a weight belt from that set on the drum.

@YoshimoshiGarage

Жыл бұрын

Nice job. Unfortunately my lathe has something wrong in the gearbox and won't go any slower

Well done job of doing with what you have! Been there....The chatter is reduced with negative rake. Carbide cutter at a guess negative seven degrees. You can wind the outside with rubber hose for a damper.

Thanks for sharing.

Wrap bungies around outside.

I’m 2 years late to the party. My comments are absolutely not intended as a criticism at all, I really just to help out anyone watching this video, setup a lathe for brake drums. So, for the benefit of others…Even bungee cords and/or duct tape and rags are enough to stop ringing. The ringing isn’t just a nuisance, it’s audible chatter (not all chatter is audible). Lathe RPM is way too fast. I’m not quite sure about feeds from the video, but if you are constantly losing a good hss edge, SLOW IT ALL DOWN before going to TC. HSS will handle Cast Iron at correct speeds (which makes heat manageable). If you’ve got TC, that’s fine, but for those of you who don’t have access to TC, don’t leave this video feeling like you NEED TC to turn down a brake drum. There is very very few things that can’t be managed with HSS, provided you have the patience. In fact, for the average at home DIY tinkerer machinist, HSS is really all you need. TC can allow you to take deeper cuts at higher speeds/feeds, but if you’ve got the time, HSS will do all the same things (and TC has its downsides too, so it’s not all roses). Having said all that, if your lathe is stuck in a higher gear and low speed is not an option, TC is a brilliant option to get the job done.

I would have machined that at about 40% slower than where you were at the 6 min mark

@YoshimoshiGarage

4 ай бұрын

Unfortunately the gear box on my lathe needs work, so it won't go any slower

Using HSS tooling on soft steel, you need to limit the cutting speed to 100 surface feet per minute. Assuming your drum diameter is 12 inches, 1 foot diameter is 3.14 feet circumference. So 100 SFM is a max of 32 RPM. And as this is hard material, maybe 50% less speed. You need much more speed reduction. Back gear should get you there. I don't know your lathe. The other issue, just how good is your 3 jaw chuck. Even Bison brand has a few thousands of runout. As all the surfaces are rusty, you compound the runout using the center pilot without some means of checking that. I turned some brake rotors on my lathe this past spring. I wanted to see if I could do them. I sand blasted them first. My big lathe has a 3 phase motor driven with a VFD, so I can slow it down to a crawl.

@YoshimoshiGarage

6 ай бұрын

Unfortunately my lathe needs to be taken apart and the low gear fixed, that's as slow as it goes right now.

@f.hababorbitz

6 ай бұрын

@@YoshimoshiGarage I watched you video, as I have 4 brake drums to do from a 1956 Chevy 1.5ton truck. These are 16" diameter drums. I know I need to figure out a way to hold them in the 4 jaw chuck. So I watched a video using a purpose manufacture brake lathe. Looks like they use a cone to center the drum center hole pilot. I'll have to fab all that stuff. I recall some specifications that say less then 0.002" of runout so the brake shoes and holding hardware does not fail. That's a pretty tight tolerance.

@f.hababorbitz

6 ай бұрын

@@YoshimoshiGarage From the looks I'm guessing a 14x40 lathe, maybe 12x36. The headstock looks very similar to my 1976 Jet brand 10x24. Same oil level sight glass and casting design (Jet was an importer that had their name put on existing manufacture equipment). If the back gear is like mine, you have to disengage a spring loaded pin the decouples the V-belt pulley from the spindle, and then an eccentric mechanism swings the floating gears to mesh with the two gears on the spindle. I hope it's just an issue with adjustment and not gear teeth that got destroyed.

@f.hababorbitz

6 ай бұрын

@@YoshimoshiGarage I subscribed. I'm the same, I fix everything. Mechanical, electrical, electronic. Best thing I did after high school was a 2 year school in HVAC. Worked as a lab tech for the Trane Company in Lacrosse, WI, and saw I was as smart as the mechanical engineers. So went back to school and got an EE degree. Also in high school they had metal working so I got that bug. Oddly all the schools sold off their votech equipment when I started work in 1984. Now they don't have the original space or equipment. I'm retired, and now need to restore the 1924 model T truck, 1956 Chevy Truck, 1957 Chevy truck and 1965 Datsun Fairlady SPL310. I have a pretty full machine shop. Oh, I measure the brake drum off the rear of the truck, 17.1 inches. So I'll have to see if it will fit on the big lathe, supposed to be 18x40. I've never had the gap out of it. Just looking at your video titles you seem to take on all the same things I would.

I doubt the cast iron was especially hard, but your cutting speed looked way too high. I mean FPM right at the cut. Use the back gear. The cutting tool simply will not survive this abuse, the localized instantaneous heating at the cut is intense, there is no "maybe I'll get away with it. " It softens and can no longer hold an edge. The rust is another significant factor, it is hard and abrasive, and will wear the tool out quickly. The loss of the sharp edge increases friction, therefore heat, adding to the cutting speed being maybe 10x too high. The vibration (singing) can be changed by the tool tip profile, a very pointy shape reduces the forces involved, and might help. But it will be more fragile and susceptible to overheating. I noticed that one of those hold down blocks is positioned between the chuck jaws, the other is over one. The drum might be distorted...bowed slightly under the block not backed up by a chuck jaw. This could make the drum out of round while cutting the hole to a round shape. Then when released, the formerly round hole becomes an oval in its relaxed state. Maybe. Maybe not enough to matter. But that RPM made me cringe...poor tool! Google "metal cutting speeds and feed rates". Not optional...get that approximately right or wreck tooling.

@YoshimoshiGarage

6 ай бұрын

It was an exercise in "working with what I have." The lathe won't go any slower than that until it gets some maintenance.

Slow down lathe speed

@YoshimoshiGarage

Жыл бұрын

Wish I could. The gear box on my lathe has something wrong with it and what you see is as slow as I can currently get it to go (other than stopped)

@DynamicSeq

Жыл бұрын

@@YoshimoshiGarage Get a VFD...Have it on my lathe and it's awesome...

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