- Joined
- Jan 1, 2018
- Messages
- 31
A while ago, whilst going through my "new" 8520, I discovered that the spindle brake was cracked in two. I removed it from service and figured I'd try to fix it once I got the mill back up and running. It had a nice clean break just next to the hole like most of them do, or so I've read. Wondered if I might be able to silver solder it back together and run it again. Well that little plan didn't go so well...first attempt I couldn't get the solder to flow and pretty much made a mess of it. Tried another time and made it even worse, so I figured I'd just run it without a brake. My previous 8520 never had one and I got along fine without it...mostly just grab the belt and give it a squeeze just behind the head pulley to lock things up while changing a tool. works pretty good and I don't think it stresses things out too much.
Then I was at the scrap yard one day and ran across a couple brass rings that looked big enough to make a new brake out of. Sure enough, so I took some measurements of my old brake and started in on the lathe. I wasn't able to measure the head on the mill so it was a bit of a guess on the inner diameter (because of the broken brake, it was two pieces). Got it turned up pretty nice, and then started in on the features...put a nice slit in it using a slitting saw, then drilled the stress relief hole and then using the bandsaw, cut a slit from the ID to the hole.
Made a little jig out of aluminum on the mill to help space out and position the tangs on the brake. The actuator handle was 3/8's inch, so I made the space just a hair under to keep them together once on the mill and hopefully eliminate any chatter from being loose. Drilled and tapped the holes for the attachment screws, then drilled the aligning holes out while attached to the jig to keep everything lined up correctly.
Finally got to install it today after having the mill head apart for new bearings. Was a snug slip fit over the boss on the head and fit under the head pulley with a few thousandths to spare! This thing might actually work!! Had to modify the actuator handle a bit to make room for the magnet I glued on the other day for the RPM sensor.
Anyways, it seems to function fine and doesn't take much movement on the handle to engage the brake. I guess this is how Clausing intended for it to work anyway, time will tell if it holds up.
![IMG_E5567[1].JPG](https://www.hobby-machinist.com/data/attachments/355/355483-5756648b2bccc133dfdf3aa7a77d8eb8.jpg "IMG_E5567[1].JPG")
![IMG_5577[1].JPG](https://www.hobby-machinist.com/data/attachments/355/355484-2cae1609420811fff0707d8b8033e0d5.jpg "IMG_5577[1].JPG")
![IMG_5578[1].JPG](https://www.hobby-machinist.com/data/attachments/355/355485-f91c00d0867229bccf7bbaf1f76c2390.jpg "IMG_5578[1].JPG")
![IMG_5579[1].JPG](https://www.hobby-machinist.com/data/attachments/355/355486-d6076d6a4a413a225693bb478aaa0349.jpg "IMG_5579[1].JPG")
![IMG_5513[1].JPG](https://www.hobby-machinist.com/data/attachments/355/355487-84ef8dbe7999e0fc5aa3c36bdc7b264f.jpg "IMG_5513[1].JPG")
Then I was at the scrap yard one day and ran across a couple brass rings that looked big enough to make a new brake out of. Sure enough, so I took some measurements of my old brake and started in on the lathe. I wasn't able to measure the head on the mill so it was a bit of a guess on the inner diameter (because of the broken brake, it was two pieces). Got it turned up pretty nice, and then started in on the features...put a nice slit in it using a slitting saw, then drilled the stress relief hole and then using the bandsaw, cut a slit from the ID to the hole.
Made a little jig out of aluminum on the mill to help space out and position the tangs on the brake. The actuator handle was 3/8's inch, so I made the space just a hair under to keep them together once on the mill and hopefully eliminate any chatter from being loose. Drilled and tapped the holes for the attachment screws, then drilled the aligning holes out while attached to the jig to keep everything lined up correctly.
Finally got to install it today after having the mill head apart for new bearings. Was a snug slip fit over the boss on the head and fit under the head pulley with a few thousandths to spare! This thing might actually work!! Had to modify the actuator handle a bit to make room for the magnet I glued on the other day for the RPM sensor.
Anyways, it seems to function fine and doesn't take much movement on the handle to engage the brake. I guess this is how Clausing intended for it to work anyway, time will tell if it holds up.
