I made an extension rod for one of my countersink drill bits. The shaft diameter of the countersink was .375. I used a .750 A36 rod that I turned down. I bored a hole to fit the countersink and turned the rest of the rod to .375 to fit on my drill. It was 8" long. I needed it for one of my applications to use on a drill. It worked but the finish was downright ugly. I used a HSS cutting tool. My lathe is a LeBlond Regal 13x30 (3hp). I think the first mistake I made was boring the hole first. Probably should have done that last to utilize a live center for the turning process. The radius on the HSS cutting tool was probably to small. Any suggestions. I am definitely a newbie.
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Turning A36
- Thread starter Scruffer
- Start date
- Joined
- Feb 25, 2021
- Messages
- 3,165
A36 and 1018, common hot rolled and cold rolled material, are VERY challenging to get a good finish. They also tend to make long stringy chips. Almost any other steel alloy will be easier to get a nice finish. Advantages of A36 and 1018 are they are relatively cheap, and they are readily weldable.
A general rule of thumb is to try to keep no more than 3:1 unsupported distance from your chuck (or collet, etc) for turning. So for a 3/4" rod you'd want no more than about 2" beyond the chuck. At 3/8" that is getting down to just over an inch. You can certainly do effective work at longer stick out, but you have to be aware of chatter. A LeBlond Regal is a fairly heavy lathe, but that doesn't help with anything for extended stickout, or a significant distance between centers on a thin part without a follow rest.
Turning speed? Feed? DoC? You generally want somewhere around 80-100 FPM using HSS. At a 1/2" working diameter, thats 800 RPM, even faster when you get down to 3/8".
For the best advice, pictures of your setup, and a closeup of the finish are really helpful.
A general rule of thumb is to try to keep no more than 3:1 unsupported distance from your chuck (or collet, etc) for turning. So for a 3/4" rod you'd want no more than about 2" beyond the chuck. At 3/8" that is getting down to just over an inch. You can certainly do effective work at longer stick out, but you have to be aware of chatter. A LeBlond Regal is a fairly heavy lathe, but that doesn't help with anything for extended stickout, or a significant distance between centers on a thin part without a follow rest.
Turning speed? Feed? DoC? You generally want somewhere around 80-100 FPM using HSS. At a 1/2" working diameter, thats 800 RPM, even faster when you get down to 3/8".
For the best advice, pictures of your setup, and a closeup of the finish are really helpful.
- Joined
- Mar 21, 2018
- Messages
- 1,611
This statement doesn't make sense. You need a hole for a live center.
Your problem on the finish is the A36. A36 does not finish well. A36 is basically scrap metal melted into a bar. As for finish, you don't need a good finish for what you were doing, so A36 would work just fine. Your order of operations was just fine - bore hole first, mount using a live center, then turn the outside to size.
You were successful in your task - don't fret over the final finish with A36.
Ok, I should have used a live center after boring. I wasn't thinking. I used the drill bit inside the bored hole to secure the rod. Dumb. I am using the countersink bit on A36 plates and having good results with slow rpm. When I fabricated the plates, I decided to use hex head bolts. After installation, I decided that countersink bolts would be a better fit look wise and had to fabricate the extension rod. Gutter project. Live and learn.
- Joined
- Dec 3, 2017
- Messages
- 1,941
Don’t turn A36.
- Joined
- Feb 25, 2021
- Messages
- 3,165
Yep. I've found machining just takes a lot of experience. Sounds like you achieved your goal of making a drill extension. Call it a success.
My gutter project.
I decided to go a different direction with my gutters install. The existing gutters work fine but I have to clean them out frequently because of all the trees and foliage around my house. I've tried different gutter covers and it's always the same, constant clearing. So, I fabricated the gutters to rotate. I had the gutters fabricated with 18 gauge galvanealed steel. Then I had them powder coated. I am using 1" aluminum shaft bolted to the ends and on pillow block bearings. Aluminum angle iron support underneath for support. We've had a lot of rain lately and they are working great. Easy to clean. The sections that are 12' and longer in length, I had to add cross supports to help from twisting. So far so good. I am going to give it
View attachment IMG_6050.mov
a year, and if all is well, I am going to try and motorize them and put them on a schedule.
I decided to go a different direction with my gutters install. The existing gutters work fine but I have to clean them out frequently because of all the trees and foliage around my house. I've tried different gutter covers and it's always the same, constant clearing. So, I fabricated the gutters to rotate. I had the gutters fabricated with 18 gauge galvanealed steel. Then I had them powder coated. I am using 1" aluminum shaft bolted to the ends and on pillow block bearings. Aluminum angle iron support underneath for support. We've had a lot of rain lately and they are working great. Easy to clean. The sections that are 12' and longer in length, I had to add cross supports to help from twisting. So far so good. I am going to give it
View attachment IMG_6050.mov
a year, and if all is well, I am going to try and motorize them and put them on a schedule.
- Joined
- Jun 7, 2013
- Messages
- 10,184
Another approach is to only have gutters over doorways --- Also, I leave the ends open, and the leaves can be simply pushed or blown out. Mostly oak leaves, the rust out galvanized gutters in a few years, so I went to copper (cry once).
I have a total of 10 gutters excluding the bay windows. Varying dimensions from twenty feet to six feet. Two bay windows in the front, One in the back. A total of 13 gutters for the bay windows For now, I am going to use gutter covers on my bay windows. Next year I'll visit doing the bay windows. Not sure about the patent idea. A lot of people have suggested it. I went through a lot of experimentation and material to get it where I was satisfied with the design. It's a really simple design. I've replaced all my exterior trim boards with pvc boards. In keeping with the same profile, I replaced the fascia boards with pvc boards. My rafter tails have a 2x6 sub fascia board so it was not an issue using pvc boards as fascia boards.
My machining part is slotting, countersinking on my mill & turning the aluminum shaft on my lathe. The pillow blocks are metric (bore is 25mm). The aluminum shaft is 1.00". So far, not to challenging. The sheet metal shop told me that galvanneal sheet metal is easier to powder coat and weld than galvanize sheet metal. They could only fabricate 10' lengths. They fabricated the ends for me also. I welded the ends and butt welded the gutters that were longer than 10' with a splice plate. They were right about welding galvanneal sheet metal as oppose to galvanize sheet metal. If you ever welded galvanize, it's a royal PIA . We've been getting a lot of rain so putting the gutters to the test. So far so good. I am rotating the gutters just 150 degrees which make them a lot easier to hose them out if need be. Don't have to stand underneath to do it. Ultimately time will tell how well they will perform. Thks