Gotcha. Thanks. The bit I'm using seems ok for bulk cutting. Also I made a few tenons. They are not trimming evenly. The butt side diameter is slightly smaller than the tip side. Is that from the bit.
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Tenons/ferrules
- Thread starter GoldCrown
- Start date
Gotcha. Thanks. The bit I'm using seems ok for bulk cutting. Also I made a few tenons. They are not trimming evenly. The butt side diameter is slightly smaller than the tip side. Is that from the bit.
1st question, did you look at the link about tool angle geometry?
There are 2 reasons for the result you are seeing, the part is too far out form the chuck and is flexing/pushing off from too big a cut.
-Or the tool is too dull for the material being cut.
3rd and most unlikely, the headstock is not true to the run of the lathe bed or the lathe is net correctly set up and leveled.
The only grinding tool I have is a Dremel with heatless wheels. Can I work with that for modifying and sharpening bits.
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The only AR cutters I've ever found that were suitably sharp enough for ferrules right out of the package were Micro 100 brand.
As far as your part sticking out of the chuck,that is WAY too far.
With mild STEEL,you are only supposed to stick it out 3x the diameter of the part without a live center,with the exception being 5x the diameter if it's over 1",and that is still based on it being steel. Tommy D.
As far as your part sticking out of the chuck,that is WAY too far.
With mild STEEL,you are only supposed to stick it out 3x the diameter of the part without a live center,with the exception being 5x the diameter if it's over 1",and that is still based on it being steel. Tommy D.
When your tool is cutting extremely well, you will be able to take a cut on a ferrule just .001" or .002" on the diameter, and have the ferrule be perfectly cylindrical (non-tapered). It should measure the same diameter from one end to the other, within .001".
Also, the surface finish will be so good you really wouldn't even need to sand it except for everyone want a high polish. You can easily start sanding with 320, sometimes even 400 or 600. The sanding should be a bare minimum. Its just to get the polish. If your sanding to remove tool marks, chatter, etc, then your cutting is not up to par.
Another factor in this is whether or not you have a power feed on your lathe. If you do, the above is very true. If you don't, you will probably have a few dwell marks here and there. But, you should strive for a very even feed rate. Try to get your body and hands into a position where you can continuously turn the carriage feed dial without stopping or changing the pace.
Forgive me for asking, but you are setting your tool on center, correct?
Also, the surface finish will be so good you really wouldn't even need to sand it except for everyone want a high polish. You can easily start sanding with 320, sometimes even 400 or 600. The sanding should be a bare minimum. Its just to get the polish. If your sanding to remove tool marks, chatter, etc, then your cutting is not up to par.
Another factor in this is whether or not you have a power feed on your lathe. If you do, the above is very true. If you don't, you will probably have a few dwell marks here and there. But, you should strive for a very even feed rate. Try to get your body and hands into a position where you can continuously turn the carriage feed dial without stopping or changing the pace.
Forgive me for asking, but you are setting your tool on center, correct?
Below are the bits I have used for both metalworking and cue repairs. (From the Mcmaster Carr catalog). These are called carbide brazed. They are hard carbide onto a soft steel shank. A right hand bit is what you want. It means it cuts from right to left. I forget on your lathe if the toolholder uses a 3/8" bit or a smaller one. I have a Hightower, but put a quick change toolpost on it, that works up to 3/8". C-6 is harder than C-2. It probably won't make any difference with our appicaltin, but I normally buy the C-6.
You can also go the insert tooling route. However, that is much more expensive. I have used the same carbide brazed tool for several years. You just keep resharpening it. I also like to have two tools set up. One for the heavy cuts, and one I keep razor sharp once I'm on the last .005 or .010 (on the diameter).
Turing talk is diameter usually, not radius. You're lathe's hand wheel might be calibrated on the radius, but most metal working lathes are calibrated to the diameter.
When I worked in a metal tool room, I think one of these bits lasted me a whole year. I think I finally dropped it and it fractured. You will get a lot of mileage out of these.
If you go the carbide route, you will need a small diamond hone to touch up its edge. Do this right before the finish cut. Get the 250 and 400 grit of these. Get the $8 ones letter E. These will allow you to touch up the edge, and also polish it so you can take that really smooth cut.
http://www.mcmaster.com/#diamond-hones/=qbs1aw
If you want to alter the angle of the carbide (or HSS tooling), you need a grinder. If you have a bench grinder, change out one of its wheels to a wheel that will grind carbide. Then you can change the angles of the tool if you so desire. But when finished grinding, if you use the diamond hones (for either the carbide or HSS) to touch up the edge, you will have a much nicer finish on your parts.
In a rough sense, the more acute you make your tool angles, the sharper the tool will be. But it will also have less "meat" behind it, and the edge is weaker. Most of the info you will find about tool edge angles will be for metalworking. Where if you make the angle too acute, the tool won't last long. But in our application, you can get away with slightly sharper angles.
When you set up your tool bit, it should be set up so that you can turn and face without repositioning it. So in other words, you angle it so it splits the difference.
If you order from them, or MSC, (same type of place), they will start sending you little catalogs of metalworking stuff. Flip through every page, and just seeing the products you will learn a lot.
You can also go the insert tooling route. However, that is much more expensive. I have used the same carbide brazed tool for several years. You just keep resharpening it. I also like to have two tools set up. One for the heavy cuts, and one I keep razor sharp once I'm on the last .005 or .010 (on the diameter).
Turing talk is diameter usually, not radius. You're lathe's hand wheel might be calibrated on the radius, but most metal working lathes are calibrated to the diameter.
When I worked in a metal tool room, I think one of these bits lasted me a whole year. I think I finally dropped it and it fractured. You will get a lot of mileage out of these.
If you go the carbide route, you will need a small diamond hone to touch up its edge. Do this right before the finish cut. Get the 250 and 400 grit of these. Get the $8 ones letter E. These will allow you to touch up the edge, and also polish it so you can take that really smooth cut.
http://www.mcmaster.com/#diamond-hones/=qbs1aw
If you want to alter the angle of the carbide (or HSS tooling), you need a grinder. If you have a bench grinder, change out one of its wheels to a wheel that will grind carbide. Then you can change the angles of the tool if you so desire. But when finished grinding, if you use the diamond hones (for either the carbide or HSS) to touch up the edge, you will have a much nicer finish on your parts.
In a rough sense, the more acute you make your tool angles, the sharper the tool will be. But it will also have less "meat" behind it, and the edge is weaker. Most of the info you will find about tool edge angles will be for metalworking. Where if you make the angle too acute, the tool won't last long. But in our application, you can get away with slightly sharper angles.
When you set up your tool bit, it should be set up so that you can turn and face without repositioning it. So in other words, you angle it so it splits the difference.
If you order from them, or MSC, (same type of place), they will start sending you little catalogs of metalworking stuff. Flip through every page, and just seeing the products you will learn a lot.
I'm using the entire set up as I received it. I have not reset the tool. It looks centered but I can't tell how accurate it is. Being inexperienced I have to make every mistake. I'll start with a new bit (Micro100) and see where the trimming goes. I'll make adjustments when I get the bit.
The dial that moves the toolbar in has a slight touch of free play or slack or creep what ever it is called. It does not engage immediately. Also the cross carriage that engages the threaded worm gear has a slight touch of play. Is that normal.
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Yes that's all normal. The free play is called backlash. Every machine has it. You have to understand how to work with it. (It's easy).
Having the cutting edge on center is very important. If it's above center, your tool will rub and not cut cleanly. If it's below center, it will cut but the angles will be different. In either case, above or below, the calibration of the cross slide dial will be wrong.
The usual practice is to be exactly on center or up to about .005" below center.
Send me a pm with your phone number if you like. I can talk you through some stuff. Lots to type...
Having the cutting edge on center is very important. If it's above center, your tool will rub and not cut cleanly. If it's below center, it will cut but the angles will be different. In either case, above or below, the calibration of the cross slide dial will be wrong.
The usual practice is to be exactly on center or up to about .005" below center.
Send me a pm with your phone number if you like. I can talk you through some stuff. Lots to type...
You really do need to do some studying online or take a course at a night school or something.The tool geometry pictures show a view looking down on top of the tool, a side view and an end view. With those are associated angles for the various materials.
To grind or sharpen your own tools, a good bench grinder is required.
The white aluminium oxide wheels work very well for hss. Or you can use Blue SG wheels( seeded gel, also known as ceramic aluminium oxide)
For sharpening carbide you need either a diamond hand lap or a diamond compound grinding wheel.
Google will show pictures of what angles work for various materials.
The main reason for recommending some kind of night school is
so you get to learn how to do things properly and there fore more safely.
Some nasty accidents have happened as a result of not using a grinder properly etc etc.
School....please don't remind me. I should have stayed in school. Hey thanks for heads up on safety. We can never be too safe. I try to stay safety oriented. I worked with small hand tools and Baldor lathe for a lifetime. Currently I'm also using a Jet 1015 for Pens. I'm wearing a Trend Air Pro with that and ear protection for the dust collector.
I will try to avoid sharping bits for now. As much as I'm going to use them a good quality one should last a while. I have been getting excellent support from members here as far as bit tip angles and general info on how to use the lathe properly. I appreciate everyone taking the time to post, PM & FaceTime. Without you my lathe is worthless.
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I received AR 1/4" Micro100 bits today from Suncoast Precision Tools inc (Amazon). Price seemed decent and shipping cost more than reasonable. I will mount, center and check it out this weekend. I'm looking forward to working with it. Now that it is in front of me I can appreciate the tip angle.