1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. PLEASE: Read the FORUM RULES BEFORE registering!

    Dismiss Notice

First lathe, tool bits

Discussion in 'A BEGINNER'S FORUM (Learn How To Machine Here!)' started by Jmanb13, Mar 13, 2017.

  1. Rustrp

    Rustrp United States Active Member Active Member

    Likes Received:
    437
    Trophy Points:
    63
    City:
    Sacramento
    State:
    California

    -Return to Top-

    If the motor is still in good condition; bearings/bushings/windings etc, I would suggest replacing the seals. If you have an ammeter check to see if it's within the rated amps when running under load. There are some features of older motors that are better than the newer ones today, even when you step into the industrial quality. Without knowing how many hours or the conditions in which the motor operated you're guessing. A good motor repair shop could help evaluate what's needed. If the varmish on the windings is breaking down they may be able to recondition those too. Take photos into a motor shop and see if they will give you a ballpark estimate.

    PS. New grease seals don't tolerate over greasing and old ones are worse.
     
    Last edited: Mar 21, 2017
    Jmanb13 and Bob Korves like this.
  2. Rustrp

    Rustrp United States Active Member Active Member

    Likes Received:
    437
    Trophy Points:
    63
    City:
    Sacramento
    State:
    California

    -Return to Top-

    Your location gives you lots of resources for the motor repair and I'm pushing the repair angle for a couple of reasons, cost and keeping the machine close to original if possible.
     
  3. 4gsr

    4gsr Global Moderator Staff Member H-M Supporter-Premium

    Likes Received:
    2,096
    Trophy Points:
    113
    Location:
    Victoria, Texas
    City:
    Victoria
    State:
    Texas

    -Return to Top-

    Old motors do not have seals. They are open bearing with dust caps that are designed to keep trash out.
    Replace bearings with modern sealed bearings for motor application.
    Take pictures to the motor shop??? Never heard of doing that. Pull the motor and take it to the shop and have them do a general cleaning, inspection, and replace the bearings. If the windings need help, they will suggest what to do. Other than that, for less $100 maybe even $50, you can get a cleaned up ready to go motor.
    Nothing wrong with older motors, most will produce a bit more HP than the nameplate rating says, especially with the bigger name brands, without over heating and burning out a motor if not continuously run at a over rated condition. Ken
     
    Jmanb13 likes this.
  4. Rustrp

    Rustrp United States Active Member Active Member

    Likes Received:
    437
    Trophy Points:
    63
    City:
    Sacramento
    State:
    California

    -Return to Top-

    My comment was a general description. My old lathe motor has oil sumps with bronze bushing and slinger rings, yes rings, not sleeves. I wasn't referring to a sealed bearing and the comment was inclusive. It's common for the ball bearing to be outside the rotor, stator winding area of the case with a seal/sheild/flange to keep the oil/grease out of the winding area. If the motor is leaking oil/grease then the shield/seal is probaly worn out or the wrong type of grease was used.



    It's easier than taking the motor out and driving a 40 mile RT into OK City.
     
  5. Reeltor

    Reeltor United States Active User Active Member

    Likes Received:
    242
    Trophy Points:
    43
    City:
    Lawrenceville
    State:
    Georgia

    -Return to Top-

    I have never taken a motor to a shop for evaluation. I am surprised to hear how reasonable an inspection and general cleaning costs. Good to know.

    Many motors have a plug 180 degrees from the grease zerk, be sure to remove the plug when greasing. Allow the old grease to come out the plug-hole. Whoever serviced my VanNorman didn't know to do this and grease is everywhere. If I can get a professional cleaning for $50-$100-I think that would be a deal.
     
  6. Jmanb13

    Jmanb13 United States Active Member Active Member

    Likes Received:
    58
    Trophy Points:
    18
    City:
    Norman
    State:
    Oklahoma

    -Return to Top-

    Thanks all!

    I've never had an electric motor repaired. What type of shop would I look for? Any specific keywords to look for in the local google search?
     
  7. Rustrp

    Rustrp United States Active Member Active Member

    Likes Received:
    437
    Trophy Points:
    63
    City:
    Sacramento
    State:
    California

    -Return to Top-

    "electric motor repair" should do it. My experience is that most shops will give you a free estimate. Call around. I like the shops that have been around for a few decades.
     
  8. 4gsr

    4gsr Global Moderator Staff Member H-M Supporter-Premium

    Likes Received:
    2,096
    Trophy Points:
    113
    Location:
    Victoria, Texas
    City:
    Victoria
    State:
    Texas

    -Return to Top-

    I don't recall any that have not been around a few decades....:D
     
    Bob Korves likes this.
  9. Rex Walters

    Rex Walters Active Member Active Member

    Likes Received:
    180
    Trophy Points:
    43
    City:
    Los Gatos
    State:
    California

    -Return to Top-

    [My first post in a long, long, while. It may be lathe envy (I've been hankering for a bigger, heavier lathe). I'm still on my first: a very nice but pretty light 10" Logan.]

    I'm still a comically incompetent beginner, but there are a few things I wish I'd known when I first got my lathe. Top of the list is all about tool bits and grinding: nothing will detract from fun on a lathe faster than a poorly ground tool.

    The most useful (and most used) lathe tool accessory is a bench grinder. [The second most useful lathe tool, IMHO, is a vertical mill, but good ones aren't cheap and while you're hunting for a bargain you can get an awful lot done with a four-jaw chuck, faceplates, and centers. Work-holding and tool-holding creativity is the second most useful skill after grinding, and nothing teaches you the former better than the lack of a mill!]

    Grinding an HSS lathe tool properly is not hard (usually). It can be done freehand (with practice). A few degrees difference in rake or clearance angles won't make a difference (except when it does). Experienced grinders know the reasons behind all the angles and can troubleshoot and correct troublesome tool bits. Unfortunately, a clueless newbie has about a 0% chance of offhand grinding a tool bit correctly to begin with, and only a minuscule chance of correctly diagnosing problems. Problems are exacerbated on a light lathe with any flex in the machine (ask me how I know).

    Apprenticing with someone would get you over the hump, but I suspect most of us hobbyists are alone in our shops, so the best options forward are one of the following:

    1. You can forego some of the pain (or at least exchange it for much more pain in your wallet) with carbide inserts and tool holders. Perhaps surprisingly, though, carbide inserts will never be as sharp as a well honed HSS tool (meaning you can't take as fine a cut with them) and you still need to know an awful lot about cutter geometry to select appropriate inserts (there are a lot of choices). You guessed it: the best way to learn about those geometries is by grinding your own HSS bits.

    2. You can take my route and begin a "YouTube apprenticeship." If you accompany watching videos and reading forums/blog-posts with actually grinding bits and making chips, you'll eventually become reasonably competent. I took the longer route of always grinding freehand, but if I had it to do over again I know it would have gone a lot faster if I'd taken the time to build a decent jig or grinding rest. It's a lot easier to figure out which changes help when results are repeatable and exact rather than random (and once you can grind a decent RH turning tool for mild steel you can pretty much just lock down the jig settings as that's all you'll need 90% of the time). I've just started building the Acute tool sharpening table from Eccentric Engineering. I'd also considered building Harold Hall's sharpening rest. I can also highly recommend the advice from Conrad Hoffman though I've not tried building his jig for honing.

    Unfortunately, you'll need decently ground tools and modest skill to build any of these, which can be a bit of a chicken and egg problem for an absolute beginner. If you've got deep pockets, you can go the buy vs. build route with a tool and cutter grinder like this one. That would be an awesome investment for the shop. Even a rank beginner could grind perfect HSS lathe tools from the start (buy two while you're at it, and send one to me!). A used Deckel T&C grinder off of eBay might be a better choice, but probably won't cost any less.

    3. You could build or buy a tangential tool holder and grinding jig like the Diamond Tool Holder from Eccentric Engineering. Like most people, I initially thought the diamond tool was just a gimmick, but if there was just one thing I could go back and tell myself right after acquiring my lathe it would be to go out and buy one of these to get started. Sharpening a bit could not be easier: just insert a tool bit into the grinding fixture and push it into the grinding wheel. You only need to grind a single face! Once you set the height on center in your toolpost, you're immediate set up for all turning and facing tasks (without needing to swing the toolpost around to switch between turning and facing). While it won't completely eliminate the need to grind your own HSS tools for special tasks, it will satisfy the all important need of demonstrating how a properly ground tool behaves on your lathe. Seriously, I now use a tangential tool for almost all of my lathe work — it rarely comes off my toolpost.

    I suspect many beginners go through these options roughly in this order (1, then 2, perhaps never getting to 3). I know starting out, I just wanted to start making chips, so insert tooling seemed attractive. The sheer number of insert options was intimidating, though, so I started learning how to grind my own HSS tools freehand. The experience gained was incredibly useful, but it was definitely tedious and frustrating — I went a long, long time before I could reliably produce a reasonably performing result.

    So my advice is to keep all those tool bits you acquired (never throw away any bits of decent HSS) and learn how to grind them, but start by acquiring a tangential tool and use that to build the parts for a grinding jig/rest/fixture as an early project. That is, 3, then 2, and perhaps eventually 1 as required. Treat those rusty old bits you have as a source of HSS stock. Often the trickiest part of machining is figuring out how to get a cutting edge where it needs to be (clever work holding and tool holding). Some of those weird offhand grinds make a lot more sense when you see them applied to their specific situation. Don't be surprised if you eventually find yourself rooting around in that pile of bits looking for something close to what you need, then taking one to the grinder for just a light touch up.

    Have fun.
     
    Last edited: Mar 26, 2017
    Fitter Bill, richl, BFHammer and 5 others like this.
  10. mikey

    mikey Active User H-M Supporter-Premium

    Likes Received:
    2,135
    Trophy Points:
    113
    City:
    Honolulu
    State:
    Hawaii

    -Return to Top-

    Really enjoyed your post, Rex. Well written and based on experience.

    Thanks!
     
  11. Jmanb13

    Jmanb13 United States Active Member Active Member

    Likes Received:
    58
    Trophy Points:
    18
    City:
    Norman
    State:
    Oklahoma

    -Return to Top-

    Thanks! Lots of good info there.
     
  12. Rex Walters

    Rex Walters Active Member Active Member

    Likes Received:
    180
    Trophy Points:
    43
    City:
    Los Gatos
    State:
    California

    -Return to Top-

    Thanks. Doubtless it was overly verbose, but if I'd just said "go get a diamond tool holder" nobody would have believed me!

    Reminds me of my favorite expression: "There's no such thing as bad experience." (Assuming you survive!)
     
  13. Bob Korves

    Bob Korves H-M Supporter - Premium Content H-M Supporter-Premium

    Likes Received:
    3,386
    Trophy Points:
    113
    Location:
    USA
    City:
    Sacramento
    State:
    California

    -Return to Top-

    I thought tangential tool bits were pretty much just for shallow cut finishing work. I have never actually used one, but have watched a few in use, trying for average (and less) depth cuts on light lathes and not succeeding. The only success I saw was with a very light depth of cut and a very slow feed rate, which worked well.
     
  14. EmilioG

    EmilioG United States Active User H-M Supporter-Premium

    Likes Received:
    294
    Trophy Points:
    63
    City:
    HUNTINGTON
    State:
    New York

    -Return to Top-

    What is T15 and is it commonly used in cutters today? I'm curious because I came across a NOS Niagra T15 4 flute end mill with Weldon shank and a curious
    ring around the end of the shank. Is T15 better than cobalt for lathe bits and other cutters? (sorry, not trying to hi jack, just saw a mention to T15 earlier in this great thread.)
     
  15. Rex Walters

    Rex Walters Active Member Active Member

    Likes Received:
    180
    Trophy Points:
    43
    City:
    Los Gatos
    State:
    California

    -Return to Top-

    Are you confusing a shear tool with a tangential tool holder?

    The former is definitely for very shallow cuts (a few tenths to about one or two thou) but leaves a fantastic finish. A shear tool is also very easy to grind, but is still plunged into the work with the tool held normally (radially). Works great for final finishing passes when precision turning. See Conrad Hoffman's article for a description of the sheer tool (about halfway down the page). The chips (shavings) really do look like very fine steel wool.

    A tangential tool holder holds the entire bit at a tangent to the work. See the Diamond Tool Holder from Eccentric Engineering. [FWIW, I have no financial interest in the company, but I did have the pleasure of meeting Gary recently — great guy.]

    I usually take about 0.040" to 0.060" off the diameter of mild steel with my tangential tool during a roughing pass on my light lathe, but I could probably take a bit more. Some might consider that a shallow cut but I think they've got much heavier direct drive lathes. My belt between the motor and the drive shaft is fairly loose and tends to slip if I attempt a cut much heavier than that.

    Here's a video of someone taking what I consider to be reasonably heavy cuts in a variety of material with a tangential tool:

    Regards,
    --
    Rex
     
    Last edited: Mar 26, 2017
    mikey likes this.
  16. Bob Korves

    Bob Korves H-M Supporter - Premium Content H-M Supporter-Premium

    Likes Received:
    3,386
    Trophy Points:
    113
    Location:
    USA
    City:
    Sacramento
    State:
    California

    -Return to Top-

    T15 is a Tungsten high speed steel that mostly uses tungsten for the hot hardness ability. It is an older design of HSS that is not often seen anymore, but I have some. M series HSS uses molybdenum for part of the tungsten amount for hot hardness ability. Molybdenum is cheaper than tungsten, so they moved in that direction. I have zero experience with using my T15 tool bits, but I assume that they perform pretty well. If you can get the end mill cheap, go for it...
    http://www.asminternational.org/doc...yNow.pdf/b8f2e317-5089-44bc-a14d-af31f80e33a5
     
    bfd and EmilioG like this.
  17. Bob Korves

    Bob Korves H-M Supporter - Premium Content H-M Supporter-Premium

    Likes Received:
    3,386
    Trophy Points:
    113
    Location:
    USA
    City:
    Sacramento
    State:
    California

    -Return to Top-

    Yes, I certainly was confused on that. I will look at your sources and educate myself. Thanks!
     
    mikey likes this.
  18. mikey

    mikey Active User H-M Supporter-Premium

    Likes Received:
    2,135
    Trophy Points:
    113
    City:
    Honolulu
    State:
    Hawaii

    -Return to Top-

    I gotta' admit, that tangential tool is pretty slick. I think Tozguy also uses and likes that tool. The only thing I can't wrap my head around is the fact that the geometry is fixed ... no tool bit works for everything. Seems to me that for smaller lathes, you would want the flexibility to reduce cutting forces, no? To do that, you need to alter tool angles and this tool holder/concept will not allow for that. On the upside, grinding the tool bit can't get much easier and that's a big positive.
     
    Bob Korves likes this.
  19. Rex Walters

    Rex Walters Active Member Active Member

    Likes Received:
    180
    Trophy Points:
    43
    City:
    Los Gatos
    State:
    California

    -Return to Top-

    The angles are fixed, but I use mine for both soft aluminum and fairly hard steel without issue. I'd probably use a different tool for turning a bunch of Delrin or really gnarly stainless, though. The amazing thing is you can even use it for threading. (The grinding jig lets you grind a 60º angle as well.)

    It's not the only tool you'll ever need (you can't grind chip breakers, for example) but it suffices for about 90% of the turning and facing I do. It does tend to generate long chips, but then so do most of the well-ground tools I've made. I never grind chip breakers myself, anyway: speeds and feeds (and a pair of long nosed pliers) suffice for my needs.
     
  20. mikey

    mikey Active User H-M Supporter-Premium

    Likes Received:
    2,135
    Trophy Points:
    113
    City:
    Honolulu
    State:
    Hawaii

    -Return to Top-

    What I meant by my statement is that a good tool can enable your lathe to take cuts that a normal HSS tool and probably that tangential tool won't allow. My Sherline lathe is tiny in comparison to a 10" Logan but it will take a 0.050" deep cut in mild steel with the right tool. Your lathe, with the same tool, could easily double that cut.

    On the other hand, if it works good enough for your needs then that is really all that matters.
     
  21. Randall Marx

    Randall Marx United States H-M Supporter - Premium Content H-M Supporter-Premium

    Likes Received:
    155
    Trophy Points:
    43
    City:
    Oscoda
    State:
    Michigan

    -Return to Top-

    I have and use a tangential tool on my Atlas 12" lathe. It works pretty well and is DEAD SIMPLE to sharpen. I have it set so that when the tip of the tool bit is level with the top of the toolholder, it is at center height in my lathe. That way, I can remove the toolbit, sharpen it, hone it, switch to a different bit (like a round one for finishing), and easily set it to center with a blank held on top of the toolholder. I have also found that I can vary the geometry by varying the grinder rest angle and how the sharpening jig/toolbit is presented to the grinding wheel. That way, I have different bits for different applications and different workpiece materials. I figured that part out after reading some of Mikey's postings about toolbit grinding. :D I'm still planning to figure out how to grind a REAL toolbit, but this works well for work that is general-purpose. If I need to reach into a tight area, the tangential tool is a no-go. Other than that, it is pretty good for me and has opened my eyes to grinding variations.
     
    Rex Walters and mikey like this.
  22. mikey

    mikey Active User H-M Supporter-Premium

    Likes Received:
    2,135
    Trophy Points:
    113
    City:
    Honolulu
    State:
    Hawaii

    -Return to Top-

    Thanks, Randall. I'm glad that someone has sought to alter the standard grind on a tangential tool because it seems to me that it would be necessary at some point. If I had this tool, I would definitely try to figure out how to incorporate more side rake into the geometry because that would reduce cutting forces and temperatures a lot. You don't think it matters until you work harden a piece of 1144 and try to do a fine finish cut; then you wonder how the heck you cannot come in on size.
     
    Bob Korves likes this.
  23. Rex Walters

    Rex Walters Active Member Active Member

    Likes Received:
    180
    Trophy Points:
    43
    City:
    Los Gatos
    State:
    California

    -Return to Top-

    Yup. That's probably (for me) the most common reason for me to use a normal tool. For most common facing and turning, though, the extra size isn't a problem.

    Easy enough to make different grinding fixtures to adjust the rake angles, but the default works well for most of the materials I work with (mostly mild steel and aluminum). As I mentioned: not the last tool you'll ever need, and it's still incredibly useful to learn how to grind a normal tool, but it's great as a standard tool to have on the lathe most of the time (and to give a beginner an example of all the angles to shoot for when grinding your own tools).

    Good tip about keeping the tip at the top of the tool holder so you don't need to readjust tool height. I did something similar (scribed a line on my grinding fixture).
     
  24. markba633csi

    markba633csi United States Active Member Active Member

    Likes Received:
    314
    Trophy Points:
    63
    City:
    Mountain View
    State:
    California

    -Return to Top-

    As far as grinding tool bits, I don't think about it I just close my eyes and grind. Usually works pretty good. My shop teacher is probably rolling in his grave to see my pathetic efforts LOL Oh well nobody has to use them but me :D
    Mark S.
     
  25. Silverbullet

    Silverbullet Active Member Active Member

    Likes Received:
    691
    Trophy Points:
    113
    City:
    Marlton
    State:
    New Jersey

    -Return to Top-

    Ill give you one extra tip I didn't read where anybody said to hone your tool edges . As far as grinding 3/8 or 1/2" or 5/8" . Most all of the shapes will cut , some will cut cleaner and quicker , easier. Others will work good on steel but not brass or aluminum. I have even made and used contour bits . Made to fit a profile those are a different game as to speeds and feeds. Even using other bits to hog out spots. Many times you will need to grind chip breakers in the tool. Clearance angles needed then stoned with an India stone. You will need a couple half round , square 3/8 Or 1/2" , usually there about 4" long. I even have a green set for carbide. Honest it helps to hone the edges the tool cuts better and last longer , at times you can touch them up in the holder . I've found rounded tools work well in cold rolled and brass. When making corners on tooling I leave the inner edge rounded , to many times I've seen sharp corners just snap.
     
  26. bfd

    bfd United States H-M Supporter - Premium Content H-M Supporter-Premium

    Likes Received:
    167
    Trophy Points:
    43
    City:
    nipomo
    State:
    California

    -Return to Top-

    your picture shows good hss bits with a little regrinding they can all still be used over and over again you don't need to completely remove the old grinding just make the tool you need at the time bill
     
    Bob Korves likes this.

Share This Page