Tuesday , February 20 2018
Home > Product Reviews > A Review of the Diamond Tangential Tool Holder from Eccentric Engineering

A Review of the Diamond Tangential Tool Holder from Eccentric Engineering

I was a skeptic. As were two of my friends who have over 50 years of machining experience between them. But now I’m a believer. As for my friends? Read on …

A few months ago I contacted Gary Sneesby from Eccentric Engineering to see if I could write a review of their Diamond Tool Holder. I had heard great things about tangential tool holders, but I was still a bit skeptical and didn’t know quite what to expect.

The tool took about 10 days to arrive, which I thought was fast considering it came all the way from Australia to Seattle. You can also buy the Diamond tool holder from a local UK or US distributor (see the Eccentric Engineering website for details). Either way the tool is about the same price, but you might get it quicker and pay a bit less for shipping if you order from your local distributer.

The tool comes with a the tool holder, an allen key, a quality HSS tool bit (8% Cobalt), the grinding jig, and full color instructions with pictures to hang by your grinder.

So, how well does it work? Exceptionally well!

Using the Diamond Tool Holder with a round HSS tool bit

Here’s why I think this tool is great for the beginner:

  1. It’s very easy to grind using the included jig.
  2. It produces an exceptional finish. I consistently get as good (or better) a finish using the diamond tool holder than I get using a properly ground HSS tool bit.
  3. It’s very rigid allowing for deeper cuts. I can take cuts of about .015-.025 deep on my small lathe using a conventional HSS tool bit, but I can remove nearly twice as much with the diamond tool holder (.030 to .050) depending on the material I’m cutting – without chatter!
  4. The grinding jig can be used to easily grind 55 and 60 degree threading tools for use with the diamond tool holder.

Eccentric Engineering has a promotional video that they put together that shows all the features of their diamond tool holder. The video seems a little dated, but it’s well done and worth watching.

They show the tool being used on a larger lathe where they take very deep cuts (as much as .100 at a time). I wasn’t able to achieve cuts that aggressive, but I have a much smaller, less rigid lathe in my home shop than what they used in their video. And since many of you have a lathe similar in size to my 10×22, I thought I’d make my own video showing the results I was able to achieve, and therefor the results you should be able to expect with a similar sized lathe.

My video is a bit long (sorry) so if you get impatient just make sure you watch the last 2 or 3 minutes where I show how well the tool cuts cast iron.

My overall impression is a positive one. The tool is well made and of excellent quality. I really do get exceptional results with it. As to the grinding jig, my first impression was that it was a bit wonky with its use of a cap screw to adjust the angle for grinding a threading tool. But after using it I realized that it’s not wonky at all. But rather a simple and elegant solution.

Using the grinding jig is as advertised – extremely simple to do. And the bit seems to hold an edge longer than my hand ground HSS tool bits do. In fact, I’ve been using the original bit for a few months now on Steel, aluminum, brass, bronze, and cast iron and I haven’t needed to re-grind it yet (although I have touched it up occasionally with a diamond hone). Initially I was concerned that the one-size-fits-all approach with the 12 degree rake and relief angles would be very effective on some meals, but less effective on others. After all, a HSS tool bit properly ground for steel has slightly different rake and relief angles than one ground for aluminum or brass. Right? But it turns out that 12 degrees is a very good compromise across all the metals I’ve tried so far.

I don’t have anything negative to say about the diamond tool holder from Eccentric Engineering. It performs as advertised and has exceeded my expectations. In fact, I am planning on purchasing a second one so that I’ll have one tool holder for a square bit and one for a round bit. I tend to switch back and fourth between a round and square bit a lot depending on the job, so it would be nice to have a dedicated quick change tool holder for each pre-set to centerline.

As for my two friends with over 50 years of machining experience? They were impressed too. They haven’t bought their own yet, but then again they get a kick out of grinding their own HSS tool bits and drills. They were convinced that a properly ground HSS bit would give better results than the diamond tool holder.

So I challenged one of them to grind a fresh HSS bit for steel and put their grinding skills to the test. The result? The finish was comparable but the chips coming off of the diamond tool holder were smaller and took more of the heat with them (turning a darker blue) than the chips from the hand ground HSS bit. The lathe (a restored Atlas) also seemed to labor less using the diamond tool holder, and deeper cuts were possible without chatter. I should give credit here to my friend Barry, his HSS bit did produce a similar finish. But he still spent a few minutes grinding it to shape. At least twice as long as it takes to grind one using the diamond tool holder jig.

So if you’re one of those guys that thinks he can grind a drill bit just as good by hand as someone using a professional drill sharpening machine (and I’m not talking Drill Doctor results, I’m talking DAREx) than stick with grinding your HSS tool bits by hand. But for everyone else, I’d highly recommend the diamond tool holder from Eccentric Engineering! You won’t regret it.

[ad]

 

[adrotate group="4"]

About Tyler

Tyler is a hobby machinist and 3D printing aficionado. He teaches computer programming and web development at Highline College near Seattle. Tyler founded Projects In Metal in 2008 because he was frustrated by the lack of free plans available for hobby machinists.

Check Also

Portable Coolant / Lube System for the Lathe or Mill

Russ shows us how he designed and built a portable coolant system that he uses with multiple machines, including his lathe and mill.

38 comments

  1. Very nicely done, Mr. Youngblood. What is the pricetag on these things?

  2. They range from between $100 to $150 depending on the size of your lathe. It sounds steep until you own one. Then the amount of time saved by not grinding your own tooling makes you feel much better about the price. 

  3.   Here and there on the Web, there are several descriptions of homebrew versions of the Diamond tangential toolholder; this list

    is probably not complete.  The constructions involve complex angles, but most descriptions include a comment to the effect that the exact angles are not especially critical, and some descriptions give some hints as to the setup required to make one of these.  Did you consider making your own, or did you try to make your own and discover that there was more to it than at first met the eye?

  4. Ah, you've beaten me to the punch. I'm planning on a follow up post discussing different options for those who would rather make their own. But I wanted to start by exposing the readers to the general idea of tangential tool holders before delving into a milling project. For one thing, many beginners start with a lathe and get a mill months or (dare I say it) years later. Also, the diamond tool holder from Eccentric Engineering is hardened, which is also beyond the scope of many beginners. So making your own isn't going to be an option for everyone. 

    As to your links, I had only seen the last one! … And here I thought I was doing such a good job researching for the followup article. Thanks for sending those my way! I couldn't access the yahoo groups link however as I'm not a member of that group. Is it worth joining?

    If I try to make my own I will either follow Gadget Builders lead (last link) or I'll make one like Jraah's. Both designs are a dovetail style so they will mount directly to my QCTP. Although I'm honestly still leaning toward purchasing a second holder rather than making my own, simply out of convenience. 

    Here's a picture of Jraah's design:

    Image Enlarger

    His layout marks suggest he was planning on making a second slot for another HSS tool bit, but I haven't figured out why. Af first I thought he was trying to make a left handed version, but wouldn't the bit be tilted the other way?

    Anyway, thanks again for those extra links. I'll add them to my list of resources for the followup article because you're right. You could certainly make your own. But for those who don't have a mill, or don't like making their own tooling, Eccentric Engineerings tool is a perfect option. 

  5. Tyler said:

    . . . The diamond tool holder from Eccentric Engineering is hardened, which is also beyond the scope of many beginners.

    *** What is the value of hardness in a non-wearing component?

    . . . I couldn't access the yahoo groups link however as I'm not a member of that group. Is it worth joining?

    *** Yes; it is not dense, but every once in a while there's something worth seeing.

    . . . If I try to make my own I will either follow Gadget Builders lead (last link) or I'll make one like Jraah's. Both designs are a dovetail style so they will mount directly to my QCTP.

    *** I am leaning toward making one that will fit in a QCTP toolholder, so I won't have to mess with getting a good dovetail fit. 


  6. I must admit, I'm fairly ignorant when it comes to heat treatment (and metallurgy in general for that matter) but I assumed that hardening might add a little extra rigidity to the tool holder. Is that not the case?

  7. Tyler said:

    I must admit, I'm fairly ignorant when it comes to heat treatment (and metallurgy in general for that matter) but I assumed that hardening might add a little extra rigidity to the tool holder. Is that not the case?


      I don't know.  I asked out of genuine ignorance, too.  I think of hardness as being primarily related to wear resistance, but rigidity might often be part of the package.  Wikipedia (http://en.wikipedia.org/wiki/Hardness) says

     

     

    so I guess it's safe to say that the two notions are not always coupled.  Perhaps a more knowledgeable member will chime in.

  8. It looks like you might be right, that's good to know. Thanks for looking into it.

    Now if I make my own I won't feel compelled to figure out how to harden it. I can just seem myself with half a dozen MAP torches trying to get a 3lb chunk of steel to a cherry red temp. I'd likely set myself on fire! Now I don't have to. 

    I really need to find a friend with a heat treatment setup … Laugh

  9. Didn't I read something somewhere else on this site that John Lawson had made some Tangential Tool Holders at one time?

     

    -Glenn

  10. You did indeed. Here's a link to his post:

    http://www.projectsinmetal.com…..-shop-use/

    Stay tuned for my follow up post on making your own tangential tool holders. John has made his own, as have several other people. My plan is to put together a comprehensive review of the resources out there for building your own. 

    But because people typically buy a lathe first, and then a mill later I figured many members wouldn't have the ability to make their own tool holders. So I decided to review a commercially available option first. 

  11. I made one out of SAE 01 tool steel, but found that it wasn't worth the effort. (I have a small heat treating furnace). The tool steel has a tendency to harden up ahead of the cut with HSS cutters that is very annoying. I have used the annealed tools for years with no bad effects. Therefore, I would say that hardening is optional.

    An option is hardening the contact area of the lantern toolpost screw with Kasenit, making heat treatment easy with only a torch.

    Next time Tyler visits, I will set him at translating the pigeon English instructions with my new tool and cutter grinder to simplify bit sharpening. (The Harbor Freight model comes with instructions that ignore the included tool holder alternatives, among other things.) Obviously, the Chinese copied a foreign tool without knowing how it works. (I wonder if their nukes are made like that.)

    I also bought one of the aGerman made tangential tool holders and found that, though it is more reasonably priced and from Canada, it is hopelessly oversized and clumsy; I plan to shorten the “one size fits them all” bit holder with a diamond saw when I get into a tedious mood.

    I found tangential toolholders in a 1900's issue of the Model Engineer and made mine pretty much to the original design, with a couple of more modern twists. All in all, a very worthwhile project.

  12. You've all peaked my interest, so I went ahead and ordered one yesterday, for the machine shop that I manage.  I'm going to have my guys give it a try and see what they think.  I ordered the B16 (largest holder) that Eccentric Engineering manufactures.  We'll be using it on three different lathes.  A Clausing 15″, a SouthBend 16″, and a Rockford 18″.  The model #B16 claims it's good for 12″-19″ lathes, so this should be just right for any of the three lathes that we run.

    If it works out, I'll probably make a couple of them so that we can have one for each lathe in the shop without having to share.  I figured since I've never heard of this thing before, it MUST be patented…  However, after visiting Eccentric Engineering's website, I see that this produce was designed by an Australian in 1985, so even if it had been patented, it would have run out by now.

    I would agree with John that Heat Treating seems to be optional.  However, I would probably make them from a very hard tool steel anyway, just for rigidity.  I might even make them from Nitronic 50, because I've got some on hand!  Although it's not “tool steel,” it's MEGA-HARD and has most of the properties of 300 series stainless steel with added strength.  (Therefore, If I make one for myself, it will be less likely to rust in my humid basement!)

    John – who is the manufacturer of the German made version that you purchased?  Also, I'm not sure I understood the problem you encountered when trrying to heat treat your parts?   Did they twist on you, throwing the angles off?  (if so, this is where a Surface Grinder comes in to play…  Leave a few thousandths over dimensions and grind them flat & true to proper dims when the parts come back from heat treating.)

     

    -Glenn

  13. My toolholder does not indicate the maker, it says:”Felsch Stahl Halter”.

    I didn't have heat treat problems; I simply didn't bother, since my use for them was limited, even though I made some to fit in my toolpost turret and would not have had to change to a lantern type toolpost.

    The tangential holders and toolbits ground to conform will do nothing that conventional ground bits will not do, if enough rake is incorporated in their design. You'll get my drift when you put one to use.

    Don't use too hard a metal… remember, you have to broach a hole, and broaches are expensive these days.

  14. John – what I was asking is what you meant by the following: 

                         “The tool steel has a tendency to harden up ahead of the cut with HSS cutters that is very annoying.”

    ————————————————–

    Also, it's not that the Tangential Tool Holders and Ground HSS Bits will do more than conventional HSS ground bits, it's the benefits of this design that intrigue me:

    • For those with Lathes who do NOT have a Quick Change Tool Post that provides tool bit HEIGHT ADJUSTMENT, typically they would have to SHIM their tool bits in their standard tool post in order to find the center of the chuck and/or workpiece.  With the Tangential design, it's as simple as loosening a set screw and raising the toolbit to the proper height, then retightening the set screw.  YOU CAN'T BEAT THAT.
    • The RIGIDITY of the VERTICAL HOLDING design will definitely reduce chatter and therefore leave a smoother finish.
    • The idea of only having to position the HSS TOOLBIT in a grinding fixture and grind once sure beats rotating a toolbit several times and grinding on several sides to achieve the cutting edge and the necessary clearances on either sides.
    • The ability to take larger cuts sure cuts down on turning time, especially if you're using a small table-top lathe where only minimal cuts are possible due to lack of rigidity

    Certainly there are other benefits that others may find, as well, however, the above list of benefits are what catch my attention.

     

    -Glenn

  15. Glen, you thought of a benefit that I hadn't considered before. The fact that turret-style tool post users wouldn't need to shim their tools anymore! I swapped out my turret tool post for a QCTP within a few days of buying my 10×22, and I've never looked back. So I didn't even think about this benefit when I was testing the diamond tool holder. Nice catch!

    Also, I received an email from Gary at Eccentric Engineering. He provided a bit of clarity on hardening, as well as on making your own tool holder and I thought I'd share his message with you guys:

    I noticed someone on the forum asking about the point of heat treating (hardening) the tool.

    The holder is cast in 4140 which is a high tensile steel and this is heat treated to 40 Rockwell, this means the tool is stiffer and will resist flexing under load.

    The other advantage with hardening is that the toolholder  will not be damaged by the toolpost clamping  screws, and abraded by tough types of swarf like stainless steel.

    On the subject of making your own tangential tool.

    All the designs I have seen seem to use a square slot for the toolbit instead of a “V” groove, the disadvantage of this is that the toolbit is only held against one face and will depend on how tight a fit it is between the toolbit and slot. I’m not sure how much clamping force you can get with the edge of a screw head and HSS dimensions can vary by up to 5 thou so the fit could be sloppy or tight between tips. Also a square slot will not be able to take round HSS. It would be interesting to do a road test between a few types of tangential tools.

    – Gary

    Gary also mentioned that he is working on a couple of new designs, including a left-handed tool. You'll notice that the tool I reviewed isn't suited to cut toward the tailstock. His new design should address this. 

    Glenn, let me know what you think of the tool holder when it arrives. I'd be interested to see if your experience in a commercial shop setting is similar to my home shop experience with the tool. 

  16. Tyler

    I can't wait for you to do this tool holder(plans)! This will be a must do project I still have to 4 way tool post and a rocker tool post on the sears lathe so I do want a couple of these tool holders. Looks like aluminum would work so I could maybe cast them. Once you get some drawings I'll see if I can make a pattern and cast a few. I'll send you a casting to try if you want to try one or a few.

    Norman

  17.   Here is a summary of the tangential bit-holders whose descriptions I've run across so far:

      Gadgetbuilder, whose work I generally admire, describes some of the alternatives he has considered and tested.  In particular, his preferred design is made of aluminum (implying that the rigidity of the bit-holder is such a small part of the rigidity of the bed-gibs-carriage-gibs-cross slide-gibs-compound-QCTP-(toolholder)-bitholder-bit system that it's not worth worrying about the material).  Also, he reports at least some experience suggesting that the rigidity gained with an intrinsic dovetail — eliminating the toolholder from the chain — can be important, especially with smaller lathes.

      I am making a bit-holder using a one-groove version of Richard's design; it turns out to be straightforward.  I started with a 1″ x 1″ x 3.5″ piece of 1015 steel, and the main setup consisted of clamping the stock in the vise at 12° off vertical and then attaching the vise to the mill table at 12° from the Y axis.  Without changing the setup, I then milled off the end of the billet, cut the groove for the bit, and drilled & tapped the hole for the retaining screw.  The rest (trimming the rear end so that it fits in a QCTP toolholder) is vanilla.

      Putting in a dovetail so that the part could be mounted directly to the QCTP is attractive, but I'm not sure about the optimum distance back from the tip to place the dovetail.  When I have a little experience with the bit-holder held in a toolholder, I may make one with a dovetail.

  18. Tyler said:

    Glen, you thought of a benefit that I hadn't considered before. The fact that turret-style tool post users wouldn't need to shim their tools anymore! I swapped out my turret tool post for a QCTP within a few days of buying my 10×22, and I've never looked back. So I didn't even think about this benefit when I was testing the diamond tool holder. Nice catch!

    On the subject of making your own tangential tool.

    All the designs I have seen seem to use a square slot for the toolbit instead of a “V” groove, the disadvantage of this is that the toolbit is only held against one face and will depend on how tight a fit it is between the toolbit and slot. I’m not sure how much clamping force you can get with the edge of a screw head and HSS dimensions can vary by up to 5 thou so the fit could be sloppy or tight between tips. Also a square slot will not be able to take round HSS. It would be interesting to do a road test between a few types of tangential tools.

    – Gary

    Glenn, let me know what you think of the tool holder when it arrives. I'd be interested to see if your experience in a commercial shop setting is similar to my home shop experience with the tool. 


    Hey, Tyler –
     

    I haven't received the Eccentric Engineering Tool yet, but I will definitely give you some feedback after my guys have put it to use in our commercial setting.  It should arrive next week.

    Also, I've been following the posts and links that others have shared regarding the homemade variations of this design.  Some good ideas out there, but there is something that I think most people are missing…  For me, one of the most attractive features of the Eccentric Engineering tool is that is is supplied with a HSS ToolBit Grinding FIXTURE.  It seems so convenient to simply be able to slide a HSS toolbit into place and grind it against a grinding wheel to acheive the perfect “diamond shaped” cutting edge.   The actual cutter Holder could be made a thousand different ways, but it's basic function is simply to hold the properly ground HSS toolbit at the proper angle to achieve best cutting results.  I tend to believe that it is the “properly ground toolbit” that will make all the difference, which is why I believe that the FIXTURE is so important.

    Like others, I've got a bunch of ideas for a re-design of this style toolholder.  However, it seems like a lot of guys have used just the heads of screws to hold the HSS toolbits in place.  Personally, I'm not really a fan of that design.  A single screw head is fine for holding the toolbit in the Grinding FIXTURE (as seen in the Eccentric Engineering video), but I don't feel that it's sufficient for the toolholder, itself.  There are a lot of very simple ways to improve the clamping pressure on the HSS toolbit.  I believe this is crucial for maintaining the rigidity of the vertical toolholding design.  You really don't want to chance the HSS toolbit slipping while cutting.

    From an engineering standpoint, I also agree with Gary from Eccentric, that the V-groove is far more effective than the square groove.  You are increasing contact area by 100% with a v-groove.

    My 2 cents…

    -Glenn

    Wink

  19. Hey fenichel, would you be willing to edit the post you made above and add pictures to it from the Yahoo groups links? That way people that aren't a member of the group can see what the tool holder looks like and decide if they want to join the group to get more information on the design. Thanks for posting the links!

    @Glenn, did the tool holder arrive yet?

    @norman, that would be excellent. I'm not sure how well a casting would work, but it would be worth a shot to give it a try. I'll take you up on the idea. I'm still working on the follow up post, but it should be published in a few weeks. It's been a busy holiday!

  20. Tyler said:

    Would you be willing to edit the post you made above and add pictures to it from the Yahoo groups links?


    Done.

  21. Excellent, thanks for adding the pictures! It looks like I need to join another group or two.

  22. JohnLawson said:

    Don't use too hard a metal… remember, you have to broach a hole, and broaches are expensive these days.


    Well, the B16 Tangential Tool Holder and Grinding Fixture arrived today.  Looks good!

    After carefully examining the tool, I don't see ANYWHERE that a “broached hole” would be required. 

     

    John – could it be that you have an earlier version???   What exactly is “broached” on your tool?

     

    The Eccentric Engineering tool holder could easily be made with nothing more than a milling machine. 

    The most challenging feature(s) of this part would be the compound angles.  Not too difficult, though.

    (Tyler – I'll let you know our feedback once we've had a chance to put it to use.  This week is year end inventory, etc. so probably won't use it until next week.)

    -Glenn

  23. Tyler –

    We finished up early today, so we had a little time to try out the Tangential Tool Holder and Grinding Fixture.

    The tool came packaged well, included a DVD, and a thick packet of Review and Instructional Literature.  (maybe a little too much literature, which can give the initial impression that the tool might be complicated to use – it isn't)

    First impression is FANTASTIC.  We faced and turned some 316 Stainless Steel 1″ round bar.  The chips came off in nice long strings.  At first, we turned without using any coolant.  We were able to take 0.080″ – 0.090″ in one pass without the chips turning color.  At about 0.100″, the chips were coming off a bronze sort of color indicating that things were starting to heat up.  We turned on the coolant and were able to achieve a 0.200″ cut without vibration or major chatter!   Over 0.200″ is where the chatter came in.  (0.100″ plunge depth, removing 0.200″ off of the 1″ diameter bar in one pass!)  Also, keep in mind that we were cutting 316 stainless steel, which is quite a bit harder than CRS.

    The Grinding Fixture worked well and is easy to use.

     

    My only complaint:

    We ordered the largest model tool holder that Eccentric Engineering sells, which is their model #B16.  However, although the tool holder itself is beefy enough for the 16″ lathe that we were using, the HSS Toolbit itself is the same small 1/4″ bit used in the smaller tool holders.  For a lathe of this size, and a toolholder as beefy as it is, I would think at least a 3/8″ HSS Toolbit should be used.

    After a quick glance, it looks like due to the design of the toolholder, it may actually be possible to hold a 3/8″ square toolbit in the B16 toolholder, however, we will have to make a grinding fixture that will accommodate the 3/8″ square toolbit, because the holding slot is limited to only the 1/4″ sized bit.  (fairly easy to do, so I'll give it a shot and let you know.)

    -Glenn

    Wink

  24. Excellent Glenn! I'm glad the tool holder is also living up to your expectations.

    As to the 1/4″ tooling, I never thought of that since I used the smaller size. I just assumed that the larger tool holders would hold an appropriately larger bit.

    It also sounds like you got more things in your package that I got in mine. I only got 1 page of instructions and no DVD. Is the DVD worth watching? If so I'll have to contact Eccentric Engeneering to see about it.

    So after using it, do you think it's worth the investment? I certainly do, but I think a lot of members who haven't used one are still skeptical. Not only is it easy to use, easy to grind, and provides a great finish, I'm finding that I don't need to regrind or touch up with a diamond hone nearly as often as I used to with my conventionally ground tooling. I wonder if you'll also see a longer tool life from the tool.

    Anyway, thanks for giving your initial feedback. Let me know what the other guys in the shop think of it once they have a chance to use it.

  25. Yes, I also assumed that the larger toolholder would be supplied with larger tool bits.  I was quite surprised that it still used only 1/4″ tooling.

    I guess if we make a few of these holders for the shop, we'll scale them up to accommodate at least 3/8″ tooling.

    I placed our order through Bay-Com.com.  Regarding the DVD, it seems to be just the same Video that they have on their website and I believe you had posted earlier in this post.

    The paperwork, however, seems to be a copy of a 1993 Review Article that was published by an independent end-user.  There are also additional notes, details, suggestions, instructions, etc. on many more pages.  I did read through it all, however, I found that it was not all necessary and may cause some confusion or prompt some questions for most novices.  If you only received one page of instructions, then I believe you received all that you really needed.

    Worth it?  Absolutely.  I have two machinists in our shop that are both in their sixties and have been machining for pretty much all of their adult lives.  About 80 years combined experience.  Neither one of them has ever seen this style tool holder.  BOTH of them were major skeptics and completely surprised at how well it works.  That says a lot!

    Last observation…  Although Eccentric Engineering is based in Australia, no where on the tool does it state that it is Made in Australia. Looks like the part is probably forged and then machined.  Although the quality of the tool is not bad, I am inclined to think that they are probably being Made in China, like most other products these days.  Having said that, I do think the price is a bit steep, however, you can't blame someone for trying to make a living these days!  I wouldn't run out and buy (6) more of them at $150 a piece, however, they would be simple enough to make in-house and I know that we would get good use out of them.  I tend to think we would prefer using these over disposable brazed carbide toolbits.

    Tyler –  does your tool holder have any “broached” features as John Lawson had mentioned???  I don't see any features on our holder that couldn't be made with a milling machine and some angle blocks or sine plate.

    -Glenn

  26. What was the rational for your fellow machinists to be skeptical about this holder, if I could ask? My first impression of the tool was “Wow! Grinding for this sucker will be quick and easy!” The only thing that would present a problem would be to design this holder without giving due clamping pressure against the tool, since the forces of the rotating part can push the tool out of place if not supported properly. Was this their concern?

     

    Chris

  27. glenn105 said:

     

    After a quick glance, it looks like due to the design of the toolholder, it may actually be possible to hold a 3/8″ square toolbit in the B16 toolholder, however, we will have to make a grinding fixture that will accommodate the 3/8″ square toolbit, because the holding slot is limited to only the 1/4″ sized bit.  (fairly easy to do, so I'll give it a shot and let you know.)

    -Glenn

    Wink


    Glenn, Do you think they shyed away from the 3/8 bit due to the possibility of the increased load defeating the holding screw and driving the bit down?  Just thinking outloud.  Thanks for the pro opin on this holder.Laugh

  28. glenn105 said:

    …I'll probably make a couple of them so that we can have one for each lathe in the shop without having to share.  I figured since I've never heard of this thing before, it MUST be patented… 


    My understanding is that you can make your own copy of a patented item, you just cannot sell it. This may also cover making a commercial profit from it but as this wasn't relevant to me, I didn't look into it. I recall it being discussed somewhere else but cannot remember where. I have the patent designs for something I was going to build but haven't found the time. From what I understand, it is a bit like making a backup copy of a CD, DVD etc that you own. The backup protects you if the original is damaged/lost. However, you cannot sell, distribute etc

  29. @Glenn – no broached features on my tool holder. I think John used a broach with one of his designs so I think that's what he's talking about, but I can't remember for for sure. 

    @i44troll – I'm not sure if you were asking me or Glenn about skeptics because both of us mentioned that we had friends that were skeptical about the tool.

    In my case my two friends have about 40-50 years of machining experience between the two of them and they have this somewhat boastful attitude (which they've certainly earned) about things like grinding their own tool bits and sharpening their own drill bits by hand. To them a tool like this seemed gimmicky. They saw it as an excuse to avoid learning how to grind your own tool bits and assumed that it's just a shortcut for less experienced machinists. They didn't seem to think that the tool could perform any better than a properly ground tool bit. In other words, the only advantage that they saw was ease of sharpening (which they scoffed at). The didn't believe the hype about the other two benefits which are increased tool rigidity and better cutting performance. These are the same types of guys who might look down their noses at people who buy a Drill Doctor instead of learning to sharpen their own drill bits by hand. 

  30. Tyler,

    I guess it could be directed at one or both of you. Gotta admit, never thought that “ease of sharpening” would be the center of the skepticism, but I can see how that the old-timer machinists would avoid something new when conventional machining processes have made little change over the years, (which really should be a comfort to us all). Do these same machinists endorse quick-change tool posts? I wonder, because the tools ground for these tool-holders are easier to grind than lantern-type holders in my opinion. They probably faced the same opposition when they first came out by those that thought nothing could be improved on.

    After teaching for the last 5 years there is one thing that I am convinced of….. if you stink at grinding your own tools it's not likely you will improve by much. As an average I would say that 25% of my students can grind tools right-of-the-bat, to any needed profile. 50% tend to grind too much or distort the profile beyond it's usefulness, and will continue to do so the longer they grind. The last 25% lack the needed comprehension to view, “in-the-minds-eye”, the first few steps needed to even get started. 

     

    Chris

  31. After reading these pages, bought a diamond tool holder from eccentric engineering.  Only took a few days to arrive in mail (I live in Australia.) 

    On my little Sieg C3 lathe, the tool overhang was hitting the top slide below the turret tool holder and with the tool pulled hard back against the tool holder, could not rotate the tool holder turret for correct facing angle.  Ended up milling away a small area of the tool underneath to allow the turret to rotate without having to rotate the top slide.  Really easy to flip between cutting and facing angles now by just rotating the tool holder turret.  I don't have a quick change tool holder

    Another small issue was that the size of the tool extending from the tool holder severely reduced the size of bar that could be cut even with the tool pulled back hard against the tool holder.  Not much travel on cross slide on these mini lathes.  I could rotate the top slide at a 45 deg angle to move the tool further back and re-align the tool holder turret back by 45 deg but this took away the ability to use the top slide for cutting angles.

    Discovered that the cross slide had almost an inch of lead screw thread hidden away unused and by some more milling to the lathe carriage to expose all the lead screw thread and a spacer managed to extend the cross slide travel enough to more than make up for the additional size of the tool.

    Tool itself is fantastic, cuts stainless bar like butter, brass looks almost polished and I can finally adjust tool height without having to shim up the tools in the turret with broken hacksaw blades.  First facing operation all the way to the exact centre. Yes!!!

    Made a cam lock for tailstock out of stainless and brass as a first test of the tool today and only area that was a bit difficult was the one shoulder of the stainless steel cam (cutting away from the chuck).  Didn't want to flip the workpiece around and try recentre the cam with it's offset.  Probably should have used another tool to finish off that shoulder but it's all working well and cam is hidden anyway.

    Hope that all makes sense as this is a fairly new hobby for me, just thought I would throw in a mini lathe perspective.

     

    Simon

  32. Thanks Simon, I'm glad the tool is working out for you! It's a bummer that you had to modify things to make it work. Did you get the smallest tool they sell?

  33. No I got the second smallest going by the dimension guide on the website, (measured from base of tool holder to lathe centre height.) 

    Smallest one may work better on the Sieg C3 and they do mention Sieg in the text against it but there are different size sieg lathes and I though it best to follow the website selection guide sizes.

    I get more out of my lathe now through some forced mods, a quality tool holder and a bit more comfortable with the lathe's inner workings so a good experience all round

     

    Simon

  34.   I have some more experience with tangential bit-holders now, having

    • made a dovetailed version of Richard's design (see my post of 27 December for a list of the various available designs),
    • bought a pre-made tool (their model A8) from Eccentric Engineering, and
    • made a dovetailed clone of the Eccentric version.

     

      I wouldn't recommend any of the one-part designs (Richard's, Barry's, Jraah's, or Gadgetbuilder's).  At least in my implementation of Richard's design, the screw's grip on the bit is marginal, successful with some screws but not with others [this is consistent with the comment from Eccentric Engineering, quoted in Tyler's post of 21 December].  Also, Richard's design holds the bit so high that there are clearance problems on a small lathe like my C4.

     

      The Eccentric design is much more satisfactory.  I can't tell any difference in rigidity between my clone (made of 1018 steel) and the hardened 4140 Eccentric version. 

     

      I found cloning the Eccentric design to be challenging, and it would have been much harder without a model to copy.  There are lots of complex 3-D angles; I found myself using setup strategies (vise-in-a vise, tilted mill head, angle blocks everywhere) that, to say the least, I don't use every day.  Fun.

  35. That's good to know Fenichel, 

    I think a lot of people were convinced that it would be an easy project to make their own. You've seen first hand that it's not as easy as one might think. Thanks for sharing your experience. Any chance of seeing some pictures of your handywork? I'd like to see how the three different designs turned out. 

  36. Tyler said:

    I think a lot of people were convinced that it would be an easy project to make their own. You've seen first hand that it's not as easy as one might think. Thanks for sharing your experience. Any chance of seeing some pictures of your handywork? I'd like to see how the three different designs turned out. 


    It was not easy, but only because it required the patience for lots of setup.  It required no great attention to precision, especially if one ignores the dovetail.  One should not be intimidated by it; no matter how many tangential bit holders you want to have, I'd recommend that you buy at most one.
     

      Here's a top view of (top to bottom) the Eccentric product, my clone, and my implementation of Richard's design.Image Enlarger

    Here they are from their right sides

    Image Enlarger

    and here are the Eccentric product and my clone from their left sides, with their clamping elements separated.

    Image Enlarger

  37. Hey Tyler, Which size toolholder did you get from eccentric for your G0602?

  38. I got the 9.5mm tool. LH and RH. It's the one recommended for 9″ lathes, and since mine is a 10″ it's just about the perfect size. I think the 12mm would be too large.