Gallery, Projects and General > Project Logs
Making a tap guide...with problems.
Russel:
--- Quote from: bogstandard on October 30, 2009, 03:21:25 AM ---
What you really require is a split die and holder. With those you start with the die sprung fully open, then gradually come down to perfect size.
Also it seems that your dienut was made of carbon steel, which really is too brittle to be used for cutting threads on harder materials. For stainless you really need HSS dies to do a good job, and also a good high pressure threading lubricant.
--- End quote ---
That makes sense! Yes, the dienut that I used was carbon steel - harder than hell. I have seen split dies, but thought that it would be a pain in the rear to get the size of the thread correct. Now I can understand the advantages of it a little better. Thanks for this bit of wisdom. Uh oh! Another project is forming in my head...a split die holder.
I read the acticle in the link you posted a while back. But, for some reason I didn't connect the dots while thinking about this little project. The size of guide spindle is not critical. I was thinking that I would make it a convenient size, so that when I make a bushing to act as a guide in the mill chuck I could use a common reamer size. I haven't made the guide bushing yet, so I will use the truing method you illustrated.
Thank you very much, this is exactly the kind of wisdom I need!
--- Quote from: geroli on October 30, 2009, 04:50:54 AM ---Russel that camera stand of yours is getting you very good pics and a nice write-up as well.
--- End quote ---
I have a little confession to make: I am still using the Nikon DSLR with a tripod. But, my little camera mount will be ready when I get lazy. I was also thinking that I might make a flashlight holder to use the mount. It would be nice to have a little light that I could focus on a particular spot sometimes.
--- Quote from: craynerd on October 30, 2009, 07:00:37 AM ---
Totally :offtopic: if you ever find chance to give us a little review of the Sherline in the Machine Shop forum I would be really greatful. I`ve been looking at the Sherline 4000 (4100), the Unimat 3 and the Taig as potential mini lathes for clockmaking in the future and getting rid of the Clarke cl300m. Sorry to be :offtopic:
--- End quote ---
I'll give it a shot sometime. I am no expert with a lathe, but I can post my thoughts. One thing that I really like is the many accessories that are avalible for the Sherline machine tools. But, now I am beginning to understand that making accessories and tools is a big part of machining. As I become more and more familiar with the lathe, I like it more and more. Size is the main drawback, but it is also an advantage when I put the lathe away on a self on the garage wall.
--- Quote from: Bernd on October 30, 2009, 09:56:10 AM ---For a machine as small as the Sherline I would get some better dies from MSC, Enco or McMaster Carr. Less frustration and they turn out better work.
--- End quote ---
Thank you, I'll take a look.
usn ret:
Russel, check out the post in PROJECT LOGS by geroli. He has just finished a tailstock die holder that will work for your application.
Adjust the recess diameter to accomodate different size dies. I use Tapmagic and Molylube for tap and die ops. I have also used STP automotive oil addative. Looks like you are off to a good start on functional projects. Photos and documentation are very informative.
Keep up the good work!!!!! :wave: :wave:
Cliff :beer:
Russel:
Usn ret, thanks for the link! You hit the nail on the head with that link. I first need to get some threading dies, as opposed to re-threading dienuts.
I take pride in knowing as much about tools and how to use them properly, but I really missed the mark with dies. I spent a little time with the Machinery Handbook and took a look at some of the tap and die manufacturer websites, and plain as day, carbon steel hex shaped re-threaders and High Speed Steel round threading dies! It is amazing how sometimes you can overlook something that has been in front of your face for years. Well, it just goes to show the value of places like Madmodders!
Here is the offending re-threading die set:
As I was sizing the digital image I noticed a chipped tooth sitting in the case with a die! In this photo the die on the right is the offending culprit. (Actually, I'm the offending culprit as the tool between my ears, that needs sharpening!)
It is interesting, I always considered this to be my re-threading set:
I remember years ago when I bought this set, I just had to have it! Notice just how much it has been used. Well, I have two different types of re-threading kits if I need them.
OK, enough whining about my ignorance. Back to the project at hand.
The tap guide I am making needs a hole drilled in the middle section for a handle to turn the tap. At this point I figure I'll make two, one two inches long for smaller taps and one 4 inches long because the distance between my mill spindle and the z-axis support is just over 2 inches. So, I need a .025” hole in the tap guide. I spot drill (with a center drill) in the middle of the half inch section of the tap guide.
Then I drill a hole with a 15/64 drill.
I have learned a new respect for T-316L stainless steel. It was slow going. I used Tap magic Pro Tap as a lubricant. The Sherline Lathe and Mill use the same motor and pully system to drive the machine tools. I usually keep the Lathe in the high torque position and the Mill in the high speed position. It didn't take long before I realized I needed to change the belt on the mill to the higher torque position.
Then I would drill until the bit got a little hot, stop withdraw the bit, clear the swarf, apply some cutting oil then drill more. About halfway I removed the drill bit to check it, and to my surprise, it was still very sharp. I just needed to take my time with my little milling machine.
Once I was done with the drilling, I ran a .250” reamer through and was pleasantly surprised that is cut smoothly without any trouble at all.
Finally! A quarter inch hole!
If you noticed the way that I clamped the part down you probably couldn't help noticing that I'm probably not the only one that could use a tap guide. These aren't suppose to be like this are they? They aren't bent, this is the first time that I used them. I guess you get what you pay for!
OK, at this point I put the mill away and take the lathe down from it's shelf and set it up on the bench. I have a little part that I made for cutting a outside radius that should work for truing the tap guide. So, I carefully center it in the independent four jaw chuck, then take a couple very light cuts until the part is true to the lathe.
Then I installed the drill chuck on my tap guide part and clamp the drill chuck down snugly to the part on the lathe. I take a couple very light cuts on the guide shaft of the tap guide and check for run out. I got about .0015, not perfect but not to bad considering the small lathe. (Thanks for the link Bogstandard)
A closer view:
I haven't had a chance to try it out yet, but when I do, I'll post the results.
Russ
bogstandard:
Russel,
You will have no need to worry with that small amount of runout.
Mainly because you will have to have at least that much clearance in the support holder for it to run in.
Once you are that close enough with the tap, it will centralise itself anyway.
Very well done.
Now you can understand why dienuts are as they are, they do a perfect job on cleaning up threads, and you will find the thread files very handy in the shop. I have just bought myself a new metric one.
Bogs
Navigation
[0] Message Index
[*] Previous page
Go to full version