Miniature tap guide and depth stop

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Brian Rupnow

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I am about to embark on a mission of drilling and tapping about 100 holes in mild steel with a #4-40 tap. I've done a bit of research, and came up with what I think are great plans for tapping small threads, to a preset depth and not having them bottom out in the drilled hole and break, or break from misalignment. These will work in the milling machine, immediately after the hole has been drilled. One tool is the hand operated tap guide/depth stop, the next is a spring loaded center which goes into the mill chuck and provides both guidance and a spring loaded "down-pressure" to keep the tap pressed into the work being tapped.---Brian
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And this is the part which is held in the spindle chuck and provides "downforce" on the top of the tap while you turn it by hand. I didn't put a spec. in for the spring, as that is best judged by the person who fabricates this "downforce" tooling.
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Brian,

I like your design. Being a model railroader, I use smaller taps. I'm going to see if I can adapt your idea to a smaller design for smaller taps such as 2-56 and down to 00-90.

Bernd
 
Brian,

I like your design. Being a model railroader, I use smaller taps. I'm going to see if I can adapt your idea to a smaller design for smaller taps such as 2-56 and down to 00-90.

Bernd
im taking a breake waiting for parts for my steamer. I have a really blank question to ask. You would think I should know the answer before asking

So I received a 1/4” 40 TPI ME tap and die. The tap works fine . So I tried the die. Now this is a straight thread not tapered. Carefully looking at the die under mag glass and attempting to figure out which side to start threading from . I detect there is no difference in engagement dia. On either side one side has the size marked on it the other side is blank. I could not get it started using either side . So I turned the copper tube down a little to make it so the die got maybe the first cutting surface engaged. No luck . Copper is hard to thread as it is but even with cutting oil of several kinds it just stopped not seized but not threading . I turned it over and tried again but it’s not going to cut threads. I ran into this a while ago on 1/4” 28 unf threads on a stainless steel rod. Even with a long taper it did not want to cut. Since that was a straight thread too I also turned the die over and it still did not thread . I had to go from 1/4” rod to almost 1/32” under size to get threads . They probably were INR 50% range at best . They actually worked but fortunately did not have to be relied on to hold heavy

I tried the 1/4” 40 TPI me on an existing thread on 1/4” brass pipe and it seems to cut using either side of the die.
So back to the question do you start from the etched side or blank side. Or just use under size stock?
Byron
 
If its an adjustable die open it all the way up, and/or make a threading pass with the lathe and finish with a die. I too have had trouble getting some of these smaller dies to start cutting.
I’ll try opening the diet have a longer screw in the die handle . I’ll taper it and run it into the split snd see if that helps. Memory says start the die from the side showing side or identification if it breaks I’ll have a split die to start with. LOL MY SON IS GOINGVTO MAKE A BETTER HOLDER as my brand new one is very loose. He just left and dropped off the flywheels snd remaining couplers . I gave him the new old ham coupler but it’s steel so probably goingvto be tough to modify . The best course will be to re order another making sure it’s aluminum and correct clamp style . So more delays. It’s been a whole week of delays. I did get some round brass stock so maybe I can make some adaptors I need. PMResearch has some I missed in their catalog so I’ll try and order from them too. They are very good at shipping promptly .
I just can’t easily get out to the sho so I have a hard time getting some of this tricky stuff made I have a mini mill drill and precision cross slide the drill spindle is almost as good as a mill spindle. I’m goingvto take it apart and see if I can make it better NO ITS NOT BUILD BACK BETTER . It build it right to begin with. I don’t like using “about” tools” because it makes only “ about” parts”
 
This tap guide and pressure device are AMAZING!!! I just drilled and tapped about 80 #4-40 blind holes in mild steel and didn't break a tap. The holes were drilled 0.250" deep with a 0.095" diameter drill, and the tap guide was adjusted so the nose of the tap extended 0.230" past the end of the guide.
 
Brian, where was the die made? I ask because when I first began machining 20+ years ago I bought two separate tap & die sets.
These were imports, probably China. I thru out $90.00 on this junk.
I kept all of the dies as they made fine sinkers. I kept 3 taps and made punches from them. The rest went into the trash.
I tried all of the Imperial taps and dies in scrap steel to see if any were worth keeping. Not one was any good. I did not try any metric taps or dies.
I then called relatives that are machinists and asked for advice.
They told me buy only American made taps and dies. They said Cleveland Drill was a good company and were fairly priced.
I bought 1/72, 2/56/3/48,4/40, and 10/32 taps & dies from them. Later I bought 10/24, 12/24 and1/420 &28.
All of these taps and dies were very good quality.
A friend of mine told me that he bought Irwin/ Hanson set from Amazon and was very happy with it.
I did the same as I sometimes used larger Imperial taps and infrequently metric. I believe I paid $99.00 . This included taps and hexagon dies from 4/40 to 1-2 /20 and all between.
Metric taps and dies also . Included is two die wrenches and 1 tap wrench. I found this set was more than adequate .
Even the smallest dies like 0/80 you determine the starting side. I found that all my dies that have the writing etched on this face is the starting side.
mike
 
Brian, where was the die made? I ask because when I first began machining 20+ years ago I bought two separate tap & die sets.
These were imports, probably China. I thru out $90.00 on this junk.
I kept all of the dies as they made fine sinkers. I kept 3 taps and made punches from them. The rest went into the trash.
I tried all of the Imperial taps and dies in scrap steel to see if any were worth keeping. Not one was any good. I did not try any metric taps or dies.
I then called relatives that are machinists and asked for advice.
They told me buy only American made taps and dies. They said Cleveland Drill was a good company and were fairly priced.
I bought 1/72, 2/56/3/48,4/40, and 10/32 taps & dies from them. Later I bought 10/24, 12/24 and1/420 &28.
All of these taps and dies were very good quality.
A friend of mine told me that he bought Irwin/ Hanson set from Amazon and was very happy with it.
I did the same as I sometimes used larger Imperial taps and infrequently metric. I believe I paid $99.00 . This included taps and hexagon dies from 4/40 to 1-2 /20 and all between.
Metric taps and dies also . Included is two die wrenches and 1 tap wrench. I found this set was more than adequate .
Even the smallest dies like 0/80 you determine the starting side. I found that all my dies that have the writing etched on this face is the starting side.
mike
I just received a metric tap and drill guide . It’s steel and fit the taps and drill I have . From Amazon. Cost twice what I could have made it if I was able to get to the shop , but it will come into use shortly as I YHINK I have most everything for air compressor test. Son brought flywheels back and one connecting rod. I’m going to try and order a better coupler Monday . Failed attempt to thread copper tube but so far I’ve been able to thread the brass tube. Copper is always an issue. The only thing it does well is take solder in wiring , if it’s clean and there is some flux.

I found my missing red and black wire plus the high temp sealer also some gorilla instant glue I forgot about. I started out with an empty plastic pocket container for misc parts. Now I need another. Because it’s full my son brought a small drill press for me to use. It works great.
Byron
 
Brian , milk is supposed to be a lubricant for turning copper. I have not tried milk myself. I have threaded copper tubing several times. I use Castrol Moly Dee for a tapping fluid. I use it for all metal tapping.
Moly Dee has been banned, I suppose it causes cancer or something. I have about 2 ounces left and when that runs out I'll have to try something else.
Maybe a bit of milk may help threading copper.
 
Brian , milk is supposed to be a lubricant for turning copper. I have not tried milk myself. I have threaded copper tubing several times. I use Castrol Moly Dee for a tapping fluid. I use it for all metal tapping.
Moly Dee has been banned, I suppose it causes cancer or something. I have about 2 ounces left and when that runs out I'll have to try something else.
Maybe a bit of milk may help threading copper.
Kwoodhands,

I think Byron was the one working with copper, not Brian - ??
 
Back in the 60's I worked in a shop that made electronic signs the backbone to the sings was a 6" x 12" 1/8" steel plate with several hundred holes drilled and taped 6-32, 4-40 we used goose grease as a cutting agent and it worked great, we also kept the taps in a tin with grease heated which made the taps flexible and not brittle. We had a tapping machine with twin disc covered with cork push in tap goes CW pull out CCW it was a long summer of nothing but tapping plates.

Mike
 

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