Threadmilling on a Tormach with Fusion 360! WW109 

John...as a newby...this is a great video. I love how you went through every step...great detail. So much info for 16 minutes!!!

I really like this format - quick overview, and then more details for those who want it!

Thank-you for what you do! Having you channel to refer to is incredibly helpful.

Great video John. Also congratulations on the new addition.

Great job John. I think its really smart how you formatted this episode by doing a quick overview of the cam then getting right to making chips and following that up with a more in depth look at the cam then adding in a time laps at the end. That's great for ppl that don't care as much about the 360 stuff. I personally don't use Fusion much, but still enjoy watching it. Excellent editing and Machining, which both seem to get better with each and every post. Quick question, what didn't you like about the recipe on that thread bore adaptive operation? Didn't look or sound that bad to me.

Very helpful, John! My 440 requires me to do thread milling so I need to get this process down cold... Best wishes, Tom Z

very cool John. I would really like to see the set up with out the flat and a straight 1/2" NPT.

1st. The reason "you need to always go a little bit further" is because the ideal thread forms are not triangular pyramids but are triangular pyramids with the major and minor peaks/valleys lopped off. The Major and Minor diameters you read from the table are the diameters at those lopped off flats, now your tool path Diameter (the way you are programming it) is the diameter at the vertex of the triangular peak which is not the same thing. 2nd. Your statement "In Theory all 12 pitch threads should have the same difference between the minor and the major (diameter)" is fundamentally correct. Where you are going wrong is the Major & Minor Diameter for an Internal thread vs External thread are not the same. Minor Diameter for 1" External is 0.8978" but Minor Dia for Internal is 0.9098" 1"-0.8978"=0.1022" EXTERNAL Minor Dia which is what you wrongly calculated. 1" - 0.9098 = 0.0902 INTERNAL Minor DIA. Which is for intents-and-purposes is the same as the 0.0905 difference you calculated for the 1 3/16 x 12 tpi. Cheers

I love your videos. What is 1045 steel? Maybe you could give us a practical lesson in common types of steel we might come across?

These are the types of videos i like!!

Nice video on thread milling and great trick on using the bottom to get your other chamfer. also save you another tool change.

Love your stuff man. Just got approved for my loan for a Tormach. 20 years of Mechanical design and I'm ready to do my own thing. Going to browse your vids for ideas of what I need to start up my home shop. Already have a few people needing quotes...lol. Love your stuff man.

Very nice! You will be building space equipment soon!

glad to hear the old theme song during time laps. great video.

Hey, I do a lot of thread milling at the shop, I use Mastercam to program but the concept is the same. for me the best way and the easiest is to create geometry of the amejor dia. of the thread you want to create and pick that geometry instead of the minor Dia. like you did for this part. it always work for me...I hope it helps!!!

Beautiful! Great work! How long from start to finish, cad/cam?

Very nice job !

Like a Pro... very nice. That was very impressive!!

I imagine it's the radius of the thread mill that dictates the amount of offset. When single point threading on a lathe there is always some difference when using a dedicated pitch insert verses a universal.

I use a lathe internal indeable toolholder as thread milling tool. It's slowers since you only have one flute, but it you broke the tip, it's only a couple or bucks

THIS IS PRETTY NICE, THANK YOU SIR.

Interesting about the thread pitch calcs. I'm guessing metric is not that way since it's based on angle vs threads per inch.... I could be wrong.

very nice work

compensate by 20% with those even threads but depends on what fit 1 or 2 or 3 and the oring factor hence the 60 percent chamfer also

VERY cool!

When I thread mill in fusion I usually select "model thread" in the threading pop up box during design, once in cam, just select the modeled major diameter as the contour for the threading op and select your pitch. No need for calculations etc.

The thread and the chamfers are for a SAE #14 O-Ring port. It will seal effectively at high pressures, something like 5000 psi. Nice video. Thanks, John 🎉🎉🎉 Woo hoo, new baby girl! Congrats again. 😊

Congratulations on your daughter

Looks to be an oring port, I did a lot of this at my last job. We mad hydraulic parts.

Hey john; The difference could be that the minor diameter of the two different thread sizes you referenced could have different tolerances on them. As you looked at the acceptable sizes not the theoretical. It could also be the flat or radius on the tip of your threadmill is not the same as the theoretical used for the calculations. As a side note, the corner radius/ flat on each tool isn't the same. It has a tolerance just like everything else. This tolerance will effect the finished pitch diameter; given that the OD of the tool is the same. However the OD also has a tolerance. This radius/flat on the tip also applies to lathe threading inserts. This is typically only noticed when trying to achieve decent thread fit.

good job and congrats :)

i am curious if you found a solution to the fact that you always have to ad a little bit to the pitch diameter offset

Funny way to hold on to a part it made everything slow. Thread mills with inserts are better for this cos it will only damage the insert if something goes wrong, you can also use some lathe tools that have round tails so that you can hold them.

I'm not sure what the Tormach's RPM maxes out at, but you should have been running that 3/8" carbide closer to 3000rpm to get a good cut on it.

John the reason that you need to take a lil more than the .905 is because that is at 100% thread engagement and the normal thread engagement is about 75% which is the lil bit more that needs taken.

Hi John, awesome work ! One question... how versatile are the thread milling tools ? I mean, is there a limited range of pitches a certain tool will allow you to make ? If so, how many different thread milling tools you´d need to cover a usable range of thread pitches ? Thanks !

Hi John, quick Q... if you could have only one thread milling tool, which size would it be ?

Is it possible your need to increase the cutting diameter might be due to tool deflection? Those long skinny threadmills don't seem super rigid. Ciao, Marco.

congratulations

Which is more precise, thread milling with a spindle or tapping with a spindle?

Love the timelapse! You should show that first, then explain step-by-step... i.e. show us the "outline" then go into detail.

Hi, John. In this video you show a 1/2" hole being drilled in what looks like one pass at 650 RPM, 4 IPM Peck. I have an 1100 and tried this setup and the spindle stalls. Are the speeds and feeds shown in the video accurate? I'm asking this because I bought my 1100 used and I'm concerned that something is wrong with the spindle if it can't drill the same hole successfully. As always, thanks for the awesome content and inspiration!

I'm sure it's been answered, but the simple answer is like this. The sharp point on the tool requires a deeper depth because thread form is based on a tip with a radius. The sharper tool requires you to go deeper because you're essentially farther away from the required PD. Think that makes sense, hope it helps.

I believe that's a fitting called "oring boss". Those dimensions are pretty critical to that fitting not leaking over time. A washer and nut typically will be on the fitting and will force an oring into the small clearance on the fitting. Your customer has a straight fitting without a nut and washer. I've dealt with them on the fluid power side of things, never in a machine shop. Burrs cut the oring and the oring size is critical. Looks nice, you'll know if your size and finish are good if it works for them.

How to buy same tool,? I see ít verry good.

Question for you John ( or anyone ) when cutting a thread on a lathe you set the cross slide to 30deg and adjust your depth of cut along this axis so you are cutting on 1 face , does thread milling do the same ?

Hey John how's Keiths grill coming on

Can we generate worm thread

Nice!

+nyccnc Hi John. I have done a lot to debunk and prove out what Fusion wants for this & hopefully help others. Below is for Internal Holes As we are using a Thread Mill, this assumes your cutter tooth tip comes to a POINT. 1: The Minor Dia calcs from your reference and any others take into account the Standards. So it is CRITICAL that with what I am about to say; that the ID hole in the fusion model is exactly the book Reference for Minor Diameter. I have checked your book figure of 1.097 and it aligns. Some web refs are wrong so use this formula to check: Minor Dia = Maj Dia- (1.0825 x Pitch) Eg: your 1.1875 12Tpi 1.1875-(1.0825 x 0.083333) =1.0972 2: Now you need to know the thread height BUT it also has to consider the above with respect to the fact Standards have already been worked in. So; Height of the cutter Triangle is: H=0.866 x Pitch. But with standards already worked in we actually need 6/8ths of this height for an Internal thread. HStnd= 6/8 x 0.866 x Pitch. e.g. Hstnd= 0.6495 x 1/12 = 0.6495 x 0.08333 =0.054125 Radial Depth of Cut or x 2 = 0.108 Diameter. NOTE: You used Maj - Minor Dia, the reason this is too low is again because of the standards. That figure you got of 0.09 is the thread measurement from Flat to Flat i.e. 5/8ths of Height. The Minor dia figure from formula or book took care of the thread peak at the hole ID (2/8ths or 1/4) and now we have to allow for the Tool tip of 1/8th thread height, hence 6/8ths in the formula above. SO: Pending material, tool deflection and assuming the correct size Single point threadmill for the pitch i.e. has enough tooth depth/height to complete our calculated Radial DOC; the figure Above of 0.108 is pretty spot on unless you want a tighter fit. WHY? Well the Minor Dia figure which we set our fusion Modeled hole ID too, basically works out to around a 73-76% thread fit hole diameter. So if you want a tighter fit I suggest sneaking up on that 0.108 Diameter offset figure in fusion AND if you have the male part, test fit. Test fit is key because bolt tolerances particularly on cheap fasteners are very hit and miss to the dimensions we have calculated, but what I have typed here will get you on your way. NOTE: If you start fudging the modeled hole ID away from the Minor Dia figure then this above will obviously be inaccurate without further maths, hence I just adjust the Offset in fusion. Also all of these formulas above work for METRIC e.g if you have an M10 x 1.5 thread; just use 10 as the Major/Nominal diameter and put 1.5 as the Pitch. The Constant I have given remains the same, results can simply be convert back and forth from Metric to Inch using 25.4mm = 1Inch. Lastly: I reported to Fusion a while back that Pitch Diameter Offset was is not the best name. It doesn't do any algorithm in regards to the ACTUAL theoretical Pitch Dia. If you check through the GCode it simply adds this 'user input' Pitch Dia offset to the 'hole' ID you have selected/modeled and takes the tool radius of the cutter into account. Hence if your Hole ID is not accurate to the theory of threads and thread fit it will vary your result. If you were to put in the ACTUAL Pitch Diameter offset figure from the ID (Minor Dia ) hole you wont even get close to a thread that fits. I have reported this a long time ago that they should change the name as it confuses everyone, nothing has changed. Hope this Helps

major diameter for internal thread is nominal. so its actually bigger. there should be tolerances too. if there no tolerances. peek pitch diameter and add half from it to nominal major diameter. you safe :P. i dont use CAM. i have build custom makros for everything. 1 line code will do same as 100000 lines cam :D

For a given pitch, you don't have to have the same delta between minor and major thread diameter. Some profiles have deeper or shallower threads. Definitely not the same for all within a given pitch.

can you thread mill 4-40 in aluminum? Steel? What is the practical limits if there is any?

How did you do a multiple pass step over with the 2D chamfer or how did you make Fusion do what would be "tip offset" in the 2d contour you used for your first chamfer? I need to do a really broad chamfer and want to do multiple step overs.

Very cool, as a tool maker from the 70,s this type of work is fantastic. Just wish you would use coolant as all you guys do the same because it spoils the filming....

You could have changed the angle for the face op to 90deg it would've did y axis instead of x

You could try a helical interpolation to rough out the hole, like you did for the rough & ream story, maybe this is a better recipe Nice work tho

I think you have to cut a little more than the actual pitch diameter offset because of the nature of thread milling. Your threads are coiling at an angle, while the flutes on the thread mill are horizontal. Basically the flutes aren't cutting at the angle that your threads are coiling, therefor, there is always going to be some material that isn't getting removed that in reality needs to be removed. This effect would probably be exaggerated if you were using a larger diameter thread mill to thread a small hole. unlike a tap, where the flutes are actually angled, I imagine this is why this happens with the thread mill. Just spitballing, it makes sense in my head, but then again, I'm sort of special so there's that.

The Reason you have to cut deeper then the Book says is the Corner Radius of your threadnill. The Book Values are calculated with sharp Angles.

first, have you lost that pucker factor with single point threading, good vid

A question not necessarily related to video in particular: quotations (pricing). How do you provide a quotation for a customer, when you have to go through a number of times (which you do not know until the appointed time), to get it right? Say the "widget" spoils and you have to use fresh materials. Also, additional machine time.

Incrementally reduce the depth of cut. Take the max # of passes you want to do. In this case 3 1st pass at whole depth 2nd pass at 1/2 the 1st 3rd pass at 1/4 the 1st so that would be 1X+.5X+.25X=1.75X Y= the single depth = 1.75X then X = Y/1.75 =SUM(D13/(1+0.5+0.25)) Paste in excel, D13 is the single depth

So in the vid you mention a "thread spring pass" and say you will discuss at the end but I did not see that. Also I don't see a Thread Spring Pass option in Fusion 360 I'm using (9/1/16). What is this spring pass?

About your perplexity regarding the necessity to sneak up on the final fit for your milled thread: The thread milling cutter's helical interpolation cylinder diameter results in the sharp tool trace being larger than the nominal OD of the thread being cut by 2 X the thread crest truncation for internal thread (Unified system). My Machinery's Handbook (16th Ed) has illustrations on page 1120 and 1121: "Limits of Size Showing Tolerances, Allowances etc" I'm sure your 28th Ed has something similar. See how the internal thread major diameter is larger than the nominal diameter and how the truncations of internal and external threads are manipulated to prevent tip/root interferance.

How would you have aligned the part if they would have (unfortunately) given you the part with the bolt pattern already drilled?

At 2:35, why were you unhappy with the recipe? Because of the chatter? Or was it going the wrong direction? I'm no machinist but it sounded like relatively normal operation and it made the chips so, why were you unhappy?

The listed major diameter is to the sharp V of a thread. If the 2 parts had the same major thread diameter, there would be no clearance for the thread to go in. It would be an interference thread (kinda like a press fit dowel). For a part to thread in and it needs clearance on both the major Dia of the thread and inside the V. The amount of clearance is referred to the H-class of a thread (that's the H# on a tap) smaller the H# the tighter the thread is. Larger diameters require larger H#. At 1-1-/2" you're around an H4-H5 fit which is .002-.0025" over major thread dia. for clearance. So you'll to take an additional amount off. But it's not a 1:1 formula. Remember the thread mill is a 60deg included angle (120deg total), so the formula for the additional amount to take off follows similar to calculating a chamfer dia for a 120 deg spot drill. There's also an additional compensation due to the helical tool path with a tool whose flutes are perpendicular to the cut.

Can you single point npt threads.?

John, here's a pic that easily explains your question. I know I usually find myself reading threading explanations 10 times before I grasp what the person is saying. If you are a visual learner like me, this should help. As you already know, UNC and UNF threads have flat roots and crests. Unless your cutting tool has the exact same radius on it's tip as what the thread calls for (it won't) then minor diameter is a poor measurement to use. Thats why we always measure from pitch diameter (in the case of external threads). You'll see in the picture that if you had a perfectly sharp tool and you cut to minor diameter, the thread will not be fully formed, you actually need to go past the minor diameter. However, the minor diameter gives you a relatively safe starting point when it comes to internal threads. s13.postimg.org/j4h0nvj6v/NYC.png

nice but try inserted threadmilling though. :-) Vargus or Carmex 16ER or IR.

John, more often than not, the tool tip radius is what forces us guys to have to monkey with the numbers. We need to remember we are touching off our cutting tools to the tip surface, with whatever radius it may have. That exact radius is often unknown. The published minor/major diameters make an assumption of tip radius and you can bet it's not the value that applies to the tool you're using. Lead angle is something else that I notice is not discussed in so many videos on single point threading. After all, most of us are cutting threads of 8 tpi to much finer pitches where the lead angle role diminishes in practical importance. If you like, I'll provide you an equation for cutting depth to take into account your tool tip radius. This will give you the numbers to make you shine first time, every time. Regards, Bill Phillips, Surrey, BC, Canada

The thread angle is 60°, but because the tool is moving axially, the thread mill should be less than 60°.

Yeah...pitch diameter isn't what...oh wait. I just read the bellow comments and they say what I was about to say. I don't remember how just looking at the full thread tolerencing diagram is how I remember figuring out.

I can't do thread milling on my manual machines. :-( Someday soon though! Just 45ft more of shop wall and I will have a shop with 4 walls!

Do not stop feed at anytime

Sorry I only have a poor mans Bob Cam.. I would not know how to to start. But great video.. I will watch out for moor...

About the thread milling problem. Take a look at this picture en.wikipedia.org/wiki/ISO_metric_screw_thread#/media/File:ISO_and_UTS_Thread_Dimensions.svg Thread diameters are specified based on the truncated triangles formed by the threads, not to the theoretical sharp points of those triangles. However a single point thread mill does cut to a sharp point of a triangle. You need to do some math to find the diameter of where those theoretical points are for a given thread specification. I made a calculator to do this. You can copy and paste this code into a text file and save it as .html then open it in a browser to use it pastebin.com/KJqERU6H This doesn't take thread tolerances into account, it's exact, I program it as is, and use tool wear compensation in Linux CNC to fine tune the fit. Also the thread pitch is the pitch not TPI, so i.e. 0.08333 not 12 for 12TPI. If I put in the thread you were cutting, I get 1.2055" for the helix diameter you wanted to be cutting, or a 0.1085" pitch diameter offset from the modeled 1.097" minor diameter.

Hi John take a look at : At-Man Unlimited on RU-vid he explains the math behind thread milling😊

hey John, I'm about to make my 1er threads experiment with fusion. The problem I have is adding the tool to my library. www.maritool.com/Cutting-Tools-Keyseat-/-Milling-Cutters-Chamfer-Milling-Cutters-Double-Angle-HSS-Chamfer-Mills/c78_231_237_239_277/p2419/Double-Angle-Chamfer-Cutter-3/8-dia-X-60-degree/product_info.html in tool type which one did you pick. Counter sink, dovetail. can't find the way to have the doble angle option. thanks.

Man. You are just so far off on feeds and speeds. The RPM was in the ball park on the drill, but you're feeding half what you should (at least 7 IPM). That end mill should be running at 6000 RPM and 75-100 IPM. Kinda sketchy how you used the 3D taster to try to find the center of the part. I would have used a square or something touched up against the OD. I always start at the bottom of the hole and climb mill out with a thread mill. Takes a lot of time to sneak up on the pitch diameter.

The handbook shows a min/max for the minor of the thread & you were going with the low of that tolerance. That might be why you needed to give it a tad more. Shoot for the middle of the tolerance.

grad of tread quality .

I love your videos - But you go way to fast to understand - please slow down in your videos.

It's the WORLD'S LIGHTEST, SOFTEST AND FREE-EST MACHINING "1045 STEEL"! And remember folks. ALWAYS USE A "CUTTER" TO MILL OUT A "PILOT HOLE" TO THE FINAL SIZE BECAUSE DRILL BITS ARE FOR CHEATERS! Or is that "DRILL BITS ARE FOR REAL MACHINISTS WITH REAL MACHINE TOOLS AND REAL EXPERIENCE AND KNOWLEDGE DOING REAL WORK FOR REAL CUSTOMERS TO REAL "PRINTS"?

heidenhain.. 2 minutes programming

You need a DMG Mori Machine ;) Tormach is a juicer ;)

Those tormachs seem to be a bit crap!