also, nice thing about doing it in a bath, stuff doesnât fly around, coolant isnât spraying everywhere, and i really should learn to combine things into one post 
and i just got another idea for this machine future post!
I want to make sure I understand. Your parts are completely (3/8â) under coolant and when your bit is going through it there is no splashing? That sounds crazy.
A hundred and 46 dollars for a tap? WTF is it made of? adamantium? No wonder I have never heard of it, must be one of those shocks to the system kind of self-protection from horrible trauma. I wouldnât dare put it into a spindle lol. hope you bought it from IDC and they guarantee replacement if you break it. You are a braver man than I.
Itâs all relative. Theyâre a standard thing in the machining world. Whether theyâre âworth it" is up to the buyer. If youâre doing a few holes once in awhile, then probably no. But if I were doing dozens or hundreds a week, Iâd buy one in a New York minute. How much does it cost me to tap a hole and how much of a PITA is it to keep the tap (& resulting threaded hole) vertical?
Not really different than the decision to buy an ATC so but changes are easier.
yet I am still in awe that a spindle turning at multi thousands of rpms can tap without shattering the tap I will have to see it done. I look forward to seeing it. i understand how the single point one works but not the other one.
The one that looks like a tap is not much different then the one that has one cutting point, the difference is the single point has to interpolate from bottom to top of hole while the tap looking one only makes one 360 deg interpolation and the complete hole is tapped, much faster but more side load on the tool, both work well.
Pat
I still want to see it done LOL.
This made it make a lot more sense to me, youâre not diving into the work like you do with a tap, but rather cutting from the sides, so your thread mill is smaller diameter than your rough hole.
This also clarifies PezWoodworks comment about side-load.
there is a tiny bit of splashing but i have my dust but to just a bit above the âfenceâ holding the coolant, so it contains most of it. If i cut close to the edges i may get a little overspray but not significant, easy to wipe up.
yeah theyâre pricey, and i shop around. i think the cheapest multi thread mill i found recently were around $130 cdn for 10-24s. I can find micro thread mills for $40 and iâve been trying them out, they have just 3 teeth on them, but you can use them as single tooth ones in a snap. The single thread mills are expensive too so havenât ordered any yet but will, because with those i can make custom threads.
But in that picture i had 200 holes to drill & tap so theyâre worth it. On aluminum have to be careful but you just run it slower and you do multiple passes, so you enlarge that thread several times.
In that picture cutting all those letters + drilling & tapping took about 6 hours, and that was 1/4â aluminum. I was running it pretty slow to avoid problems, but i left it to work on its own while doing other projects so didnât want any issues.
Now I see. Would it gall in aluminum/ how slow should/can I go with one of those in a spindle?
You forgot the oil puddle underneath , how do I know that? Had three now down to two 
That looks great. I have a lot of questions here.
How do you hold your work?
What is the coolant?
What kind of tub is it? Did you glue it to the spoilboard?
Is there a video or where can I learn about this method?
I use the single form for threading aluminum. I like the flexibility they allow for different thread sizes/pitches but also feel they match the type of machining I often do - higher speed with lighter cuts (I recently purchased a second one for larger threads). This type of threading also lets you modify the parameters to match your needs, so it is very easy to get loose or tight fits for your fasteners. NYCCNC has a great Excel tool that helps calculate the correct settings in Fusion, which is the CAD/CAM I use. Here is a video that explains the calculations, and a link to the Excell doc âŚhttps://www.youtube.com/watch?v=ou5j1R4nNf4 ⌠https://www.youtube.com/watch?v=ggo24jmlpWA
I have an older video from a few years ago that shows my first thread milling. I start using machinable wax to test the CAM, then move to aluminumâŚhttps://www.youtube.com/watch?v=zt8RzZAr_VA&t=175s
Even today after many many threaded holes behind me, I still hold my breath when that tiny and expensive thread mill enters the hole with just a fraction of a millimeter clearance.
the aluminum is held down on all sides, you can kind of see it in the picture. i also turn the table vac on while itâs running (built my own, another thread).
for coolant i use this stuff, you water it down
there is no tub, i tape 1/2â acrylic scrap pieces (i laser our leftovers often) with tesa to the edges (you can see in pic) then silicone every edge before running to seal it, then fill to almost full with coolant. bottom has many layers of premask + a final layer of packing tape to seal it.
final cutout is gauged to be right in the middle of that masks, so nothing leaks.
Iâll be doing a video about it soon since iâm training a new guy, iâll make a note to send you the details soon as i write them up.
Do they make cheap ones for folks to start out with?
The only inexpensive thread mills of this type I have seen are from the typical overseas online marketplaces, but the quality is unknown, shipping times often lengthy, and final cost to the door questionable given the current global economic climate.
I would love to see this too. Something I was always interested in, but too afraid to try.
