View Full Version : Mikini/VFD post-conversion cutting videos

02-19-2014, 11:01 PM
Hi everybody,
I've just been humming along with the new motor so I'm going start posting videos in this thread for those whose wish to see them. I'm also trying to pick up more subscribers so please subscribe and share.


02-19-2014, 11:03 PM

02-19-2014, 11:04 PM

02-19-2014, 11:05 PM

02-21-2014, 07:31 AM
Good Stuff !!!! I recently acquired a 5 inch, 45 degree face mill. I'll give it a try....I may be installing new spindle bearings sooner than I thought ...lol

02-21-2014, 12:13 PM

03-03-2014, 02:28 PM

03-05-2014, 01:25 PM

03-06-2014, 08:19 AM

03-07-2014, 07:12 AM
Great work!! The mill sounds great !!!!! Keep the videos coming :)

04-04-2014, 08:38 PM
Hi guys,

Well I've been working hard on getting a website set up so I haven't been doing much machining lately. Hopefully that is about to change because the website is finally done for now and you can go there to follow my blog posts, see new machining videos (if you are not already subscribed to my Youtube channel (https://www.youtube.com/user/SIMEYFACE)), and brainstorm with on product development. It also has a store for anyone interested in supporting us and buying some of the really cool things I make. I'm totally new to web stuff so if I am doing something wrong or there is a problem with the site please leave me some feedback or feel free to also leave comments in the blog.

I hope you all enjoyed the titanium dice making videos, they were so cool that I decided they need their own name. I call them the "Luxors". Bob Warfield of the CNC Cookbook and the ubiquitous GWizard calculator wrote an article about the making of the Luxors and I've linked to it on my blog. Also Hackaday published my submission to a contest where I was trying to win some money last year, as an article. I didn't know it was going to be published and I didn't win for technical reasons but it seems to have garnered some attention and I hope it helps others who are having a hard time with their endeavors to know that they aren't the only ones. I've also linked this article on my blog as well.

The website is warmachinellc.com (https://www.warmachinellc.com)

Anyway the next project that I've started working on (or I should say started working on again from a long hiatus) is an AR15 component I invented and provisionally patented in 2006-2007ish. I had a few prototypes made by another machine shop but the cost was borderline prohibitive and the only shop willing to make it decided it was too hard to make and not worth their time. That is what ultimately landed me here. I did a little machining on it when I first got the Mikini but decided I couldn't afford to keep breaking endmills with the spindle problems it had. Now that the spindle problems are completely gone it's about time to bring this thing full circle. I've spent the past couple of days brainstorming fixture ideas as I've decided the previous fixture I made was not going to be good enough. I will detail all of these things on my blog soon and hopefully some of you fine folks can help me come up with a better mousetrap to fixture this thing.

04-15-2014, 11:19 PM
Hey guys,
I finally got around to working on the gasblock again, here is the latest video. You can read more about my methodology with the fixturing in the blog on my website: Did I mention this new motor is sweet?


04-25-2014, 10:25 AM
Here is the 2nd video in the AR15 gasblock machining video series. Most of this one is revisiting operations from the 1st video after I discovered a process error which would lead to a lot of problems down the road. I'll put up more content and some more pics about my thought process in the blog (https://warmachinellc.com/blog). Feel free to add a comment, tell me what could be done better, or just tell me I'm an idiot.


04-29-2014, 10:42 PM
In this one I actually blast a 0.5" roughing endmill into pieces!

The latest episode in the series:


Here is the link to the blog post with more info on the machining ops:

05-07-2014, 04:19 PM
Here is the latest video. It may appeal to many here because I go back and revisit making a whole bunch of test cuts again to tweak MRR, tool life, chatter, and surface finish. I would say I largely failed in the surface finish department with both boring and finish milling so maybe some of you who are much better machinists than me can offer some suggestions. As far as MRR goes, I think I hit one out of the park using some new Lakeshorecarbide (http://lakeshorecarbide.com) tools and some recommendations from Carl the owner. What he suggested had me pretty nervous given my history with the old spindle snapping and breaking all my tools from halts but the new AC/VFD motor didn't even bat an eye at these cuts.The main issue now is rigidity. I also tried boring again with no success.

4140 HT alloy steel
0.5" 2.5" long carbide rougher from lakeshore carbide
2125 RPM
22 IPM
0.6" DOC !
0.07" WOC

Early in the video you can see the effect that the collar coming loose had on the cuts. Make sure those things are at least snug, mine was completely loose. I may go back in there and snug it more based on the Tormach manual procedure.

Here is the blog post with more content and write up:
AR15 High Rail Gasblock CNC Machining (4): test cuts revisited and profiling | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-4-test-cuts-revisited-and-profiling/)

Here is the video:


05-14-2014, 11:08 AM
Latest video is out. This one I get into the machine backlash issue, the Haimer 3D taster, and finally some good machining.

As usual there is more info on the blog page: https://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-5-top-side-picatinny-rail-and-bottom-features/.


05-22-2014, 11:00 AM
Blog post:


Fixture plate 2 machining video:


Brian L
05-22-2014, 12:45 PM
You should use the round boss in the center, and then a diamond shaped pin to locate the parts rotationally. It will make it worlds easier to get the parts on and off.

05-22-2014, 08:24 PM
Interesting. I guess the idea is less contact area for friction? Do you have a link to these diamond shaped pins? I wanted to use pins instead but couldn't find any of the exact right size and the main one needed to be threaded anyway so I decided to just mill them in a steel plate.

Brian L
05-22-2014, 09:23 PM
The idea is even few tenths of a thou variation in center to center distance can really muck things up for fit. So you use a round pin, or boss in your situation, and then the rotational locator would be a diamond pin with the locating portion at 90ยบ to the axis between the two holes. Very common in the machine shop, all of our fixturing uses diamond and bullet locators, have even made pallet changers using them. Here is a link to the Carr Lane catalog showing a variety of them...

LOCATORS, LOCATING PINS :: Carr Lane Manufacturing Co. (http://www.carrlane.com/catalog/index.cfm/27025071F0B221118070C1C512D020609090C0015482013180B041D1E173C3B2853564659)

Brian L
05-22-2014, 09:30 PM
Just as a second thought, you could always diamond the smaller locating pins on your fixture, they don't even have to be diamond shaped, you can just mill flats on two sides so the pin only locates in the axis it needs to.

I've just done a lot of production work and you want your fixturing to be as easy and quick to use as possible.... like I don't know how you expect to get at the bolts for the parts in the rear? Take the fixture out of the machine? I think I would have investigated a fourth axis and used a tombstone for the parts.....

05-22-2014, 09:35 PM
Thanks Brian that's very good info. I did not know about the diamond pin theory. I guess since I already made the fixture, if it becomes an issue I can still make the small round boss a diamond shape and see how that works.

06-07-2014, 12:48 AM
Latest installment in the series. Finally some 3D profile machining using the new fixture plate!

Blog article: AR15 High Rail Gasblock CNC Machining (7): side gutting and 3D profiling | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-7-side-gutting-and-3d-profiling/)

AR15 High Rail Gasblock: (pt.7) Side gutting and 3D profiling


06-10-2014, 03:07 PM
Here is the latest episode. Maybe some of you machinists can offer some advice on a few issues I've been having. They are detailed in the blog post here:

Blog Post: AR15 High Rail Gasblock CNC Machining (8): roughing, finishing, and bayonet test cuts | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-8-roughing-finishing-and-bayonet-test-cuts/)


Brian L
06-10-2014, 07:27 PM
For your center bore, what size hole prior to milling the .750 stepped bore? What sort of tolerance on the bore do you need, any further machining to it afterwards? If the clearance hole is already in there, and you just need a .750 hole, I would buy a 3/4" end mill with a small corner radius ground on it. skip the roughing and just plunge feed it down there. You might have to peck to clear chips, but it will act just about like a reamer and has a whole lot more room in the flutes to evacuate chips, especially in a deep hole like that.

For your drilling issues, use your high speed peck, usually a G73 to a depth you feel comfortable with, then change to G83 (full retract) and finish the hole from there. Some machine (lathes in particular) have a G-code that will allow variable depth pecking, I can't remember the G-code, but you can use percentages of the hole depth or distances and have then decrease per peck to a minimum peck amount which it will then use to the bottom of the hole.

Your last issue on the outside, with the end mill springing away, or the part pushing away.... not sure of your radii, but if by chance it was the same as that .750 EM you could use on the i.d., you could go to position and plunge in Z only and get a lot less deflection.

I'm doing a part at the moment that's 1.25" thick aluminum with a odd shaped inside "window" thru the part and I found roughing the part using the spiral pass.... think it's 5 loops around the interior with a tad over .25 change in Z depth each pass... kind of like thread milling, does a much better job of keeping some of the sharper corners with the same amount of final pass stock. I spiral mill at .002" material left, then make one loop around the part at full depth a slightly reduced feed rate to do the final finishing.

Just a few ideas for you.....

06-11-2014, 02:37 AM
Thanks very much Brian! The drilled hole is 14mm then I rough it to approximately 0.742 or so with a 1/4 step at the bottom. Tolerance I would say is -0.0005, +0.001 of the finished bore. I thought about using an endmill but a 3/4 reamer is a heck of a lot cheaper than an 3/4 endmill. My other objection is that I'm paranoid about chipping the flutes plunge cutting with an expensive endmill. I mean a Lakeshorecarbide 3/4 endmill is over $160. I just bought a 3/4 reamer for $60. I need to keep replacements costs in mind.

Are you saying drill the 14mm (0.5512) hole then plunge mill the final bore with the 3/4 endmill and eliminate the roughing? Isn't that hard on the flute tips even being radiused? That suddenly seems like an attractive option despite my paranoia about plunging endmills, especially $160 ones. It just doesn't seem that endmill would last that long with all the cutting on the tips. Am I wrong?

I'll check into optimizing the drill cycle again later but that is kind of what I thought about doing. G73 for like the first half of the hole, then G83 for the bottom half. That's not a huge issue though.

My main issues in order of importance are:

1. getting a nice finished accurate bore
2. eliminating the chatter from the roughing ops to extend tool life
3. getting a really nice finish around the outside in as few passes as possible and without chatter.

Brian L
06-11-2014, 09:28 AM
I would try a HSS end mill first and see how it does.... I probably have a half dozen rolling around in my roll away. But I suspect you wouldn't have any trouble with corner chipping and you should be able to hold that size as long as the tool doesn't runout in your holders. As for longevity, you making thousands? Or hundreds? Or 40-50 pieces? Even HSS in this situation should give you probably over 100 pieces. Oh, you can hand stone a slight radius or chamfer on the leading corner of the EM if all you have is sharp cornered.

Using an EM will give you as nice or nicer of a finish than the reamer, now if you have trouble holding size, you could always use a reground EM that was say .740" and then ream to the .750", would still most likely beat the pants off interpolating the hole with a smaller end mill.

Eliminating chatter is a tricky situation, you want smaller end mills than your tightest radii, but then too small and they tend to chatter and scream. That was part of the reason for my suggestion of plunging rather than side cutting. If you could get adequate size and finish in the radii, then have your finish end mill that profiles just skip across that internal radius, you can blend into it and out of it, especially as you say you will sand blast after machining.

Brian L
06-11-2014, 12:22 PM
As a follow up with more information, I just got this email in my inbox about an article concerning Helical interpolation vs. rough boring on holes, might prove an interesting read:

Manufacturing Engineering - Tool Time for Fracking (http://www.sme.org/MEMagazine/Article.aspx?id=74604&taxid=1476)

06-12-2014, 02:50 AM
Thanks for the article Brian. I'm still looking into the plunge milling angle. I am fascinated with this now but still have some reservations coming from inexperience.

Here are some of my worries:

1. boring the hole oversized with a 3/4 nominal endmill. A regrind could solve that issue but where is a good place to buy regrinds? I might ask Carl at Lakeshorecarbide about making a 3/4 pre-ream sized endmill.
2. It sounds like it could be much slower than roughing interpolation. What speeds do you suggest doing the plunging with?
3. tool llife (i.e. the flute tips) since this is for my flagship product I will be making these exclusively for awhile. That's why I'm trying to get everything dialed in as best as I can from the beginning.

If I were to use an endmill what should I use? 2 flute, 4 flute, etc. What is a good HSS endmill? I only have experience with carbide. Is it true that carbide endmills are all slightly undersized?

Brian L
06-12-2014, 09:47 AM
Lakeshore already makes pre-ream end mills: METRIC PRE-REAM ENDMILL (http://www.lakeshorecarbide.com/imperial.aspx)

Rpm is whatever SFPM you are currently using, feed per tooth could be upwards of .005" per rev as you aren't taking that much material and no full length side loading. Program it that way and run your simulation and see if it's faster or slower... always been faster in my experience.

Tool life, well, like I said, how many do you need to run? If you can get a HSS or Cobalt EM fro $40 and it will run 100 pcs. and a carbide is $160, you better be able to get 400 out of the carbide, although there is something to be said for the extra rpm you will be able to run with carbide. No end mills are "slightly undersize", they are made to size within the tolerances the grinder has, usually about .0002". Good HSS end mills, Putnam, Weldon, Melin, OSG and the list goes on, just stay away from generic stuff that most likely comes from China.

Oh, I would go with 4 flutes as you double the ipm of the 2 flute.... so it will be twice as fast and still should have plenty of room for chip clearance. I have a 3/4" HSS Putnam in my rollaway, it's a 2fl and I'd need to know depth of hole, but I could send it to you so you can try out the situation.... I got it when I paid $100 for a whole box full of end mills at a yard sale.

06-13-2014, 12:52 AM
They do but I didn't see any 3/4 ones. I got the reamer today but it will be at least next week before I can try it. The bore needs to go down about 2.25 or so. I was looking to order one from Enco but I realized that I just missed the 20% off + free shipping promo by one day damn it. I very much appreciate the generous offer to try your endmill but I suppose I should just buy one because I'm sure I could find another use for it even if the plunging doesn't work out.

06-13-2014, 04:13 AM
I SO need to upgrade my spindle... I stall on EVERY use of a 1/2" tool even in aluminum. I would not even dream of trying a 3/4" in steel!!! I had a solution "on the way" from SkyfireCNC, but he seems to have vaporized, so back to the search for a "simple, effective, available" solution...

Brian L
06-13-2014, 09:34 AM
Well, Enco has 13% off today, and I'm sure the free shipping code is still there for the month. Better than that, I have a slightly used 3" length 2fl that somebody modified the shank slightly on.... if you want a freebie to try out, email me your info at blamb11 at cox dot net and I'll mail it to you to try out. Going to try to add a picture of it...


06-13-2014, 04:25 PM
Ok Brian I'll try the endmill and put it in one of my next videos! Thanks a lot! Email sent.

06-13-2014, 05:08 PM
Hey Mike,
Yeah I vaguely remember back when my spindle sucked...it seemed like as if a bad dream. Like I repressed those memories with selective amnesia the way a victim of traumatic abuse might. Details of that time period still only come out under deep hypnosis. Now when I watch the spindle cut I breath a sigh of relief and tell myself it was all just a horrible dream. I still have a little PTSD from it though like how my heart sinks when I inadvertently and unknowingly hit a soft limit and the spindle suddenly stops. Then I realize what happened and again breath a sigh of relief while I mummer to myself "it's OK it's OK that is what is supposed to happen".

Sorry to hear about the Skyfire thing. I bet Defeng will get his business straightened out one day, but how long to wait is the question. You can tell he's put a lot of effort into it but is charging up hill.

In the meantime if you are ready to pull the trigger on the VFD conversion I'll help anyway I can. Under normal circumstances I would offer to come over and help since I think you are only a couple of hours from me if that but my family obligations are too great right now (taking care of a toddler full-time and the wife is about to drop another). I have figured out how to do a seemless conversion from the existing BLDC to a VFD. I even have a spare REX84 card V1.0 laying around I could put together for you for no charge if you wanted. Which works fine and is what I'm still using. If you wanted the upgraded and improved V2.0 card I would have to send off to have some printed so there would be a small cost. I can give you a parts list of every thing you would need like VFD, motor, cabling, etc. and I can even send you some of the left over materials that I have extras of like connectors and Cat7 cabling and stuff. I'll also send you the 3D model of the motor mount but it is designed around a certain size motor (145TC frame C-face). I never got around to updating the model with the very slight changes I made to it but I can easily tell you what I changed and you can update them in solidworks. The changes were really just dimensional tolerance issues like a bolt hole being a little too tight or something.

I'm convinced the 2HP vector duty motor I'm using is massively powerful for this machine probably even overkill. I haven't even come close to stalling it with the kind of cuts this machine can handle. This motor easily exceeds the rigidity of the machine (which I even think is pretty good). Keep in mind the vector duty motor and this particular VFD while rated for 2HP can actually cut at 4HP (200% over drive capacity) under load for a period of time before starting to get too hot with excess current so the few times when you might "accidentally" exceed a 2HP cut it won't just crap out and stall, it will do the cut albeit at higher than continuously rated for current. If you do that for too long you will just get a thermal alarm stating the motor is getting hot, under normal cutting loads it is just slightly warm to the touch.

I always get excited about a potential Mikini makeover.

06-16-2014, 03:59 AM
If you don't mind sending info to me that would be great. I would like to see what would be involved. I have too many projects going on right now (building a house, so the associated move. Motor swap on 1 car, need to repair radiator leak on second car, need to install suspension on the truck, travelling out of the country about 50% on business travel, etc.), so I don't want to dive in to a "more than a day long" conversion right now. That's why Defeng's solution was so tempting - I think it would truly be "plug and play" (at least after the first person figured out the right settings, etc.). But I am thinking that road is now a dead end...

06-16-2014, 04:02 PM
If you had all the materials and knew exactly what to do I think you could do it in a day, maybe two. I'll work on putting together a list of what I used and a writeup later tonight or tomorrow maybe and you can decide if it's something you want to jump into right now. Probably the first thing I would do is machine the new motor mount since this will not take the machine out of commission and order the main things like motor and VFD.

I'll start a new thread for it.

06-17-2014, 09:52 PM

06-17-2014, 09:54 PM
New video up. Thanks again Brian for the endmill and I apologize profusely in advance for...well watch the video and you'll see.

Blog Post: https://warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-9-reaming-vs-plunge-milling-main-bore/



06-17-2014, 09:56 PM

06-17-2014, 09:57 PM

06-17-2014, 10:04 PM

06-17-2014, 10:24 PM
Sent from my SCH-I545 using Tapatalk

07-23-2014, 04:11 PM
New video and blog write up. This one may be especially helpful to machinists because I detail an issue (especially in the blog write up) that I don't think I've ever read about before that can certainly lead to an elusive cause of chatter.


Blog post: AR15 High Rail Gasblock CNC Machining (10): chatter and interpolation | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-10-chatter-and-interpolation/)

07-30-2014, 12:12 PM
New video and blog post

Blog: AR15 High Rail Gasblock CNC Machining (11): 3D machining lightening pocket and sling swivel socket | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-10-3d-machining-lightening-pocket-and-sling-swivel-socket/)


08-05-2014, 02:25 PM

09-02-2014, 09:27 PM
New video and blog post

Blog: AR15 High Rail Gasblock CNC Machining (12): 3D machining side ops revisited | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-12-3d-machining-side-ops-revisited/)


09-03-2014, 02:43 PM
Couple ideas for your issues on the 1/4" tool. Have you tried plunge milling just the corners, then doing the rest of that toolpath? You may also try drilling the corners before you take out the field in your first operation, and plunge mill the corner after drilling. That would have the part kept supported and vibration free when you do those 2 inside corners. Then go on with the rest of the operations as you have done in the video...

09-03-2014, 02:59 PM
Thanks for the suggestions Mike. That's exactly what I'm going to try.

09-03-2014, 10:46 PM
I tried plunge milling the corners and it worked pretty well, much better actually. It was a little tiny bit chattery but I'll play with lowering the RPM a little.

09-04-2014, 08:16 AM
Did you try it in the same order as the video, or before you did the main material removal portion? Would also be best to use a tool with a small corner radius on it, not a sharp square edge...

09-04-2014, 10:32 AM
Yes same as video. Roughed out first with the 3/8 rougher, then plunge milled the corners, then finished profiled with a small radius in the corners to avoid engaging the corners again. Worked great, just need to adjust the rpm down a little.

This endmill has sharp corners but its replacement has a corner radius. I agree that should work better.

09-09-2014, 02:50 PM
New episode:

Blog: http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-13-double-down-and-fixture-fixing/


09-26-2014, 12:06 AM
New installment. A lot of useful info for aspiring machinists, inventors, product developers, and numb nuts (like myself) in this blog post from hard fought and won experience.

Blog post: AR15 High Rail Gasblock CNC Machining (14): finalizing side ops | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-14-finalizing-side-ops/)


10-15-2014, 05:05 PM
Latest video is out and a significant milestone has been reached!


Blog post: AR15 High Rail Gasblock CNC Machining (15): first test production run | War Machine (http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-15-first-test-production-run/)

10-16-2014, 09:22 AM
Looks great! Congrats on the bio-machine - I didn't see that option in the list when I got my Mikini!

10-16-2014, 10:44 AM
Ha! It didn't come with the machine it was a parameter setting in the VFD I think. The Mikini just came standard with bio-hazard for a spindle driver. Lol.

11-06-2014, 02:55 PM
New video up: Soft jaws


Blog Post:


01-19-2015, 10:06 PM
Next video in the series is out.

Blog: http://www.warmachinellc.com/ar15-high-rail-gasblock-cnc-machining-17-soft-jaws-ii-squaring-stock-and-barrel-pinning/


01-20-2015, 10:54 AM
Watching at work with sound off. Is that a Harbor Freight bandsaw? Model #? Looks quite capable at cutting thick steel...

BTW, the part looks GREAT! Must be satisfying to see the end result after so much hard work. Hope you do well in sales of these guys!

01-20-2015, 01:47 PM
Hey Mike,
Yes that is the harbor Freight saw. I would say it is marginally adequate. It saws the steel fine with a good Starrett blade but getting it to cut straight and without breaking blades took cumulatively several days of tweaking and ordering replacement parts. It works for my purposes but I would probably look for a higher quality one if I were to do it again. I think I paid around $150 or so, so I'm not crying too hard about it. It seems to cut fine now but some of the bone headed design choices are so very irritating to work around.

01-23-2015, 01:48 PM
Do you by chance have a specific alternative recommendation for under $500?

01-23-2015, 01:57 PM
From what I gathered when looking for a saw all of the 4x6 saws are the same design, casting, etc.. They are even probably made in the same factory in China. The higher priced ones like the Jet will probably just have tighter QC and perhaps some better components. Hell, my HF came with broken and cracked bearing races right out of the box. I don't have any experience with the Jet but if I had to do again I would probably rather had taken the chance with them than to save the money and get the HF. The HF is adequate and is only tolerable to me since I worked so hard to get it cutting right and it was so inexpensive. When I can afford a better saw and have the space for it you bet I'm going to upgrade. Then I well say how bad the HF sucks compared to the new one, but for right now it is adequate. The best deal would probably be to get the Jet from Enco when they have a 20% off sale with free shipping.

03-01-2015, 10:47 PM
Couple of new videos:

Follow up barrel pinning with improved parameters:


03-01-2015, 10:49 PM
Making some wood brands out of steel:


09-18-2015, 03:46 PM
New video: Subprograms and Offsets


01-31-2016, 06:53 PM
Quick new video: