KMT 101 - Lathe spacers part3

[@SteelRinger]

Really liking all the Quality and innovation you are building into your knives.

[@chrisyboy666]

Every machinist in every country in every corner of the world has done what what you did quality it's like the horse you got to just get back on no bad

[@YCM30cnc]

Nice vid, especially the part where you showed what didn't go correctly (the crashed EXPENSIVE tool). Someone in school told me we learn more from what goes wrong than what goes right, and your willingness to share your learning experiences with the rest of us is very appreciated (and maybe will save us an expensive tool too). Thanks also for the info on the Shars micrometer. No Tormach lathe in my near future, but those guys at Tormach have done a nice job with it. Keep up the good work, and as always, thanks for sharing your passion for high quality and high efficiency, it is contagious :) :) :) :)

[@JohnGrimsmo]

YCM30cnc Thank you! I'm glad you enjoyed learning from my mistakes. That's a theme I've always tried to carry on for the past few years, if I happen to film a mistake or a crash, it gets posted.

[@liston13]

Great stuff John! Tool making is a real artwork!

[@kenmarapese9085]

Excellent vid, There was a huge difference between your spacer and the spacers you could no longer tolerate. Nice job.

[@PioneerSaturnDougie]

Exactly what more people need to do, show real world measurements for their products, very nice. I'm good with my +/- .001" on my manual lathe for now, need to do something similar.

[@ovd33]

Hey John, quick suggestion. I notice after you part off, your tool goes directly to bump stop position. This is fine if your part-off goes as planned. If your part off tool is worn or broken, your part will stay on the stock and your tool body is going to rapid through the part. 2 quick safety lines should always clear your part off blade from the same way it came in. Program in a way that assumes the part didn't separate! Great video, keep it up!

[@crashes3221]

This is a really good reccomendation and deserves a look. Great stuff there btw John.

[@JF_Fabrications]

When that tap squealed I think my heart skipped a beat.

[@JohnGrimsmo]

Ha! I think a thicker coolant would help that a lot. I just put in a new tap (the first one broke after about 100 parts) and it didn't squeak for the first dozen or so, then it started squeaking too.

[@kchigley5309]

First crash? Gotta love it. There's more to come, trust me. :P Luckily the damage you could do on that machine is trivial compared to industrial lathes. I think your drill block is under spindle center. The tap seemed to deflect up slightly. That might produce the squeaking as well. I'm actually quite impressed with the accuracy and repeatability of that Tormach lathe. I certainly did not expect that out of steppers and dovetails. It's still WAY too slow and small for my needs, but hats off to Tormach for the consistency.

[@Southardknives]

Those look awesome!! Man, that lathe is quite impressive.

[@JohnGrimsmo]

Thanks Brad! I think we're long overdue for a phone catch up.

[@Max_Marz]

I have a part at work that I have to hold -0/+.0002 on and temperature plays a huuuge factor at that level of precision. Fun stuff.

[@volodimirkun]

nice, dude! enjoyed a lot!

[@captainbackflash]

What you need is a holder or a stand for the micrometer, so you don't have to hold it in your hand. I let my apprentices do those things in the first year of learning. They design and draw it. all by hand. and then they form the steel by hand filing and hand threading. for their pre exam at the end of their second year they do it again, but this time with milling maschines, lathes and drilling maschines.

[@colinworobetz6662]

Finally!

[@bucheron87]

Hey John and Erik! Nice job, as usual ! About your measurment gauges, don't forget it's kinda cold in your shop. Usualy, those kinf of gauges reach the specified size when it's 20°C ... And a little tip for your measures, your digital micrometer normally has somekind of 'pressure sensor" ( sorry for the bad english, i'm belgian). For exemple, on a casual mitutoyo micrometer, you have to twist the little knob on the end of the micrometer to make it "clik". Make it clik four times, as said in the user's manual, and you're sure to apply the same pressure, every time. I'm pretty sure the same system equip your digital micrometer. Continue that excellent work, and don't forget to tell us what you think about the lathe :-D Geoff

[@JohnGrimsmo]

Thanks Geoff, yes my micrometer has the clicking feature too. It's much warmer now that we got our radiant heater! It's almost t-shirt weather inside the shop, but you're right that temperature definitely plays a role and I try to be aware of that.

[@high2hal]

JohnGrimsmo John, For practical purposes, with the size of the parts you are manufacturing, as long as your parts, and measuring devices are at the same temperature you can ignore the linear coefficient of expansion or the differences between the linear coefficient of expansion of the material of the part and the material of the measuring device. The difference between your titanium parts and the steel/iron/stainless of your micrometer is about 1 to 2 millionth of an inch per inch degree F.

[@russtuff]

fantastic. you're fingers are huge!

[@dexon555]

Sorry to see that broken tool. Love the videos.

[@devjock]

Alright, so you're 101 episodes / weeks in; Are you guys finding that there's now more knife makers that are adopting the same level of transparency / style? Because, as a youtube project alone it's amazing, but this is all kinds of awesome. Tutorials, full disclosure, client rapport building, and it shows how awesome you guys are. I'd be cool to see a bit of research done on your end if your competition is feeling left behind by your format. Because ofcourse, they should ;) Thanks again for the informative and entertaining video John! edit: Typo's, and i'm using the word awesome waaay too much these days..

[@JohnGrimsmo]

No. You can never use the awesome word "awesome" too awesomely much. I don't think there are very many other knifemakers doing youtube videos with the detail and transparency of mine, although lots are sharing great stuff on instagram and other formats.

[@high2hal]

John, When you use the micrometer to measure your parts you should not use the ratchet if you want the best accuracy. You can feel the micrometer anvil touch the part long before the ratchet clicks. If you want to use the ratchet you should use the small ratchet on the end but it will not provide the accuracy your touch can provide.

[@MrLiamCooley]

I feel bad for laughing when you pointed at the insert and it just crumbled away bhahahaha

[@MrLiamCooley]

Awwww now Im at the part where the tool holder is actually broken and I feel really bad :|

[@rippsgaragetech9025]

Very nice!

[@Iceblastr72]

Hi John. Really like this series. I've been watching for a while now. My question... Wouldn't it be possible for you to just machine another tool holder exactly the way you want it? Just wondering. Keep these coming.

[@JohnGrimsmo]

Yes I could absolutely machine a tool holder like that boring bar exactly how I want it. Although when the Shars one is only $30 it's not worth my time. But they are pretty easy, so I'm sure I'll end up doing it for certain jobs in the future. If/when I do, I'll be sure to do a video!

Working with micro daily I check and rezero every 2 hours. I take a gage near what I measure. I measure with micro and wiggle the gage and at the same time turn the ratchet. Then I press origin or set in your case. Then I remove the gage and close the micro which will show ex. -10.000mm. I turn the ratchet and move about until shifts from -9.999 to -10.000 then origin it again. Perfect zero every time. Recheck with gage if it shows barely 10.000mm.

[@hampfi747]

Loved the series! Could you make a video or a short comment on the strength the framelock spring has after you bend it? In my experience as a knife maker, especially with bearings, the detent drag is the main faktor to get a smooth action. To get a minimum of drag one hast to polish the track or reduce the force Of the spring. Unfortunately I haven't have the chance to handle one of your knives so I would love to hear with how many ounces the lockbar pushes the detent against the blade. One can easily measure that by pressing the lock frame with the lockbar against a scale until the frame and the lockbar is flush like when the blade closes. Many thanks in advance from a big fan from Germany

[@JohnGrimsmo]

hampfi747 I don't know how much strength my lockbars have, but you're right it would be fairly easy to measure. Mine are very light compared to most knives out there. My lock geometry is so precise and consistent that I don't need a lot of pressure to lock it up solid. I spinewack every single knife 45 times, they don't fail. I also flatten my detent ball so that the drag is spread across a flat polished surface, not just the very tip dragging into the blade. My knives are very very very very smoooooth. Okay I just measured one of my handles on a scale, I zeroed the scale for the weight of the handle (44g by the way) and it took around 650-700g of force before the entire handle touched the surface.

[@hampfi747]

JohnGrimsmo Awesome! Thanks a lot. Flattening the detent was mentioned by fellhoelter in a thread on the usn,i started a while ago of the factors of a smooth action, to smoothen out a knife but as i tired it i experienced the opposite. Maybe i give it another shot. It definatly gets snapier. What degree do you use on your tangs? Best regards from germany.

[@Southardknives]

JohnGrimsmo How thick is your lockbar cutout these days John?

[@alexskrydlak7168]

Setups man, there's always something. Air (like you did, inch away) and 360 brass at 1/4 speed, titanium at full.

[@andregross7420]

That "Squeaking on the way out" is the tap spinning in the ER collet holder. Watch the video closely and you can see it spin.

[@JohnGrimsmo]

I never thought about it like that, but I just watched it probably 10 times and the tap is not spinning in this video. You can see it at 6:16, the coolant drops on the tap don't rotate and the base thread on the tap doesn't rotate. I think the squeak makes it vibrate, so the threads look like it's spinning. Also, I think if it did spin there would be lots of problems with alignment, it would surely break right away. I think I can buy tap collets that actually have the square at the bottom. In the end, I think the squeak is just the sliiiiight imbalance between the RPM and the feedrate. A floating tap holder should cure this.

[@alexskrydlak7168]

JohnGrimsmo Does Tormach recommend coming to a full stop before reversing the spindle? If it has a C (spindle position) axis control, it wouldn't matter unless the encoder "jumps" a position or something. But if you don't, and you just throw it into reverse, there could be some imbalance between X and C position, making the tap drag on the back side of the thread.

[@andregross7420]

That's a good point, and for a tooling perspective it might be hard on the tap.

[@tom7]

As a machining noob-thanks for showing your mistakes!

[@rlockwood2]

Use a micro boring bar to break a chamfer on the back of the threads before part off :)

[@JohnGrimsmo]

My thoughts exactly, I think I asked you about this a little while ago. It would have to be under 0.100" and reach 0.250". Although as it is, there is basically no burr and I haven't needed to chamfer them on that side because they fit and work fine.

[@xxsicknasti48]

Could you do an in depth video on your measuring tools?

[@JohnGrimsmo]

I'll keep it in mind, thank you for the suggestion! I love measuring, so it should be a fun and easy video to do.

[@Warmachinellc15]

JohnGrimsmo Funny I've developed a bit of a metrology fascination myself as well. Up until about a year ago the only thing I had were the calipers my dad bought me from a hardware store for my 5th grade science fair project. Those got me by just fine but I have mostly Mitutoyo stuff now.

[@xxsicknasti48]

I'm trying to figure out what to buy. I ordered a dial caliper and a center punch this week. Also what are the best drill bits for titanium?

[@jarisipilainen3875]

you try run it it did same thing. now you never know was that expensive holder worth it. BANG

[@romeoneverdies]

just a small idea néodymnium magnet on the cutter head ?

[@donaldreeder6933]

Where did you get the hardened fixture plate you are using under your vacuum plate?

[@JohnGrimsmo]

Do you mean on the mill? It's a Mitee Bite Vac Magic sub plate, and it's anodized aluminum. If you're asking about something else I'm not sure if I follow.

[@donaldreeder6933]

JohnGrimsmo Thanks, Started looking on the internet and I found a hardened and ground sub plate, a TT1234 by TOSA. Nice but expensive.

[@willacademic]

what type and brand of tap was that?

[@dementedpaintballer]

Why profile first and then drill and tap, especially while thread forming? Keep the rigidity of the added mass there, drill, tap, and then profile.

[@helicrashproprocrasher2367]

Where do you get your taps?

[@JohnGrimsmo]

I usually buy them from my local tool store so they're either OSG or YG.

[@helicrashpro]

JohnGrimsmo Thanks, where do you get your inserts?

[@aserta]

You should recut the tool holder. You know the size, you have the tools, why not? It's just another piece of metal.

[@randallkelley3599]

Take the imperfect spacers, color them, and run paracord thru them, and give em away and or sell them….as knife lanyards...

[@petascherling854]

shouldnt just plunge with the cut off at the end of the programm to act as a stop. cut off to zero, pull out, zero return and position from the front. for those cut off blades, normally just the blade breaks on cut off and the holder stays intact. just my five cents. thanks for sharing ;)

[@JrFreak300]

You identified (3) CTQs... See, you're already doing SPC. :o)

[@JohnGrimsmo]

JrFreak300 I had to google those terms LOL, but I've got it now. Yes I'm learning!

[@JrFreak300]

Those dimensions might be also considered CTPs (critical to process). If those weren't held to tight tolerances, you would have difficulty assembling. I've been out of the Six Sigma field for a few years, so I'm wracking my brain trying to remember some of this stuff. SPC is pretty much why all of the new products you buy feel so flimsy and under built. Companies use SPC to try and minimize the amount of materials used to save money. SPC loses a lot of its benefits in job-shop settings such as your business, though it can have benefits in some areas.

[@jarisipilainen3875]

you can hit zero on that micrometer. push button behind. i guess:)

[@JrFreak300]

I'd bet you're actually better than you think (ie - .00020" on width). A certain percentage of the variation is due to the error in your measurement system. Both the appraiser and the micrometer add to the variation. If you get bored enough sometime (haha), conduct a gauge R&R study and see just how much of the variation is from the measurement system and not the actual parts. The study wouldn't be difficult at all to conduct and probably wouldn't take more than 15 minutes.

[@JohnGrimsmo]

JrFreak300 I definitely do notice that I can measure the same shoulder 10 x and come up with results varying a few tenths. So I do it enough times and rotate the part until I see a number that seems right, one that shows up most often. I'm assuming that a better caliper would help with this, but lack of experience on my part must also be a big factor.

[@hellohun7331]

You've got the tools at your shop to re cut your tool holder.

[@frollard]

That first failure was a butthole clench moment...sorry about your tool!