Machining the DIY Repeat-O-Meter Top! WW154

[@jimmykelley9209]

Hey man I went to college for 2 years for machine tool technology. all they teach you is how not to get hurt. I've been doing machine work for about 15 years and your great. I watch every video you put out. along with adam, keith, and stab. yall keep up the good work. god bless

[@ajtrvll]

Love your video editing with screen captures and explanations as the machining is happening... keep it up!

[@ROBRENZ]

Looking forward to seeing this thing assembled! ATB, Robin

[@skiffworkshop]

John, I really enjoy the new overlays in your videos. I would think this is due to your new media person since this looks like it takes more effort and I know you are putting your effort in better places lately. Thank you.

[@matthewlennox2488]

John to get rid of that little piece left by adaptive you don't need to change stepover, you need to go to that tool in the tool library and just increase its corner radius slightly.

[@edrees3874]

"I kissed the nuts..." Tobias Funke, is that you? Loved that workholding for the second set-up, and the ghosted CAD overlay at 6:10!

[@bcbloc02]

Did the thin middle section remain at the end of the 1st op because the tool is undersized or is that just something about the cam path? I would have just milled all that off with a shell mill in one pass. :-)

[@3DTechDrawCulemborg]

I'm pretty sure that happens here because he told the cam system the tool was straight with a sharp corner, but when he zooms in for the spot drilling you see that the tool actually left radii. So the tool most probably has a small radius instead of a sharp corner. The CAM system doesn't know and thus can't know that it leaves some material still.(The small strip of material deflects so if you don't cut a flat bottom usually it stays on)

[@crabxcorelol69]

I think I remember seeing/hearing chatter in a previous video when the bed(?) was moving in the +x, + y direction. That seems to be where you get the random chatter in this video also.

[@SolidRockMachineShopInc]

Hi John, Nice video. If you added a nut on the bottom of the stud you could have fastened the stud to your table making the setup more ridged. Steve

[@3DTechDrawCulemborg]

John, the reason for that silver(The center strip you are talking about) is quite simple. You defined the tool as a straight mill but the tool has a radius. The adaptive doesn't know so can't compensate for it. If you define the tool as it is you will not see the silver.

[@lmccleary411]

Im not a tormach user but i assume they have ball lead nuts , not half nuts , so there should be little to no back lash even though we don't live in a perfect world, so there must be some... I would do a test,....machining the same material and using the same tool and machine a cylinder in the same axis to the spindle(vertically) on the mill , from square stock and do a moderately heavy contour clean up.... I'd say if you have chatter at 12 o'clock, 3 o'clock ,6 o'clock ,9 o'clock when your lead screws are changing direction to machine a cylinder, it may be back lash in the lead screws/lead nuts.... if you you have chatter at 1-2 o'clock, 4-5 o'clock ,7-8 o'clock, 10-11 o'clock, it could be loose gibs that makes the tool bind up on the work piece when climb milling, and chatters as 2 axises are moving at the same time to machine the cylinder. OR it can also be G code lock up....if you have low tolerances in the cam you may have lots of g code lines that your machine has to execute at the speed of you feed rate...ie..your machine may travel to the g code coordinates faster then your computer can read and execute the next line so your machine will stop and sit there for a split second and wait for the next coordinate from your computer... this will get exponentially worse when moving in more then one axis at a time like it would be in those non vertical and horizontal corners of the cylinder. that's why some Smoothing in the cam side is better to have ,than non at all because it decreases your amount of g code lines you have for your part. If it is g code lock you should only have chatter in adaptive strategies and not contours because it has high amount of g code lines .... in a contour clean up I think there should only be 4 lines to travel around a circle because your g code that your machine would use, would be a caned (arc ) routine and your computer can handle 4 lines to travel in a circle at those feed rates.

[@GeofDumas]

Tightening the gibs made all the difference for me on the 770

[@LarryRPark]

Instead of making the lower spreader bar as a separate piece and screwing it in - why not make it part of the spacer bar between the top and bottom piece? The gap between the top and bottom spreader bar will be larger, but makes simpler and more rigid construction without the extra screw operations.

[@MakeItWithCalvin]

I know it is a "doh" question but why use cold roll vs hot roll? I know hot roll has that nasty scale but fears of stuff moving is less. If I had to use cold roll I would have roughed it to within ~0.03" then put it into an oven to anneal [or just left it to sit] to let it stress relieve THEN gone and finish machined. Overall an interesting project!

[@jimsvideos7201]

I'd be happy with video produced at this level from at least a company like Haas; I have enough of an idea of what it takes and I'm impressed.

[@jimmykelley9209]

alot of times we sent our cold roll out to stress relieve at the heat treaters. not that expensive and save alot of problems.

[@stuarthardy4626]

John The strange thing is I get that same chatter/squealing one the same position as you did , the only really common is Fusion360, my mill is small but it’s all cast iron and quite heavy for its size, Seeing the same problem leads me to think there may be a error in the way the code is implemented on the change of direction Yes cold rolled, or as I call it banana steel will move , now for the small hobby work I do I just get it red hot and let it slow cool when I get the stock in Good video again

[@stuarthardy4626]

SeptrothFFXI Hmmm that is interesting because as we know HSM and fusion share the same code generator That’s three different mills that get the chatter but only one source of the code IMHO there is something amiss As I said my mill is small Johns Tormach is not that big Will have to get the brain cell out of retirement after 70 plus turns round the big ball it’s a bit dim now

[@robr3015]

Looks like your CAM toolpath is broken on the chamfer at 7:34

[@hdfanboy]

If I had to guess the reason the chamfer your referring to is in two arcs instead of a circle is because there is going to be a saw cut right in the middle of that circle which will be a pinch point to lock onto the micrometer being used so there is no need for the chamfer to go right around since there will be about a 2mm gap right in the middle.

[@robr3015]

Oh, now it makes sense, thanks. Would it mess up the cut?

[@davidl9410]

Are they carbide sport drills or hhs?

[@lmccleary411]

Hay John is your spot drill that you are pushing in to the material at 20ipm carbide or HSS?

[@Eggsr2bcrushed]

looks like hss

[@lmccleary411]

Eggsr2bcrushed.. Unless it's just me , but I think that spot drilling at that speed is insanely fast for HSS , I guess buying premium tools pays off. I feel like if I did that with my spot drills they would just burn up.... your spot drill speeds and feeds in steel are my speeds and feeds in aluminium.... crazy cool.I guess I know what I'm trying next.

[@bcbloc02]

I just did some 3/4" hole drilling in steel at .010"/rev and it took it fine with a regular HSS bit.

[@thomasutley]

bcbloc02 I don't think your little radial drill cares about feeds and speeds, Brian. If the bit doesn't snap, a hole will be made where metal used to be. 😎

[@DoRC]

8:44 man the side walls of that pocket are thiiiiin

[@boelwerkr]

What i don't understand is why is the shelf so small. You remove nearly 50% of the material to create a small shelf so you can skew on the second path. Why isn't the second path as long as the hole first part? The raw stock can be thinner and you don't have to remove as much material making the operation much faster and with less material wasted. This also means that the connection is more ridged. For me it looks like the skew connection is not ridged enough to lift up the top half. I think It will move in the connection and so the added part below not the massive element above.

[@cschwad559]

How do you get by with so much climb-milling? Could that be causing the chatter?

[@brandonfedorick8106]

Conventional milling is pretty rare on CNC machines. It is useful in some situations though. There's a good article on CNCCookbook about it.

[@warsuper4681]

no guarantee but when you go around an external radius the surface speed changes if you don't have CCS turned on and that can cause chatter.

[@seindich1769]

5:40 you get chatter because holding the part with a long thin bolt is obviously bad idea

[@juanrr347]

Thank you

[@gunkguzzler]

9:27 Hey Jarod

[@caseyboutillier7510]

Good lord John get some sleep. This video is going up at 9:30 on the west coast!?

[@ikbendusan]

it was *published* at that time

[@andrewsampsel9295]

Does anyone know the full specs of this machine? This just seems very very slow... I have an 8000 rpm spindle and wish I had more for the 1/4" end mills especially on the profile milling

[@cochbob]

Andrew Sampsel www.tormach.com/product_pcnc_main.html#techspecs

[@DoRC]

4:36 kiss the nuts!!

[@andrewgiles6192]

Do R/C! I laughed at that too

[@christofferliljeberg5908]

Please! I've been watching your videos for some time now and I love them. I'm setting all my political ideas on the shelf, because I love machining. But you've got to use bigger end mills and go faster. Using small tools because they are cheaper, that only takes longer time with increased tool wear. I don't know if you're talking about this in the video because I've got to lower the volume, my wife would think it's stranger to watch machining videos than porn... so there you go. But please use bigger end mills and increase surface speed and feed!

[@occamssawzall3486]

Christoffer Liljeberg It's a Tormach. It's limited to 100 IPM and about 1HP at the spindle. That's about all it's got.

[@jongmassey]

"I kissed the nuts" yeah you did... ;)

[@Dakakeisalie]

Sees new video. Likes new video. then watches video.

[@sirknosrebam455]

how do you pay the bills with such little experience, supplemented by youtube vids?

[@tunafish3216]

Not enough experience here

[@shiro-r4m]

I've never heard John claiming he's a master

[@TjallingBlackCat]

Definitely not. He always says he's right there learning alongside all of his viewers, which I think is the best attitude to have.

[@ninetwenty]

Excuses Excuses Thought of hiring a machinist?