Machining a T-nut ... a photo essay

[precisionworks]

In honor of our resident photog (W Quilles) here's a start to finish project

Both X & Y gibs were just a little loose, so I ground & hardened a screw turn from W-1 drill rod:

With both gibs tightened, it was time to deburr the table surface. To do this, coat the table with any thin lubricant (WD-40 does well, but so would an ISO VG5 or VG10 mineral oil, like Mobil Velocite). Let a hard Arkansas stone float over the surface of the table so it just knocks down any burrs left from previous jobs.

Test for smoothness with a bare hand ... a bloody finger indicates that a burr was missed

Turn the mill vise upright (or upside down) and wipe the bottom surface with an oily towel ... any grit on the vise will mar the table:

Indicate the fixed jaw of the vise by traversing an indicator back & forth until there's no more than .0010" TIR from end to end:

Snug down both nuts, recheck, and the mill is ready to work.

Here's the unmachined T-nut, sitting on parallels:

I like to really crank down on the handle, as seen from the strained expression

A Post It Note is measured at .0035" thickness, to allow setting down feed zero:

The feed knob is set .0035" short of zero:

T-nut thickness is measured:

Quill is moved down .055", locked, and the part is fed into the end mill:

Part is measured after first cut to verify thickness:

Quill is moved down another .016", final thickness cut is made, and part is measured again. Will (DarkZero) wanted .500" +/-, and part finished out at .501" ... close enough for space shuttle parts

Milled surface, as machined:

Will sent a dimensioned photo showing actual dimensions, and asked me to leave a thou or two for filing to fit:

Part was flipped over (so that hole chamfers were facing up) & the face mill was brought in & down to make a starting cut. This was measured to indicate how much lower & farther in the quill & table needed to be moved. Downfeed was easy, as down is down, even as the part is rotated 180 degrees. Infeed movement is one half of total, which is important to remember

All done, leaving about .0015" of filing for final fit:

 

[G1K]

I really like threads like this, seeing how everyone approaches a project. Thanks for the write up

R

 

[darkzero]

Awesome, can't wait to get the T-nut fitted & Dorian mounted! Couldn't have asked for more (I'm glad you took notice of the side with the chamfered dowel pin holes) or have picked a better man for the job. Thank you very much for the work Barry! :thumbsup:

Perfect pictorial too, I love these threads. As discussed, FYI it loads just fine on my cell phone which is not even on a 3g connection. I'm glad as I didn't have to get home to view this.

 

[precisionworks]

Thanks for the nice comments

The pre machining photos show steps that are common in most job shops or production shops, but that many home shop machinists may not be aware of. My old boss would whack me on the head (much like Gibbs does to DiNozzo in NCIS) if the mill vise bottom wasn't wiped clean before every remount. After just a couple of whacks, wiping the vise base becomes second nature :thinking:

Same with indicating the fixed jaw. Interapid indicators are so convenient because of the adjustable stem, plus they're tough as nails. Mount them in an Indicol, or a collet, or a drill chuck ... one way is as good as another, and all are about equally fast.

it loads just fine on my cell phone which is not even on a 3g connection

Good point, Will. IrfanView has a plug in called "save for the web" - first resize the photo to what ever size you like (I use 800x600), then click "file", then click "save for web ... plug in". It takes any photo, even 12MB, and compresses it to around 50k, depending on your setting. Look at the photos in this thread and none are larger than 50k, with quite a few at 25k and some at 10k. I do that for all the viewers like myself who have a "slow" connection (mine is DSL with 3MB/second download). Unless a person has fiber optic broad band, which is not yet widely available, a thread like this using less compression can take over 30 seconds to load.

 

[wquiles]

Awesome work Barry - thanks for taking the time to create the photo essay :twothumbs

Plus I learned a couple of tips as well, so I hope this will not be your last project photo essay/blog

 

[precisionworks]

I hope this will not be your last project photo essay/blog

Most jobs are billed on a per minute basis, currently at $1.00/minute + materials. Clean up is billed out at the same rate. I don't normally shoot images as there isn't any way to subtract out the time to shoot the photos, down load the images, run each through a quick PhotoShop session, resize & compress in IView, and upload to PhotoBucket. On those images, probably an hour in total.

Maybe when I retire

 

[wquiles]

Most jobs are billed on a per minute basis, currently at $1.00/minute + materials. Clean up is billed out at the same rate. I don't normally shoot images as there isn't any way to subtract out the time to shoot the photos, down load the images, run each through a quick PhotoShop session, resize & compress in IView, and upload to PhotoBucket. On those images, probably an hour in total.

Maybe when I retire

I guess my customers are grateful (or should be grateful) I don't charge for "actual time" spent on projects. If I were truly running a small business I would have to charge 3-5 times more than what I charge today, and that would be "before" charging for the time for photos, resizing, FTPing, posting, etc.. But I see what you mean. Hard to spent time on something you are not going to be paid for - perfectly understandable

Will

 

[alexmin]

Thank you Barry and Will for your photos.
I find it a million times better to see a picture vs. reading description no matter how good it is.

Keep it up! :goodjob:

 

[precisionworks]

Hard to spend time on something you are not going to be paid for

+1

The reality of a small shop is that every minute is precious. Customers today are price sensitive more than ever before. I handed a customer an invoice for $3450 last week & he didn't bat an eye ... that means my pricing is either too low or about right :nana:

I rarely charge for every minute spent on a job. If the job took an hour longer because I screwed something up, I eat that hour - it wasn't the fault of the customer. People appreciate fairness & honesty above all else, and they want to be sure that the job is done well the first time.

If you haven't tried to run a for profit shop, you'll certainly find it interesting

 

[fyrstormer]

There's something endlessly impressive about having the tools and skill to make something you need out of a chunk of raw metal. Cool story, would read again.

 

[darkzero]

Thanks again Barry, my appreciation. I know it's not as useful as a flashlight but I'm sure you have enough of those so here's something fun to play with.

 

[precisionworks]

WOW, that is awesome :thumbsup:

Fantastic attention to detail. I can't imagine how much time you have in the build.

 

[wquiles]

WOW, that is awesome :thumbsup:

Fantastic attention to detail. I can't imagine how much time you have in the build.

+1

Very, very impressive :twothumbs

 

[darkzero]

WOW, that is awesome :thumbsup:

Fantastic attention to detail. I can't imagine how much time you have in the build.

It was my first time making a body from scratch, I only had to use the BFH once.

 

[65535]

Just now seeing this picture I found myself thinking to myself, looks like Barry's trying to knock over his mill.

Always get a kick out machining tools, huge expensive precision equipment, and totally normal to torque as hard as you can and hit stuff with hammers when you want them to move. Truly wish I could find a machine shop apprenticeship.

 

[precisionworks]

looks like Barry's trying to knock over his mill.

It depends on the shape & size of the part being clamped, but I tend to tighten as much as possible plus a little more. The photo shows an upward push on the handle, which is good for moderate tightness. To go even tighter, position the handle around 1:00 or 2:00 & pull down with full body weight.

 

[KC2IXE]

RE T-Nut(s)

I miss him

 

[Illum]

:kewlpics:

I'm imagine it would be pretty difficult taking pictures in the workshop without getting drilling fluid and grease all over the camera case

 

[darkzero]

Just now seeing this picture I found myself thinking to myself.....

And only now did I notice Barry sporting a Ti PD light & a Ti McClickie Pak, pretty cool. I wonder if there's a Chris Reeve, Hinderer, or Strider in them pockets too?

From Barry's sig I'm assuming a PD-S & Sundrop, a perfect combo of lights to carry IMO. I too carry a Ti "PD-K" which by far is my absolute favorite EDC.

 

[bstrickler]

Most jobs are billed on a per minute basis, currently at $1.00/minute + materials. Clean up is billed out at the same rate. I don't normally shoot images as there isn't any way to subtract out the time to shoot the photos, down load the images, run each through a quick PhotoShop session, resize & compress in IView, and upload to PhotoBucket. On those images, probably an hour in total.

Maybe when I retire

You could actually set Photoshop up to automatically adjust the levels, and resize/compress the pictures, so you can save a lot of time. Takes a max of 5 minutes to set it up the first time, and after that, it's maybe 60 seconds to tell it to do a whole batch of files. I've been having to resize 10+ gigs of pictures at a time, and that would take forever to do manually. I just tell PS which action I want it to do, click "OK", and go do other stuff while my computer is chugging away.

If you want, I could make a quick picture tutorial on how to do all that. If you're using CS3, I might even be able to make the action for you, so you can just download it, put it where it needs to go, and then restart Photoshop.


Nice job, by the way. I'd love to have a good mill (although a good lathe is more useful for me right now. Stuck with a Garbage Freight one until I get more $)

~Brian