Indicator Holders...first Project With Milling Attachment

[TTD]

Now that I finally have some limited milling capabilities thanks to my new milling attachment for the 7x12, the first little project I wanted to do was to make some indicator holders…one for the vertical axis of the attachment itself as well as one for the lathe cross-slide. FYI, don’t look too close as I did make a few little boo-boo’s…

After seeing Mark_F’s gem of a holder for his cross-slide http://www.hobby-machinist.com/threads/cross-slide-indicator-holder.37113/ , I shamelessly borrowed his basic design, with a couple alterations made for my application. Raw materials were all 6061 aluminum - ¾” x ½” x 11” long flat bar, 1” round bar and a little scrap piece of ½” thick plate from the junk bin.


First, I milled a full depth .250” slot x 3.750” long c-t-c in one end of flat bar and then a .375” wide x .250” deep slot on top of that for indicator mount to slide in. On the other end I milled a pocket .375”wide x .500”deep x 4.750” long to fit on lathe saddle. Marked & drilled two .191” thru-holes on top w/.312” x .100” deep counterbore for low profile 10-32 SHCS’s to attach bar to saddle.

Next I made the mount between indicator and flat bar. After squaring up the scrap piece, I mounted it in the 4-jaw and turned it down to .500” for 1”, then went back and turned it down to .250” for .750”. Finally threaded the end ¼” - 20 by .500”.

Lastly, I made the knob out of 1” diameter round bar x .750” long. Turned one end down to .650” x .250” long and drilled/tapped it ¼ - 20 x .600” deep. I don’t have a knurling tool yet, so to grip the knob I just cut 8 slots .050” deep with a 3/16” ball end mill (only ball-nosed end mill I currently have). Not very fancy, but it works.

Finished pieces (other than sanding out machine marks):


Next up was the holder for milling attachment. Pretty much the same idea again with a couple obvious differences. The goofy looking piece at top of pic mounts to the plate with vice (moveable) while the rest mount on the angle plate attached to cross-slide (fixed). Threaded piece made from ½” 1144 round bar.


Here they both are mounted and ready for action:



Hope you enjoy..and any criticism/suggestions are certainly welcome!

 

[f350ca]

Very nice work Todd.

Greg

 

[jeff_g1137]

Hi
Yes very nice work, looks good, i would be happy with the holders.

 

[Mark_f]

Excellent job well done!

 

[Ulma Doctor]

A job well done indeed!

 

[TTD]

Thanks guys!...I appreciate the comments more than you know!

Like I said earlier - I made a few minor mistakes in the process and no doubt probably did some operations bass-ackwards (I'll attribute that to a general lack of experience/knowledge..), but to get the "nod of approval" from the likes of you guys with your seemingly endless supply of knowledge and abilities means the world to me and gives me confidence that I'm at least on the right track.

 

[jeff_g1137]

Hi
The more you do, the more you know.
As for mistakes i have made 1 or 2 LOL but you get there in the end, & you do it right the next time.

Jeff

 

[brino]

Very nicely done!

You should be very proud of those.....and the feeling that comes from adding greater ability/accuracy to your equipment.

I think I have a couple of those exact indicators

-brino

 

[rex21]

Very nice work.

How, may I ask, did you index the knob to cut the slots?

 

[TTD]

Very nice work.

How, may I ask, did you index the knob to cut the slots?

Oh, crap...that was the ONE question I was hoping nobody would ask me about! Some of you more experienced fellows may read this and shake your head wondering what the heck I was thinking, but hey, welcome to my world!

I have no spin index, rotary table, dividing head or anything of the sort yet, so I had to scratch my head for a bit wondering how I was going to get the 8 slots evenly spaced. Looked around at what I had to work with (which isn't much...machines or material),spied a piece of 1/2" square aluminum bar and had a "light bulb moment". Granted, it was a dim light, but a light nonetheless!

Cut a couple inches off, chucked it in the 4-jaw, turned one end down and threaded it 1/4"-20 for the knob to screw onto tight to 1/2"sq. My thinking(?) was that I could then mill the first 4 slots (90* apart) by just flipping the square bar in milling vice, then remove knob and add whatever thickness of shims were required so that when knob was once again fastened tightly I could mill the final 4 slots...hopefully 45* from the first ones. I have quite a few shims (basically, really thin washers) anywhere from .005" - .030" for adjusting the output pressure on some 3000 psi regulators I have, just had to find the right one(s) to "index" it. IIRC, .026" was needed.

Accurate? Not too likely at all, but not bad either for what it is and who it's for.

I didn't take any pics of the original process, just mocked it up tonight to show you what I'm babbling about:



It's a crappy pic and really doesn't show anything, but here it is with shim in place:


I can be fairly clueless at times, so if anyone knows of a better, more accurate way other than this McGyver-ized setup, I'm all ears!