Todays Project - What did you do today?

[dallen]

(12-05-2014, 09:59 PM)f350ca Wrote: Good job on the gear. It seams to mesmerize the average person when you show them a gear you made.

Greg thanks, I've made a couple, nothing fancy. I usually have to do make the one I'm working on a couple times cause of getting lost in the turns and sweeps of the index head.

if this one works I plan on making a two or three out of bronze to have on hand. This damn lathe likes to eat them for some reason. wouldn't surprise me if the next thing I have to make for the old gal will be the worm that drives this gear.

DA

[Sunset Machine]

I keep a couple of gears on my desk at work for show-n-tell. My in-tray is actually full of junk (broken stuff), it has surprised me how many people dig through it to play with those gears. Conversation pieces. Helical, left and right hand, one is cross ground for a pretty pattern. They sparkle, people like shiny things. They have been good advertising.

Your worm wheel, it doesn't look worm-ish to me. Normally they envelope the worm somewhat. More of an acme than involute, but it's hard to say. Many mysteries are involved. The bottom line is that you need specific instructions (and tooling) at to how they were originally made, or make both the worm and wheel as a pair yourself. Make two worms, one to become the cutter. Those worms will likely require a custom lead, which means making custom change gears for your lathe unless you have one of those electronic CNC hoohaws.

[dallen]

(12-06-2014, 09:21 AM)Sunset Machine Wrote: Your worm wheel, it doesn't look worm-ish to me.

The worm is still in he lathe hiding behind the apron which I don't plan on pulling out until I get ready to see if this gear will fit. and yes the worm is an Acme Thread.

And no it doesn't drive the leadscrew, it drives the carriage feed.

Biggest thing is that if this doesn't work all I've lost is some time, but if it does I've save myself a hundred bucks cause that's about what it would cost me to get one shipped in from Grizzly with their crazy shipping schedule where they now charge you on the shipping based off what the amount of purchase is or some such crap. Anyway 70 bucks for a gear that was made in China they can stick that one where the sun doesn't shine.


DA

[Sunset Machine]

I was addressing the rapid wear. A straight sided screw running against a curved gear face means a tiny contact point.

Btw, that same shipping scam is also used by other companies too - a wiring harness cost $1500 to ship, the harness itself like $3500 and 10-15 lbs. They inflate the price and charge more to ship?! Really, just a wad of wire in a cardboard box. And not even a kiss..

[dallen]

The thing that ticks me about the shipping is that they would probably ship it in a padded envelop from Springfield Mo which is about a 5 hour drive from my front door, with the actual weight of the part and the padded envelope being well under 8 OZ.

Whats really funny is a buddy of mine has and Enco 14X40 which probably has the same gear setup in it that mine does and he's never had a problem. I even added a line to put lube directly onto the gears, of course I also had to make from scratch the bracket that holds the worm in place behind the apron. I found that it was loose and floating around and when I took it off a couple years ago found that it had cracks in it, Grizzly was out of stock so I made one out of a hunk of 4140 that was laying around here.

Guess I could take some measurement when I tear the thing apart and use the rest of the hunk of 4140 Annealed round bar to make a Hob by cutting the Acme Thread on it then putting in a bunch of relief cuts for chip clearance and harden it.

Now if I can just remember where the Shop Monster put that 4 MM broach at when I told him to stop chewing on it that it wasn't a Rib Bone I'll be doing ok.

DA

[PixMan]

Yesterday was a gathering of my wife's side of the family, so no shop time. I got oover there today for about 4 hours of work and a half-hour of cleanup.

First order of business was to add a detail I'd forgotten on the last part I'd made for dallen (David.) It was a flat measuring .094" x .125", only .0079" deep in the Ø1/2" round. It's for an index mark of the sight assembly, so I also added that using the tip of a 1/32" (0.0312") ball mill I have.



Now on to the tougher part, the "sight leaf". It's challenging to make (as discussed earlier), but I got a good start on it. I found a piece of tool steel about 5 feet long and 13/16" x .525", which I believe is A2 air-hardening steel, a very stable material. It won't be heat treated, I just needed something that wouldn't warp like a banana when I mill and grind down to .151" thick x .562" wide and over 4" long. All the 1018CRS I have would definitely get a bow in it.

Just two photos. One of the part roughed out, the other with the "easy" machining of the long, thin section.




It'll be next weekend before I can finish it, but I have a plan. First, mill the fat end to the overall length required. Locate and drill for the 1/4'-40UNS thread through, and tap it. (I'll need David to send me his tap or I'll buy one.) Use a 5/16" (.3125") corner rounding cutter to form the bottom semi-circular cylindrical shape. Now move to the surface grinder.

Take one of the 1" wide Ø8" wheels I have, a Norton 32A60-LVBS and finally use the radius/profile dresser I bought a couple of years ago. With that I can create a form on the wheel with 60º of a .155 radius to a flat face. That will allow me to take off the .0035" per side that it's oversize as I creep into the corner and make the full 300º radius. Sounds easier than it will be, but I have the tooling. All I need to gather up is the patience!

[dallen]

pm me your address and I'll send the tap, and you can drop it in the box along with the parts

David

[PixMan]

Will do David!

I'm actually enjoying this challenge, very much. BTW, I need to get a set of good reamers. I didn't have a Ø.125" reamer for those two holes, so I used high quality 1/8" drill. Checking with the shank of a carbide end mill which measured (with my Mitutoyo 293-344 digital electronic micrometer) right at 0.12495, and it was a very snug fit. Perfect size!

I used a 6mm carbide end mill to rough out the slot, leaving about .001" per wall for the finishing end mill. For that I used a 3/32" (.09375") two-flute solid carbide end mill, and crept up of the final .251" width. It may be just a touch snug on that dimension, though a 0.2500" spotting drill shank slid up & down smoothly. I used a smooth face "safety edge" file to get the corners sharper, though may want to touch them up again before I ship the parts out.

[Mayhem]

Ken that sight looks fantastic and I'm glad you will finally get to use the radius/profile dresser. Are you going to be doing the graduations on your mill?

If you recall, the ToolMex reamers are reasonably priced and appear to be well made. The 6.5mm one I purchased was $14.48.

[PixMan]

Darren,

David and I will discuss the graduations on the "sight leaf" part. I can get the lines done, but my mill is too hard to program every little move for every number. I was talking with Russ, and he has a legal copy of BobCad that he's going to let me try. It's the only CAD/CAM software package available which has written a post processor and made a custom cable for the Prototrak Plus control on my machine. I think it would take too long for me to get the cable, relearn the software (I last used it about 10 years ago) and work out any bugs before the parts would be ready to ship off to David.

As for the reamers, I was thinking of contacting FHC about the reamers but I'm looking around. Holiday time and gifts for others are the priority right now, but to make matters worse my daughter's car is dead (she killed the motor) and I have to buy out my company car coming off lease (new one due in any day now) and give her my wife's 2009 Malibu. Money's getting tight, though I got lucky and sold off that De-Vi-Bar for $500 and made a little over $300 on the deal.