Todays Project - What did you do today?

[wrustle]

(12-29-2013, 08:20 PM)PixMan Wrote: I went to the shop and remade the blank for the 70T Mod 1.75 change gear I need for my lathe. I made one out of "scrapbinium" and it cut a lot like 1018CRS. The guy who's going to cut the teeth for me said it would not hob to a decent finish, so I went to a local steel supplier (Peterson Steel, Worcester MA) and got a Ø6" x 7/8" thick round of annealed 4150. I figured I might as well make a new one because I went .0012" oversize on the 20mm bore on the crappy material one.

Here's the stock as I faced off the sawn side. It was out of being parallel by almost .040" (1mm).


Here's the finished front side, it came out quite nice and the bore in now right at 20mm.


Now I've turned it around to finish the back side. Too thin to simply snug it up against the chuck jaw faces and the bore too small to get in there with an indicator. So what I did was use an indicator on the cross slide and "zero out" the DRO in Z axis. By retracting the cross slide just enough to velar the 6" diameter, I could move the carriage out to index between the jaws and then return the carriage to zero and run the cross slide back in. If anyone has a better way of doing it I'd like to hear it. The blank came out parallel within a "couple of tenths".


Finish turning done, now I need to figure out a good way to get the 6mm keyway in it before shipping to the gear hobber.

Ken,

On thin parts like that where you can't locate the piece off the jaw face, just grab three drills the same size that are small enough in diameter to get the holding stock faced off while still being able to hold the OD with the jaws. Lay the drill shank across your jaw face, place the piece against it, and then do the same with the next jaw, and then the one after that. Clamp your part lightly and check that your drills are being held. If not, tap the part to seat it but do it lightly. Once all are seated, remove the drills by pulling them out from between the jaws and the part and clamp your part solidly.

I've done that many times over the years, and it works great! Just remember to pull the drills out before you turn the machine on!! The face will come out as good as the face of your jaws are square to your spindle center line.

Oh, and while I'm thinking of it, be sure to actually measure the shanks of your three drills. There can often times be a .001 difference in diameter. New drills work the best as they do not have battle scars on them from drill chucks, and jobbers drills are eaisier to use because they have a longer shank and are easier to remove because of the length as well.

Part looks good by the way.

You know where to get them broached. You just need a broach, a shim, and a 20mm bushing, I've got the press.

Happy New Year!
Russ

[PixMan]

Thanks Russ. Good idea.

Though I don't think I have more than two of any particular size drill, I do know I've got a dozen or so packages of 5 to 10 is sizes too small for this particular task. Because of the out-of-parallel condition of the stock, I could barely face it off and get the O.D. turned to a 1/2" length. I was holding onto perhaps a 1/4" or so for the first side, and had a lot of material to remove as the finished thickness is 11mm (.433") and the diameter needed to come down from 6" to just under 5".

When I turned it around the finish the second side, I had to gingerly turn that 1/4 off the face and there was holding onto a little bit more but had to reach inside the projecting top step of the inverted jaws. A bit scary.

I can just imagine that doing mostly one-off parts (like this one) I'd always need a different size drill, so I think I'll get some stock and grind some square/rectangular spacers.

[Mayhem]

Well I got a few parts of the mill back together today.

   
   

[TomG]

Looks like you are making progress Darren. Did you ever get the part issues worked out with Kondia?

Tom

[PixMan]

Nice to see it going back together Darren! What condition were the ways? Will it have central lubrication?

[Mayhem]

Thanks guys!

I received a very apologetic email from Kondia, with an updated list of parts that I had asked to be quoted on when I first stripped the head. Unfortunately, none of the parts I need for the remainder of the mill were included

To make matters worse, three items that were available when I first received the quote are now listed as out of stock. One of which is the feed trip bracket, which I need as the bottom part of the casting has broken off of mine. I've asked that they look again but I will have to measure what I have of mine and see if it is the same size as a Brigeport one.

Kondia are closed but the person I have been dealing with came in on their own time to finish off the list. She is going to go back in on Friday, so I hope to have a response then.

The ways look pretty good so I'm hoping that once I get it back together and adjust the gibs, I should be good to go. It does have a one-shot oiler on it but the pump is missing parts (of course), so I will order a replacement.

[PixMan]

Darren,

Is there any way you could "reverse engineer" any of the parts and let me make them? I'm always looking for an excuse to go make chips for other people.

[Expat]

I have been replicating some motorcycle parts with the help of Pixman. We have been making some front and rear axles and swing arm spindles for a couple of projects I am working on. One set is original replicas for an 84 Yamaha RZ350 and the other are for a custom build to fit some Aprilia RS250 wheels and swing arm to an 86 RZ frame.
I made the parts from 316 grade stainless. I work in the oil and gas industry so have pretty good access to some off cuts of material. The high chrome and nickel content make it quite challenging to work with but Kens equipment and expertise dealt with it with ease!
Some of the challenging operations included through drilling and boring over 12"+ lengths and fine pitch metric threading. Again, Kens knowledge made these tasks a breeze!
I have attached a few pics (as you can tell, photography is not my strong point!) and will repost once I have the parts fitted to the bikes!
Cheers Ken for all your help!

[EdK]

Those pictures are good enough to show the excellent workmanship!

Welcome to the forum Expat.

Ed

[Expat]

Thanks, I am having a blast working on these parts with Ken. It's been a long time since I got to play on decent machinery! I used to work on a Scharmann horizontal borer waaay back when machines were operated by humans, not computers!!