My buddy's 13x40 Clausing-Colchester wore itself out, needed a gear in the front carriage power feed ditty. Yeah, Clausing wants $800 for one gear, about 3.5" diam, 54 tooth. Goodgawd....
Dare I say it--but another gigantic PV??
Fortunately, my buddy makes gears, so this wasn't the biggest deal in the world--he could make 40 for $800!
How he did it is pretty neat. Not having any cast iron to match the gear material, he bought an oversized gear from a local power place, turned off the teeth, redid the ID, and cut the teeth.
Ackshooly not hard iffin yer familiar w/ gear cutting indexers, at least for non-exotic stuff. Pretty tricky, otherwise. Can also do them in a 4th axis in a VMC, much more straightforward.
But for people not set up to cut gears, that is one whopping bill--never mind the labor involved in the tear-down/rebuild, etc.
All this sorta makes me nervous about running my machines....
---------------------------- Mr. P.V.'d formerly Droll Troll
A ratio of 80/63 is SO close to 1.27 it is within .015 percent. If you want to do the ratio with other gears, you nead a 20, 21 and 4 to 3 tooth combination of gears for compound gearing. You might be able to find a 21 tooth gear cheaper than a 127 tooth gear. The others needed for the 80/63 ratio should be common, or will factor out once you look at your quick change gear ratios. IOW if you already have a 21 tooth gear, you might easily be able to make up a gear train that will do the metric threads you want.
I didn't spoon feed the exact combination of gears to use, since I don't know which threads you are shooting for, or how you lathe is set up, or what gears you own. But I did toss out an idea about how to do metric threading without needing a 127 tooth gear.
Another combination that is not as close, uses a 47/37 ratio. That combination comes out within .027% but does not factor out to smaller gears than a 47 tooth. Pete
Do you have a mill? Index head or rotary table? If so, what's preventing you from making the gears you need for the Tray-Top?? Using a similar gear as a template, hand grind a HSS toolbit with the proper tooth form and have at it. The gears can be generated a tooth at a time, with a fly cutter. It's slow, but a very rewarding experience. You could make the gear(s) from free machining brass if necessary, then invest in the $20 metric plate for the box.
You likely understand that your tool would represent a tooth, and it would form the mating sides of the teeth in the gear you'd generate. The tool would, therefore, look like a gear tooth as viewed from the side. A little tough to hand grind, but very possible to do. Been there, done that. Didn't get the T shirt, though.
For $800, Id sell him another identical lathe. With a good gear.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
I dont think they have such in stock, but manufacture them as they are ordered. Doing them one at a time reallllllly adds to the cost.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
That's right. I've got a 5310 Clausing lathe that was made in 1956. I was pleasantly surprised to see how many parts of it were still in stock with the Clausing people. Yes, they're expensive. Big time. I also have made attempts to try and find new old stock parts for a Panhead Harley that was made in '56 too. Nearly nothing out there and what is available is marked up at a much higher ratio than the Clausing parts. I'm just glad the Clausing people are making an attempt to stay in business and help people keep these fine old lathes running. I would imagine if they didn't charge so much for them, they'd fold. Just my .02.
"Rewarding experience" is not the phrase I'd use--"sorta inneresting big pita" might be more apt.
But goddamm, $6600 takes the cake!! wow....
If Vince wants to sleuth this out himself, I'm sure the good people here would be a big help. If he'd rather my buddy make him a gear (or anyone else) on the cheap, email me and I'll set it up. You'll need to provide accurate dimensions/tolerances, or a print, or a sample--or, in some cases, a piece of a sample. .
Rather than grinding a tool bit, you're better off buying a gear cutter, with the right profile. But you'll need the gear indexer ditty on your BP, which is not cheap, either. Ahm no 'spert, but Boston Gear is the MSC of this sort of stuff.
Sounds like the makings of a half-decent bidniss, making ones-ies/two-sies of busted gears for older machines.
Start off with brass replacementss for all those zinc/Zemac gears from
109 and Atlas lathes that have been rotting away.
GUnner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
I'm starting to think along these lines. Haven't been able to find brush holders for a huge old B&D 1/2" drill, so I drew it up in CAD and am programming it now. Think I'll make a dozen sets and see if anyone else can use some. From one-off to short runs, there's probably some money to be made keeping good old tools from being recycled into cheapo new trinket tools...
From what I've seen of waterjet machines, I doubt they'd be accurate enough. Although they're much more accurate than oxyacetylene, the jet diverges as it passes through the material, so you end up with a sloping edge. This was a few years ago, though - they might be better now.
From what I've seen of waterjet machines, I doubt they'd be accurate enough. Although they're much more accurate than oxyacetylene, the jet diverges as it passes through the material, so you end up with a sloping edge. This was a few years ago, though - they might be better now.
Seems like waterjet would be ideal for short runs of gears since they are basically flat. Here's a crazy idea... How about cutting the change gears from phenolic using a laser. Would they be tough enough? On modern CNC equipment would they just make a single gear when one is ordered or run a batch of say, 6, and save the rest for future orders? Not much material in a gear so they wouldn't take up much space to store in case another order came in next week. I would never make just one of anything if making more only used another 3 bucks worth of material and
All depends on how damned cheap you are. I'm so tight fisted I squeak when I walk. :-) You're right, of course, but not everyone wants to invest in task specific tooling. This is an easy way out.
I'm one of those lucky bastards that can hand grind toolbits that work. Not too long ago I hand ground one for a spur gear--inspecting it with my trusty comparator. It was symmetrical within a thou----which pleased me no end. Gear turned out fine, although the idea sucked, so the entire project was for no good reason.
Doing things like hand grinding difficult forms is what keeps your skills up. I've always taken great pride in my ability.
Linen based phenolic has been used for gears-----often when one must be sacrificial, so, yes, the idea would work. Don't have a clue if they could be cut by laser, though.
My in-ability to grind shit is almost equally impressive--in a perverse way, I could be proud of it as well, as it makes the fact that I get anything done at all somewhat of a miracle. :) :(
Quick Q on tool grinding, in particular lathe bits: Is a Dremel an instrumental part of bit grinding? I've seen some nice bits with chip breakers, grooves, reliefs, that look like they could not have been done on a standard wheel, but I've never actually seen anyone make these.
Also, I've seen custom lathe bits so perfect, no grind marks, it looks like they couldn't have been done by hand. EDM? some other way? We inherited a box-ful of these, and it's almost a shame to now scuzzy them up with our primitive alterations.
In my opinion, *only* for chip breakers, and not often even then. One good place would be for a compound cutting tool, where the chip breaker changes angles. One uses serious grinding wheels and masters their application to be successful in hand grinding toolbits. Anything less simply cheats you of the learning curve--which, for some--can be really frustrating. As a result, the do anything and everything to avoid going through it. Some even resort to running carbide when it's not justified. Damned shame!
I've seen some nice bits
I hand grind chip breakers on a pedestal grinder that is chest height, with no tool rest. The wheel becomes your reference point, so it's important that it runs dead true. For chip breakers, you use the corner(s) of the wheel, which are slightly radiused, smaller than the desired radius of the chip breaker. You control rake angle by manipulating the tool as it relates to the wheel. The side of the wheel is used for straight portions of the chip breaker. The correct tool form is ground, then the chip breaker is carefully ground to the cutting edge. It's truly an art form, one that I cherish.
Such tools can also be ground using a cutter grinder, but it takes more time to make the setups than it does to do them offhand.
When I was actively machining and ground tools on a regular basis (I've never operated CNC machines and have always used HSS in conjunction with carbide--including brazed tools, not just inserts), my tools looked like that. With my years away from the machines and my advanced years, coupled with poorer eyesight and poorer reflexes, I'm not convinced I'm as good as I used to be, but I can still do it. It's not hard to grind each face without chopping it up once you get used to it, and you abandon the crazy concept of a tool rest. They're truly a PITA, although it's hard to make others understand that.
We inherited a
Look at them carefully and try to emulate the grinds. It's not really hard, you just have to be serious about doing it. Keep your wheel well dressed and square, without bounce, and apply the tool such that it floats on the wheel face. Don't try to remove a lot at a time, give the wheel time to grind, which, in turn, gives you time to direct it as it relates to the wheel.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.