What's It Going to Be

Its been a long time since I did one of these, so here we go.
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Reply to
Bob La Londe
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Hint #2
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Reply to
Bob La Londe
Hint #3 I think if somebody doesn't get it now you just aren't trying.
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Reply to
Bob La Londe
Hint #4 (no picture this time) This is a fixed size test proof of concept. If it works an adjustable one will follow.
Reply to
Bob La Londe
Looking with interest. Apologies not otherwise engaging. Rich S
Reply to
Richard Smith
Its been a long time since I did one of these, so here we go.
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I bought 3, 4 and 6 jaw lathe chucks on 5C mounts to machine similar round parts with wrench and socket flats that need to move between the lathe and mill without losing registration. The 6 jaw is useful on plastic parts such as the leaking compression cap whose OD I threaded yesterday for a metal reinforcement.
Reply to
Jim Wilkins
I run D1-5 back plates on my primary lathe so removing chucks is fairly quick and easy. I would have to get creative in order to mount them on the mill table, an indexer, or a spacer or rotab.
For part one I tried a couple processes and concluded it was fastest to machine the hex and flat in a six sided collet block on the mill first. Since I started with nominal size stock this left me to turn a single radius on the part before parting it off and facing to length.
This is a "fixed" application tool and a proof of concept prototype. I'm sure the concept is fine as I have seen similar tools that worked just fine. I am developing two two things for this. A knowledge of processes to determine if I can (eventually) make them time effectively, and to develop a "universal" version with a range of adjustment.
Reply to
Bob La Londe
Complete and tested. Works as intended.
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The locking collar is redundant. If I go ahead with the plan to make the adjustable version I will probably eliminate it. It was part of the original plan so I went ahead and used it on this prototype.
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I've got a number of small refinements that will improve function, machine time, and material cost.
I wanted to change the plans and build the one I see in my head, but I disciplined myself to stick to the plan, and save all the refinements and improvements until the prototype was done and tested.
Its a simple tool, but I suspect the users will find it very helpful. I will probably make five or ten of the refined adjustable version and offer them for sale on Ebay or Etsy. CNC and batch parts. If they sell then I can see if there are any other refinements I can do.
Reply to
Bob La Londe
I run D1-5 back plates on my primary lathe so removing chucks is fairly quick and easy. I would have to get creative in order to mount them on the mill table, an indexer, or a spacer or rotab.
For part one I tried a couple processes and concluded it was fastest to machine the hex and flat in a six sided collet block on the mill first. Since I started with nominal size stock this left me to turn a single radius on the part before parting it off and facing to length.
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You could chuck the hex collet block on the lathe.
In general I'm looking for ways to hold work that allow removing it to check the fit with another, then replacing it sufficiently in registration to continue cutting a thread. The need is more for repair or modification than for making all the parts to planned dimension.
The recent job was mounting a sink spray hose on a garden sprayer, which makes it serve as a quick response brush fire extinguisher in summer or hot water supply for taking a shower with stove-heated water during a winter power outage. The spray hose outlet gland nut leaked until I replaced its O rings with a short length of rubber tubing. I also threaded a snug-fitting knurled aluminum cap over the plastic to keep it from cracking.
Reply to
Jim Wilkins
I do some repair work, but generally I try to think of order of operations that require as few setups as possible. For turning I will sometimes sacrifice order of operations convenience for being able to machine all concentric surfaces in one operation.
For example the ID and OD of a tool holder. I use TTS tool holders on the Tormach mill. Generally they are cheap enough I just buy them from Tormach if they make the one I need. Sometimes I need a special one outside the range they think is "safe" or perhaps with low enough demand its not worth it to make for them. A piece of 1144 will make a tool holder that will hold up for hundreds of operations. I will turn the shank OD, recess, and tool size bore in one setup from the rear of the holder. All the critical dimensions are done in the first setup. Important concentricity is established. Then I'll flip the part and shape the nose of the holder. Not so critical, and since the top RPM on the 1100S3 is just 5120 balance is not a huge deal either. I wouldn't make a tool holder for a 24K ISO20 spindle this way, but its perfectly adequate for most machines running under 6K. I'll refrain at this point from getting into my knowledge and ignorance for tool balancing.
The main chuck I use on the 1440 lathe is a Set-Tru 6 jaw with 2 piece jaws. I can setup the chuck for a particular diameter with sub .0005" repeatability, and if I machine soft jaws turned to size I can get under .0003". The set tru feature is a bit fiddly and I haven't done it enough to be good at it though. It takes me 15-20 minutes. When I can I prefer to use setup and order of operations to make more important surfaces concentric. For general use it tends to be better than any other scroll chuck I have used anyway.
In this case the part is very non critical and it was designed that way. The hex is very low speed intended to be used by hand with a wrench. (anything faster would be catastrophic) As long as it doesn't "feel" off its good enough. The flat is just for a set screw for a locking collar, and the locking collar has already been deemed redundant. There are two radii that could be the "bearing" surface and it doesn't matter which one for how the tool works. Since cold rolled stainless (what I keep on hand) tends to be within a thousandth of dimension (usually 304 is pretty close and 303 is slightly under from my experience) the nominal OD of the stock is the planned bearing surface. The secondary OD is turned under size and floats. Its just there so the part can pass through the other part, and not fall out. The only "critical" dimensions are the as shipped nominal major OD, and the length of that first section. Basically it just needs to be .003-005 shorter then the depth to the shoulder it rests on. The whole thing was designed to be non critical.
I also do have a 16C lathe chuck I picked up a while back. The plan was to set it tru on a back plate, but the 6 jaw set tru is good enough I have not needed to play with it. Besides I like having my spindle bore clear. Maybe if I was doing more production work on the lathe, but most of the production or semi production stuff I do is fast and loose tolerance. I also picked up a Taiwanese turret lathe with a 5C spindle a while back, but its still resting on the furniture movers. There are a few parts I make that I could do very fast on it, but the demand has not has been high enough to get the machine off its rollers and setup.
Anyway, I try to make critical dimensions all in one setup if possible. Even if its not as convenient otherwise for things like work holding. In this case nothing is really critical. Maybe less than a couple thousandths slop of the round part in the hole.
Where I can run into issues is with clocking. In this case not really an issue, but there are parts where clocking is very important. I have an array of tools for that from adjustable parallels to a machinist level. I definitely do not have a fast "good enough" process dialed in for clocking. Generally I try to avoid it being an issue by choice of order of operations, but well sometimes I'm not as smart as I think I am and I find myself screaming at the top of my lungs in the shop where nobody can hear me because I realize I just spent all day designing and building something to go in the bit bucket. I'm not talking about simple clocking where you stick the part in a spindex or rotab and do everything. I'm talking about moving a part from machine to machine and back. Usually I think about it and realize if I had chosen a different order of operations it would not have been an issue.
Wow! What a ramble. LOL.
So do you know what it is yet?
Reply to
Bob La Londe
I do some repair work, but generally I try to think of order of operations that require as few setups as possible. For turning I will sometimes sacrifice order of operations convenience for being able to machine all concentric surfaces in one operation.
For example the ID and OD of a tool holder. I use TTS tool holders on the Tormach mill. Generally they are cheap enough I just buy them from Tormach if they make the one I need. Sometimes I need a special one outside the range they think is "safe" or perhaps with low enough demand its not worth it to make for them. A piece of 1144 will make a tool holder that will hold up for hundreds of operations. I will turn the shank OD, recess, and tool size bore in one setup from the rear of the holder. All the critical dimensions are done in the first setup. Important concentricity is established. Then I'll flip the part and shape the nose of the holder. Not so critical, and since the top RPM on the 1100S3 is just 5120 balance is not a huge deal either. I wouldn't make a tool holder for a 24K ISO20 spindle this way, but its perfectly adequate for most machines running under 6K. I'll refrain at this point from getting into my knowledge and ignorance for tool balancing.
The main chuck I use on the 1440 lathe is a Set-Tru 6 jaw with 2 piece jaws. I can setup the chuck for a particular diameter with sub .0005" repeatability, and if I machine soft jaws turned to size I can get under .0003". The set tru feature is a bit fiddly and I haven't done it enough to be good at it though. It takes me 15-20 minutes. When I can I prefer to use setup and order of operations to make more important surfaces concentric. For general use it tends to be better than any other scroll chuck I have used anyway.
In this case the part is very non critical and it was designed that way. The hex is very low speed intended to be used by hand with a wrench. (anything faster would be catastrophic) As long as it doesn't "feel" off its good enough. The flat is just for a set screw for a locking collar, and the locking collar has already been deemed redundant. There are two radii that could be the "bearing" surface and it doesn't matter which one for how the tool works. Since cold rolled stainless (what I keep on hand) tends to be within a thousandth of dimension (usually 304 is pretty close and 303 is slightly under from my experience) the nominal OD of the stock is the planned bearing surface. The secondary OD is turned under size and floats. Its just there so the part can pass through the other part, and not fall out. The only "critical" dimensions are the as shipped nominal major OD, and the length of that first section. Basically it just needs to be .003-005 shorter then the depth to the shoulder it rests on. The whole thing was designed to be non critical.
I also do have a 16C lathe chuck I picked up a while back. The plan was to set it tru on a back plate, but the 6 jaw set tru is good enough I have not needed to play with it. Besides I like having my spindle bore clear. Maybe if I was doing more production work on the lathe, but most of the production or semi production stuff I do is fast and loose tolerance. I also picked up a Taiwanese turret lathe with a 5C spindle a while back, but its still resting on the furniture movers. There are a few parts I make that I could do very fast on it, but the demand has not has been high enough to get the machine off its rollers and setup.
Anyway, I try to make critical dimensions all in one setup if possible. Even if its not as convenient otherwise for things like work holding. In this case nothing is really critical. Maybe less than a couple thousandths slop of the round part in the hole.
Where I can run into issues is with clocking. In this case not really an issue, but there are parts where clocking is very important. I have an array of tools for that from adjustable parallels to a machinist level. I definitely do not have a fast "good enough" process dialed in for clocking. Generally I try to avoid it being an issue by choice of order of operations, but well sometimes I'm not as smart as I think I am and I find myself screaming at the top of my lungs in the shop where nobody can hear me because I realize I just spent all day designing and building something to go in the bit bucket. I'm not talking about simple clocking where you stick the part in a spindex or rotab and do everything. I'm talking about moving a part from machine to machine and back. Usually I think about it and realize if I had chosen a different order of operations it would not have been an issue.
Wow! What a ramble. LOL.
So do you know what it is yet?
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I'd guess a jig or fixture latch but I don't know enough about mold making to recognize the specifics. Some of the custom tooling I've machined makes no sense unless seen in action, such as a collet draw-in cap with a 1/2" hole to center an S&D drill bit shank, to sharpen it on the surface grinder in an end mill fixture. The angles are close enough.
I have a Sanou 6" 6-jaw bookmarked on my shopping list for whenever I might decide to spend the money, though it just lost out to a 100 tooth gear for the metric change set. When I bought the gears I was doing laser optics and a 120 tooth gear gave more fine lens thread sizes. My 4" 6-jaw on the 5C mount is quite useful for stock that doesn't fit a collet but it's of limited capacity.
Where/why would you use 1144 versus 4140HT?
Reply to
Jim Wilkins
Mush easier to machine and the local metal butchers stock it. Machines nearly as nicely as 12L14, but a little stronger. Also heat treatable, but generally not weldable. I do keep some 4140HT on hand as well, but I am stingy with it since I have to order it. I've even been known to make tool holders out of 304 stainless in a pinch. (almost everybody stocks 304.) The 304 just gets harder the more you use it. LOL.
Reply to
Bob La Londe
Mush easier to machine and the local metal butchers stock it. Machines nearly as nicely as 12L14, but a little stronger. Also heat treatable, but generally not weldable. I do keep some 4140HT on hand as well, but I am stingy with it since I have to order it. I've even been known to make tool holders out of 304 stainless in a pinch. (almost everybody stocks 304.) The 304 just gets harder the more you use it. LOL.
Reply to
Jim Wilkins
Metal yards are pretty much always cheaper than hardware stores for steel. I suspect most anyplace with a population 60-80K give or take should have a metal yard in the area. I have dealt with a few that don't want small customers though. Most will sell a full stick to just about anybody. We had one that would sell cut bits, but they shut down earlier this year. The other I deal with locally will sell full stick or half stick. I can get them to shear sheet, but only if I buy the whole sheet.
A local metal yards is almost always a lot more expensive than a mill direct vendor.
Speaking of such. You remember the guy who came on here a while back shilling for an online metal company? I sent them a quote request last year. I don't remember exactly, but it was around 1500-2000 worth of stock. Small order for them probably. Big order for me. They were literally the MOST expensive quote even before shipping cost. I knew they could do better because I have ordered cheaper from other vendors that arrived drop shipped from them. Just to see I dropped them an email letting them know they were literally the most expensive quote of everybody in the country, and I knew they could sell cheaper for the reason I mentioned. They back pedaled and sent me another quote. Before shipping they were the cheapest quote in the country. After shipping they were a hundred bucks higher than my regular vendor for that material.
I have to back pedal a bit here. I did try to get a quote from another in state metal vendor who told me they didn't have a single item I was looking for. I was a bit stunned so I asked if that was for real. The person I was dealing with said he'd double check, and shortly after I received a quote for about $12K. Obviously that was his way of telling me to F'Off. They were the most expensive quote, but that doesn't really count as a quote.
Anyway a local metal yard will pretty much always be cheaper than the hardware store if they have what you need.
Reply to
Bob La Londe

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