[aarongough]

Hey all!
I'm starting to make small batches of a product I designed and I'm looking for recommendations on ways to streamline the turning operations.

Here is a picture of the product:


The pen is made of 3 parts: barrel, grip and cap.

The barrel and grip are joined by a 1/4-20 thread. The cap is a friction fit over the o-rings on the pen body.

The barrel is drilled with a #42 1.578" deep to seat the ink cartridge, then turned to an OD of .35". The first 0.5" of the barrel is then turned to 0.25" and threaded 1/4-20 with a die. The grooves for the o-rings are cut with a form tool, the barrel is then polished and parted off.

The grip is turned to an OD of 0.35", then knurled. It is then faced off and drilled 0.9" deep with a #7 drill. It is then counter-bored with a 1/4" drill for 0.15", then tapped 1/4-20 to depth with a tapered tap. The grip is then parted off, and flipped end for end. The nose is machined, the o-ring grooves are cut and then the #42 hole for the ink cartridge is drilled.

The cap is simply drilled 3/8" 1.5" deep, then turned to an OD of 0.425". It is parted off, flipped, faced and drilled #42 again (if I don't drill here then the o-rings seal so well that the air can't escape and you can't put the cap on the pen!)

All the parts are polished on the lathe to 600 grit (I'm covering the ways, don't worry!)

I'm doing all this on a small 7x12" mini-lathe, and the pen is currently made from 6061-T6 aluminum, though I'll be trying 7075 as I've heard it chips nicer.

My thoughts right now are:
* Build a cam-lock for the tailstock
* Buy a small turret for the tailstock to speed up all the drilling operations
* Make the tailstock lever-action to make peck drilling faster
* Use stock that is closer to the finished dimensions (3/8" rather than the 0.5" stock that I'm using now.
* Buy a die holder for the tailstock to make threading faster
* Make a tap holder for the tailstock so I don't have to use a tap wrench
* Getting some sort of collet chuck for the lathe (maybe the ER32 collet chuck from LMS?) so that secondary operations don't mark the parts as much.
* Making a rest for stock protruding from the headstock so I can use longer bars (right now I'm limited to about 12" to avoid whip)
* Make stop rings for all drills so that I can avoid measuring as much as possible

Problems I'm currently encountering:
* Drilling those small deep holes takes way too long
* I can't get the aluminum to break chips, and I keep having to stop the lathe to clear long coils of swarf

Right now for financial reasons going to CNC is not really an option. I would also prefer not to farm out the production as part of the appeal for customers is that I make these items personally 'by hand'.

With all my naive equipment and setup making a pen from start to finish take about 1:45. If possible I'd like to get it down to under an hour per pen.

Any and all thoughts greatly appreciated!

[txcncman]

Use a quick change tool post and tool blocks and do all ops off the tool post/cross slide. Don't mess with the tail stock except to run a center when needed. Build some kind of stop to work with the spindle so that you can repeat part location when inserting into the chuck/collet.

[hndswthtshdws]

Look into a vibratory or tumbling parts finisher. I bet you spend a good amount of time polishing, you should be able to dump in a batch and do something else.

[hoss2006]

You aren't making one pen at a time are you?
Setup the lathe and do 10-20 or whatever pieces of the same operation then repeat for the next setup.
For manual work most time wasted is setting up the same operation over and over.
Getting a tailstock turret would really help speed things up.
http://www.littlemachineshop.com/pro...1877&category=
Hoss

[wizard]

I suspect one of the cheapest things you could do is to buy another lathe and keep it setup for one part. Possibly for the cap. With the right set of stops and with tools mounted on the cross slide you should be able to knock out the caps pretty damn fast. Also consider cross drilling the pressure/vacuum relief hole via a live spindle on the cross slide. It does become a question of how much space you have on the cross slide but you can make tool holders for specific jobs and likewise a simple light weight live spindle.

This is actually a job for a screw machine of some type but then it wouldn't be as hand made. So when looking at your lathe or lathes consider simplicity. For example a live spindle for cross drilling doesn't really even need a chuck, just a hole drilled in a shaft and a set screw to clamp the bit would do. Find the right motor and you might be able to put the drill bit right into the end of the motor shaft.

For the other half you might want to find a replacement for the tail stock that consists of a turret assembly. I'd cheat a bit here to add electronic feed to run peck cycles to drill your holes, admittedly this is 90% of the way to CNC but short peck cycles would reduce your chip issues. Of course if you are really inventive you might find a mechanical way to feed with short pecking with a continuous input on a crank or something. Also consider alternative grinds for the drill bits to try to break the chips. One thing I wouldn't do is bother with a turret attachment for the current tail stock as I don't see them being worth it.

Your little lathe is a nice machine but I[d keep an eye out for an old Hardigne tool room turret lathe. Or something similar. Not a big lathe mind you but one that was designed with a turret for production usage. Most lathes like this are rather old as they have been replaced by other machines in industry but are just the nuts for what you want to do.

[hoss2006]

Another note, the tailstock turret can be used for more than just drilling, I set ours up at work
for chanfering, forming, turning and threading too.
You should search on youtube, there are some nice videos of folks using a turret to make parts really fast.
Most are on a Hardinge collet lathe like I used which could be something to keep an eye out for on ebay/graigs list.
A depth stop in a 5C collet helps speed production too.
Hoss

[aarongough]

Use a quick change tool post and tool blocks and do all ops off the tool post/cross slide. Don't mess with the tail stock except to run a center when needed. Build some kind of stop to work with the spindle so that you can repeat part location when inserting into the chuck/collet.

Interesting idea! I already have a nice Tormach OXA toolpost that I'm using, so that would be very achievable.

Is there an easy way to line up drills mounted on the toolpost so that they are on center? I assume that I'm going to have to re-align them between each part as I will have moved the cross-slide...

[aarongough]

Look into a vibratory or tumbling parts finisher. I bet you spend a good amount of time polishing, you should be able to dump in a batch and do something else.

The polishing is actually surprisingly fast. Only a minute or two per part... I've been managing to get a really good surface finish on the turning operations so that definitely helps there.

[aarongough]

You aren't making one pen at a time are you?
Setup the lathe and do 10-20 or whatever pieces of the same operation then repeat for the next setup.
For manual work most time wasted is setting up the same operation over and over.
Getting a tailstock turret would really help speed things up.
Tailstock Turret Tool Holder, 2MT - LittleMachineShop.com
Hoss

I was making one pen at a time, but only because I hadn't finalized the design yet. Now that I'm moving onto production I will definitely doing batches of parts.

That tailstock turret you linked to was the exact same one I was looking at. Definitely something that's at the top of my list I think.

[aarongough]

I suspect one of the cheapest things you could do is to buy another lathe and keep it setup for one part. Possibly for the cap. With the right set of stops and with tools mounted on the cross slide you should be able to knock out the caps pretty damn fast. Also consider cross drilling the pressure/vacuum relief hole via a live spindle on the cross slide. It does become a question of how much space you have on the cross slide but you can make tool holders for specific jobs and likewise a simple light weight live spindle.

This is actually a job for a screw machine of some type but then it wouldn't be as hand made. So when looking at your lathe or lathes consider simplicity. For example a live spindle for cross drilling doesn't really even need a chuck, just a hole drilled in a shaft and a set screw to clamp the bit would do. Find the right motor and you might be able to put the drill bit right into the end of the motor shaft.

For the other half you might want to find a replacement for the tail stock that consists of a turret assembly. I'd cheat a bit here to add electronic feed to run peck cycles to drill your holes, admittedly this is 90% of the way to CNC but short peck cycles would reduce your chip issues. Of course if you are really inventive you might find a mechanical way to feed with short pecking with a continuous input on a crank or something. Also consider alternative grinds for the drill bits to try to break the chips. One thing I wouldn't do is bother with a turret attachment for the current tail stock as I don't see them being worth it.

Your little lathe is a nice machine but I[d keep an eye out for an old Hardigne tool room turret lathe. Or something similar. Not a big lathe mind you but one that was designed with a turret for production usage. Most lathes like this are rather old as they have been replaced by other machines in industry but are just the nuts for what you want to do.

Yeah, I've been eyeing some Hardinge second operation lathes with a lot of envy. Not sure I can afford something like that, but I'll definitely be keeping an eye out... It's also much easier to justify the cost after I've started making some money off the pens.

[aarongough]

Another note, the tailstock turret can be used for more than just drilling, I set ours up at work
for chanfering, forming, turning and threading too.
You should search on youtube, there are some nice videos of folks using a turret to make parts really fast.
Most are on a Hardinge collet lathe like I used which could be something to keep an eye out for on ebay/graigs list.
A depth stop in a 5C collet helps speed production too.
Hoss

I've seen a few of those hardinge lathes around for decent prices. If I was already making money off the pens I could justify the cost pretty easily, but right now I need to prove out the market before I take the plunge.

Am I right in thinking that the little turret you linked to from LMS is much less useful than a proper turret lathe because the part can't pass through the turret? Or are they essentially the same thing only smaller.

Any idea where I can buy box tools, etc, for a turret? I haven't seen much tooling like that anywhere I've been shopping.

[wizard]

Such a lathe would allow for vastly increased production while still being "hand made". Most of these turret assemblies from the past allow for a lot more tooling options than just morse taper or chucks allowed for on a tail stock adapter.

Sadly a lot of these lathes went for scrap iron.

Another note, the tailstock turret can be used for more than just drilling, I set ours up at work
for chanfering, forming, turning and threading too.
You should search on youtube, there are some nice videos of folks using a turret to make parts really fast.
Most are on a Hardinge collet lathe like I used which could be something to keep an eye out for on ebay/graigs list.
A depth stop in a 5C collet helps speed production too.
Hoss

[hoss2006]

I've seen a few of those hardinge lathes around for decent prices. If I was already making money off the pens I could justify the cost pretty easily, but right now I need to prove out the market before I take the plunge.

Am I right in thinking that the little turret you linked to from LMS is much less useful than a proper turret lathe because the part can't pass through the turret? Or are they essentially the same thing only smaller.

Any idea where I can buy box tools, etc, for a turret? I haven't seen much tooling like that anywhere I've been shopping.

The turret is a tool holder not a part holder but you could set it up to hold parts.
I wouldn't though, you want the part in the spindle to keep it as rigid as possible for accuracy and repeatability.
Here's a cheaper turret by the way.
Revolving Tailstock Turrets (WT)
Should be accurate enough for drilling, chamfering and threading operations.
Most of your tools would be drill chucks and finding staright shanks should be no problem.
You can always make or mod your own to fit the turret, you'll likely cut them shorter to fit.
Hoss

[hoss2006]

CDCO has 5/8" straight shanks for a number of drill jacob tapers for $5.
Drill chucks too, find under die makers tools../drill chucks..
CDCO Machinery Corp.
Hoss

[aarongough]

CDCO has 5/8" straight shanks for a number of drill jacob tapers for $5.
Drill chucks too, find under die makers tools../drill chucks..
CDCO Machinery Corp.
Hoss

Thanks for taking the time to have a look around Hoss!

I've seen a couple of Hardinge DV-59 lathes that I would love to have bought, also had a Monarch 10EE offered to me for $2250 in working condition which is crazy. No turret on that one though!

I'll probably get one of these tailstock turrets for the moment, then make sure that I keep an eye out for a real turret lathe later on.

[wizard]

Here is a video of one being used:[ame=http://www.youtube.com/watch?v=tUt3P2_lfm0]Hardinge Turret Lathe - YouTube[/ame], here is another of an actual Hardinge from times long gone: [ame=http://www.youtube.com/watch?v=DO1Y710P9v4]Hardinge DSMA Turret Lathe.mpg - YouTube[/ame]. Turret lathes where at one time they way to mass produce stuff.

I've seen a few of those hardinge lathes around for decent prices. If I was already making money off the pens I could justify the cost pretty easily, but right now I need to prove out the market before I take the plunge.

That is one way to look at it. However being able to make the parts in quantity is critical. Besides once you have such a lathe you can put it to work in other ways to pay for itself.

Am I right in thinking that the little turret you linked to from LMS is much less useful than a proper turret lathe because the part can't pass through the turret? Or are they essentially the same thing only smaller.

The videos should help answer that question, properly set up a turret lathe is very much a production machine. Here is a video of a Warner Swasey turret lathe: [ame=http://www.youtube.com/watch?v=aglDmz19Onw]Warner & Swasey #3 turret lathe, first parts - YouTube[/ame]. This is actually a smaller turret lathe as there use to be some real beasts in this family of turret lathes. Obviously you don't need one that big but it should be noted the your tooling options increase dramatically on the larger lathes.

Any idea where I can buy box tools, etc, for a turret? I haven't seen much tooling like that anywhere I've been shopping.

Box tools? What do you mean buy that? If you mean ready to go tooling this is a used market for the most part, I'm not even sure if you can buy quality turret lathes any more. So tooling and attachments for the most part are now either used or DIY. These guys are an example of what can be had on the market: Small Tools New and Used Tooling Of All Kinds


Before writing the above I forgot about the instant capability of the internet, It looks like you can buy knock offs of Hardinge's finest still. For example: cyclematic toolroom lathe Precision lathe small lathe ???? ???? ???? ???? ????. Still for the most part the lathes are a thing of the past as I'm not even sure you could find a large in production turret lathe like the old Warner Swasey of the past.

[txcncman]

As far as drilling off the tool post, once you find the X center line, record the number on the dial. As long as you do not move the dial, it will be the same every time. Same for all other tools. Just go back to the same numbers. If for some reason you need to move the dial, touch the tool to the side of a known diameter, back off in Z, move in half the known diameter and then move in half the known drill diameter. Easy peasy. Again, this is production though. You are going to face all pieces, then turn all pieces, then drill all pieces, etc. That is what the stop in the spindle is for, to relocate all of the part identically for the same Z, each and every operation. So, once your drill is set on the first part, all pieces get drilled, and then so on.

[aarongough]

As far as drilling off the tool post, once you find the X center line, record the number on the dial. As long as you do not move the dial, it will be the same every time. Same for all other tools. Just go back to the same numbers. If for some reason you need to move the dial, touch the tool to the side of a known diameter, back off in Z, move in half the known diameter and then move in half the known drill diameter. Easy peasy. Again, this is production though. You are going to face all pieces, then turn all pieces, then drill all pieces, etc. That is what the stop in the spindle is for, to relocate all of the part identically for the same Z, each and every operation. So, once your drill is set on the first part, all pieces get drilled, and then so on.

Gotcha. Funnily enough I hadn't thought of machining them that way. I figured I would do all the operations on one part, the move onto the next identical part...

[aarongough]

Here is a video of one being used:Hardinge Turret Lathe - YouTube, here is another of an actual Hardinge from times long gone: Hardinge DSMA Turret Lathe.mpg - YouTube. Turret lathes where at one time they way to mass produce stuff.


That is one way to look at it. However being able to make the parts in quantity is critical. Besides once you have such a lathe you can put it to work in other ways to pay for itself.

The videos should help answer that question, properly set up a turret lathe is very much a production machine. Here is a video of a Warner Swasey turret lathe: Warner & Swasey #3 turret lathe, first parts - YouTube. This is actually a smaller turret lathe as there use to be some real beasts in this family of turret lathes. Obviously you don't need one that big but it should be noted the your tooling options increase dramatically on the larger lathes.

Box tools? What do you mean buy that? If you mean ready to go tooling this is a used market for the most part, I'm not even sure if you can buy quality turret lathes any more. So tooling and attachments for the most part are now either used or DIY. These guys are an example of what can be had on the market: Small Tools New and Used Tooling Of All Kinds


Before writing the above I forgot about the instant capability of the internet, It looks like you can buy knock offs of Hardinge's finest still. For example: cyclematic toolroom lathe Precision lathe small lathe ???? ???? ???? ???? ????. Still for the most part the lathes are a thing of the past as I'm not even sure you could find a large in production turret lathe like the old Warner Swasey of the past.

When I say box tool I mean a turning tool that has it's own follower rest, so you can turn long work without a tailstock. I would need something like that for the barrel of the pen.

Those Cyclematic lathes are things of beauty. I would happily buy one of those in a heartbeat.

[Runner4404spd]

this is silly setup a gang slide on your 7x12 lathe and have at it. you can mount all of your tools to your slide either in individual holders or to a single multi station larger holder. i bet you could mount enough tools that you wouldn't even need to change the setup for doing the individual parts, just have to keep them close together.