# Some StarWars Model Parts



## wildo (Jun 18, 2019)

A buddy of mine asked me if I could make three of these small little plastic parts out of metal. Seemed easy enough. Yeah- it's small, but so what?
God... I'm such a newb. Projects like this are a frustrating reminder of just how much I have yet to learn. And also a serious kick in the backside to get my new lathe operational. The more I use the old worn out SB, the more frustrated I get. That said, here's another 'getter done.' (Sorry- I don't have a clue what StarWars model he's working on.)


"Hey can you make me three of these plastic parts?"



Yeah, probably- send me some dimensions.
"Here you go."




...Hmmmm... Twelve attempts later I finally got three parts complete without breaking off the long stem. That was WAY harder than I think it should have been.


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## dave_r_1 (Jun 18, 2019)

Obviously, you should have been using a follower when making the shaft section :-O


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## mikey (Jun 18, 2019)

One word ... Sherline.


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## Choiliefan (Jun 18, 2019)

...and sharp HSS cutting tools.


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## markba633csi (Jun 18, 2019)

There is where a tiny lathe like a Unimat would really shine-
M


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## wildo (Jun 18, 2019)

So let's turn this into a learning thread...

1) I know that HSS would have been ideal for this. Unfortunately, I just don't have a good grinder setup yet and so it's not easy for me to grind HSS right now. I used a new CCMT060204 carbide insert and tried to take big, real cuts. It worked, but I had many failed attempts. HSS is absolutely the way to go and I really need to get a good grinding setup.

2) Why is a small lathe better suited for making parts like this? Is it because of the mass of the carriage? Do the smaller lathes have higher spindle speeds and finer control? It's unclear to me why a smaller lathe would make it easier to create this part over a hobby sized lathe like the SB9a. What am I missing??


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## brino (Jun 18, 2019)

Good job. Sometimes the small ones are harder than the bigger jobs.
I bet a lot of effort went into the small bag of parts in your hand.
-brino


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## ThinWoodsman (Jun 18, 2019)

wildo said:


> 1) I know that HSS would have been ideal for this. Unfortunately, I just don't have a good grinder setup yet and so it's not easy for me to grind HSS right now. I used a new CCMT060204 carbide insert and tried to take big, real cuts. It worked, but I had many failed attempts. HSS is absolutely the way to go and I really need to get a good grinding setup.
> 
> 2) Why is a small lathe better suited for making parts like this? Is it because of the mass of the carriage? Do the smaller lathes have higher spindle speeds and finer control? It's unclear to me why a smaller lathe would make it easier to create this part over a hobby sized lathe like the SB9a. What am I missing??



Fair point on the HSS. You way want to try honing the carbide inserts a bit using a diamond stone. It might help, might not.

I don't buy the "small lathe" argument either. The controls are smaller, setup is more cramped. There may be some merit to an argument like "a larger spindle means a greater surface area over which an imperfection could induce runout", but really you can resolve this with a test indicator - so you know before you even start whether your particular lathe is accurate enough for the job. Some mention might also be made of small parts being more difficult to grip in an 8" chuck, but a) collets, and b) grip a smaller chuck in the large chuck. Hey, even c) centers - use much larger stock than you need turn down the middle, part the ends.


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## Choiliefan (Jun 18, 2019)

An old-timey lathe hand would turn these out on a jewelers lathe with a couple gravers on a tool rest.


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## wildo (Jun 18, 2019)

Choiliefan said:


> An old-timey lathe hand would turn these out on a jewelers lathe with a couple gravers on a tool rest.


Gravers are so cool!


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## mikey (Jun 18, 2019)

Choiliefan said:


> ...and sharp HSS cutting tools.



Okay, and that, too.


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## mikey (Jun 18, 2019)

wildo said:


> 2) Why is a small lathe better suited for making parts like this? Is it because of the mass of the carriage? Do the smaller lathes have higher spindle speeds and finer control? It's unclear to me why a smaller lathe would make it easier to create this part over a hobby sized lathe like the SB9a. What am I missing??



I can only speak to the Sherline lathe but as to why it is better for this kind of work vs a typical larger lathe:

It is small, so you can get close to your work. Most Sherline owners work sitting down, often with an Optivisor on their head. You're comfortable, stable and you can see.
Unlike most larger lathes, a Sherline lathe has 20tpi leadscrews and accurate laser-cut index markings on the zero-set hand wheels. This allows for very accurate movement in X and Y; I can interpolate and dial in a 0.00025" depth of cut by eye and the lathe will cut it assuming you have the right tool. Contrast that to most lathes with a 10 tpi leadscrew; they are a knife, the Sherline is a scalpel.
The tool post on a Sherline lathe mounts directly to the cross slide; a compound is not used for most operations. Once locked in, the tool is essentially a part of the structure of the lathe. Although small in size, a Sherline lathe is extremely rigid. With a good tool, a Sherline lathe will easily take a 0.050" depth of cut in mild steel and 0.100" on aluminum; yeah, I mean 0.100" off the diameter in steel and 0.200" of the diameter in aluminum. Not too bad for a small lathe.
Sherline cross slides have T-slots running the length of the cross slide table. This allows you to mount a parting tool at the rear of the part. This is used for parting but also for precision grooving. On your part, I would have used a parting tool to accurately demarcate the two larger sections by cutting down to the dimension of the smaller diameter; then I just have to turn the small diameters down and I'm done. A rear mounted parting tool on a Sherline lathe can part most materials at very high speeds - brass and aluminum at 2800 rpm, mild steel at half that speed - and it will have zero issues with chatter or digging in. Try that on your 9" SB.
My lathe has a variable speed DC motor connected to the main leadscrew to give me complete control of the cut. By independently varying the speed of the spindle and feed screw, I can dial in a cut on the fly in real time. Imagine the finish you would get if you took a finish cut on aluminum at 2800 rpm with a very slow power feed while using a sharp HSS tool optimized to cut aluminum. Cannot get that with carbide on a lathe tied to its gearing.
The Sherline is a change gear, manual drive lathe. Most think this is a disadvantage but when working with small, precision class threads it is actually an advantage. When was the last time you cut a Class 3, 4-48 thread 1/4" long in tool steel? I did that three weeks ago and hit my thread tolerances the first time. This involves turning the diameter of the screw to within a few tenths, then cutting the threads accurately. Try that on a 1340 and let us know how it goes.
I suspect most guys who look down on the Sherline lathe have never even seen one, much less used one to turn real parts. If they had, they would have a different opinion of this lathe. It definitely has its limitations, mainly the size of the work that can be done on it, but within its work envelope it is a real tool meant for precision work like you needed for this job, Wildo. 

As @Choiliefan said, add some good HSS tools that are capable of taking fine cuts without deflecting much at all and you have a very good system to use when you need it.


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## wildo (Jun 18, 2019)

Mike- **thank you!!**

This is exactly what I was hoping someone would chime in with. I've seen regularly that people say "Oh- that's easier on a small lathe" and I've never understood why. They both have cross slides; they both have lead screws; they both have rigidity. But actually, some of the points you made I was not aware of. I can't even take a 0.050" cut on the SB... hahaha!

It seems maybe I need to look into a Sherline lathe! I actually really love making super small parts; I just really hate working with a worn out lathe while doing it. Big thanks for the explanation; that's exactly the learning I was looking for.


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## mikey (Jun 18, 2019)

What actually makes the Sherline lathe work well for me are the cutting tools I use. The typical Sherline lathe using a standard geometry turning tool can maybe take a 0.020" DOC max. The geometry I use enables the lathe to work much better and more accurately. It may be that learning to grind a good tool will greatly improve the function of your lathe, too.


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## markba633csi (Jun 18, 2019)

Actually, when you think about it, what would you use to make tiny parts for a watch? 
Most of the points Mikey made apply to the Taig lathe as well
Wildo: why can't you take a 50 thou cut on your SB?  It should do it I would think


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## wildo (Jun 18, 2019)

markba633csi said:


> Wildo: why can't you take a 50 thou cut on your SB?  It should do it I would think



Because it's an old worn out POS. lol!


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## mikey (Jun 18, 2019)

I suspect the tool is another key reason for the reduced performance of your lathe, Will. Carbide on a small lathe just doesn't work as well. Maybe time to jump into HSS tool grinding?


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## wildo (Jun 18, 2019)

mikey said:


> I suspect the tool is another key reason for the reduced performance of your lathe, Will. Carbide on a small lathe just doesn't work as well. Maybe time to jump into HSS tool grinding?


No question about it. And it's an area I really want to improve on. I'm hoping to win a pedestal grinder in an auction here in the next few days.

I also got a picture of the parts installed on the model. He's making a stage scale model of the escape pod from the beginning of Star Wars Episode 4. Apparently that means that this model is the exact same size as the one they used to film the scene.


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## mikey (Jun 18, 2019)

Very cool! Your parts came out nice, Will, honest. I wish you were close to me. I would love to show you how easy it would be to make those parts on a Sherline lathe. 

If you don't win the pedestal grinder, maybe consider a good belt sander as an option. I find it to be a better machine, for me anyway. If I can help you, please let me know.


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## chips&more (Jun 19, 2019)

Nice job!!! I do a lot of micro machining…A LOT! And after reading this thread, I just had to chime in. Sorry to some folks, but there is absolutely no need for a small lathe to make those parts…not at all. I have several Levin lathes, that’s beside the point. My 14” lathe could have done the job without hindrance. And I understand the need for Carbide tool bits. But for the Hobby Shop (not a production environment) using Carbide for everything, IMHO can be a waste of money. I use HSS for almost everything and carbide when HSS does not hold up…Dave


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## markba633csi (Jun 19, 2019)

Wildo you will be amazed how much you can cut with a properly sharpened HSS bit-  you're missing half the fun bud!  Put the carbide jazz away


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## wildo (Jun 20, 2019)

Well now. I think I solved my grinder issue tonight. Everyone- meet Big Bertha! Perhaps a bit overkill, but I guarantee I won’t outgrow it! This is a 3Hp 2x12 Baldor grinder, and I am SO excited! The guy just put new wheels on it three months ago at the cost of about how much I paid for it.


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## mikey (Jun 20, 2019)

That grinder VS HSS ... the HSS is going to lose!


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## wildo (Jun 20, 2019)

mikey said:


> That grinder VS HSS ... the HSS is going to lose!


Pretty sure that’s the point of a grinder! Hahaha! He said you have to be careful- it will eat it up quick!


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## wildo (Jun 20, 2019)

Here’s a better pic from the listing


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## ThinWoodsman (Jun 20, 2019)

That thing is a beast! Makes my 1.5 HP Dayton look puny.


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## chips&more (Jun 21, 2019)

That’s a beautifully grinder! Is it 3 phase? One down side though. If you want to put on a white wheel, wire wheel etc. You will fall over with sticker shock. The size you have is great for the iron worker. That pedestal alone is worth more than a typical 6” grinder….Nice!


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## brino (Jun 21, 2019)

chips&more said:


> That pedestal alone is worth more than a typical 6” grinder….Nice!



...and weighs considerably more too.
-brino


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