Harbor Freight Mini Lathe Upgrade

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It seems these little machines are popular with hobbyist like us. This lathe is known around the world as a C2. It is sold under dozens of brands. They are inexpensive and don’t take up a lot of space. However if you find it to be a little undersized I found a solution to the problem. It’s a 16” bed extension from Little Machine Shop. It has a modest cost of $170. http://littlemachineshop.com/products/product_view.php?ProductID=5000&category=1070498684
This is not a direct bolt on but required the drilling and tapping of 9 holes. But it is pretty straight forward. Doing this upgrade increases the usability of this machine.

Here is a list of compatable lathes.
• Harbor Freight 33684 Central Machinery 7x10 Mini Lathe
• Harbor Freight 93212 Central Machinery 7x10 Mini Lathe
• Bolton CQ9318 7x12 Mini Lathe
• Cummins (Tools Now) 5278 7x12 Mini Lathe
• Grizzly G8688 7x12 Mini Metal Lathe
• Harbor Freight 93799 Central Machinery 7x12 Mini Lathe
• Homier 03911 Speedway 7x12 Mini Bench Metal Lathe
• Tormach 30689 7x12 Duality Lathe
• Warco 3005 7x12 Mini Lathe (Imperial)
• Warco 3004 7x12 Mini Lathe (Metric)
• Big Dog BD-0618Ax300 7x14 Mini Lathe
• Big Dog BD-0618x300 7x14 Mini Lathe
• LittleMachineShop.com C3 SIEG 7x14 Mini Lathe
• Micro-Mark 82710 MicroLux 7x14 Mini Lathe
• Warco 4800-350 7x14 Mini Lathe (Imperial)
• Warco 4820-350 7x14 Mini Lathe (Metric)



durMKdV.jpg


The barrel is an AKM 16". It easily fits through the factory chuck.

vXOltyq.jpg


It goes in this far from the rear. The rear trunnion will not go through the rear of the spindle.


Yu5egHz.jpg


This is how much of a barrel will fit between the centers. It's a 16" AKM. As you can see pretty much anything you need to do.


Ed8GKjU.jpg


This is measured from the face of the chuck. If you use a dead center you can gain real estate.
xekLN9R.jpg
 
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pastera

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not bad. i wish i knew about it before i dumped almost $1300 on my lathe. much cheaper way to go if you not planning on going much past 16"

Not the same - you have a more versatile lathe.

If you like, we can put them side by side and compare (I have a 12" version)
 
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Not the same - you have a more versatile lathe.

If you like, we can put them side by side and compare (I have a 12" version)

You have to decide whether or not you can live with a 16" version that cost $630ish complete including the bearing upgrade or spend another $700 more. It all depends what you goal is. BTW pastera are you considering upgrading to the 16" version? I intentionally purchased the 10" version knowing I was going to upgrade the bed.
 

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You have to decide whether or not you can live with a 16" version that cost $630ish complete including the bearing upgrade or spend another $700 more. It all depends what you goal is. BTW pastera are you considering upgrading to the 16" version? I intentionally purchased the 10" version knowing I was going to upgrade the bed.

No plan on an upgrade - next lathe will be a large piece of old iron once the kids are through college.

You can also ream the headstock out to 13/16" safely - I haven't done it but there have been a couple of times it would come in handy.
 
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i like your lever lock. how did you make it exactly?

Not the same - you have a more versatile lathe.

If you like, we can put them side by side and compare (I have a 12" version)

i know i do. and i'm happy that i have it but also not so happy with the amount of tweaking and mods neede to be done to it in order to match my needs.
and yeah it's great to have 29" long bed but also not great that it's 120V and all gears are belt driven and to switch speeds you need to mess with gears and belts. also it's highest speed is not fast enough sometimes. tool post is oddly sized and i have hard time finding tooling of that size. so it needs to be re-worked. that's aside from the fact that it has some play in it as well that i also need to figure out how to eliminate. some day it'll be good. but not yet.
 

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i like your lever lock. how did you make it exactly?



i know i do. and i'm happy that i have it but also not so happy with the amount of tweaking and mods neede to be done to it in order to match my needs.
and yeah it's great to have 29" long bed but also not great that it's 120V and all gears are belt driven and to switch speeds you need to mess with gears and belts. also it's highest speed is not fast enough sometimes. tool post is oddly sized and i have hard time finding tooling of that size. so it needs to be re-worked. that's aside from the fact that it has some play in it as well that i also need to figure out how to eliminate. some day it'll be good. but not yet.

I'll take it apart and post pictures or stop by and examine in person.

My 7x needed a lot of tweaking to run half way decent - On yours, you need to replace the compound slide with a solid block when you aren't threading or cutting tapers. That one mod alone will tighten the lathe up considerably.
 
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that's what i'm planning on doing as per your advices earlier.
BTW that Z-motor issue was a fluke of some sort. next day it was working as it supposed to. i could not reproduce it. there is a gremlin somewhere in the system but i haven't found it yet. need to retest X, after flipped bearings last week. check for backlash. i tried doing it there and than, and it gave me 0, which i do not believe can be true. need to do it more methodical to be sure. also found that Y mount is not flush against base completely. looks like that spacer did slip out. i wonder if i can take that up and get Y backlash down even more.
 
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You can also ream the headstock out to 13/16" safely - I haven't done it but there have been a couple of times it would come in handy.

Harbor Freight says the hole in the chuck is 5/8" but I measured mine at .702" and it looks like it can go a little larger.

Would you consider doing the tapered bearing upgrade in the headstock?
 
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pastera

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Harbor Freight says the hole in the chuck is 5/8" but I measured mine at .702" and it looks like it can go a little larger.

Would you consider doing the tapered bearing upgrade in the headstock?
I have a larger four jaw so the head stock is my limitation.
As far as the bearings, I would probably go with 7206 angular contact because I use high spindle speed often. Not certain I would see much improvement either way so it's low priority.
 
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I bought a 4"-4 jaw chuck with a 1" bore to give more usability. It is quite a bit larger than the stock unit. I'm in the middle as we speak of boring out the stock 3 jaw chuck. I don't know if I feel comfortable going to 13/16". I can see through the back of the chuck and at 3/4" it is touching the screw heads.

With the taper bearings there is zero run out on the spindle.
 
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7.62x39 I looked at your thread before I bought my X2 mill. Thanks it was very helpful. I would like to do a CNC conversion but I got side tracked by getting the lathe which was totally unexpected.

pastera as you said there is a lot of tweaking involved in setting these up. I got the stock chuck out to .753" that's .050 over stock and I think it can go a little further. I will have to research that. The only issue is it's just starting to break into one of the openings for one tighteners.

For some reason I have more run out on the chuck (.002") than I had before (.00025"). Ugh!

This is a pic after I bored it out. It looks like I can go a little more.

sFB9PU7.jpg
 
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pastera

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Chuck runout is a pain.
You will need to run through 9 configurations to get minimum runout.
All three jaw rotations for each of the three mounting positions.
Mark the chuck to spindle orientation and jaw 1 to chuck orientation with a center punch.
However, on these cheap chucks this is only good for stock close in diameter to what you used to orient everything. I find myself using the four jaw for anything I'm worried about concentricity on.
 
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Here is an update on my HF mill and lathe. My son and I milled an AR lower and it went well. I really like the control you have with the mill over trying to use a drill press there is no comparison. You are limited on size but for general AK, AR and 1911 stuff it is fine.

The lathe works well too. I’m still fine tuning it. I’ve been messing with the stock chuck to get it to run true. That was a bust so I bought one from Grizzly http://www.grizzly.com/products/3-3-Jaw-Plain-Back-Scroll-Chuck/G9828 Wow what a difference less than .001” run out. Not mushy either. It is machined very nicely inside and out the scroll is uniform. The back is cast iron versus the HF plastic. The jaws are snug too. I also bored the Grizzly chuck out to ¾”. That’s much as you can go without breaking into the pinion holes.

I also got a real milling vise from Enco. It’s a 4” monster. It barely fits on my mill and I can’t use the swivel base because it’s too large. Once you sign up for their emails you can get some great offers like 20-25% off and free shipping.


Getting your drill aligned with the trunnion hole is much easier with a mill.
j3N4AN2.jpg



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Grizzly chuck Left HF chuck Right
2gEwa3L.jpg



Milling makes a lot of shavings
5GBejca.jpg



dy7a6mK.jpg
 
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pastera

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Please edit your second sentence in the previous post or the ATF will COME AFTER YOU.

Malodave

+1

Also, it looks like you are milling with a drill chuck. This is not a good idea as the chuck is only held on by a taper and not meant for side loads. If it comes loose, and it eventually will, you will be lucky if it only damages the work as it transits your shop like the Tasmanian devil.

A collet is only $10-15 and is designed to hold an endmill securely.
 

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...

I also got a real milling vise from Enco. It’s a 4” monster. It barely fits on my mill and I can’t use the swivel base because it’s too large. Once you sign up for their emails you can get some great offers like 20-25% off and free shipping.

Next time you get an Enco coupon, check out their small toolmakers vise - much easier to work with on the mini mill.

Little Machine Shop has a page on mini mill vises that's a nice reference.
 
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Thanks Malodave and pastera. I do have collets but this was our first project so I wasn't sure. The collets definitely are more secure. Also was not happy with run out of the chuck. Not going to use the chuck for that again. There's a lot to learn.

KMM696 Thanks. It's good to get some input from someone who knows. It's hard to picture how big something is until you actually have it in hand. The website you referenced is a great resource. http://www.mini-lathe.com/Mini_mill/Accessories/Vises/Vises.htm
 
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