Little Machine Shop Hi Torque 3990 Mini Mill

  • The most powerful milling machine among all mid-sized mills
  • Lowest torque speed for effective machining
  • A gearless spindle drive
  • Mini mill with the largest X-Y travel and table size
  • R8 spindle for an extensive tooling
  • Solid column to prevent tilting
  • Powerful 500 Watt spindle motor

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SKU: LMS Hi Torque 3990-1 Category:


The Little Machine Shop (LMS) Hi Torque 3990 mini mill is truly the most powerful mini mill featuring a large work table and the most torque for diverse milling operations.


A stiff construct and a solid column ensure that this mill machine doesn’t tilt to the sides, which is unique among mini mills. And with an air spring head support, you’re sure to get even support throughout the Z-axis during machining.


The Little Machine Shop 3990 mini mill has a large-sized worktable which provides you with 50 percent more table area than other similar mills. Also, the mill machine has 30 percent more travel in every direction. And with its resettable feed dials, you can bring the feed to zero whenever you want.


With a 500 Watt brushless spindle drive motor, the Little Machine Shop Hi Torque 3990 mini mill generates enormous low-level torque, along with an extensive variable speed ranging from 100 to 2500 RPM. And since there are no gears, this Little Machine Shop mill is the quietest in its class.


We customize the LMS milling machine to match your exact requirements and ship it to you completely assembled, so you can simply plug in and run it hassle-free.


Also, a Little machine shop 3990 mill CNC conversion kit can turn this milling machine into CNC.

HiTorque Mini Mill 3990: FAQs

What does a HiTorque Mini Mill package include? 

Our HiTorque mini mill packages are equipped with all the essential accessories for effective milling and drilling operations, including: 


  • Drawbars 
  • Locking pin for the spindle
  • T-slot nuts 
  • Drill chuck arbor
  • Hex, open-end, and spanner wrenches of all sizes


In addition to this, we also provide a detailed user guide from Little Machine Shop with each of the mini mill units. 

Can you assemble the LMS 3990 mini mill by yourself? 

Yes, you can. 


Unlike its heavy industrial counterparts with complex machining components, the HiTorque mini mill is a very basic and straightforward machine. And that not only makes it simple to use but also easy to assemble. 


In fact, the LMS HiTorque mini mill user manual, which is a part of the milling machine package, includes a detailed step-by-step assembly guide.


This makes the 3990 mill machine assembly highly DIY-friendly, something you can complete by yourself without any expert assistance. 

How to make a HiTorque 3990 mini mill operational? 

Making a HiTorque milling machine operational is effortless. So much so that your mill should be up and running in three simple steps: 

Step 1: clean the mill up

After you’ve unpacked the mill, you’ll need to thoroughly clean and degrease it. 


You see, the LMS mills we ship have a grease coating to make them corrosion-resistant. So, you should wipe this grease layer off, clean the machine surface using paint thinner, and apply an oil coating on it.

Step 2: assemble the mill

Having finished the initial cleanup, you can now assemble the milling machine. 


Assembly includes installing the X and Y axis handles on the respective axis wheels, among others. And you can complete this by following the user guide. 

Step 3: mount the mill on a bench

Before you can start running the mill, it’s important that you mount and bolt it atop a compatible bench or worktable. 


Running a HiTorque mini mill without mounting and bolting it to the worktable is highly dangerous and poses safety risks. 


Thankfully, you need not wait for a machining professional or expert to do the mounting for you. That’s because you can mount the mill with the help of two-three people and by following the user manual. 

How to maintain your LMS mini mill? 

Maintenance is one of the most important aspects of long service life and optimum machining on any mill. 


And while the large mills need extensive maintenance, that’s not the case with a HiTorque mini mill from Little Machine Shop, which only needs regular cleaning. 


Chip formation during milling is a common issue across mill machines of all sizes, including the HiTorque 3990. And if left unattended, this can damage the machine in the long run. 


Nevertheless, you can clean and remove chips off your HiTorque mini mill easily with the help of a 1-inch brush. 

Are LMS HiTorque mini mills CNC? 

The HiTorque mini mill from Little Machine Shop is available as a manual milling machine. 


However, LMS also manufactures CNC conversion kits for these manual mills to help turn them into CNC milling machines. 


For instance, the Little Machine Shop 3990 mill CNC conversion kit is available on the market as a cost-effective solution to turn these mills into CNC.

How to turn your LMS mill into CNC? 

Turning a manual mini mill using a CNC conversion kit isn’t easy since it calls for expertise and years of experience. 


Nonetheless, you can rest easy, as we’ve got your back. 


We are seasoned CNC conversion experts with decades of hands-on experience in turning manual mills into CNC. So you can send your LMS HiTorque mini mill to us, and we’ll convert it to CNC. 

Can you get a customized LMS HiTorque mini mill?

Certainly, yes. 


You can reach out to us for any personalization requirements on your LMS mill or just about any turn key machine. We will optimize the mill to precisely to your specifications and ship it back to you. 

How to get a HiTorque mini mill delivered? 

We offer quick pan-American shipping of all our products, including the LMS HiTorque mini mill. Meaning you can get these mills, and more, wherever you’re located in the country. 


Also, you can avail of our special shipping offers, including free shipping on CNC conversion kits.