3D-Printable cover for 7x10/14/16 Minilathe Apron Gears

thingiverse

Many inexpensive mini-lathes use a rack-and-pinion system to move the carriage when the half-nuts are disengaged. This gear system is exposed to swarf and can jam with debris after extended use. I experienced this issue, and this part is my attempt to prevent it from recurring. There are several options for fixing this, e.g. [a homemade cover](https://sites.google.com/site/pjsminilathe/my-modifications/apron-mod), and this 3d-printable cover is inspired by that design. Installation: * Remove the Apron > Remove the set screw from the right end of the leadscrew. > Unscrew the leadscrew end bushing from the right end of the leadscrew. > Support the leadscrew with a block of wood or similar > Remove the right leadscrew mounting bracket > Disengage the half nuts > Remove the two Carriage to Apron mounting bolts while supporting the apron > Gingerly slide the apron off the end of the leadscrew banging it as few times as possible. * Prepare the casting > You do not need to remove the half-nuts, half-nut locking lever, or handwheel > Thoroughly clean the inside of the casting to remove swarf and oil. A solvent may be helpful, but use caution to avoid damaging painted surfaces. > Align the 3-D printed cover to the bottom edge of the casting and use the cover as a guide to center punch the location for the two mounting holes. > Confirm the mounting screws will not intersect the half-nut gibs or other mechanisms. > Drill, and tap the two mounting hole locations for M4 screws. > Clean the casting again to remove debris. * Installation > Lubricate the gears with grease. I use White Lithium grease from my local auto parts store. >If necessary, enlarge the holes in this 3-d printed cover to fit your screws. A printer that holds good tolerances won't need this. My printer does not, > Mount the cover with two M4x8mm screws. I used [Sutemribor 240 Pieces M4 Stainless Steel Button Head Hex Socket Head Cap Bolts Screws Nuts Assortment Kit + Wrench (Amazon Affiliate Link)](https://www.amazon.com/gp/product/B07CYM1N8R?ie=UTF8&psc=1&linkCode=sl1&tag=egreene-thingiverse-20&linkId=6134569d80110be15e2ddae01d87d16f&language=en_US&ref_=as_li_ss_tl) from Amazon because it's what I had on hand. [McMaster-Carr 97763A816](https://www.mcmaster.com/97763A816/) would also work. > Clean and lubricate the half nuts and dovetail mounts. I use grease sparingly for these as they are difficult to access, but oil might be better since it would trap less debris. * Reassembly > Slide the apron over the leadscrew > Reattach it to the carriage > Reattach the leadscrew support, end bushing, and leadscrew using care to keep the leadscrew straight. Sliding the carriage to the right end of the bed and engaging the half-nuts can help hold it in the correct position during reassembly. This was specifically designed to fit my Homier Speedway series Mini-lathe. Check the fit carefully before drilling holes in your machine. Note: I don't consider the swarf accumulation here a defect in the mini-lathe; Despite poor maintenance it worked properly for more than a decade. This is an improvement, not a bugfix.