• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
  • PLEASE: Read the FORUM RULES BEFORE registering!

An improved swarf shield for a mini-mill

hman

Active User
H-M Supporter-Premium
Joined
Feb 17, 2013
Messages
1,530
Likes
1,045
#1
Quite a while ago I mounted a DRO to my Harbor Freight 44991 (X2 mini-mill). I'd mounted the X axis scale on the back side of the table and used a piece of aluminum angle to cover it and protect it from swarf. Unfortunately, the "acccordion" swarf shield between the back of the saddle and the front of the column never did play nicely. I would get bunched up behind the saddle and restrict -Y tarvel. I finally figured out a way to improve the situation.

The basic idea was to mount the front of swarf shield at the top rear of the aluminum angle, about 3/4" behind the rear edge of the table, and the back at the top of the column mount. With no part of the shield below table level, it would leave that area free for the DRO scale, as well as a stop rod I wanted to add to the X power feed. But how to allow for the X motion of the table? My solution was to devise a sliding mount for the front end of the shield.

The sliding mount consists of three parts - a length of 1/2" OD copper tubing attached to the aluminum angle, a shorter length of 3/8" OD carbon fiber tubing (from a hobby shop), and a length of 1/8" rod. The first photo shows how the new swarf shield (a piece of .040" thick vinyl shower membrane) wraps around the rod and is captured in the carbon fiber tube. This tube slides freely inside the copper tube.

kHPIM4932.jpg


I drilled and tapped the top of the column mount to hold the back end of the swarf shield.

kHPIM4928.jpg


The next photo shows the setup I used to cut a 3/16" slot in the copper tubing.

kHPIM4918.jpg


The tubing was held in a wooden nest mounted on the mill table. The lower edge of the rear vertical board extended a little below the base, to align against the back edge of the mill table. The front board captured the tubing. A small nail, visible at the right end, kept the tube from rotating.

Because the slot had to be longer than available X travel, I milled as far as I could, then without moving Y, drilled another hole through the bottom of the tube, removed the nail, moved the tube over until the hole lined up with the original nail hole, replaced the nail, and milled some more. Rinse and repeat as necessary. The carbon fiber tube was slotted in a similar manner, using a 1/8" cutter.

The next couple of photos show my initial proof-of-concept test.

kHPIM4921.jpg

kHPIM4922.jpg


Seemed to work pretty well, allowing full motion of the table in both X and Y. The only downside I could see was that the clips I'd used to hold the copper tube in place got in the way a bit when I tried to brush away the accumulated swarf. I decided to mount the copper tube to the aluminum with epoxy instead. I first sandblasted a 1/2" wide area on top of the angle and on the lower part of the copper tube. These surfaces guaranteed excellent adhesion of the epoxy. The open ends of the tube also allowed making a somewhat wider swarf shield. Here's the result.

kHPIM4933.jpg


I'm continuing to test the new system. So far, so good. I now have full (4.1") Y travel available!

Though some swarf does get inside the copper tube from above, the open ends make it easy to sweep it out. The only downside I can see so far is that the tube will limit the size of work pieces I can mount directly to the table - I can only go about 3/4" beyond the rear edge. If necessary, I can slide out the swarf shield and raise the work piece with a couple thicknesses of 1/4" MDF.
 

9t8z28

Steel
Registered Member
Joined
Aug 16, 2016
Messages
28
Likes
2
#2
Looks good.
I mounted my Igaging scale to the front side of the X axis table. Instead of it mounted vertical I mounted it horizontal. The read-head was just below the surface of the table. I I did not use any of the factory mounting hardware, instead I used 6061 1/2" aluminum and made my own brackets and cover.
 

hman

Active User
H-M Supporter-Premium
Joined
Feb 17, 2013
Messages
1,530
Likes
1,045
#3
I'd considered mounting the scale on the front of the table, but couldn't figure out how to provide clearance for the table lock. Please post a picture of your installation!
 

9t8z28

Steel
Registered Member
Joined
Aug 16, 2016
Messages
28
Likes
2
#4
I'd considered mounting the scale on the front of the table, but couldn't figure out how to provide clearance for the table lock. Please post a picture of your installation!
Depending on how old your X2 mill is, it either came with short lock arms or long lock arms. The shorter arm came on earlier mills. Heres a link to the shorter arm http://littlemachineshop.com/products/product_view.php?ProductID=2885&category=
Heres a link to the longer arms which you most likely already have
http://littlemachineshop.com/products/product_view.php?ProductID=1477&category=
I purchased the shorter arms for another project I was going to do but wound up using it for the X axis table lock. Its shorter handle length gives better clearance for rotation beneath any vise mounted on the center of the table. I also lengthed the threaded portion so that it protruded just enough to clear the scale shield and the Y axis handwheel. I will try and upload pictures in a bit .
What kind of scales are you using?
 

9t8z28

Steel
Registered Member
Joined
Aug 16, 2016
Messages
28
Likes
2
#5
Here's a couple photos. Ignore the masking tape that says 6" scale. I had an issue with one of the scale readers so I was swapping them to see if I could find what was causing the problem. Also I started to add a homemade power feed so the left table endcap is made of aluminum. You would need to make a short aluminum plate to connect the left side scale mount which replaces the plastic endcap. I have since upgraded to a solid column and larger table. I have these custom pieces sitting aside already made up and not in use becauseI mounted the scale verticle on the back side of the larger table
http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/2A7F1AB4-A186-40D0-AB87-DFF8B579469B.jpg

http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/1DFF5D6A-760B-4477-A74E-2ADD56348ACE.jpg

http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/E888EABA-4F19-42A8-BB9F-017BEE5285C2.jpg

http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/4542121A-A361-4E2C-AF7B-BAD479766E8A.jpg

In the below photo you can see how I lengthened the threads of the lever and also how I attached the scale reader
http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/545A3DDB-408A-43DA-BA3D-86760F4F3864.jpg

http://i118.photobucket.com/albums/o89/9t8z28/Mobile Uploads/B3D65F75-56CB-4E2E-9576-C73CAF26C21F.jpg
 
Last edited:

hman

Active User
H-M Supporter-Premium
Joined
Feb 17, 2013
Messages
1,530
Likes
1,045
#6
Durn! Couldn't get photobucket to play nice on my computer, even when I disabled adblocker. I don't know how many posts you have to have to allow you to start adding photos to a post. But try clicking "Upload a file" just below the text area.

I'm definitely interested in what you've done!
 

9t8z28

Steel
Registered Member
Joined
Aug 16, 2016
Messages
28
Likes
2
#7
I cant figure this out. I've never had an issue posting photos on other forums :dejected: