More Accessories for Small Machinist Jacks

**Paul Jones** · Jul 30, 2015, 09:35 AM

I created a set of various accessories that swivel in the top of the machinist jack adjustment screw. The small machinist jacks (1.3” to 2” high) were previously described at Homemade Tools (see Homemade Machinist Jack ). I also added a knurled threaded ring (1/2-20 threads) as another way to lock the jack in place along with the original side screw used for positioning and locking the jack.

The parts were made from 1018 CRS and 0.250” O-1 drill rod. I left a narrower section at the bottom of the 0.251” reamed hole in the top of the jack screw for trapping a 0.250” ball bearing. The trapped ball bearing at the bottom of the hole acts a swivel point for the accessories. The machinist jack accessories include 5/16” ball bearings for uneven surfaces, v-groove and ball bearing swiveling head, and 0.250” rod for wedging into holes and narrow openings.

I used this same tool design of the machinist jacks for the 2016 "What's in your box too giveaway" tool donations to aspiring machinists (see http://www.homemadetools.net/forum/s...giveaway-51860 )

**DIYer** · Jul 30, 2015, 09:18 PM

Great writeup and detail. Thanks for this post.

**PJs** · Jul 31, 2015, 12:14 PM

Really nice Paul. So versatile and well thought out! Thanks for sharing the build. ~PJ

**C-Bag** · Aug 3, 2015, 05:16 PM

Very clean and nicely executed Paul. Good pix too. Thx for sharing.

Would love to see some of these in use. I'm learning everything about machining off of U2oob and now here. Machining more than anything I've ever done is improv. Engineer to stock as a colleague once said. So seeing the different points in use would help get my old inexperienced noggin' inspired. I recently acquired an old Starrett jack and it's already come in handy.

**Paul Jones** · Aug 4, 2015, 10:17 AM

C-Bag,
Normally we see these screw jacks used on milling machines to support long parts that must extend way beyond the mill table vise. However, I have seen some very good examples of machinist jacks in use from YouTube videos by Keith Fenner. See his YouTube video starting at about 24 minutes into the video "The Manual 3D Metal Printer Part Seven" where he uses screw jacks to support a part on a spinning lathe chuck. It looked dangerous but his screw jacks fit perfectly into the back of part so there was no chance of these flying out when the chuck was spinning. That is where I got the idea of adding the 0.250” rod attachment for wedging into holes or to use the ball bearing to wedge into a part recess. Thanks for asking, Paul

**kbalch** · Aug 4, 2015, 03:46 PM

Thanks Paul! I've added your Machinist Jack Accessories to our Jacks and Lifts and Machining categories, as well as to your builder page: Paul Jones' Homemade Tools. Your receipt:

Machinist Jack Accessories by Paul Jones

tags: machining, jack