June 2021 Scraping Class Photo's In My Cottage Grove, MN shop.

I will add captions tomorrow: More pictures too:

The following pictures are a MN student Duane testing parallelism of a Surface grinder column before we scrape it. It is close for a 30 year old machine. .0015. Note we have it on 3 points.

Here are some more. Duane Brought his newer Harig grinder that was like new, but he wanted to know how good it was. We tested the ways with a straight edge and King-Way and it never was worse then .0003" We tested everything on 3 points or some call it the Kinematic Mount Principal. Also Josh scraped the Bridgeport column.

Duane also brought a Sanford Surface grinder that was out .003 to .006" and we decided he would machine it and put on Rulon 142 in the July class starting in 3 weeks. We have room for 2 more students.
Pic's from L to R 1) Duane scraping his Sanford table flat just so we could check it, Duane testing table on surface plate, table sitting on the chuck surface we scraped flat prior, he is using a V block and dowel pin. It was out .006" so he is going to mill it and come back in 3 weeks when we do the July class 3) Harig Saddle sitting on 3 Points using the balance beam set up. That is where we use an oak 2 x 4 across the rear wings with a single block under the 2 x 4. Note we were able to move the single point and get the test to improve by .0003". We placed the single point under the center of gravity where the factory located the saddle feed screw. 4) Class picture of 2 men. Theses classes I teach inside my home shop you get more one on one instruction. 5) Josh scraping the ways on the Bridgeport column. They are coming to the July class: Josh is going to install new spindle bearings, install Rulon on the headstock, and finish scrape the machine.

Hi Rich, at first I thought you had mislabeled the pictures. That's because I had never heard of the 'Sanford Miniature Surface Grinder': I didn't recognize that little rectangular thing as a surface grinder table! Here's some info and photos for others in the same boat: Sanford Miniature Surface Grinder . Small is beautiful! Cheers, Bruce

I also thought pic 5 on second set of pics was mislabeled. It’s not a Bridgeport column. Probably a surface grinder column.

Nice to see the class reports.

L7

lucky7 said:

I also thought pic 5 on second set of pics was mislabeled. It’s not a Bridgeport column. Probably a surface grinder column.

Nice to see the class reports.

L7

Click to expand...

Josh said it was a Bridgeport surface Grinder column, he owns it. Bridgeport made grinders for a few years. I found this for a reference. 8'' Width 15'' Length Bridgeport 815 SURFACE GRINDER (Ref No: 152551) - Machinery Values

Hmmm, I stand corrected, thanks. Didn’t know Bridgeport made or badged surface grinders. I just knew it wasn’t a mill column….

L7

Duane Dickey wrote this review on the other forum at bottom on a thread I wrote.

Richard King 2 said:

Member Duane Dickey is attending this past weeks class and he is getting educated on how important it is to set columns, tables, saddles on 3 points when scraping and measuring for co-planer or parallelism. Cast iron bends and sags. If you just set a part on a table it will flex to it's own weight. Maybe not a lot, but if you scrape it as it sits, when you go to assemble or match fit it to the mating part it will be off. I am teaching today, so I can only post a few pictures now I posted more on my company forum (in the other forum, I have a King-Way forum) at the top of the lists. Yesterday I showed him what's called the balance beam or bridge support. Also on the photos' we put the single point under the feed screw hole on the saddle as when the factory built the machine that is the center of gravity of the part. We originally set it at 1/2 of the appearance and it was not as accurate. The machine we tested was a Harig surface grinder that the scraping looked new. The first pictures show the column of a Bridgeport grinder.

Duane wrote:
I knew about three points but I had never really checked or thought about checking. To actually see the readings change with the Kingway was quite educational and eye opening.
Thanks Rich for putting the class on, learned a lot.

lucky7 said:

I also thought pic 5 on second set of pics was mislabeled. It’s not a Bridgeport column. Probably a surface grinder column.

Nice to see the class reports.

L7

Click to expand...

Lucky, I was feeling a bit slow one morning and I recalled what you and the other guy at the Bourn $ Koch class you attended said to me. I went an drank 3 bottles of water...and in 20 minutes I was feeling good! Lance Baltzley has told me the same thing when he attends the classes (he's Adam Booths friend and they do You Tube shows together). Lance is a Vet...lol

Your student is going to do a much better job scraping than Bridgeport ever did. In about 1980 a shop I worked in bought one new. Within a year the scraping was gone between the table and saddle. It just rung together like a couple of gage blocks. And this was a shop where we were taught that grinders got oiled before you operated one.

The column on the grinder on the vertical ways the flats that face the operator the 4 corners were dead nuts and low .00015 in the middle due to wear. The inside vertical ways that hold the head sideways were also worn .0015 low in the middle, but were tapered from bottom to top .0015. The spindle head was built with no gib, so there is no way to adjust it or tighten it. We could slide in .009" on the bottom side of the spindle head. He is thinking about milling it so he can glue Rulon on the head or mill a taper and make a gib. He is buying new spindle bearings too. PS the fat ways also don't have gibs so he is going to have to either Rulon it or have the hold downs step ground. Pretty crappy design.