Scraping base with saddle

[Mel]

Hello all:

I'm scraping the ways of a mini mill base. I'm using both the saddle and a straight edge for bluing. Do I use the base first and scrape until I have full contact and then use the straight edge to scrape for bearing? Alternatively, do I scrape with the saddle, then scrape withe the straight edge, then go back to the saddle, etc?

Mel

 

[Richard King]

Hello all:

I'm scraping the ways of a mini mill base. I'm using both the saddle and a straight edge for bluing. Do I use the base first and scrape until I have full contact and then use the straight edge to scrape for bearing? Alternatively, do I scrape with the saddle, then scrape withe the straight edge, then go back to the saddle, etc?

Mel

Dear Mel,

I would first make a master out of the saddle and scrape flat on both sides on a surface plate be sure to hinge it to get the 30% airy /rotation points,. Indicate the saddle and keep it parallel to .0002" with 10 to 15 PPI. You will need t be a detective again and check the dovetails and cut out the bottom of the V so there is no ridge or burr down there. We discussed with a 3 bladed saw the edge of your scraper as shown in the Connelly book. Then with a short straight edge that you may have to make scrape the dovetail of the saddle flat and straight with say 2 to 5 PPI. It is so important to get it straight and not high in the middle. Once this is done use it alternatively with your straight-edge to scrape the top of the base.

I recall you first relieved the back of the base as I had warned you that you need to sub consciously scrape harder under the dovetail as it is harder to scrape and see under there But I believe you scraped to much sort of free handing with out bluing or the yellow highlighter to keep it the same angle. While scraping indicate the top of the base and saddle on top of the base ways to be sure all 4 corners are the same height again with-in .0002". When you have the top finished set the base on edge and scrape the least worn or best side of the dovetails using your angled straight edge keeping in mind the scrape it the same angle and get the 30% rotation points. Then set it on the base and slide in some dowel pins onto the dove tails and mic them or use a surface gage or small King-Way t get the dovetails parallel to within .0002" / 20 PPI

When you have the base mastered finish the saddle to 20 PPI using the base as a master, scrape the gib and when they are all done relieve the middle 40% low about 0005" to .001" on the saddle and gib only. So as it wears it gets flatter other then leaving it flat as it wears on the end it starts to get high in the middle and will "rock like a rocking chair".

I know this sounds like a lot of work, but after you get into the swing of it, it will go fast Call me if you can't understand my writing. I will attach some photo's of his mill plus some others that should help from other classes. Look at the Schubian Mill post and see the one picture where we ae standing around the surface plate. One of the other guys in the GA class has the same mill you have and he is indicating the table. Jan in that post is holding the little 8" triangle straight edge, I had it at the CA class. That will be something like the one you will need yo make to do the saddle dove.

To all the other readers Mel was a student in the CA scraping / rebuilding class. When we started his base was a mess, the bottom pads were not the same height. He had to get them all touching first and then we fly cut the base ways so it was parallel to the base. On a big machine this is no possible because you can't set the base on a surface plate, but on those mini mills you can and it helps speed up the job. I have attached some photos.

Rich

 

[Richard King]

More Photos: The Mini King-Way is set a little different then you will, set the cross bar on the bed and up against the dove and use a indicator
to check the other side. I think you will figure it out. Also see below how we held a gib for scraping. These were taken at the Alabama class we did in 2011. I also saw a guy in Germany scraping a lathe compound on You Tube that might be worth a watch. Now a days there is lots of places to learn. But I will always be on this forum. Rich

 

[Mel]

Thanks Rich. I'll let you know how it comes out.

Mel