Mill tramming device

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Mr Ron
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Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Mill tramming device

Post by Mr Ron » Sat Jan 05, 2019 12:36 pm

Harold_V wrote:
Sat Jan 05, 2019 2:59 am
Mr Ron wrote:
Fri Jan 04, 2019 9:10 pm
I have a 6x26 vertical knee mill, made in Taiwan in 1976. The ways are hand scraped.
I would be shocked if such a machine had scraped ways. They typically do not.
Easy enough to determine. Look at the ways. Do you see repetitive lines that parallel one another, often in a circular pattern? They're real obvious on a Bridgeport, even those with chrome ways. You also see what most folks think is scraping---which, in a sense----it is. It's flaking (some folks call it frosting, a term I don't care for), which is intended to do two things. One of them is to mislead you to think the mill is scraped, and the other one is to provide minute cavities in which a film of oil can reside.

True scraping will display a mottled surface, that has been flaked.

H
My mill is a Select model OB and unless they are lying, on page 2 of the service manual, it plainly states as a feature that; "ALL "WAYS" ARE HAND SCRAPED FOR PERFECT BEARING AND ALIGNMENT. THE TABLE IS GROUND FOR PERFECT SQUARENESS." In addition,it states "castings are high strength material. They are aged for several months, before normalizing and tempering, to minimize deformation." It goes on to state; "Anti friction bearings are procured from famous manufacturers such as SKF, FAG, NSK, etc....completely interchangeable world wide."

The mill was advertised in an old issue of Live Steam and that is where I learned about it. I bought it locally in the San Francisco area around 1977. At the time I was looking around for a used Bridgeport, but too much money. Overall, I'm very pleased with it. I only wish it had more X & Y travel, but for a hobbyist, I think it is ideal.

I have a picture of the scraped way on my phone and I will post it as soon as I can figure out how to transfer it to my computer.
Mr.Ron from South Mississippi

Harold_V
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Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Mill tramming device

Post by Harold_V » Sat Jan 05, 2019 5:11 pm

Interesting, and likely a reflection on the time period in which it was made. Current production techniques pretty much avoid the need of hand scraping, which is labor intensive. That process also limits the degree of precision of the machine, as it will be only as good as the equipment on which it was made, with no error corrections that are the result of hand scraping.

I'd enjoy seeing the picture of the ways, although I don't doubt anything you're saying.

One of the most impressive sites I ever saw was the day a new Fosdick jig borer was installed at Sperry Utah Engineering Laboratories, where I was trained. The scraping and flaking of the machine were much like fine art. Pretty beyond belief, really. Can't see it in this picture, but it gives you an idea of the machine in question.

H
Attachments
Fosdick Jig Borer.jpg
Wise people talk because they have something to say. Fools talk because they have to say something.

Mr Ron
Posts: 1825
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Mill tramming device

Post by Mr Ron » Sun Jan 06, 2019 5:30 pm

Harold_V wrote:
Sat Jan 05, 2019 5:11 pm
Interesting, and likely a reflection on the time period in which it was made. Current production techniques pretty much avoid the need of hand scraping, which is labor intensive. That process also limits the degree of precision of the machine, as it will be only as good as the equipment on which it was made, with no error corrections that are the result of hand scraping.

I'd enjoy seeing the picture of the ways, although I don't doubt anything you're saying.

One of the most impressive sites I ever saw was the day a new Fosdick jig borer was installed at Sperry Utah Engineering Laboratories, where I was trained. The scraping and flaking of the machine were much like fine art. Pretty beyond belief, really. Can't see it in this picture, but it gives you an idea of the machine in question.

H
Here is a picture of the way on my mill. Can you tell from it if it is scraped or frosted?
20180807_143940.jpg
Mr.Ron from South Mississippi

Harold_V
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Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Mill tramming device

Post by Harold_V » Mon Jan 07, 2019 2:37 am

I can't tell, but I'm also not well versed in scraping. What I can see is that the familiar pattern generated by grinding isn't there, which lends credence to the idea that the machine was scraped. No question it was flaked, though. That's real obvious. There's enough wear on the ways to disguise any of the original scraping, and I'm assuming it was there at one point in time.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

WJH
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Re: Mill tramming device

Post by WJH » Mon Jan 07, 2019 3:19 am

I bought the small one for my Taig CNC mill. You calibrate both DI's at the same point, parallel to the Y axis. Yes, yes. Mount a DTI off the spindle, on an arm. Did that for my Bridgeport, didn't feel like making one for the Taig. Dual indicators make the job go lightning quick.
Was it a luxury Gucci purchase? Yes. Is it super nice quality? Yes. Does it work? Yes. Am I happy with the purchase? Yes. Also supported a US manufacturer, and American jobs by buying it.

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MikeH
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Location: Greenville, SC

Re: Mill tramming device

Post by MikeH » Mon Jan 07, 2019 11:57 am

Mr Ron
Here is the first video in a 4 part series on build the Mill Tramming Device you are asking about.
Perhaps they will answer your question and/or give you some ideas.

Mr Ron
Posts: 1825
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Mill tramming device

Post by Mr Ron » Mon Jan 07, 2019 6:27 pm

MikeH wrote:
Mon Jan 07, 2019 11:57 am
Mr Ron
Here is the first video in a 4 part series on build the Mill Tramming Device you are asking about.
Perhaps they will answer your question and/or give you some ideas.
Thank you for the video. He makes it easy to make.
Mr.Ron from South Mississippi

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