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J Harp

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Hi All

I haven't been making much except mistakes lately. Made some parts for my mower last fall, then was out of the shop because of my wife's surgery.

There is a Gremlin in my basement who likes to carry off and hide my tools. In late 2011 I got an HF carbide grinder. I worked it over and got it reasonably well trued up and the rough edges taken off. The miter gauge was very sloppy, so I cleaned up the table slots and made a well fitted replacement bar for the gauge. The slots were unequal in width and roughly milled, I used files and abrasive paper to work them into shape, don't have a mill.

About the time I finished with the miter gauge the mowing and gardening season hit, and the shop work came to a halt for the season.

After various delays I got back into the shop about the first of this year. Did a few odds and ends, then needed to grind some lathe tools. I went to the ketch-all room where I had mounted the grinder and started to set up. Guess what, the Gremlin had taken the miter gauge. I searched the house from top to bottom, cleaned the basement, and moved scrap lumber and various storage containers to look for it. Still haven't found it, so decided to make a replacement.

A search of the junk box uncovered a piece of eighth inch steel with about a 5/8 inch flange on one edge. I set to work on that and after a few sessions of making tools to make tools to make tools, I got it made into a good solid miter gauge ready for graduating.

Then the fun started. I don't have anything with 36 divisions of a usable size, so I tried to use a protractor and pointer. I've spoiled three attempts, but I'm stubborn, so I'll sacrifice a bandsaw blade and make a disc for the left end of the lathe spindle, then grind off the marks I've already made and start again, and hope to get it right.

Question. Can someone who apprenticed and was made to file for 6 months or so give a tutorial on filing. I need to learn how to avoid the rocking-horse motion and rounded over edges which I'm plagued with? I've been filing for about 70 years now and still can't do it right.

Tip. When tapping blind holes in small sizes, take a narrow coping saw blade and cut off the end which will leave the teeth going the right way, put the blade into the hole and give a little twist and you can pull the chips right out. This will loosen chips which an air blast won't.

A link to online books. I was searching for filing tutorials when I came across this. Don't be put off by the list of woodworking books at the top, scroll down and you'll find machining and metalworking books.

http://chestofbooks.com/home-improvement/index.html

Jim
 
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Suddenly filing is a hot topic again. One of the things that I think is forgotten is that it is hard to be precise when the file is dull. Add impatience to the task and it's easy to start rocking the file and bearing down hard with one hand in an effort to see a lot of metal removed.

I got better when I bought some new files, including some that are kept in reserve: I see them as a supply, like drill bits or lathe tooling. Besides, I can try buying different types of files a couple of times a year when I order from tool vendors.

Don't forget that handles are required, unless you cut off the tangs as some do.

In no particular order, here's things I have tried to do to get better:

- Lift the file, only contact the work in the direction of the cut.

-Draw filing, pull toward you on the cut stroke.

-Pressure directly down on the file over the center of the work piece with one hand, lightly pull or push the file with the other hand.

-Count strokes: it's amazing that one-three strokes will do most of the work with a sharp file.

-Try the Course - Medium - Fine approach with different files, rather than whaling away with one file.

-Try to get closer with your machines before filing.

-Maybe filing is not the only approach: maybe another approach like sanding with a flat backup to the abrasive paper is more useful.

-Try filing buttons for rounded corners and guides for flat edges.

-Stroke file at different angles to see where you are working.

-Use dye to check your progress.

-Take workpiece out of vise and check with squares and calipers often, you'll see if you're going too far before you get so far you'll have to re-machine.

-find a method of workholding that is comfortable for you and also allows you to see your progress well. I found that a flat vise on my bench is better that the higher vise I was using before. Make jigs for workholding when required.

--ShopShoe
 
Another tip for filing, don't go at it like crazy, take your time. With a nice sharp file, slow strokes will let you feel what is going on better and help you keep it flat.

Yes, I did several weeks of filing when I started my apprenticeship. Made some 45/90deg and some 30/60deg angle setting plates. Moaned and groaned all the time while doing them, until the boss was happy with the result. Still use them today.

Paul.
 
Thanks for the replies.

dclark; No I don't have a filing rest, but it's on my to-do list. Thank you for the link, I have it bookmarked. I never imagined there were so many attachments for the Cowells lathe.

ShopShoe; I do try to practice most of the things you listed. I'll print this page and put it near my workbench so I can try to do better. I don't have a very good selection of second and smooth cut files, most of what I can find is mill bastard. Most of my better files come from flea markets, I look for those without scratches of other signs of abuse. After degreasing them I hang them in household vinegar for two or three days or a week and they come out sharp. Wash them off with hot running water and a fine brass brush, dry them with an old towel, give them a blast with a hair dryer, and they are ready to go.

Swifty; I try to do it the easy way as much as I can. I get as close to the line as I safely can with a small belt sander, a bench grinder or an angle grinder before starting with files and abrasive paper. The abrasive paper goes on a piece of cast iron on which I practiced scraping. If I'm working on an edge, I use a 1 2 3 block or something similar to help keep the piece square, this fence is just put down on the paper, not slid around.
 
Another tip for filing from another ex-apprentice who stood at a vice for weeks and months making try-squares and G-clamps and Toolmakers Clamps all by hand.
Before filing rub a stick of chalk along the face of the file. It stops filings "pinning" and sticking between the file teeth.
Then clean the file regularly with a proper "file card" short wire brush.
You'll be surprised at how much difference it makes. Particularly so with softer non-ferrous metals but also with steel etc.
 
Another tip for filing, don't go at it like crazy, take your time.

Best advice Swifty. Pinning is caused by to much pressure on the file.

Work at elbow level. Feet set at shoulder width. Rock the whole body with the stroke not just the arms. Rest the index finger on the top of the file and curve the other fingers gently under the handle. Let the file do the work, not you wrists. A tight wrist will skew the work.

Pick up the file at the end of the stroke and measure often to correct your stroke. Concentrate on getting a full stroke with the file with an ever-so-slight lift at the end.

Material is important. Close grain CI is a joy to file as is older stocks of 1012. Mistery metal and melted down automobiles don't make for a pleasant day of filing.
 
Thanks Hopper and starbolin;

I started on some filing today, but had too much to remove and found that an angle grinder and belt sander got rid of it a lot faster. I'll try to finish it by filing just to see if I can get it anywhere close. Got top find my granddaughter's sidewalk chalk. It's a small piece of plate I'm working on, a semicircle about 2.5 inches lengthwise. I have it down where one end is about .002 thicker than the other, but the middle is high as shown by the blue. If I can't get the hump down with a file, I'll go the scraper, and abrasive paper on a small CI flat.

My Google search didn't find Deanofid's tutorial in Tips & Tricks, I found it while browsing, a good read.

I was hasty when I posted the link to chest of books. It doesn't show the books directly, it gives the title and author, you copy and paste that into a Google search, and it will find the book which you can read online, get a PDF, of whatever.

Jim
 
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