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Discussion in 'MACHINE RESTORATION & WAY SCRAPING' started by expressline99, Jun 3, 2017.
OK great I will see if I can get a 6"
A 12" . 0005 per foot level is plenty accurate and precise enough to level your plate. Without a good foundation isolation pad, your concrete floor will move the plate more than that.
I ordered the Shars 8" .0005 level. I am picking up 2" .120 square tubing to build my stand Monday. At least with the level and a 3 point support system I should be able to check it occasionally and fix any movement that happens. I've got to do the same with my lathe once I have the chip pan done....and the mill also. I hope to scrape both in but I will need some large squares also to get that done. After I make the straight edges. If I got done this year with one machine I'd be happy.
We used to call this a Gasoline overhaul, clean, flake, paint
You can do a lot using the tailstock base, a precision level and an indicator.
Just out of total curiosity what is a foundation isolation pad? I don't have that I've got a 43+ year old concrete floor that isn't level.
I can tell you the logan and the bridgeport didn't get any kind of overhaul. the BP was a total mess and still going. But until you guys told me about it I wouldn't have guessed people did this.
Getting closer everyday. The replacement level is here(first one was broken in shipping) and I got an indicator base that is adjustable enough to get where I need it...I think.
It should be known that reading the Connelly book will warp your mind...at least it has mine. Now I've got this twisted thought process that is a datum point chain of surfaces interlinked into cumulative errors. Any of which could be multiplied by missing anything on your own test record...if you don't continuously update it and recheck constantly. The lathe not so bad on interlinked points if you follow standard operating procedures in getting it back to proper alignment...flatness and parallelism. Scrape straight down...not a problem if you do that everywhere based on all nearby points of reference. The mill TOTALLY different amount of points of reference and various datum collection areas and how it can end up way off down the chain if you are not careful! &)
Agreed, Paul. Taking shortcuts or using an ill advised sequence of operations when trying to get a mill geometrically correct will only make it more difficult to achieve and less likely to succeed in the end. Everything affects everything else. All corrective work must start from the machine datum point, in the case of your vertical mill the column face. Trying to fix a problem by working where it is first discovered will only make things worse overall and waste time and effort. Things work out better if you get each surface tested correct and finished in the proper order before moving on to the next one.
OK I gave practice scraping a shot. This was on a piece of scrap CI I had laying around. ...I spent forever and learned I do a lot of side gouging. Anyhow....8hrs on something that has no use on purpose. Gotta learn before I touch those machines! I did not mill this flat...milling machine table still in pieces. So there were band saw lines and it was a sloppy mess. I will mill before I try again and it will be on a usable tool of some sort.
Don't slaughter me I'm being brave throwing these out there. I'm not impressed with how it looks either. But it's a start.
This was actually about 10 passes in. The piece was just a cut off Cast Iron throw away piece...lots of bandsaw lines. by expressline99 posted Aug 20, 2017 at 3:05 PM
20 passes in ...can't really see much difference from the beginning. Except I've gouged a bunch more. by expressline99 posted Aug 20, 2017 at 3:05 PM
30 passes in. Slow going A little difference... by expressline99 posted Aug 20, 2017 at 3:07 PM
40 passes in. Changes take a long time. But keep going. lol by expressline99 posted Aug 20, 2017 at 3:07 PM
50 passes. confidence was low at this point. by expressline99 posted Aug 20, 2017 at 3:08 PM
60 passes. End of first 4 hours of trying. by expressline99 posted Aug 20, 2017 at 3:08 PM
70 passes and seeing some real progress I think. by expressline99 posted Aug 20, 2017 at 3:10 PM
80 passes and my contact points were breaking up as I went. Probably a bit too soon. Edges still really low. by expressline99 posted Aug 20, 2017 at 3:10 PM
90 passes and bearing points still too far part.... by expressline99 posted Aug 20, 2017 at 3:14 PM
100 passes. Between 90 and 100 I started using a much smaller scraper blade..and lots sharper. It took material off quickly. by expressline99 posted Aug 20, 2017 at 3:14 PM
100 passes different view... first time trying without help. by expressline99 posted Aug 20, 2017 at 3:16 PM
Paul, it is really difficult to learn the bare basics of scraping without a mentor looking over your shoulder and telling and showing you how to make it work. Some of what is being done by the scraper is not learnable from reading a book or watching a YouTube video. Once you have each bit explained and demonstrated to you, progress will be much faster, with the mentor also coaching you on what to do from where you are in the process. I am certainly not that person. I did show you your first hour or so of scraping on a small part, but that was only intended to start the engines, not to let you be pilot in command. You are gaining on the piece, but also making mistakes that greatly slow down the work.
What scrapers did you buy, and what radii do the blades have? To help stop the scratching, use a tool with enough radius to keep the corners away from the work. Also dull the corners of the blade each time you sharpen it, including the corners of the insert and the ends of the working edges. Make sure you are getting a smooth sharpening job without scratches in it, finishing with a fine diamond hone on both the cutting edges and the flats adjacent to them. If you can see or feel scratches or nicks on the tool, you will get scratches on the work. You must keep the scraper parallel with the work, which is mostly done by watching where it is cutting along the edge of the blade. You must have it cutting close to the center of the tool, especially as a beginner. I still have that problem myself at times, and it is damned annoying. Like everybody does, you are changing to finish scraping long before the work is flat. It is a huge waste of time, but all of us do it until we really learn better. Until the piece is flat, cut off metal with vigor, lowering the high areas until they are even with the lowest area, and not a bit more. After the area coverage of the work is good, no blank spots, then start working the highest and brightest spots, moving into finish scraping. But you are not nearly there yet on the piece you posted. It is really frustrating removing a lot of metal from a part with a scraper, a mill does a lot better job. When the work is within a couple thou at worst, over the entire area, then start scraping...
Don't lose faith, you WILL get there if you keep trying, and lots faster if you do it the right ways. Get some real help from a good mentor...
Sandvik handle. I used only the donated scraper blade you gave me and one from several that another member graciously gave me. Both were Sandvik with the identical radii.
I went back to the "book" tonight and was rereading. I caught the same error you just pointed out. The switching to finish scraping too early. The second I read it again in the book I knew that's what I did. There were some other factors in the odd scraping...I was in a rather demanding stance. This should get a laugh. the only workable vice I have setup is a large work vice. It's mounted to the workbench. The workbench is higher than scraping height....the vice adds about 8-9 inches higher. Did I mention I had to stand on a milk crate to get up high enough? Thought I'd make it hard on myself. I realize the piece posted isn't even close. But I started. So I can start correcting. As well, I've learned that I can go through the motions for hours and not be in physical pain even with poor results I can't be the pilot yet? The engine is moving WOT.
I need a diamond wheel setup for sure and I'll be doing that shortly.
With all the time I spent working on this. I'm not even beginning to lose faith. It's a fine art I will work at until I get it right. Getting help from a good mentor is hard if they aren't right here. A lot of time in between "classes" is even harder. I don't want to know how to scrape by yesterday. But I want to know I am learning today and tomorrow and I want to go to the actual scraping class when it becomes available to me.
Keep helping me I do really appreciate it. Even if you have to pull on the brake as hard as possible sometimes.
I still spend more time correcting my mistakes than any part should need and I'm slow at it.
When you have to scrape a lot of material because you haven't the capacity to machine a part flat, there's a tendency to
use too much force as well as hurry which results in scratches , gouges, and rolled edges.
Then you have to take the surface down even further to clean it up.
Or, as Paul pointed out, you might find yourself scraping gingerly when there's a lot of material yet to come off.
Well, that's why they call us beginners or amateurs.
What's real fun is that I need to do work on the mill....and take pictures while I do so. Right now the table is off of it and other pieces....And my other lathe project requires parts to be milled to being what needs doing on that. Plus my scraping bits could use some milling to have a decent place to start.
I was doing all of that. Not taking off enough... then pushing too much. Rolling the tool Causing scratches and gouges. The edges are still under the plane of the mostly high center now. I might mill it off If I put the table back together this week. Ken was going to help me shim the gib on the saddle to take up the slop. ...the gib is high in the center for whatever reason. So some control over that would be good.
I really need a proper way to sharpen these. Accu finish seems way outta range at $800+++. I've got a green wheel so I can probably manage the initial grinding. But the honing I am not sure of. The blades I have now were sharpened by the donors. Anyone use a tormek? Or any reason not too?
The 30mm wide Sandvik blade I gave you is pretty big for that small work piece, but useable. The real problem is with the radius on that blade, which is way too shallow for anything but a real pro doing a big surface. It is almost impossible to not have gouging with that blade as Sandvik made it, regardless of the beautiful grind on it. When you reduce the radius, I think you will be much happier with it, at least on bigger surfaces...
Edit: I thought I mentioned that when I gave it to you...
Ulma Doctor (Mike Walton) made this one for dirt cheap: https://hobby-machinist.com/threads/shop-made-diamond-tool-sharpener.34775/
It works great!
I made an attachment for my surface grinder for $10 invested in the wheel and scrap around my shop. I would like a Glendo -- for free!
You may have mentioned it but I think I totally spaced it. Good then my gouging is because of that.
Others have had the very same problem... Also make sure you hone the blade often, and check for chipped carbide or a dull blade any time you see scratches in the work. For me, it is usually the nut behind the handle that is the real problem.
So I actually had to read that and come back and read it again "NUT" I thought I should probably check and see if that is tight. OH the"NUT" lol
I'm sure it was a dull blade most of the time. Figure I didn't hone anything....don't have a way to yet. Add another strike.
What is the bare minimum speed of a a Diamond wheel setup? I swear the setup motor I've got is geared way down. So maybe too slow even at full speed? I've played with the controller to the point I think I've reached it's max frequency for this motor. But seems slow. I'm going to setup a Diamond wheel hone and have most of the parts already. Wheels/backing plate/controller/motor. Small bench top stand yet to be built But I have the steel. A Simple tilt table...only need 3 degrees so that might just be a fixed setup super simple.
I ran 220 over to my bench to run the controller so that part is in place...anyway. What RPM? I don't know if this gets up to 300 even. I can post pictures of the motor plate and gear box if that helps. Maybe I have the controller setup wrong?
The speed (surface feet per minute, SFM) is dependent on the diameter where the contact is. SFM is determined by diameter and rpm.
OK Gotcha, I'll be using 6" wheels. I'll figure out the max RPM so I can see what it is.
My GrindRLap runs at about 400 rpm. It has a 5" OD diamond wheel with a 1" wide face on it. I don't remember the grits, something like a 240 and 800. Also have a disc that can be charged with diamond for lapping.
OK I've got the word that my motor runs at a max of 200 RPM with a 6" disc I will be mounting. So looks like 314 sfm at outer edge of disc. I really want to find one of those Grind-R-Lap tables. Otherwise I have to make one. That'll be fun I don't have a rotary table yet.