Building a Factory Engine, Elmer's #41 (Finished on 2-28-10)
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Here's some information on the subject of lapping and lapping compounds. Also give you an idea of what products are available.
http://www.americanlap.com/Lapping Compound.htm
-MB
http://www.americanlap.com/Lapping Compound.htm
-MB
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#84 In my last build post I machined up the crank disc. Before starting on another part I finished it up and added a .250" stainless steel shaft. I included the 'connecting rod' in the picture, with the use of my modified two piece version of a 'crank screw'.
#85 It was time to get back to the 'floor' and finish it up by drilling all the counter sunk holes.
#86 The 'base' shown in this photo required an assortment of clearance oles and tapped holes. I need to get back to this piece and mill the two slots for the 'anchor lugs', and mill the 1/2" wide clearance slot for the flywheel. There are a few "fake" details on this plan that I will omit, but the "optional" draft (angled sides) detail will add a nice visual that's worth the effort.
#87 In the picture below, and from the top down is the 'floor', 'sub base', and 'base'. I broke off the tip of a #44 drill bit in the 'base while drilling the second hole at the top to be tapped 4-40. Luckily I was able to plot the location, and flip over the base to drill from the underside. When I hit the broken off piece I stopped the machine and pushed it out. Two bits hit the can, but much better than loosing the work piece.
#88 To make the 'bearing's' I started by drilling and tapping them from the underside.
#89 The optional 5/8" hole detail was very strait forward. Using a 1/2" collet mounted edge finder, I zero out the spindle axis on two edges of the work piece. After shifting the tables to the proper location, I switched it out for a 5/8" collet and center cutting four flute end mill to add the hole.
#90 On a second 'bearing' block I wanted to try out the idea of eliminating the "optional" hole detail, and adding an arched detail at the bottom instead.
#91 With the experimental stuff out of the way, it was time to profile a usable 'bearing' block and continue on with the build's progress. I scribed the profile lines as a way of over seeing the cuts I would make using calibrated table moves. I determined the angle to be 20 degrees, and used an angle plate taped to the fixed jaw to set up the part for milling.
#92 Before milling the taper's it seemed a logical first step would be to mill down the upper part of the 'bearing' block to a 3/4" width by taking off a 1/4" from each side.
#93 The fist step in making the bearing cap detail was milling down 1/8", and up to the scribed line at the 9/32" radius. In the plans there are fake hold down studs and nuts shown. I don't care for this "fake" detail and I will not be adding them to my build. The rounded cap detail is cosmetically pleasing, adding the phony hardware seems to cheapen it with dishonesty. I think I'll pass on this detail, thank you.
#94 The next step was to machine up some steel buttons to aide in the hand filing needed to create the rounded bearing cap detail.
#95 Below is a picture of the bearings finished up with the cosmetic caps filed to shape. There is a faster and more accurate way to create these from two pieces by drilling a hole to match the radius, and adding a machined bushing after milling down the cap 1/8". The bushing will be held captive by the top of the (milled down) block which will be higher than the center-line of the drilled hole. Depending on the metal of choice, a little Loctite or solder will hold it together nicely.
-MB
-MB
#85 It was time to get back to the 'floor' and finish it up by drilling all the counter sunk holes.
#86 The 'base' shown in this photo required an assortment of clearance oles and tapped holes. I need to get back to this piece and mill the two slots for the 'anchor lugs', and mill the 1/2" wide clearance slot for the flywheel. There are a few "fake" details on this plan that I will omit, but the "optional" draft (angled sides) detail will add a nice visual that's worth the effort.
#87 In the picture below, and from the top down is the 'floor', 'sub base', and 'base'. I broke off the tip of a #44 drill bit in the 'base while drilling the second hole at the top to be tapped 4-40. Luckily I was able to plot the location, and flip over the base to drill from the underside. When I hit the broken off piece I stopped the machine and pushed it out. Two bits hit the can, but much better than loosing the work piece.
#88 To make the 'bearing's' I started by drilling and tapping them from the underside.
#89 The optional 5/8" hole detail was very strait forward. Using a 1/2" collet mounted edge finder, I zero out the spindle axis on two edges of the work piece. After shifting the tables to the proper location, I switched it out for a 5/8" collet and center cutting four flute end mill to add the hole.
#90 On a second 'bearing' block I wanted to try out the idea of eliminating the "optional" hole detail, and adding an arched detail at the bottom instead.
#91 With the experimental stuff out of the way, it was time to profile a usable 'bearing' block and continue on with the build's progress. I scribed the profile lines as a way of over seeing the cuts I would make using calibrated table moves. I determined the angle to be 20 degrees, and used an angle plate taped to the fixed jaw to set up the part for milling.
#92 Before milling the taper's it seemed a logical first step would be to mill down the upper part of the 'bearing' block to a 3/4" width by taking off a 1/4" from each side.
#93 The fist step in making the bearing cap detail was milling down 1/8", and up to the scribed line at the 9/32" radius. In the plans there are fake hold down studs and nuts shown. I don't care for this "fake" detail and I will not be adding them to my build. The rounded cap detail is cosmetically pleasing, adding the phony hardware seems to cheapen it with dishonesty. I think I'll pass on this detail, thank you.
#94 The next step was to machine up some steel buttons to aide in the hand filing needed to create the rounded bearing cap detail.
#95 Below is a picture of the bearings finished up with the cosmetic caps filed to shape. There is a faster and more accurate way to create these from two pieces by drilling a hole to match the radius, and adding a machined bushing after milling down the cap 1/8". The bushing will be held captive by the top of the (milled down) block which will be higher than the center-line of the drilled hole. Depending on the metal of choice, a little Loctite or solder will hold it together nicely.
-MB
-MB
Glad to see you back at it! Quick question: What is a "tenths micrometer"? I know that I just exposed my newbie side but hey, we're family here, right?
Ed
Ed
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BigBore said:
A micrometer with graduations that show a fourth digit. Example would be .5002, the 2 is the fourth digit that indicates two ten thousands (2 tenths) . .0008 more and the reading would be .5010. meaning .501
Some mikes don't have the secondary graduations and can only be read in thousands (three digits,).
When doing plan conversions it's good idea to calculate using four digits to avoid cumulative errors. They can and will happen if you don't.
-MB
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BigBore said:
Ed. Here is something you might read and find interesting.
Lots of good information with good pictures and also incudes adjusting information.
http://www.starrett.com/download/222_p1_5.pdf
-MB
Much appreciated. I know what a .0001 mic is just haven't learned all the lingo yet. I'll get there (with you guy's help)
Ed
Ed
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BigBore said:
I' not sure if that IS the correct "lingo".
I spend most of the day talking to myself.
so...I usually understand what I'm saying...I think. ???
-MB
Sounds like you and I went to different schools of thought together. scratch.gif
Ed
Ed
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Nice build you got going here. One thing that always strikes me is how clean your mill and vice are? Are they really that clean or do you dress up the photos a little before posting??? :big:
Chuck
Chuck
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cfellows said:
Hi Chuck. That's a good question. Some of the pictures are taken after brushing off the work piece and vise, But, many are taken mid stream by stopping during a machining operation. Those usually include all the resulting swarf. Sometimes I take a picture while the part is being (power feed) machined using my free hand(s).
During the course of a typical day I take time to keep thing somewhat civilized. If I'm making a lot of swarf I stop and vacuum up the mess before taking the next cut. In some of my pictures you can see tools becoming buried under the mess. This can become annoying enough to stop and clean up, but just enough to continue with the current piece. I usually do a 90% clean up at the end of the day. Its a nice to start out the next day in a clean shop.
I was milling a lot of aluminum today, and stopped five or six times to clean up the bulk of the mess. Aluminum is amazing stuff, you mill a half pound off, and end up with half a bushel of fluffy swarf! :big:
-MB
zeeprogrammer
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1hand said:
Ah...hadn't noticed. I agree with Matt.
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I appreciate all the supportive comment posted by the wonderful members that I also consider to be friends.
Sorry, but I can't do it! It seems like the 'real' part of me died. I made the decision hastily and already regret the change. The change makes me feel like a sleaze bag. I have a long way to go to become a "Master" at metal work. I can't go forward living with a lie. I hope you can understand where I'm coming from.
A butcher cuts meat, and a metal butcher cuts..well, metal. The name never meant anything more or less.
"To thyself be true"
MB
Sorry, but I can't do it! It seems like the 'real' part of me died. I made the decision hastily and already regret the change. The change makes me feel like a sleaze bag. I have a long way to go to become a "Master" at metal work. I can't go forward living with a lie. I hope you can understand where I'm coming from.
A butcher cuts meat, and a metal butcher cuts..well, metal. The name never meant anything more or less.
"To thyself be true"
MB
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#96 I'm back with very little progress to report. It may be a while till my next post. I ran into a major 'snag' in the eleventh hour of this build. More on that a little later.
In the following picture I show the 'base' being milled with a tapered end mill to add the optional 'draft' detail. On a previos build of another model I used a 3 degree tapered end mill and produced a very acceptable taper. On this build I used a 5 degree tapered mill that gives approximately a .444" offset on a 1/2" work piece height. The plans call for a 1/16" offset which would require roughly a 7 degree taper. since I don't have that on hand I settled on the 5 degree taper, and it turned out well.
#97 I held the workpiece with 1/16" of it in the vise. After test cutting a piece of scrap to determine the depth of the cut, the two long sides were tapered with one pass. Since the bottom end of the end mill didn't reach the bottom of the work, I moved the cutter in .003" creating a step that would file off easily to complete e the taper all the way to the bottom of the sides. This remaining 'step' can be seen in the pictures. The area that the bearing block bolts to is not tapered like the rest of the other three sides.
#98 I tapered the ends by advancing the cutter .001" at a time towards the work, and hesitating. I watched the cutter carefully for the little plume of dust, and listened for the following low pitch squeal, indicating the cutters "kiss" as I call it. After off setting the cutter the table was advances .040", and the taper was cut with one pass. This is an easy way to mill an non-critical area were plus or minus a few thousand's won't make any difference, can't be seen by eye, and isn't easily measured.
#99 When I milled the clearance slot for the crank disc I deviated from the plan. The way its shown in the drawing indicates cutting it out with a 1/2" wide x 2-1/2" mill cutter held in an arbor with the work held on its side. There are other ways to accomplish this but it seems the beginners that would try this build were not considered. I used a 1/2" end mill lowered to create a .500" deep trough, and did it with one pass up to a scribed stop line. This would be a simple and easy task for a horizontal milling machine.
#100 OOPS. I deleted the wrong picture. This is the one that's supposed to show the 'anchor lugs'. I used a tight fitting pivot pin held at the far end of my mill vise to round over the ends on the 'lugs' using an end mill. Sometimes I do this type of profile using a vertical belt sander. It takes a bit of practice to get good results, but its a really easy and quick method. I haven't re-grown the extra layers of skin (finger prints) protecting the nerve endings on my fingers from the last time i used this method. I guess I could use a little more practice to perfect my 'belt sander' method.
#101 Here's the "snag" that I ran into. The fly wheel casting I planed on using turned out to be full of what appears to be black sand. I kept cutting to remove them and ran into more. It was a futile attempt that left me frustrated. I tried to machine a second one and ran into the same problem. I continued the machining and now I have two under sized fly wheel with holes. Wonderful, what are the odds of two bad ones in a row. I'm very close to the end of the build, and the replacements will probably take a week, if I"m lucky. I can't contact PMR till Monday to see if their willing to replace them. I might just get up tomorrow or Monday and decide to make my own. What a miserable waste of time it was machining up these defective castings.
#102 I added this second picture so the problem could be clearly seen.
Back to the drawing board.
-MB
In the following picture I show the 'base' being milled with a tapered end mill to add the optional 'draft' detail. On a previos build of another model I used a 3 degree tapered end mill and produced a very acceptable taper. On this build I used a 5 degree tapered mill that gives approximately a .444" offset on a 1/2" work piece height. The plans call for a 1/16" offset which would require roughly a 7 degree taper. since I don't have that on hand I settled on the 5 degree taper, and it turned out well.
#97 I held the workpiece with 1/16" of it in the vise. After test cutting a piece of scrap to determine the depth of the cut, the two long sides were tapered with one pass. Since the bottom end of the end mill didn't reach the bottom of the work, I moved the cutter in .003" creating a step that would file off easily to complete e the taper all the way to the bottom of the sides. This remaining 'step' can be seen in the pictures. The area that the bearing block bolts to is not tapered like the rest of the other three sides.
#98 I tapered the ends by advancing the cutter .001" at a time towards the work, and hesitating. I watched the cutter carefully for the little plume of dust, and listened for the following low pitch squeal, indicating the cutters "kiss" as I call it. After off setting the cutter the table was advances .040", and the taper was cut with one pass. This is an easy way to mill an non-critical area were plus or minus a few thousand's won't make any difference, can't be seen by eye, and isn't easily measured.
#99 When I milled the clearance slot for the crank disc I deviated from the plan. The way its shown in the drawing indicates cutting it out with a 1/2" wide x 2-1/2" mill cutter held in an arbor with the work held on its side. There are other ways to accomplish this but it seems the beginners that would try this build were not considered. I used a 1/2" end mill lowered to create a .500" deep trough, and did it with one pass up to a scribed stop line. This would be a simple and easy task for a horizontal milling machine.
#100 OOPS. I deleted the wrong picture. This is the one that's supposed to show the 'anchor lugs'. I used a tight fitting pivot pin held at the far end of my mill vise to round over the ends on the 'lugs' using an end mill. Sometimes I do this type of profile using a vertical belt sander. It takes a bit of practice to get good results, but its a really easy and quick method. I haven't re-grown the extra layers of skin (finger prints) protecting the nerve endings on my fingers from the last time i used this method. I guess I could use a little more practice to perfect my 'belt sander' method.
#101 Here's the "snag" that I ran into. The fly wheel casting I planed on using turned out to be full of what appears to be black sand. I kept cutting to remove them and ran into more. It was a futile attempt that left me frustrated. I tried to machine a second one and ran into the same problem. I continued the machining and now I have two under sized fly wheel with holes. Wonderful, what are the odds of two bad ones in a row. I'm very close to the end of the build, and the replacements will probably take a week, if I"m lucky. I can't contact PMR till Monday to see if their willing to replace them. I might just get up tomorrow or Monday and decide to make my own. What a miserable waste of time it was machining up these defective castings.
#102 I added this second picture so the problem could be clearly seen.
Back to the drawing board.
-MB
Wow!
That's a whole bucket of suck! :redface2:
How common is something like that? What causes it? A small conciliation, I know, but for a beginner like me to see this is a good thing. I would not have had a clue. Your situation (unfortunately at your expense) has fulfilled the purpose of a forum like this. You educated several of we newer wannabes in a situation that is bound to haunt us someday. "K" point for your trouble. Thanks for posting.
Ed
That's a whole bucket of suck! :redface2:
How common is something like that? What causes it? A small conciliation, I know, but for a beginner like me to see this is a good thing. I would not have had a clue. Your situation (unfortunately at your expense) has fulfilled the purpose of a forum like this. You educated several of we newer wannabes in a situation that is bound to haunt us someday. "K" point for your trouble. Thanks for posting.
Ed
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ozzie46 said:
I had just the one 3 degree end mill last year. It came in a big box of mostly new assorted cutters, you name it, assorted stuff. Just about a month ago I bought over two (2)hundred new and re-sharpened end mills from a scrap yard for $72. Most of them tapered, tapered ball 1, 2, 3, 5, and 10 degree end mills. I'm bragging a bit, but for me it's the find of a lifetime.
Check out the price for new ones. Just make sure your sitting down in a comfortable chair. Their not carried by every supplier. I don't think Enco has them so don't bother looking there.
-MB
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Rick, when you get sand in a casting it's from either a poorly rammed mold or not blowing the loose sand off the mold before casting, in any case I don't see why they wouldn't replace them. I had good luck with my lathe castings but some of the engine castings and parts don't look that good.
George
George
