AND, the cool part of that is that the Peace Tower was finished in 1927, Canadians, eh?
Another Rupnow 1 by 1
- Thread starter CFLBob
- Start date
Help Support Home Model Engine Machinist Forum:
You could try Basil's idea, it won't take off as much as you have left, but it should finish and polish your journals.I dreamed about this last night
Keep your fingers out of the way!
Doug
Keep your fingers out of the way!
Doug
I had an adventure trying to get Popsicle sticks last week without ordering them from Amazon or Walmart and wasting a couple of days waiting for them. Instead, I decided to use my 3D printer and wasted the entire week.
Starting from the beginning, I needed a G-code file and to get that, I needed a 3D solid model of a Popsicle stick. This didn't take long, and I quickly made a version 1 of what I started calling the Fat Popsicle Stick - because I wanted to put a nice handle on it.
The dimensions are that it's 5 inches long, the thick part of the handle is 1/2" tall, and the stick portion is 0.4" wide by 1/16" thick. Those numbers were completely PFA. I mean, I've had Popsicles, just not in the last 40 years or so. They seemed about that thick.
The first print failed. I watched it for the first few minutes and came in to do other stuff during the remaining hour the print would take. Just as I was about to go check on it my wife came in to tell me the thin, stick part was off the table. I went out to check it out and figure out what to do. I thought about putting a spot of glue under that end and pushed on the very end to see if it was flexible When I did that, the whole thing popped off the print bed. No choice left but to kill the job. The good news was that it was about 3/4 done and probably usable. So I gave it a try and found two problems. First, it was too wide. The design was 0.40, but it came out a little wider. When I wrapped sandpaper on it, it was too close to the .438 of the journal. The second problem was that it felt too flimsy.
Within a few minutes, I had a redesigned "Version 2" stick ready to print. I doubled the thickness of the stick portion to 1/8" thick. Stiffness in bending here is proportional to the fourth power of the thickness, so doubling the thickness should make it 16 times stiffer. The minor change was to drop the width to 3/8".
This began some arm wrestling with the printer that still isn't fully resolved, but during the start of this print, I noticed the right front area looked thin, meaning I should re-level the printer bed. That turned into updating the software in the printer to use some new features I found out about in a video refresher on how to level the bed.
OK, time to print Rev 2 and very quickly found a problem. The G-code was having it print the 1/8" thick part but left it the original 1/16" on the back. Then it went back to print the handle on top of that thinner area and it didn't even attach to it. A real mess. I ended up with two parts barely attached to each other.
So I removed it, started printing again and went into the house for dinner. After eating I went to check it and found it had printed the bottom half of the 1/8" thick part and then got lost. The extruder went the width of the stick up in Y and some random offset to the left in X. Totally FUBAR. It left me puzzling over which piece of software screwed up or if it was the printer hardware. There's three possible sources of software errors: the new firmware in the printer, the slicer software that creates the G-code, or it could be that my CAD model had defects I can't see.
I decided to start everything over from scratch, except for leveling the bed. I redrew the model and sliced it with the other slicer software I have but isn't the one I regularly use, Cura. That required me to convert the model to metric in Rhino. That's not hard, just another step to do, but not having to do that is one reason I switched to the other slicer software, Prusa. Then I started printing the new G-code. This one printed fine and was done in an hour.
If you lost count, I had to print it three times to get one to come out right. The one that came out in two pieces is usable, I had to cut off the loose filament and glue that one together.
The Fat Popsicle Stick family. In the back is the Rev. 1 stick that popped off the bed before it was done, but was usable - except for being too wide. It has 220 sand paper glued to it and I actually ran that on the journal for a little while. The one on the left is a second Rev. 1 that I printed accidentally. Second from left is the first Rev. 2 that printed in two pieces. I shaved all the loops of filament off the bottom of the back's top piece and glued it to the bottom. The odd looking white mess is what came out of the printer losing its X and Y coordinates. The last one on the right is the finished Rev. 2 stick that printed properly.
This was Saturday. On Sunday I went to work on the journal, which I had previously used a needle file on to get down to about .001 over. I used 220, 400 and 1000 grit. One end measures 0.3751 with my micrometer, the other end was 0.3752.
After that aggravation with the printer, I started a thread for help over on the 3D Printers forum and seem to have improved things. It's not as good as it was before all this started, but it's close.
Meanwhile, it's on to the rest of the lathe work on the crankshaft, after I make a couple of little tools.
Starting from the beginning, I needed a G-code file and to get that, I needed a 3D solid model of a Popsicle stick. This didn't take long, and I quickly made a version 1 of what I started calling the Fat Popsicle Stick - because I wanted to put a nice handle on it.
The dimensions are that it's 5 inches long, the thick part of the handle is 1/2" tall, and the stick portion is 0.4" wide by 1/16" thick. Those numbers were completely PFA. I mean, I've had Popsicles, just not in the last 40 years or so. They seemed about that thick.
The first print failed. I watched it for the first few minutes and came in to do other stuff during the remaining hour the print would take. Just as I was about to go check on it my wife came in to tell me the thin, stick part was off the table. I went out to check it out and figure out what to do. I thought about putting a spot of glue under that end and pushed on the very end to see if it was flexible When I did that, the whole thing popped off the print bed. No choice left but to kill the job. The good news was that it was about 3/4 done and probably usable. So I gave it a try and found two problems. First, it was too wide. The design was 0.40, but it came out a little wider. When I wrapped sandpaper on it, it was too close to the .438 of the journal. The second problem was that it felt too flimsy.
Within a few minutes, I had a redesigned "Version 2" stick ready to print. I doubled the thickness of the stick portion to 1/8" thick. Stiffness in bending here is proportional to the fourth power of the thickness, so doubling the thickness should make it 16 times stiffer. The minor change was to drop the width to 3/8".
This began some arm wrestling with the printer that still isn't fully resolved, but during the start of this print, I noticed the right front area looked thin, meaning I should re-level the printer bed. That turned into updating the software in the printer to use some new features I found out about in a video refresher on how to level the bed.
OK, time to print Rev 2 and very quickly found a problem. The G-code was having it print the 1/8" thick part but left it the original 1/16" on the back. Then it went back to print the handle on top of that thinner area and it didn't even attach to it. A real mess. I ended up with two parts barely attached to each other.
So I removed it, started printing again and went into the house for dinner. After eating I went to check it and found it had printed the bottom half of the 1/8" thick part and then got lost. The extruder went the width of the stick up in Y and some random offset to the left in X. Totally FUBAR. It left me puzzling over which piece of software screwed up or if it was the printer hardware. There's three possible sources of software errors: the new firmware in the printer, the slicer software that creates the G-code, or it could be that my CAD model had defects I can't see.
I decided to start everything over from scratch, except for leveling the bed. I redrew the model and sliced it with the other slicer software I have but isn't the one I regularly use, Cura. That required me to convert the model to metric in Rhino. That's not hard, just another step to do, but not having to do that is one reason I switched to the other slicer software, Prusa. Then I started printing the new G-code. This one printed fine and was done in an hour.
If you lost count, I had to print it three times to get one to come out right. The one that came out in two pieces is usable, I had to cut off the loose filament and glue that one together.
The Fat Popsicle Stick family. In the back is the Rev. 1 stick that popped off the bed before it was done, but was usable - except for being too wide. It has 220 sand paper glued to it and I actually ran that on the journal for a little while. The one on the left is a second Rev. 1 that I printed accidentally. Second from left is the first Rev. 2 that printed in two pieces. I shaved all the loops of filament off the bottom of the back's top piece and glued it to the bottom. The odd looking white mess is what came out of the printer losing its X and Y coordinates. The last one on the right is the finished Rev. 2 stick that printed properly.
This was Saturday. On Sunday I went to work on the journal, which I had previously used a needle file on to get down to about .001 over. I used 220, 400 and 1000 grit. One end measures 0.3751 with my micrometer, the other end was 0.3752.
After that aggravation with the printer, I started a thread for help over on the 3D Printers forum and seem to have improved things. It's not as good as it was before all this started, but it's close.
Meanwhile, it's on to the rest of the lathe work on the crankshaft, after I make a couple of little tools.
I thought I'd wait to update this thread until the crankshaft was finished, which I would have sworn would be a week or more ago but kept eluding me for various reasons. Most of which come down to learning a lot as I'm going. This picture is just posing. The counterweights are just sitting on top until I get a couple of screws for those spots.
Today's last operations were to cut the keyway slot on the long side, which required I make a tool to hold that long side the proper distance off the vise bottom and allow me to crank the mill's vise down onto it. I considered printing the tool but went with machining it out of aluminum.
I found a piece of slightly under 1/2" aluminum bar in my scrap bin, squared it up and drilled/reamed a hole. Since the shaft is 0.375, I used a .001-over reamer. When I cut the unneeded top off, I left it a bit higher than cutting the thing exactly at its midline, and lucked into the shaft snapping into the metal.
And now for my "oopsie". While cutting the short side to length, something bound on the lathe slide and then the cutter popped forward. The very end is boogered up. For about the last 1/32 or 3/64, the diameter is undersized.
I'm not sure what's next. I got my cast flywheel in from Martin Models and it needs to be readied, but I still have lots and lots to do. Plus I need to look at the lathe in terms of some maintenance. There seemed to be a bit too much play in it, and not just this one cut.
Today's last operations were to cut the keyway slot on the long side, which required I make a tool to hold that long side the proper distance off the vise bottom and allow me to crank the mill's vise down onto it. I considered printing the tool but went with machining it out of aluminum.
I found a piece of slightly under 1/2" aluminum bar in my scrap bin, squared it up and drilled/reamed a hole. Since the shaft is 0.375, I used a .001-over reamer. When I cut the unneeded top off, I left it a bit higher than cutting the thing exactly at its midline, and lucked into the shaft snapping into the metal.
And now for my "oopsie". While cutting the short side to length, something bound on the lathe slide and then the cutter popped forward. The very end is boogered up. For about the last 1/32 or 3/64, the diameter is undersized.
I'm not sure what's next. I got my cast flywheel in from Martin Models and it needs to be readied, but I still have lots and lots to do. Plus I need to look at the lathe in terms of some maintenance. There seemed to be a bit too much play in it, and not just this one cut.
I'm watching Bob. It is incredible what you learn from "Doing stuff". It really does become an incredible journey.---Brian
That is one fine looking crankshaft Bob! Can you just chamfer the end that got "boogered" and no ones the wiser?
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Thanks. That's better as a question for Brian; I'm trying to understand where that side goes and if simply cutting it off would even matter.
Bob---Look at your main assembly drawing. If you are asking about the crankshaft end, don't worry---it just hangs out in the air as I show on the drawing.---Brian
Just an update so that I don't want to fall so low in this category that I have to go into the second page.
I had been looking at the engine mounting plate for the next thing to work on, after I did some adjustments to my lathe to tighten the gibs and stop the compound rest from wobbling. It seemed like a fairly straightforward part to make, so I did that.
There's one spot where I went away from the prints. The bottom of the plate is relieved like this:
That's a 5/16 radius and depth. I can see two ways to do that. One is drilling vertically with a 5/8 drill bit and the other would be cutting those corners with a 5/8 ball end mill. I don't have either of those tools.
After a lot of puzzling over how to make this or if I go buy a new cutter, probably too much puzzling, I decided to change both of those to reflect what I actually have, a 1/2" drill bit and the cutout 1/4" deep. I don't see this as being particularly critical. There are some screws that go through the small holes, and worst case need to be 1/16" longer.
My real problem is that I've been following Mayhugh's 300 Ford Inline Six build and between his bead blaster (another tool I don't have) and the way he's painting his parts before they get assembled, they're so pretty that these parts just off the machines just look too raw now.
All that aside, time to pick the next part. Probably the cylinder.
I had been looking at the engine mounting plate for the next thing to work on, after I did some adjustments to my lathe to tighten the gibs and stop the compound rest from wobbling. It seemed like a fairly straightforward part to make, so I did that.
There's one spot where I went away from the prints. The bottom of the plate is relieved like this:
That's a 5/16 radius and depth. I can see two ways to do that. One is drilling vertically with a 5/8 drill bit and the other would be cutting those corners with a 5/8 ball end mill. I don't have either of those tools.
After a lot of puzzling over how to make this or if I go buy a new cutter, probably too much puzzling, I decided to change both of those to reflect what I actually have, a 1/2" drill bit and the cutout 1/4" deep. I don't see this as being particularly critical. There are some screws that go through the small holes, and worst case need to be 1/16" longer.
My real problem is that I've been following Mayhugh's 300 Ford Inline Six build and between his bead blaster (another tool I don't have) and the way he's painting his parts before they get assembled, they're so pretty that these parts just off the machines just look too raw now.
All that aside, time to pick the next part. Probably the cylinder.
Bob--For an internal radius like that, drill thru with a 5/8" drill, (or a 5/8" endmill if you're right on the edge of the material) then bring the saw cuts in tangent to the hole, and presto--A 5/16" radius.---Brian
Unfortunately, the biggest drill bit I have is 1/2" - except for some spade bits for wood.
I didn't even think of those spade bits until now. I've never tried a spade bit on aluminum, but so many other wood cutting tools work on aluminum at the right speeds and feeds that I wonder if it could work.
I didn't even think of those spade bits until now. I've never tried a spade bit on aluminum, but so many other wood cutting tools work on aluminum at the right speeds and feeds that I wonder if it could work.
I wouldn't use a spade drill. I have a complete set of metal drills ranging from 1/32" diameter up to 1" diameter, by 1/32"s.
Spade bits are usually made of relatively soft carbon steel, in many cases they can be sharpened with a file. You might get them to cut aluminium if you keep the speeds low, but I'd expect the sharply pointed pilot and prongs to break down very quickly.
Large diameter Morse taper or reduced shank twist drills can be had rather cheaply from the usual suspects on eBay, Banggood, AliExpress etc and from local suppliers that buy from the same factories in China. They're not going to be the best drills you've ever used, but for this sort of thing they're ok.
Greetings,
I've used spade drills a few times to provide a counterbore for a large washer or the like in aluminum out of desperation to get a job done. Rather scary, the large edge engagement with the work and the spindly shank flexing, twisting, and bouncing around gives a fairly poor finish and tends to grab. Sides of the hole were ragged and tapered. If you think how many times you've had a spade drill snag on break though in softwoods it's MUCH worse with aluminum. Maybe it would go better with the drill shank cut down to reduce whip and flex and pucker factor. Even in a heavy drill press or mill it's a pretty sketchy stunt. Maybe a reduced length 5/8 spade would be stiff enough to at least poke a hole that only needs a huge amount of clean up, seems my efforts were usually in the 1 inch or larger range.
In your application, is there a reason the radius has to be 5/16? If it's just to eliminate stress risers, most any radius will be fine and look decent.
Cheers,
Stan
I think it's mostly cosmetic, to make a nicer looking part while also getting some screw heads off of the bottom, but the designer (Brian) is watching the thread and might comment. Right now it's 1/4" radius and the whole bottom isn't the nicest looking surface I ever machined, but it is the bottom and will disappear in use.
Bob
Nah, not important. it's just there for "pretty".
Bob,
Glad to see you back at it. You said of your lathe, "after I did some adjustments to my lathe to tighten the gibs and stop the compound rest from wobbling."
One thing you might consider doing is get a piece of steel as the one shown below, drill the four holes so you can mount it to your cross slide in place of your compound, then another hole in the middle and mount your quick change tool post directly to it. This gives our lathes more rigidity for those tough jobs that really need it. One way to eliminate the wobble of the compound is to elimiate it!
When I was making my cylinders I also needed a drill bit larger than 1/2" and went on the cheap and bought this:
https://www.amazon.com/Premium-Shan...MSN6/ref=dp_prsubs_1?pd_rd_i=B075FGMSN6&psc=1
It was only $37 bucks and totally NOT worth it. The cutting bit is NOT AT ALL concentric with the shank. So, be warned, if you do decide to buy some larger bits, get a nice set you will be happy to have for a while. I relegated my set to a drawer of old wood drill bits and may never use them again.
Glad to see you back at it. You said of your lathe, "after I did some adjustments to my lathe to tighten the gibs and stop the compound rest from wobbling."
One thing you might consider doing is get a piece of steel as the one shown below, drill the four holes so you can mount it to your cross slide in place of your compound, then another hole in the middle and mount your quick change tool post directly to it. This gives our lathes more rigidity for those tough jobs that really need it. One way to eliminate the wobble of the compound is to elimiate it!
When I was making my cylinders I also needed a drill bit larger than 1/2" and went on the cheap and bought this:
https://www.amazon.com/Premium-Shan...MSN6/ref=dp_prsubs_1?pd_rd_i=B075FGMSN6&psc=1
It was only $37 bucks and totally NOT worth it. The cutting bit is NOT AT ALL concentric with the shank. So, be warned, if you do decide to buy some larger bits, get a nice set you will be happy to have for a while. I relegated my set to a drawer of old wood drill bits and may never use them again.
I went looking at just buying a Silver and Deming bit in 5/8 and saw several individual bits that cost more than that set. Pricey for one drill bit, and not that different from two flute, ball end, 5/8 mills. I have several drill bit sets, but none go over 1/2" except for those spade bits I was talking about. My main, go-to set is from 1/16 to 1/2 by 1/64", which is a handy thing to have. Those are straight shank except for three flats to help chuck jaws grab the bits.
Thanks for the tip on getting rid of the compound, too. I need to look into making sure I could do that on my Sieg SC4 lathe.
I'm surprised looking here that my last post was before Thanksgiving. I would sworn it was last week, Monday or Tuesday.
After the base, the path I decided to go down is to make the cylinder, connecting rod and piston. The cylinder is cast iron and pretty much 2-3/8" in length, with the largest remaining metal being 1.750" diameter and a 1.750" on a side square flange. It looks like this, except for some drill holes I haven't drawn in.
I had to buy a foot of cast iron bar as rough stock; it's just a bit over 2-1/16" on side, pretty much 2.08". I cut off a piece about 3-1/4" long on my 4x6 bandsaw and squared that down to 1.875 - that's 7/8 so .062 too big on each side. That's when I got into a real puzzle about how to proceed. My original thought was to do everything on my big lathe, the one that just needed adjustments.
What bothered me is that the intermittent cutting of the rectangular crankshaft blank broke a few cutters and I don't want to do that again. Most of my cutters are carbide and while I rarely run the RPMs high enough to meet the recommendations for carbide, I would think that would be gentler impacts and speeding up the RPMS would be the wrong way. So I tried to see a way that I could cut down the pointy corners and turn the square into an octagon.
I got the idea I could make some Vee blocks to hold one of the points of the square and cut off the opposite corner. While I have some metal Vee blocks, they're too big for the mill vise, so I thought I'd make some. It looked like this
All well and good, except I'd need some taller jaws for the vise. No problem, I had some scrap 3/8" thick 1018 steel, so I could make them. But could the piece really take cutting forces with just those sharp corners being grabbed by the vise jaws?
Yeah, I could mill a small groove where the points hit, but for the first two cuts those jaws are holding the pointy corner, but after you cut those points down they're replaced with flats that are 3/4" wide. Two sets of jaws?
I decided the prudent thing to do would be to chamfer the edge of the square block with it held by the flat faces in the vise jaws but I had a stupid and overcut the piece by cutting the entire side, thereby taking off one of the corners of the square flange. (waving hand like a Jedi in Star Wars) You don't care about the divot from the cutter in the middle.
So I'm starting over. Thankfully, I have enough cast iron to spare another 3-1/4" long piece. I cut this one down to 1.800 on a side, .025 on a side oversize.
After the base, the path I decided to go down is to make the cylinder, connecting rod and piston. The cylinder is cast iron and pretty much 2-3/8" in length, with the largest remaining metal being 1.750" diameter and a 1.750" on a side square flange. It looks like this, except for some drill holes I haven't drawn in.
I had to buy a foot of cast iron bar as rough stock; it's just a bit over 2-1/16" on side, pretty much 2.08". I cut off a piece about 3-1/4" long on my 4x6 bandsaw and squared that down to 1.875 - that's 7/8 so .062 too big on each side. That's when I got into a real puzzle about how to proceed. My original thought was to do everything on my big lathe, the one that just needed adjustments.
What bothered me is that the intermittent cutting of the rectangular crankshaft blank broke a few cutters and I don't want to do that again. Most of my cutters are carbide and while I rarely run the RPMs high enough to meet the recommendations for carbide, I would think that would be gentler impacts and speeding up the RPMS would be the wrong way. So I tried to see a way that I could cut down the pointy corners and turn the square into an octagon.
I got the idea I could make some Vee blocks to hold one of the points of the square and cut off the opposite corner. While I have some metal Vee blocks, they're too big for the mill vise, so I thought I'd make some. It looked like this
All well and good, except I'd need some taller jaws for the vise. No problem, I had some scrap 3/8" thick 1018 steel, so I could make them. But could the piece really take cutting forces with just those sharp corners being grabbed by the vise jaws?
Yeah, I could mill a small groove where the points hit, but for the first two cuts those jaws are holding the pointy corner, but after you cut those points down they're replaced with flats that are 3/4" wide. Two sets of jaws?
I decided the prudent thing to do would be to chamfer the edge of the square block with it held by the flat faces in the vise jaws but I had a stupid and overcut the piece by cutting the entire side, thereby taking off one of the corners of the square flange. (waving hand like a Jedi in Star Wars) You don't care about the divot from the cutter in the middle.
So I'm starting over. Thankfully, I have enough cast iron to spare another 3-1/4" long piece. I cut this one down to 1.800 on a side, .025 on a side oversize.
Bob--Glad to see you are still at it. I was beginning to worry. The way I made that cylinder is to first cut a piece of cast iron about 1 1/2" longer than the finished size, stand it on end in my milling machine vice and center drill one end with a center drill until I had a divot on center big enough for a lathe live center to fit. Then I chucked the entire length up in my lathe 3 jaw and supported the outboard end with a tailstock live center. Then I turned everything to finished size, even the portion that is rectangular. Then I put a 15/16" drill in the tailstock chuck and drilled out the center and reamed it to finished size all in the same set-up. I then used my parting off tool to part off the cylinder at the correct overall length. This leaves you with a "stub" of cast iron about 1 1/2" long that you will eventually use on some other build. After it comes off the lathe, the 4 sides of the square part can be band-sawed or milled off, leaving it square.---Brian
