Werowance attempts Upshur Vertical Single

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Awake, I was doing one turn on the handle per cut which was close to 2 deg per cut. I hope I understand your question right.

have made it almost to the tip and I stopped as it was getting late. but I do have a question. the plans say to radius the tip to .025 (not critical) it says. now I have only used my radius gauges once since they were given to me and they are stamped in fraction. just so I don't go the wrong direction with the math I'm double checking. .025 radius x 2 =.050 diameter right? 3/64 as the picture shows is the closest gauge I have to it which is .04687 - close enough you think? ill have to hand file it anyway so it definitely wont be perfect


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Mmm, maybe not. Here's how I understand the process:

Center RT with blank; lock the Y axis. Adjust boring head to appropriate radius. Move the X-axis until the boring head just makes contact with the blank. Raise the boring head, move the X-axis another .010" or .020" (or however much you want to take off each time) and "bore" down the blank (actually, the inverse of a bore since you are cutting the outside). This will shave a little off the flank, but not yet down to the base circle. Move the X-axis another .010" or .020" and "bore" again. Repeat until your X-axis setting is at the point that the boring head is cutting the blank right up to the base circle. Now lock your X-axis. NOW you rotate the RT a couple of degrees, and "bore" again, and repeat until the full shape is reached - you don't have to work your way down to the base circle after the first time, because only a little bit has to be cut with each couple of degrees of rotation.

From your description, I'm wondering if you skipped the part in red above - went straight to where the boring head would cut right up to the base circle, and "bored" down. If so, you would have been taking off a rather big bite on that boring pass. After that, as noted above, when you were at the base circle and turning the RT a couple of degrees each time, you were only taking a small "bite" each time.

Again, even if you skipped the part in red, you succeeded and nothing broke, so no harm done. If your mill and boring head can handle that big a bite in one go, it certainly would save time!

On your last question, it sounds like you are deciding how far around to go with the RT based on the nose radius. I can see that this is the way the plans are written, but I would say ultimately it is not the best approach. What you really want to do is to figure out how long (how many degrees of camshaft rotation) you want the valve to be lifted, and by how much. That said, let me see if I can reverse-engineer what you've got on the drawings. Here's a diagram that reflects the known parameters from the drawing - base circle is .334"; the blank is cut to .480"; the nose radius is .025"; and the flanks are cut using a jig with a .958" cutting diameter. The heavier cyan line shows the cam that results from these parameters:

known_parameters.png


Now we can work out the resulting angle of duration and the lift. Presuming that the blank (diameter = .480") is to represent the outermost part of the cam, the lift can be calculated as the difference between the base circle radius and the radius of the blank: (.480-.334)/2 = .073" of lift. With the help of a CAD package, we can easily find the lines that are perpendicular to the point where the flank circles are tangent with the base circle - or to say it another way, the point at which the shape starts to follow the flank outline rather than the base circle outline. Furthermore, the CAD package lets us measure the angle between these lines:

lift.png


So, if all of my assumptions are correct (probably a dangerous assumption in and of itself!), then the duration of the resulting cam will be 124.42°. Let's round it up to 125° just to make life easier. This will let you set the valve timing for something like opening 20° BTDC and closing 15° ATDC, which seems reasonable based on my limited knowledge and experience.

But here's the key thing: the best way to cut this is not to keep on rotating the RT until you can fit the .025" radius gauge; rather it is to rotate the RT the desired amount to achieve the 125° of lift duration. So, 360° - 125° = 235°; if you rotate the RT a total of 235° (a couple of degrees at a time, "boring" after each turn), then the resulting cam will be correct, and you will only need to file the nose round (IOW, smooth out the transition around the nose) and smooth any slight irregularities around the rest of the cam introduced by the steps in cutting.

Clear as mud?!? :)
 
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Clear as mud?!? :)


lol, yeah clear as mud. i am glad that i made sure the rt was on 0 when i started. ill check to see how close to 235deg when i get home.

and you are correct i did skip the text in red above and went for a direct bore down to hit the base circle. plenty of rapid tap cutting fluid and a very very slow going downward. i got through it and everything survived. i think next time i will start further out and work my way in with mulitple down feeds until i hit the base circle radius and then start rotating a degree or 2 at a time. i did not like all that chatter on the first pass down.

Thank you to all of you for helping with this

when i get them cut and get ready to lock tight them in place on the camshaft i was thinking about just printing out a degree wheel on paper, poking a hole in the middle so i can set the location on the cams. plans say about 101 to 102 degrees from each other. is that how you all do it? you all probably have professional degree wheels or protractors but i dont. figured a paper one would work on the cheap.

or do you set the first cam at full lift on the lifter and then rotate 101 degrees and set the second cam at full ift on the other lifter? either way i will need a degree wheel.

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when i get them cut and get ready to lock tight them in place on the camshaft i was thinking about just printing out a degree wheel on paper, poking a hole in the middle so i can set the location on the cams. plans say about 101 to 102 degrees from each other. is that how you all do it?

I don't know how others do it, but the way you describe how you're going to do it is almost the same as I used to be and it worked for me
I don't know the engine drawings you are making, but before you lock tight them , review their design position carefully.
 
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although the pictures i have dont really look that great, still needed some cleanup when i took them. the cams came out really good. and Awakes measurements were spot on, i put the radius gauge up to it after cutting to 235 degrees and it was right on it. thank you all for all your help on this. learning to do it was the hardest part. now i feel like i can do this again without to much trouble. everyones patience was above and beyond and you have taught me how to make a cam now.

the cams are just pushed up on a shaft for the pics. lower cam in first pic especially needs deburring after parting off which i have already done but the pics dont show it.

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also did the points cam while i was at it. on this pic its also just pushed up on a scrap shaft to hold it for the pic. wasnt much to do in its construction

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You've done well Werowance. I know all the steps in making cams that way, but since I only do it about 3 or 4 times a year I have to read thru all of my old posts and learn it all over again each time. I will be making cams for my engine sometime in the next couple of weeks using that method.---Brian
 
Going to take few days off from the build to play with / assemble my new toy that just arrived. A cnc 3018 pro cutter/engraver with 15w laser attachment
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Alright no instructions and no link sent with kit however plenty of YouTube videos for it. Here it is as I stop for the day with it. Nothing square and not tightened up

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Also no USA power cord however I have plenty
 
Looks like a fun diversion for a few hours or days.

I've been meaning to figure out how to put a laser on my Sherline mill instead of it's headstock (90 W motor; less than 1/10 HP).
 
last night i started on the tappets and after i made one i realized i may have made a mistake. plans in the lower right say material drill rod, but on the tappet guide it says brass. it does not specify for the tappet itself. i think the lower right is refering to the cam lobe which is also on the same sheet.
so my question is, should the tappet also be steel ? it will be riding on the steel cam lobe so i originally assumed it should be brass for wear reasons then thought about briggs and strattons and other small engines, they are all steel on steel.

easy enough of a part to make. just want to make sure i use the correct material.

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I make my tappets from 01 drill rod, than heat and quench it to harden it. The cams should be the same. The tappet guide can be bronze or brass. There is tremendous "wiping" motion as the cam rubs the tappet to open the valve.---Brian
 
not much progress lately. in fact I think I took a step backward even. I made the tappets in steel and that went well, started making spacers for the cam shaft to space the gear and the cams. used brass and cut it to a thin walled tube. then woops I dropped my cams in the floor. I also re did the solder job on the cylinder to the plate which went well also. found a neat trick to remove the heat bluing on the fins after soldering. muratic brick acid mixed with water. about 50/50 mix. just a little on a qtip and rubbed on the fins only lightly and they were back to shiney brite again. I was careful to keep it off the solder joint or the inside of the cylinder as I am told it will leach the solder and weaken it. but figured I was safe cleaning the fins back up with it. then rinsed with water, dried it up and oiled it really good.

but the step backward part is I dropped my cams in the floor. I could only find one of them last night. I was so agrivated with my self. hopefully I will find the other one tonight.

I didn't think to take pictures of anything yet.
 
but the step backward part is I dropped my cams in the floor. I could only find one of them last night.

How many times have you dropped something or put something down and it disappears, then the next day or two days later you go back and it's exactly where you looked? It happened to me at least once last week. A friend of mine said the thing you dropped time travels and goes into the future and you don't find it until you catch up to that time.

You'll find it in a day or two.
 
No, no, you only find it AFTER you have made the replacement. Or at least, that appears to be the rules of the universe in my shop! :)

I know for sure that's the law if you have to buy the replacement. I can't tell you how many times I've proved that law. I hadn't thought of what happens when you have to make it. Hmm. I bet it depends on how much of a pain in *** it is to make the replacement.
 
Oh yes, absolutely. Easy to make parts are also easy to find - that's the rule. Parts that are fiddly and take forever spend a proportionate amount of time* hiding.

*I believe the proportion is, for every hour it took to make, it spends a week in hiding.

:)
 

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