Thread: My Invicta 4M arrived

I just found out my timing on my shaper was way out.... It was still feeding when the ram was moving forward..

The correct way is the slot to be horizontal at the end of the return stroke...

Oh of course.. its clear once someone else works it out. Not the same thing at all as being Horizontal at the front of stroke.

Thanks

Stuart

That is right because on a shaper the return stroke is much faster then the power stroke that is why at the end of the power stroke the slot is not horizontal but past the horizontal so that gear moves for example 260 degrees on the power stroke and 100 degrees on the return stroke..

Originally Posted by Stustoys

If you cut both sides at once and cut deep enough that the top of the "ridge" is sharp, wont tops on the ridges be concave so they will only meet with the matching part on the perimeter?
If you stop the depth as soon as the inside came to a sharp point, wouldn't it then meet across the entire face?
No I haven't made either, just trying to visualise it.
You could tilt the dividing head to allow for it but no idea how much.
Maybe I am over thinking and under doing again. hehe


Stuart

My brain hurts when I try to think about it.

Jordan

Originally Posted by nadroj

My brain hurts when I try to think about it.

Jordan

Sometimes it's easier to draw than think. This shows both extremes. I think what is actually happening in those shots is in between. A big hole in the middle helps too.

Edit: Sorry, I wasn't clear. I think there is only full contact on the periphery.

Here is the thread where those pictures originated from...

http://www.practicalmachinist.com/vb...nation-194069/

Thanks Bryan
I think the one on the left is as it would be in the pictures, you just cant see it because of the hole. As you can see the one on the right wouldn't mesh as is, but if you increase depth of cut until the point of the triangle where the cuts meet is about 1/6 the Dia from the edge, I think they will mesh nicely.
If I ever get this thing going I'll find out.

Stuart

Been looking at images of these hirth couplings. It's hard to see what's going on, and I haven't yet found a clear description of the geometry. But consider this: If the cuts are straight, the spaces between them must taper - both inward and down. So the valleys are straight but the hills taper, if you like. That's why I said they only contact at the edge.

But I can think of two ways to get full contact along the teeth. One is if the angle narrows toward the centre, so it becomes like a folded fan shape. But that's really hard to machine. Maybe impossible.

The other is if you incline your cut upwards. Let's say the downward taper in the first example is 2 degrees. If you incline your cut up by one degree, you should have the peaks and troughs tapering equally toward each other, so the hills of one piece will exactly match the valleys of the other. Does that make sense?

Sorry to distract from your shaper, Stuart. I'm reading with interest as it's the closest I'll get to one for a while. I just thought the geometry was interesting.

Edit: Been trying to figure out how to draw it and I think it may be a load of rubbish. As you were.

Thanks RC there is some reading in there for me. I've been looking at a few planers on utube today. There is a 30' one!!

Bryan
The one on the dividing head seems to be cutting both sides at once, so it must be straight therefore it must taper.(right?)
As for machining it "straight" if you work out the depth of cut you want at the perimeter, set the angle so you taper from that depth on the perimeter to 0 depth at the center, that would work wouldn't it?

Distractions are fine Bryan, I'll be making one of those holders soon enough i hope. I'm just about over cleaning and I think I'm about halfway there. I'm going to make a tray to go under the shaper as they must drip oil everywhere.

Stuart

Originally Posted by Stustoys

Bryan
The one on the dividing head seems to be cutting both sides at once, so it must be straight therefore it must taper.(right?)
As for machining it "straight" if you work out the depth of cut you want at the perimeter, set the angle so you taper from that depth on the perimeter to 0 depth at the center, that would work wouldn't it?

Stuart

Stuart, I think you are correct on both counts.

From what I can see, the V's in the photo taper down towards the middle like Bryan's first photo.
For that type of tool holder I don't think it would need full engagement because the cutting pressure would be pushing them together.

Dave

Dave All the pictures I can see the cutting pressure is pulling them apart. Which is another thing I was thinking about doing differently, but that would mean the nut would be at the back(unless I come up with another idea).

Not trying to say that holder is no good guys, just wondering if maybe it can be improved. They may well be as good as they need to be, but the distraction is good.

Stuart

Must have been a late night moment and I didn't put the brain in gear.
They do get pulled apart not together.

Hows the cleaning and assembly going? I always cop "you smell like the shed" off the kids and the wife, it's the kero. LOL

OT
I have been working on my mill and every time I fix something, something else goes wrong or needs fixing. I will be glad when it's back together. Thoughts of selling it have crossed my mind.
I will post the details in a new thread when I am done.


Dave

Luckily I don't make stupid mistakes

Cleaning is so slow, I think it would come up better if I cleaned it again after I finish. Its just so dirty, the brown is thin and I'm sure there is paint under there some where but I'm not getting it all. Not sure how to go about cleaning the motor, but as the vents were almost completely blocked I guess if its still working now a little dirt inside it wont worry it. Then of course there are those stupid mistakes I don't make like pressing the feed nut into the false table then remembering out I can't get it on the machine like that and having to press it back out. Or getting the crossfeed leadscrew set up just right and realizing that I left the self act brace arm thingy off so having to pull it apart again.
The gearbox will go back on with permatex 3. I think I'll leave the clutch alone as it seems to be working fine and isn't hard to get to. The last question is "should I pull the rocking bracket and stroke adjustment out?"(its filthy in there as well)
This has taken me way longer than the mill.

I'm been watching your messages about bearings I guess you only need to fix so many things.... and then they will all be fixed . But I am glad I bought mine, my lathe and shaper are more than enough to keep me busy in the "to do" department. I look forward to your thread.

Stuart