AOG's take on Elmer's No 2 Twin Vertical Wobbler

[AOG]

Part 4

These are the shop sessions that try men's souls

As you can tell from the title this was not a good shop session. It started out ok. I cleaned up a piece of brass rod to make the pistons from



Then I turned the middle diameter of each piston. That was more than a little hairy. In retrospect I should have turned them between centers.



Then it was into the collet block and over to the mill to drill the crank pin hole



Then the crank end was milled to width



Then back to the lathe for parting off.



When I parted the pistons off it felt weird. At the time I discounted it as the normal problems I have with parting brass.  Next up was the 2 crank disks. I put the stock in the lathe and cleaned it up.



Then I drilled the stock for the shaft.



Then it was put unto the collet block and the crank pin hole was drilled. The original intent was to drill the holes for the center and crank pin deep enough that I could just part off two crank disks from the same stock. That way there would be no possibility of the throws being off.



Then it was back into the lathe for parting off..



That's when my trouble started. I could not get that piece parted off no matter what I did. I reground the tool I changed speeds nothing. That's when I realized that the parting tool was slipping in the holder. I went to retighten the holder when I realized the adjustment shaft was stripped out. I finished cutting off the crank disk using my hacksaw and I moved it over to the mill to drill for the grub screw



I started the tap using my mill and then moved it over to the vise to finish tapping the piece. I then proceeded to snap off my 4-40 tap in the hole. I took that as a sign and stopped for the week. I'm traveling for the next 10 days and then I need to order some tools so it will probably be a few weeks before I get back to this build log.

Tony
 

[90LX_Notch]

Tony-

Sorry to hear about the tap.  It stinks when that happens. Luckily it happened on a simple part to redo.

-Bob

[AOG]

For some reason I really struggle with these small taps.  It's a feel thing. I couldn't tell I was already through and hitting the far side of the center hole. It didn't feel any different to me than when it was cutting. I guess it's just something I'm going to have to practice.

Tony

[Kim]

Tony, I feel for you with the Tap.  I've had that happen more than I care to admit.  In fact, on my current project I've broken two 4-40 taps.    In one situation I was able to get the broken tap out.  In the other, I had to scrap the part
You'll get it all worked out.  But it certainly is frustrating!
Kim

[b.lindsey]

Broken taps sure take the wind out of your sails Tony, but it happens. As Bob said, at least you didn't have hours and hours in the part...look at it this way, you got the pistons made and found a problem with the cut off holder without major incident

Bill

[AOG]

True enough, I think I will just take the opportunity to try out the new version of the cut off blade holder that LMS is offering.... And buy some new cut off blades .... And buy some new tool holders that I have been meaning to get.

Tony

[AOG]

I'm back from my work trip and my new cut off holder is here so let's start by finishing off the crank disk by parting off and then pressing in the crank pins.



The next piece was the flywheel. I started by facing off the blank



Then I profiled the edges of the flywheel.



Next I drilled and reamed the hole for the shaft.



Then I went to the mill and drilled for the set screw. Then I started the tap in the mill and finished tapping it on the hand tapper



Then I put the flywheel on a mandril and turned the wheel true.



The last piece was the base. I started by trueing up a piece of Corian scrap.



Then I tranfer punched the holes from the sub base to the base.



I picked up the holes with my spotting laser.



Then I drilled the mounting holes.



The holes were tapped 4-40



That was the last part so here is the final family shot.



Now it's time for my least favorite part. I will spend some quality time with the sandpaper and buffing wheel and then I will post a pics of the finished product.

Tony

[AOG]

It's done but I ran into problems getting it to run. It turns out I screwed up drilling the ports in the cylinder. As you can see in the next picture the port is offset from centerline. Based on how they are offset, I think I must have forgotten to apply the edge finder width correction before I drilled the holes.



I ended up plugging the holes with JB weld, filing off the extra and relapping. I ended up with this.



I redrilled the holes and it worked. The moral of the story is that I got lazy and didn't mark out the holes. I just coordinate drilled them from the DRO. I won't make that mistake again.

Here is the finished product.



More pics and a video will be in the showcase later.

Tony

[b.lindsey]

That looks great Tony!!  Will look forward to seeing the video too...maybe that will give me the kick in the pants I need to finish mine that I started over a year ago now.

Bill

[Don1966]

Nice work Tony she looks great. 

Don

[philjoe5]

Nice work Tony.  Looking forward to a video of it running

Cheers,
Phil