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Square dial compound question

bll230

Hot Rolled
Joined
Jun 14, 2007
Location
Las Vegas
I was setting my compound to 0 degrees, and I noticed it wasn't. Upon further inspection the degree markings are about 3 degrees off square, so to speak. Is the degree wheel a separate part from the compound base? I had thought the degree circle was integral with the compound base, but if so that would mean Monarch really messed up that part when they made it. In the picture the black mark is exactly in the center of the base, and the 90 should be symmetrical on the mark. Before I started pressing on things I thought I would get other opinions.

If Monarch did mess up the degress that much it would have been an egregious manufacturing error.

IMG_0861 copy.jpg
 
Ok, put it all back together and then measure if it is off with the hashmark on the crosslide. Where the graduations are to where your black mark is, is not where it is important. Remember one side of the compound dovetail has a gib, so that dovetail is offset to accommodate that. It looks like the graduations are done to accommodate that offset. Put the compound on '0' and then run a dial indicator down the side as you move the crosslide in, and the compound should be "square" with the centerline of the spindle. Usually there is a slight inward bias of the crosslide a few tenths over the entire travel, so that when facing off a round, it cuts a slight concave so the round sits flat. Unfortunately, looks like you have a bit of damage to the graduations. Also, it is not unheard of that certain components (like a compound screwed up in a crash) are not necessarily original to the machine. If all of this is off, then you will have to make new hashmark. I had to to this, as I completely reground, rescraped all of these components, and was able re-engrave the hashmark to be spot on. On mine, the compound graduations go all the way around,so you can put hash marks on both sides of the crosslide.
 
Daryl, I am going with your thought that the compound was replaced. Maybe Monarch wasn't concerned whether the degrees were perfect and scribed the marks on the cross feed to match the compound. I have a mark on both sides of the cross slide as well as the front. I can line up 0 degrees, -90, and +90 perfectly on the marks, but the compound is not square. I'll just add 2 1/2 degrees to my settings until I can scribe new marks.

Thanks - I have a 16 DP hob coming and will have your 60/57 made sometime this week or next.
 
Ya know....since your graduations are all damaged. You could turn those off and make a new slip-on ring with the graduations (dust off that ole dividing head :rolleyes5:) and a setscrew. Dial it all up and then move the new graduation ring to perfection. Just a thought.
 
It would be hard to believe the marks were off from the factory. There are many parts that are hand fit, and some like levers that were hand drilled for taper pins, so they usually wont line up on another machine.
On the other side is the Atlas lathe, where I don't think anything was hand fit.
 
I went and eyeballed my compound and it is dang near identical to bll230's pic. The 90 is just shy to the left a couple of degrees. So obviously it is intentional. So something else is amiss.
 
Again, I asked Steve at Monarch this question. Saves a lot of time to ask the source...

He explained that the witness marks were put on after assembly on each lathe, and that when swapping cross slides or compound bases the marks will probably not line up. Daryl's judgment was right, I likely have a non-original compound base. When I take the lathe aprt to install new Bijur fittings I will scribe new witness marks.
 








 
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