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Clausing 8520 Drawbar?
- Thread starter Finster
- Start date
- Joined
- Jan 28, 2016
- Messages
- 253
I'm thinking of machining some type of hand wheel I can attach to the top of the drawbar instead of using a wrench. Seems like it would be easy enough. However, it's only a .375 drawbar. I'm wondering if it would be to unstable and fly off at higher speeds and hit be between the eyes? 
Or cause other problems. Has anyone tried it on an 8520?
Or cause other problems. Has anyone tried it on an 8520?I'm thinking of machining some type of hand wheel I can attach to the top of the drawbar instead of using a wrench. Seems like it would be easy enough. However, it's only a .375 drawbar. I'm wondering if it would be to unstable and fly off at higher speeds and hit be between the eyes?
My first thought is balance, which would be an issue at any speed developed by the mill. Even at 50-100 rpm's anything out of balance would create problems, vibration etc. and the size needed to apply the torque would be significant. Do you have the clearance between the drawbar and obstructions, motor etc? I have weighed using the wrench against a quicker air operated drawbar operation and I don't think the time saved is worth the negative offset. I choose to use a ratchet box end. The one step in the removal of the collet that's left out in most alternate operations it the tap to loosen the collet. The more distance I place between a hand operation and my project, the more out of touch I become with the project and the machine.
- Joined
- Nov 25, 2015
- Messages
- 8,234
I wouldn't. I picked up an 8520 this morning, and it's a light duty drawbar. Much smaller than the one I use on my SB 9a for milling.
My unit came with a collar for the drawbar, so the drawbar self ejects the collets.
Admittedly I know nothing about the 8520, other than seeing it for the first time today. But I quickly became aware that this is not a machine that will require a pneumatic draw bar.
Now to find larger collets, I got 3, upto 3/8 which I have a ton of end mills in 3/8 body, but I have a ton more in 1/2 so hopefully I can find one that can do the 1/2.. Not having used an MT2 , I'm not sure what options I have, all my MT2 stuff is for my drill press, w/tang, which I don't think will work on this at all. I hate to have to buy another chuck setup. I do have a Jacobs in a 1/2 straight shank.. again 1/2..
My unit came with a collar for the drawbar, so the drawbar self ejects the collets.
Admittedly I know nothing about the 8520, other than seeing it for the first time today. But I quickly became aware that this is not a machine that will require a pneumatic draw bar.
Now to find larger collets, I got 3, upto 3/8 which I have a ton of end mills in 3/8 body, but I have a ton more in 1/2 so hopefully I can find one that can do the 1/2.. Not having used an MT2 , I'm not sure what options I have, all my MT2 stuff is for my drill press, w/tang, which I don't think will work on this at all. I hate to have to buy another chuck setup. I do have a Jacobs in a 1/2 straight shank.. again 1/2..
- Joined
- Jan 28, 2016
- Messages
- 253
You can pick up a set of cheapo collets on E-bay. They are China made naturally but they are good enough to get you started. I have a set and they are ok. However, they are not real deep so I don't like putting double end mills in them. I'm on the lookout for better USA made ones when I find a good deal. Here's a link if you are interested:
http://www.ebay.com/itm/2-Morse-Tap...440089?hash=item1e9944c619:g:lPoAAOSw5cNYQFck
You'll like your 8520. Post a pic when you get the chance.
- Joined
- May 4, 2015
- Messages
- 3,583
Finster, first I'd ask how much pressure are you applying to the drawbar? Why do you say the new one sucks? Could be your collets no good , or you have a China metric one slipped in by mistake. I have several 2 morse for my atlas , and I'm looking at the China made tools to fit . So I'm going to need a metric drawbar for it too.
- Joined
- Jan 28, 2016
- Messages
- 253
It's kind of hard to explain but to sum it up, the original drawbar was a different design than the replacement. The replacement has a nut that needs needs to be drilled and pinned or brazed/ welded and then turned. Also, on the new one, they give you a cap nut for the top of the drawbar that gets pinned with a roll pin. So now you have a little .375 drawbar with a hole or two drilled through it. It's just a bad design. I can make something better than what they sell for probably 1/5th the price.
I notice that too and I was wondering if this was what they were selling. Drilling holes through the muscle end of the draw bar is a bad design.
- Joined
- Jan 28, 2016
- Messages
- 253
It's been over a year since I bought the new one. I got it when I bought the mill because the original was on it's way out. However, I think it was $40-60 or something outrageous like that. It's just a piece of .375 round threaded about 2" on each end. I don't even think it's 2' long. You get two nuts with it also. YIPPEEE! It's a joke and I won't be buying another. I'll make a few when I get set up that should last me years.