I’ve had a couple of projects lingering around here longer than normal, waiting for some press work, and decided tonight to get to work. A while back I bought a cheap 3 ton arbor press from a new (to me) supplier. From the price, it was obviously Chinese, and I knew it was bound to be a project from jump street. I wasn’t really prepared for what I got. To be fair; the company I bought it from (which will remain nameless) disassembled the press and shipped it in two boxes, so that it would meet the UPS 80 LB limit, which was good of them as it saved me a big chunk of change. I was so bummed by the quality of the press that it has sat un-used for about six months; crude would be an understatement. The casting looks like it was cleaned up by an epileptic with a chainsaw. The first time I tried to use it, the drawbar slipped in the ratchet and d@mn near knocked me out. I stuffed the turd in the corner and started looking at other options, and my projects I had bought it for sat on the shelf. I had a nice hand wheel that I wanted to mount to my horizontal mill and a $100 broach to cut the 3/8″ square hole, and no press to do it with. Tonight I decided to fix the problem. Heres a look at the ratchet ring that came on the press.
You can see that the problem is that the gear was cut with more than a 90 degree step in it, and the ratchet cog would slip right off of it. I had to get a step that would capture the cog better. I figured the best way to do that was just under-cut the ratchet tooth with a dovetail cutter. The only cutter I had was a 60 degree (would have been better off with a 45), but I figured there was enough meat there so I gave it a try.
This was the high-tech set up I used the index the part. It is a slow rotating part, so I figured this was all the accuracy I would need. It turned out to be more than adequate.
The first cut went well, so I just kept moving.
It took about 20 minutes to undercut the 12 ratchet teeth, and despite how crude the cuts look, it turned out fairly nice. The steel seems to be a blend of tin foil and cookie dough, but should hold up for some time to come.
Back together and tested, I decided to tackle the broaching job that has been patiently waiting all these months. First thing was to drill the hand wheel to the proper size for the square broach.
With the hand wheel properly supported on the press plate, the broach went in the hole and got a liberal dose of Cool-Tool cutting oil. I have to say I was a little nervous about trying to push a $100 broach through the hole with a somewhat suspect press.
Well, here is the broach about 1/2 way through. I was relieved that it went as smoothly as it did with no mishaps. I had envisioned broken broach parts scattered all over the shop. The press still needs some help, but at least it is useable now (which it WASN”T right out of the box). I’ll get around to fixing some of its other deficiencies when time allows, but at least now I don’t feel taken for $169 or whatever I paid for a tool that didn’t work. Once repaired, it did pretty much what it was designed to do, but still needs help to really work WELL. Heres a shot of the finished job on the hand wheel.
I think once I get it straightened out a little more I might just tackle a few more of those press jobs that have been hanging around here………………More later.