The Gorton Mill (the green thing in front of the Tormach) is non-functional and on the chopping block. The thing is, it’s a lovely hunk of vintage American iron - heavy and rigid like a machine tool should be. If it ran, it’d be nicer mill (though completely manual) than the Rong Fu we’re using now.
So what’s wrong with it? For starters, the factory motor is borked. At some point somebody got it running by strapping another on the side, but that motor is also borked. The scope of repair would include either repairing the (oddball? obsolete?) factory motor or fabricate a means to mount a modern 2-3hp motor of appropriate speed in place of the factory one - no more motor backpack.
Is it worth it? Not Sure! The project should start with evaluating the mill. Check out the ways and bearings, bits and bobs, determine if there’s anything else wrong with it. Complete an evaluation, make a plan for repairs. If the thing’s completely knackered maybe it’s best to send it on its way and keep an eye out for something better.
Does this sound like your thing? Now’s your chance! We’ll provide help when we can, but we’re looking for somebody willing to figure it out with little specific direction.
I will start scanning the manual. I used it a whole bunch. The ways are much smoother than the Rongfu.
The factory motor is 480v. I hear it is expensive to rewire to another to type such as 220v single. I will see how much Hamilton Electric is wanting to rewire. If it can be rewired. The original Allen Bradly switches can be used.
We have all of the collets, drawbar, and wrench. I think the vise should replaced. After it is functioning we can look at adding a DRO (digital read out).
I think it is a fun and useful project for a person or team to learn on. It would benefit the space.
I probably lack the expertise to make decisions on what needs to be done, but I could probably contribute some time to getting some of the work done once that’s been determined.
What RPM is the original motor? This would likely be 1750rpm or 3450rpm. Pulley ratio may be able to adapt for a different motor, but there is a lot of difference there. If it already has a large reduction to the spindle, then we could have a limit where making the motor pulley smaller would result in that pulley slipping, and there might not be room for a larger pulley on the load side.
I have a 3450rpm 3hp 3ph, but given that this is a low-RPM final goal, the OEM design would probably call for ~1750rpm.
Id hope that the future of this mill should mesh with the overall target for manual milling capabilities in the shop but I’m not aware of a plan in that space. As a user of the Rong-Fu I would like to see a comprehensive maintenance plan for that machine so that it is operating within spec before another machine is added to the lineup. For example talking about adding a DRO someday to a currently non-working machine when the DRO on the Rong-Fu is not working doesn’t make sense to me.
DRO for the Rong-Fu is in flight and should be available well before the Gorton is back online (if indeed we decide to keep it).
The short(ish) manual milling goal is to have two functional machines so we can have classes with 4 students that don’t involve spending 3/4 of the time waiting on the machine.
I’m not super-attached to either of the mills we have on site now, but some mill is better than no mill. If somebody were to donate a Bridgeport tomorrow we’d find room for it and kick one of the existing ones to the curb.
We are looking to move away from the Rongfu. Shoulder mills are ok. The space needs a beefier knee mill. The Gorton was the 1st real machining tool. Prior to the Gorton we had a Harbor Freight table top mill. Like Jon said in his original post. I also have an affinity for old cast iron. I was warming up to adding a DRO. I changed jobs and stopped using the shop as much. The Gorton fell down in the process.
We can fix the DRO on the Rongfu. I believe there is discussions to do so. You are correct that the machine shop has not gotten the maintenance level that the wood shop has gotten. The stewards are working to get a maintenance program for the of the different shops.
I would like to see the Gorton run beautifully again.
Thanks for the update on the Rong-Fu DRO and overall vision. Sounds good on two mill strategy, agreed on wanting a Bridgeportish knee mill be one of them.
I’d be willing to help on the stewardship on the machine shop so please let me know who I should contact to offer some help.
Well that’s the external motor that someone hacked on.
When I looked, I forgot that the cast iron Gorton housing has the original motor inside. I don’t know its hp, and also I need its dimensions to determine if we can gut it and still fit a TEFC 3ph inside to maintain its aesthetics. I will look again.
Another possibility would be to replace the wires up to the windings. They’re coated in something that looks like tar, which I haven’t seen before. They look good other than where the wires join in, where it looks a bit toasty.
Inside needs degreased, but the bearings feel good.
It’d be nice to keep the belt-tightening mechanism intact too.
