awesomenesser wrote:Also do you guys think I will have issues cutting aluminum with my setup?
If you stick to smaller end mills and your goal is mostly oriented toward cutouts and engraving in aluminum sheet, if you restrict your cutting to slow feed rates, I think you'll be fine. If you want to hog out big chips of aluminum and do some serious machining of billet aluminum, you'll want a Bridgeport style milling machine or a vertical machining center. I have an inexpensive Grizzly G1006 benchtop milling machine that's paid for itself five times on the little work I've done on it. Almost every time I use it, I think about converting it to CNC, but then I come to my senses and plan to sell it and buy a used Bridgeport clone and convert it to CNC. Actually, I saw a very nice conversion of the Grizzly (also offered under many other names). Not much of the original remained , but it became a mini vertical machining center, which would be difficult to accomplish with a Bridgeport knee mill. It was fully enclosed in a cubical shape, with an integrated flood coolant system. The iron is probably suitable for a 1 HP or 1.5 HP spindle. Mine shipped with a 2 HP spindle, which is probably over powered for the rigidity of the cast iron.
awesomenesser wrote:I think the flood system will help out a lot (at least hopefully more than the mess it is going to create).
I'm trying by best to avoid flood cooling. My shop is in the basement, and I don't want the house to smell like a machine shop, and most of that smell is the coolant. There are low odor coolants, but they still stink too much for a basement, IMO. If you're machining in your garage, that probably wouldn't be a problem. But you still have the problem of coolant flying everywhere. Shoot a stream of coolant at an end mill spinning at 10,000 RPM and see where it goes! If I was converting to flood cooling, I'd put the entire machine in a big box, and I'd probably interlock it so the spindle and flood coolant are disabled unless the door is closed. I'm planning on short run production on my lathe once I convert it to CNC, and I'll be turning steel parts, and I'm going to try to get by with compressed air for coolant and carbide tooling (that I expect to replace much more often because I'm running without coolant). We'll see. For occasional hobby use or even small scale manufacturing, I think conventional coolant systems are probably more trouble than they're worth.
awesomenesser wrote:Here are a couple pictures of my progress.
Totally awesomenesser! Very nice job. Much better than the original, I'm sure.
awesomenesser wrote:I guess I had one other quick question how much cooling do these Chinese spindles need? I was thinking of installing a dual 120mm radiator and pump loop, is that too much or too little?
I just designed the cooling system for my 80W laser tube, and the water cooled spindles and water cooled laser tubes typically use very similar setups. In the case of my laser tube, I guessed I'd need to remove 800W of heat. I used a 120mm X 240mm radiator. With a good fan, a 120mm X 120mm radiator would have probably worked. I think your spindle will have considerably less waste heat. Electric motors are much more efficient than laser tubes. You may only have 200W or 300W of waste heat. That's a complete guess. The manufacturer should provide that spec. But for hobby CNC machine conversion, most people don't go to great extents to quantify and calculate everything. It's more TLAR engineering (that looks about right). Err on the more cooling side and call it done.
I did notice that the little submersible pump shown in the Automation Technology video demonstrating the coolant setup on their comparable gantry router (from your earlier link) was tiny and pathetic compared to the manly coolant pump that I selected for my laser cooling. That small pump implies that not much cooling is needed. The delta T of the water is pretty much fixed by the room temperature on one end and the maximum motor temperature (or the boiling point of water!) on the other end, so the amount of cooling is purely a function of flow rate, assuming the radiator and cooling fan is large enough. That tiny pump isn't moving a lot of water, so it's not sinking a lot of heat. The 120mm radiator should be more than enough. BTW - If your muffin fan isn't pushing enough air through your radiator, you can always upgrade it in the same form factor. I went hog wild and bought a pair of the very nice looking fans from LightObject.com when I ordered the radiator. I checked after placing the order, and they were cheaper than the eBay prices for the same blower. That was true for a lot of LightObject components.
http://www.lightobject.com/Ultra-Strong-12cm-DC12V-Cooling-fan-200CFM-P605.aspxIn fact, you might benefit from browsing their entire selection of cooling components.
http://www.lightobject.com/Cooling-C52.aspx?s=OrderBy%20ASC&c=52&p=1In addition to low prices and fast shipping, Marco was extremely pleasant. He's very customer oriented.
Water cooled lasers always use a flow switch to ensure that the coolant is actually flowing, as opposed to simply turning on the pump and hoping it's flowing. The laser power supply is not enabled if the water isn't flowing. I'd do the same thing for a water cooled spindle. I'd have the flow switch wired to an enable pin on the VFD. Barring that, I'd have the flow switch operate a relay that supplied power to the VFD that powers the spindle.
http://www.lightobject.com/Search.aspx?k=flowAs to your question about too much or too little cooling... for hobby CNC machines, I'm inclined to agree with Robert Smith's advice in a song by The Cure. "Too much is never enough."