Hey guys welcome back to the shop today we're going to be doing something a little different and we're going to be upgrading my mini mill. I get a lot of questions on this mill where I got it and if I'd recommend it I got mine from Harbor Freight but there are a multitude of companies that sell this exact same mill it's called a SEG X2D Mini Mill and like I said there are multiple brands that basically slap their labels onto the same mill. The little machine shop.com actually sells a version of this mill that's probably your best option since it has a fixed column and some other upgrades on it already. But I got mine from Harbor Freight and I would very much like to upgrade this mill's spring system on the head. It comes with this torsion spring which does a very poor job at holding this head up. You can see here if I unlock it at the top position and let go the head will fall down and that is not what we want. So I ordered an air spring conversion kit from littlemachineshop.com and today we're going to be installing that onto my mini mill. Alrighty so just to show again this is the problem the head will not hold itself in the top position with the torsion spring. But the top position the bottom of the drill chuck is around 7 and a quarter inches from the table. I did not measure the lowest position of the head which with the torsion spring there's actually a limitation on how close you can get to the table. With this new longer rail you can get closer to the table and I did not measure that and apologize in advance. So this is the kit that you get from the little machine shop. It is number 2,250. I'll put a link to this air spring kit in the description below. So I'm moving this mill over to a separate workbench so I can get some better angles of the bill then I can move around it a little more easily. Be careful when you're moving these things around because they're pretty top heavy. Step one is to take that cover off and then measure 15 inches down the column. This is where we will be drilling a hole into the back of the column to accept the bottom of the air spring connector. So I measure 15 inches down, transfer that line over, find the center of the column and then drill a hole into the back of the column. I start with an eighth of an inch drill bit, step up to a quarter inch and then I end with a letter T bit. This is the appropriate size for that bolt to pass through on the bottom of the spring. When looking through the directions I found that the diagram supplied was not printed to scale. It was off by a few millimeters. So I decided to draw this out myself. The two dimensions that are important are the 60 millimeter and the 18 millimeter dimension. I also marked a 30 millimeter dimension in the middle so I can line everything up easily. It's worth mentioning at this point that I think that 18 millimeter dimension could be slightly larger because my air spring system seems to not be perfectly square in the final assembly. So if you're going to be doing this I would think about bringing that up maybe to a 20 millimeter dimension and you'd be slightly more square with your final product. Using my calipers I then mark the center line of the head so that I can line it up with the center mark on my template. Once I have these lined up I take my template down and use it as a guide for my center punch. I will be drilling number nine holes into these two locations in order to tap a 6 millimeter by one thread. I start off with an eighth of an inch pilot and then move up to the number nine drill bit size. With the motor sitting here this is a fairly precarious spot to work and tapping will be slow so take your time. This would be a good situation to have some sort of power tap that you can put on a drill or maybe even a tap guide so that I can make sure that these taps are nice and straight. But in this case I just took my time and tried to get them as straight as I could. This motor being in the way might have been the reason why little machine shop went with the 18 millimeter dimension opposed to a 20 or 22 so there could be some method to their madness. The next step is to remove this stop for the head. Get that out of our way and go ahead and clean it up a little bit while we're there. We're going to be drilling a hole and tapping it to the same 6 millimeter thread for the new stop location. So you can see I have a little bit of an angle there. I didn't like that so I removed the cover from the motor here and it allowed me to get my drill a little bit more square with this hole. So this hole is a little bit taller so you can see that we're going to gain a little bit of height and the rail system that we're getting with the new air spring is also taller. So we're going to get a little bit more upward travel on this system as well as downward travel. So now that we have all of our holes drilled and tapped we're going to start messing around with this air spring system. First thing we're going to do is put an M8 by 30 millimeter socket head cap screw on the bottom of this air spring. This is going to be passing through our column to exit the hole that we drilled 15 inches down from the top of our column. Then we put two nuts on our bar here and then add the upper and lower mounts onto that bar. The directions that come with this air spring assembly kit do a great job of explaining it these steps in order so please refer to those when you're putting this assembly together. The next thing we're going to be doing is removing the rail system for the Z-axis on our machine. So we're going to bring the head all the way to the top, physically lifting it in some cases all the way to where it's flush with the top of the column. Once it's here we'll lock it. Using a Torx T30 we will remove the screws that are attaching the Z-axis feed. So once we have these screws out this feed will come off very easily. Then we can thread in our Z-axis feed the new one into the top of our column. This how much lower this feed goes on the column and also how much higher it goes. So you will have a significant amount of travel added to your system with this feed. In the up direction I actually measure it later and I think it's about a half of an inch but you get a significant amount of travel in the downward direction as well. Once we have our Z-axis nice and tight we will move on to installing our air spring system. We're going to be trying to pass through that M8 by 30mm bolt through the hole that we drilled in the back of the column. This can be fairly precarious. I found the easiest way is to use a flashlight shining through the hole in the column until you see it line up and then push it through. Once you get it on there you put a washer and a nut on it to that M8 thread. We can then get the top bracket hooked up to the M6 holes that we drilled in the top. I start off with everything nice and loose to get it hooked up and then I tighten everything down securely. Here we're putting that column stop back on in its new location. Notice that it will hit the top mount and we will fix that later on in the build. But before we do that we're going to be removing this Torgent Spring system. With the air spring installed this Torgent Spring is no longer necessary. It also limits the travel of the air spring cylinder inside of the column and it limits the travel of the head towards the table if we leave it on there. So we're just taking this all out. This is now trash. Who knows, maybe we can use it for something else down the road. We get all that off. I'm going to go ahead and put the cover back on the motor just to make sure we're all back together here and then we're going to address this issue. The top mount is preventing the head from reaching its tallest position possible. So we will reduce the thickness of that stop so that it clears that top mount with the belt sander. We gained about a half inch an upward travel and unfortunately like I said before I did not measure what we gained in downward travel. I then came across this piece that I did not use in the build but came with a kit. I'm not sure what it's for. I tried using it as a stop but it did not work very well in that regard. So if anyone has any ideas of what that piece is used for, please let me know. It's always kind of disconcerting to have a piece left over when you are installing something that was designed as a kit. You can see here that the upward and downward travel is working very well with an air spring installed. It stays where you put it which is a big reason for this install. When you stop moving the handle, the head does not move anymore after that. You can see I'm bringing it all the way to the top here and when I let go the head does not move. The handle does but the head does not move. So this is a major success for a very cheap price. You can replace the torsion spring on your mini mill and have a much more locked up tight precision piece of equipment in my opinion. So I hope you guys liked this video. If you did consider subscribing to the channel. And until the next time, I'll catch y'all on the flip side.