How to Adjust the Tablet Size
So today, I'm going to show you how to adjust the dies, both the fill depth and the ejection depth, for the TDP range. As you can see here, I have got my working TDP 5 pill press, freshly arrived, but the punch dies are completely unset. So the first thing that we're going to do, is we're going to have to adjust them. And the first thing that we're going to adjust on the dies, is the ejection height. Now, the ejection height is really, really important. If you're getting halved or broken tablets coming out, often it will be down to the ejection height. What happens in the process of the machine, is the die comes up, as you can see here, and if it's too high, as it is in this scenario, the TDP will get jammed (video on how to un-jam a TDP here).
Adjusting the Ejection Height
So the first thing we're going to have to do, is actually lower the ejection height. Now, all of the heights are controlled off this side pin here. And there should be a little bar and an Allen key holding it. So the first thing you're going to want to do is loosen that off like I've done here, so that you can get to your nuts and adjust them. Now, if you spin the top bolt towards the right, that will move your ejection height down, as it is in this scenario, as it is in this case. If I zoom in, we'll see if we can get a better shot on that. Okay. So if I move the top die to the left, it raises the ejection height. And if I move it to the right, it lowers the ejection height. So you can see in this situation.
Before you go to adjust your ejection height, you need to make sure that the desktop tablet press is at its highest point in its rotation. So the best way to tell this, is to start moving the machine clockwise until, bam, this arm gets to the highest point possible. At that point, you want to just loosen it off a bit, because otherwise, it will be tight to move, and then just start moving it so that your ejection height here, starts to line up. So mine is too high. So at the moment, I'm moving it to the right. Then, you just want to bring it back in. And it's still a little bit too high.
What you can see is happening, is that the tdp 5 boot - which does not only the filling, but it actually ejects the tablets off the die - is catching on the die just as it's about to come off. You can see it just catching there. So that shows me that I need to drop it down just a little bit further, until it's completely flush and smooth. There we go. We're getting an absolutely smooth action over that. And if I just run my finger over it very, very gently, I can tell that it is absolutely perfectly flush. You want to try and get it just little half turns, little quarter turns, little, little turns, right until - oh, a little too high there, move it down a bit - that's perfectly in line there, just until it's perfect. Now, once you've got your upper ejection height sorted out, the next thing that you're going to want to do, is you're going to want to calculate your fill depth. So what you're going to want to do, is you're going to want to move it around until you get to the bottom, and that will show you your fill depth. Now, you can see this bottom nut here. If I move this bottom nut to the left, I am decreasing my fill depth. And if I move it to the right, I am increasing my fill depth. Like so.
Cleaning TDP Punch Dies
At this point, what you're going to want to do, is you're going to want to clean out your dies. So you need to clean out your dies with a dry lubricant before you get to work with putting any other powders in there, which is the next step that comes along. And in this case, we use magnesium stearate. So just tip some generally into the hole at the top, and across the die face. Be quite sparing with it at first, because you really just want to make sure that those dies are clean before you get to work with anything else. And this dry lubricant really is very, very important in ensuring that your TDP machine does not jam up at a later date. So it is good to just get it done at first, get some magnesium stearate in there, work it through a couple of times, just so that you know that it's all present and correct, like so. Right.
Choosing Fill Depth
The next thing that you're going to want to add, after you've popped your dry lubricant in, to help you calculate your fill depth, is you're going to want to pop in a little bit of your microcrystalline cellulose, which is your binder. And then, we will be able to start looking for the right sized tablets. So I've popped in some microcrystalline cellulose into my die, and it's produced the first tablet, which is, in my mind, far too full. The fill depth is far too full. So what I'm going to have to do, what I want to do, is I'm going to want to decrease the fill depth. So clean out the die, move it to the filling position like so, and now I want to adjust the die up.
So to adjust the die up, you have to twist it to the left, or clockwise, like so. I want to do it to about half. Ejection height still isn't quite right. Oh, no, it was. Just continues to move up a little bit further. There we go. That has given me my first tablet out of this machine, which is starting to come good, and it's pretty solid as well, just absolutely perfect. So if you want to increase your fill depth, you roll it all the way to the bottom like so. And you need to move it towards the left to decrease, and the right to increase. Just continue to very, very slowly increase it here.
Once you've aligned up your fill depth, you need to tighten up the locking nut on the side, which also has the bar that holds the cogs in place. Really make sure that this is very tight, you don't want this to be loose at all. There we go. Lock that up. And then, we pump out a couple by hand now. There we go. We're getting them out by hand, which is absolutely perfect. Now, if I just clean off some of the excess white powder around here. Sometimes it's good to have a painter's brush to do this with. So there we go. We're getting three tablets. We've got three tablets out of here.
Changing Punch Pressure on a TDP
Now, the next thing that I need to do, is I need to decide whether or not my punch strength is strong enough. So let's take a look at this tablet here. It doesn't take - as you can see - a lot to pop it open. Let me show you with another one, a fresh one. Just pop it in between my fingers. All right, it is relatively strong, but there again, it goes quite easily. I think if you were to have a thousand of these inside a bag, they'd go quite quickly. So the next thing that we're going to do, is we're going to move up the machine a little bit. We're going to adjust the punch strength.
The punch pressure is controlled by this top bolt here, which sits snug against this pin here, which is the part that actually controls the punch pressure. ( please wacht this video to see how to change the punch pressure on a TDP 6s or TDP 7)
To increase the punch pressure, we're going to rotate it towards the left very, very slightly. To decrease, move it towards the right, obviously. Let me show you, actually. If you increase the punch pressure too far, like I've just done now.
Okay, so the best thing to do to calculate the upper punch pressure, is to move the die until, bam, it's absolutely solid. Then move it slightly up, until you can see this die, and start twisting it to the right very slightly, bit by bit. Then try it back into the machine. Will the machine turn over yet? Bam. Perfect. So that is the tightest you are going to be able to make your tablets, which is the ideal amount, really. You want to be able to get them as tight as possible.
Then, once you've selected that depth, you want to twist this upper bolt down. Then get two sets of monkey wrenches or pliers, adjust one up to fit the bottom nut, like so, and do another one up until you fit the top nut. And then twist them in opposite directions until they lock up against each other. Now, this can be quite a hard thing to do, keeping your die in the right position, but it can be done. So once you've done that, that should be absolutely solid and that will stop it from moving around later on in the process. And bam, away you go. You can start producing your tablets. And that is how you select an upper and lower fill depth, and that is how you adjust up your machine. And that should be giving you very, very solid tablets.