# Under Pressure - How to check the Heat Press pressure?



## Moo Spot Prints (Jul 16, 2006)

IMO, one of the greatest rock songs of all time, btw. As this isn't the proper forum for discussing the Merits of Queen or David Bowie, I'll focus on clamping pressure for heat presses.

I read yet another 'my transfers aren't coming out right' post and again there was more discussion about 'medium' vs 'heavy' pressure. Arrgh! 

Yeah, here's another one of my 'let's quantify' exercises. Sick of 'em yet? 

I've seen two basic types of pressure guidelines. Most are in the 'light', 'medium', 'heavy', etc. category. A minority actually specify pressure in lbs. Neither help me as my press doesn't come with a way to measure said pressure. Frustrating. How do you achieve consistency from job to job?

So I started thinking about how to measure the camping pressure. Did a little digging and found this paper.

I found at least one company making the stuff. No idea how much it costs... yet. Neat application pictures. in the brochure.

Have any of you tried to measure the relationship between the crank on your press and the pressure exerted by the platen? Even something as basic as '3 turns = 10lbs' would probably be enough. Crud. That reminds me that I know enough math to just calculate it. Anybody know the thread pattern for the pressure knob on a Phoenix Phire press?


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

Found some pricing.

About $50/foot.


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> IMO, one of the greatest rock songs of all time, btw. As this isn't the proper forum for discussing the Merits of Queen or David Bowie, I'll focus on clamping pressure for heat presses.
> 
> I read yet another 'my transfers aren't coming out right' post and again there was more discussion about 'medium' vs 'heavy' pressure. Arrgh!
> 
> ...


I have a Hotronix but also have no idea what pressure is being used when I press. I pretty much do it by feel at this point. I set the pressure as light as it will go and then do a few turns and call that light pressure. A few more for medium and even more for heavy. The heavy I go so that the magnet will still hold the top down. Too much pressure and the top won't stay. At this point I now know by pressing the handle down and locking it whether it's medium or heavy. I haven't noticed any problems with the transfers or rhinestones.


----------



## Fluid (Jun 20, 2005)

*Re: Under Pressure*

*Bowie Rocks!*


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*

by feel all the way. 

since you change shirt types often too, and usually you bring the plate down to warm them up, thats when a turn the know to adjust the pressure. 

-----------------------------------
Young Americans


----------



## Rodney (Nov 3, 2004)

*Re: Under Pressure*



> Have any of you tried to measure the relationship between the crank on your press and the pressure exerted by the platen? Even something as basic as '3 turns = 10lbs' would probably be enough. Crud. That reminds me that I know enough math to just calculate it. Anybody know the thread pattern for the pressure knob on a Phoenix Phire press?


This would definitely be some helpful info. That's something I never understood from all the talk about pressure, since the actual heat presses don't have an acurate "light/medium/heavy" pressure gauge button.

Seems like a digital (or even analog) pressure gauge would be a good feature for a heat press manufacturer to add to their machines.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



Rodney said:


> Seems like a digital (or even analog) pressure gauge would be a good feature for a heat press manufacturer to add to their machines.


Curse you Rodney!  

I got into this because it had very little to do with computers. That last post of yours got me thinking how to adapt a strain gauge into my press. I really don't have time for this right now!!

Josh -- can you hook me up with a schematic for the microprocessor on the phoenix (not the electrical one)? I'm sure there's an extra input line in there somewhere. It's theoretically possible to add another line in the set mode to show the pressure. I'm betting that there's a simple 8-bit cpu in there. Atmel or TI-MSP. Maybe a stamp?

That's the more elegant solution but I would have to hack the micro (and hope the program is in eeprom). Another approach is to have an external lcd mounted that just shows the clamping pressure. Any other embedded hackers here?


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Rodney said:


> This would definitely be some helpful info. That's something I never understood from all the talk about pressure, since the actual heat presses don't have an acurate "light/medium/heavy" pressure gauge button.
> 
> Seems like a digital (or even analog) pressure gauge would be a good feature for a heat press manufacturer to add to their machines.


However, the medium pressure setting for a lightweight tee would be much different than the medium setting for a hoodie. You still have to adjust it for the different thicknesses of the garments.


----------



## Rodney (Nov 3, 2004)

*Re: Under Pressure*



> I got into this because it had very little to do with computers. That last post of yours got me thinking how to adapt a strain gauge into my press. I really don't have time for this right now!!


Too late, now you're hooked in  I get that way too with when a new idea pops up.



> Josh -- can you hook me up with a schematic for the microprocessor on the phoenix (not the electrical one)?


Just in case he doesn't see this right away, you may want to send him a PM or email.



> That's the more elegant solution but I would have to hack the micro (and hope the program is in eeprom). Another approach is to have an external lcd mounted that just shows the clamping pressure. Any other embedded hackers here?


I'm not one, but I'm very interested in seeing what you come up with. Heck, I bet the press manufacturers would be interested in seeing what you come up with.

My wife and I always talk about some new improved ideas as "ideas that should have been done in the first place" 

Like how they now put your grocery deli meats in a ziplock bag to keep them fresher longer. That should have been done as soon as ziplocks were invented (and cereal should come in those as well). 

But I digress  Seems like a pressure LCD would be a perfect addition to a heat press.


----------



## MotoskinGraphix (Apr 28, 2006)

*Re: Under Pressure*



Fluid said:


> *Bowie Rocks!*


 
My favorite..."Rock and Roll Suicide" I love that ****!!!!


----------



## Rodney (Nov 3, 2004)

*Re: Under Pressure*



> However, the medium pressure setting for a lightweight tee would be much different than the medium setting for a hoodie. You still have to adjust it for the different thicknesses of the garments.


Dangit, that's a good point  

Maybe there's a way to make the pressure measured relative to the item being pressed? 

I know this is something I'll try to document in my heat press "journal"


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> Curse you Rodney!
> 
> I got into this because it had very little to do with computers. That last post of yours got me thinking how to adapt a strain gauge into my press. I really don't have time for this right now!!
> 
> ...


Is there a big drop in quality between pressing a tee at 10 lbs. of pressure or 8 lbs. of pressure? I've been doing it by feel for a long time and not one has fallen off the shirt.


----------



## MotoskinGraphix (Apr 28, 2006)

*Re: Under Pressure*

Info from the stock plastisol transfer folks say......adjust your press by placing a sheet of paper between the platons with the ability to pull it out. Now adjust the platons with enought pressure to not be able to pull it out. Now that is a silly variable. I think it doesnt take much rotating the knob to achieve heavy pressure...I probably use way more than actually needed. The press actually achieves great pressure rather quickly.

I know that doesnt solve a thing but there it is.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



gmille39 said:


> However, the medium pressure setting for a lightweight tee would be much different than the medium setting for a hoodie. You still have to adjust it for the different thicknesses of the garments.


You sure about that? If you have a gauge, medium would be medium for all thicknesses. Obviously you would have to adjust to get the same reading for both but that's the point, there's no way of knowing how much to adjust by.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> You sure about that? If you have a gauge, medium would be medium for all thicknesses. Obviously you would have to adjust to get the same reading for both but that's the point, there's no way of knowing how much to adjust by.


Duh, I'm actually agreeing with you. I misread your post. Sorry.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



gmille39 said:


> Is there a big drop in quality between pressing a tee at 10 lbs. of pressure or 8 lbs. of pressure? I've been doing it by feel for a long time and not one has fallen off the shirt.


I seriously doubt it but I attest that I've cooked a few because I've had too much pressure. By how much? I have no idea...

I don't have enough experience to intuitively know how many turns to apply and the engineer in me cringes at having to flounder about until I do.


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> You sure about that? If you have a gauge, medium would be medium for all thicknesses. Obviously you would have to adjust to get the same reading for both but that's the point, there's no way of knowing how much to adjust by.


 


since you change shirt types often too, and usually you bring the plate down to warm them up, thats when you turn the KNOB to adjust the pressure. 

-----------------------------------

Sorry, had to fix some typos.


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> I seriously doubt it but I attest that I've cooked a few because I've had too much pressure. By how much? I have no idea...
> 
> I don't have enough experience to intuitively know how many turns to apply and the engineer in me cringes at having to flounder about until I do.


I figured you had an engineering background. You guys always need a black and white answer for everything with no gray areas.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

I tried to slip my kitchen scale under the press to get a ballpark figure but it was too thick. Fiddling around with it, I discovered that the platen does not close evenly -- it hits the front side first. Normally I don't think this would be a problem as it should have enough float to balance itself out at close time. My particular press has a bolt that prevents it from floating around much. This bolt is keeping it at an angle and it's exerting more pressure on the front than in the back. 

I'm going to ream out the bolt hole later to add some float. Hopefully this will help in getting rid of the pronounced press line I've been seeing.


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*

You're not related to McGyver by any chance, are you ?  

wow! good job.


----------



## TaylorTees (Nov 8, 2006)

*Re: Under Pressure*



T-BOT said:


> You're not related to McGyver by any chance, are you ?
> 
> wow! good job.


I think their cousins!!!!


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> I tried to slip my kitchen scale under the press to get a ballpark figure but it was too thick. Fiddling around with it, I discovered that the platen does not close evenly -- it hits the front side first. Normally I don't think this would be a problem as it should have enough float to balance itself out at close time. My particular press has a bolt that prevents it from floating around much. This bolt is keeping it at an angle and it's exerting more pressure on the front than in the back.
> 
> I'm going to ream out the bolt hole later to add some float. Hopefully this will help in getting rid of the pronounced press line I've been seeing.


Good luck with that.


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> I'm going to ream out the bolt hole later to add some float. Hopefully this will help in getting rid of the pronounced press line I've been seeing.


I think it should float a little, this will even it self out when the top hot plate comes down and you clamp it. I should double check my test press, i cant remember for sure but i think it floats.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

Macgyver? Did somebody say Macgyver?

1. Take some common household objects. Say, a ball of string, a toothpick, a clove of garlic, a laser thermometer, a lint brush, a pack of gum, a disco ball and a ball point pen.

2. Find the offending bolt.

3. Use the string to remove the bolt.

4. Use lint brush to catch shavings. You don't want alzheimer's do you? (yeah, disproven, I know).

5. Use the toothpick to ream out a slightly larger hole.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure (cont)*

6. Cook garlic and take temperature.

7. Have lovely assistant bring drinks.

8. Party like it's 1999!


Did it work? Not as much, but the platen is certainly more level than it was before. It's off by about 1mm now -- noticeably less than before. There is definitely more float and less resistance now when I close it but there is still something keeping it from being totally flat. I'm too tired to care at the moment. Maybe Macgyver will come pay another visit again soon. Who knows?


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> Macgyver? Did somebody say Macgyver?
> 
> 1. Take some common household objects. Say, a ball of string, a toothpick, a clove of garlic, a laser thermometer, a lint brush, a pack of gum, a disco ball and a ball point pen.
> 
> ...


6. I think you forgot to LIST the wine.  

After all that is your press still working ? .....any better.


Exelent Job.


----------



## Jasonda (Aug 16, 2006)

*Re: Under Pressure*

I hope you're not voiding your warranty by doing all this experimenting.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

Only 5 pictures per post allowed. Didn't mean to keep you from your daily drama!

There is more float but it wasn't a complete success. The press works fine. This was a minor tweak, nothing more.

The unevenness and temperature variation (+5 around the edges) has been there all along. I went back and checked some earlier pressings and sure enough, the bottom edge is visible on all of them. It pressed hotter and harder than the others.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

The wine since you asked is a 2001 Reserve Merlot (75% merlot 25% Cab Franc) from Dover Canyon, a small winery in Paso Robles (their Cujo Zin is out of this world!). Dry farmed vineyard I think. It was quite delicious! Not like a typical Merlot. Full bodied, slightly jammy. The Franc gave it a nice, unharsh bite at the end. 

For the record, I'm not a wine snob. My favorite beer is Labbat's Blue.


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> Only 5 pictures per post allowed. Didn't mean to keep you from your daily drama!
> 
> There is more float but it wasn't a complete success. The press works fine. This was a minor tweak, nothing more.
> 
> The unevenness and temperature variation (+5 around the edges) has been there all along. I went back and checked some earlier pressings and sure enough, the bottom edge is visible on all of them. It pressed hotter and harder than the others.


Now I'm even more confused. Not about the press, but, since when are engineers getting hotties like that. LOL. Ahh, almost 2 am and I have a couple hours to go before I have to get a little sleep before I have to get up to go to my normal job. Argh!


----------



## T-BOT (Jul 24, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> Only 5 pictures per post allowed. Didn't mean to keep you from your daily drama!
> 
> There is more float but it wasn't a complete success. The press works fine. This was a minor tweak, nothing more.
> 
> The unevenness and temperature variation (+5 around the edges) has been there all along. I went back and checked some earlier pressings and sure enough, the bottom edge is visible on all of them. It pressed hotter and harder than the others.


its usually less temp around the edges not more. Are you sure your meter is not toasted ?


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



Rodney said:


> Maybe there's a way to make the pressure measured relative to the item being pressed?


If there's a pressure/force gauge it should read differently if you change the thickness of the garment. You will still have to turn the knob and adjust the clamping pressure in order to press at the same pressure for dissimilar items.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*



gmille39 said:


> since when are engineers getting hotties like that.


Circle of life my friend. It's the circle of life. 

I suffered through school and early carreer with slim-to-none prospects. The tables have turned and now suddendly geeks are in demand. Who'd-a-thunk it?


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

The garlic was reading 58 degrees. If that doesn't tell you something, I don't know what will. 

No, it was consistently reading -4 to -5 degrees in the middle. Surprised me too as I was expecting a more waffle iron type of distribution. 

It could be the way that this particular press attaches to the clamp screw. It may have less wire in that area causing it to be a little colder. Dunno.


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> Circle of life my friend. It's the circle of life.
> 
> I suffered through school and early carreer with slim-to-none prospects. The tables have turned and now suddendly geeks are in demand. Who'd-a-thunk it?


I do like the show Beauty and the Geek. Does she wear one of the tees that reads, "I heart Geeks" ?

My wife always calls me a Dork, but I think there's a difference between a geek and a dork. I'd much rather be a geek I think.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Under Pressure*

You mean like this one?

Standard issue stuff around here!


----------



## kentphoto (Jan 16, 2006)

*Re: Under Pressure*



MotoskinGraphix said:


> My favorite..."Rock and Roll Suicide" I love that ****!!!!


Time takes a cigarette... 
When the horns kick in, I always punch the air and scream "Vive le Bowie!!!"


----------



## gmille39 (Oct 18, 2006)

*Re: Under Pressure*



Moo Spot Prints said:


> You mean like this one?
> 
> Standard issue stuff around here!


Pretty much. I've seen them like that and I love geeks, I love dorks, etc.
I funny one I was recently read, My other ride is a Blonde.


----------



## Fluid (Jun 20, 2005)

*Re: Under Pressure*



> My other ride is a Blonde


 awesome


----------



## Moo Spot Prints (Jul 16, 2006)

*The fix is IN!*

Ok, so I went to bed not entirely satisfied. About the press you pervs!

I took a second look when I got home from work and I figured out what the problem was. The joint that holds the bolt to the platen really doesn't have a whole lot of wobble. This is preventing the platen to even itself out when I lower it.

I *almost* put on the Macgyver hat again but quickly decided that a chewing gum free approach was in order. Instead of mucking with the top again, I decided to readjust the lower platen. Two washers were all that was needed. Do I have pictures? You bet!

1. The lower platen rests on the two aluminum bars you can just make out. Loosen the two bolts holding it down. No need to remove them.

2. Insert a washer (or two) to level out the lower platen. I adjusted it so that it was close enough to level so that the head could adjust itself as I brought it down.

3. Washer in place and bolts tightened back up.

4. MUCH better! I can actually feel the head adjusting as I close it. It's also much easier to turn the knob to bring it down so that it just rests on the bottom.

I'm now a happy camper. The press should have been like this from day one.


----------



## Moo Spot Prints (Jul 16, 2006)

*While I was at it...*

I couldn't resist. Ever wonder what's inside your press?

1. Only 4 screws separate you from the brains of the operation. See Lucy, no need to be afraid. I'm willing to bet you have a LOT more hair than I do!

2. OMG, the wires are trying to get out!

3. A rats nest of wires greets you at first.

4. Dig a little deeper and you will see the logic board:

Transformer on the left. Probably to drive the electromagnet?
Temperature adjustment knob on top. Not sure what the 2nd potentiometer is for. 
Farenheit/Celcius jumpers.
3rd jumper is for the momentary switch?

Just below that is the microprocesor. It's pretty old software (2000) and written by Stahls. Makes sense since theyr'e the parent company.

A little lower you have the chip used to drive the LED display.
To the right is the clock crystal for the CPU. 

Below that (the big black thing) is the speaker. I've never heard mine beep or buzz. Wonder if it's disabled in the software.

5. Under the sticker you have the chip id. I was close but got the manufacturer wrong. It's a PIC Microcontroller - PIC16C57C

There *will *be a quiz later on.


----------



## T-BOT (Jul 24, 2006)

*Re: The fix is IN!*



Moo Spot Prints said:


> Ok, so I went to bed not entirely satisfied. About the press you pervs!
> 
> I took a second look when I got home from work and I figured out what the problem was. The joint that holds the bolt to the platen really doesn't have a whole lot of wobble. This is preventing the platen to even itself out when I lower it.
> 
> ...


Glad you fix it.
Its important for it be flat and level, it does make a big difference if its not when working with some super thin fabrics and quick apply 3 second type transfers.


----------



## Solmu (Aug 15, 2005)

*Re: The fix is IN!*



Moo Spot Prints said:


> The press should have been like this from day one.


I was wondering the same thing. Seems to me that either 1) You've overlooked a good reason it was manufactured that way, and the modifications are now placing extra stress on some other part of the machine, *or* 2) The press could/should have been designed better from day one, as per your improvements.

So the question is... do you feel lucky punk?

(rhetorical really... you obviously do, and obviously know what you're doing)

Time will tell.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: The fix is IN!*



Solmu said:


> So the question is... do you feel lucky punk?


I _always _fee lucky. That's my problem. It's fostered confidence where there should be none. 

You're right, I may have missed something obvious. It wouldn't be the first time, nor the last. I was just thinking a little while ago that I may have been able to just rotate the lower platen 180 degrees to see if that evened things out. I may try later just to be sure. In any event, I had to do something. I've ruined a few shirts now and the prospect of spending another couple hundred bucks in freight was not sitting well.

I think I just happened to get a unit that was slightly out of spec. The design engineers should have caught on to the fact that if the manufacturing tolerances were too tight this would invariably happen and should have provided a mechanism for adjustment by the end user.

In any event, the flaw and the fix are documented now. I'll get in touch with them to make sure they know about it. I'm otherwise very happy with the press. The auto open feature is awesome!


----------



## Moo Spot Prints (Jul 16, 2006)

*Let's do some math!*

Did I lose you? Come on, it's not THAT hard!

I still want to figure out how much pressure my press puts down. Hooking up a sensor and a display is going to take a while, so again, let's go low-tech.

I can't get a measure between the platens, so I'm going to try and get a reading for how much effort it takes to turn the screw and bring them together. If I can determine this, I should be able to derive the force. The operative keyword here is _should_.

How to do this? Tools baby, you gotta have tools. I shall name this segment: *Enter the Torque Wrench*

1. The tool. It measures torque in lb-ft.

2. The knob on my press. What's that little hole in there. If you guessed 'set screw', you'd win NOTHING! You'd be right however.

3. 1/2 turn with an allen wrench and off it comes.

4. Uh oh. The top is round. How on earth am I going to attach the wrench to this??

5. Aso grasshopper, use the same allen wrench as a shim for the smallest socket that will fit over the bolt.

If you're still with me on this thread and are one of the naysayers that keep wondering when my luck would run out... This is your moment.

This is when things go horribly wrong...


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Let's do some math!*

The story continues...

1. Uh oh. The socket that fits is for a 1/2 drive but my torque wrench is 5/8. It doesn't help that the lowest force I can measure is 10lb-ft. What to do? 

2. I did the only rational thing. I went to one of my neighbors and borrowed a gauge type wrench (mine is the easier-to-use-on-a-car click type). It went down to 2 lb-ft and was the right size. Woo Hoo! Irv is a nice guy but he doesn't get out much. I had to sit and listen to him talk about cars, donuts, gardeners, the weather.... for about an hour for this. You guys owe me big time! 

The results? 

Every quarter turn of the bolt corresponded to a 2.5 lb-foot increase in torque. It was consistent up to 15lb-ft. I didn't go higher because I had no idea what that was doing at the platen level. The pressure felt firm on the press handle.

So does this mean that 1 turn equals to 10 lbs of pressure? Well, if you've made it this far, I have to issue some *
Fair Warnings*

1. My math is a little fuzzy here. I might have to dig up my physics book.

2. I'm not exactly sure what units we ultimately need. 

3. I am assuming that the force measured by the wrench is equivalent to the one the press is exerting when you close it. After all, you don't turn the knob once the press is closed, right? 

4. I'm ignoring friction.

If we take out anything to do with the screw (assuming assumption #3 is correct) we're left with just the force we measured -- *2.5 lb-ft per 1/4 turn* or *10 lb-ft per full revolution*.

Is this right? I don't know. I bet it's pretty close though.

I will test it once I figure out a way to messure force between the platens. Stay tuned.

Still, I'm not convinced this is exactly right. Shouldn't the pressure be in psi or something like that? lb-ft is a unit of torque. Does the ft part of it drop out because it all gets converted to linear force thus leaving just pounds?

Feel free to doubt, correct or mock my math.


----------



## Solmu (Aug 15, 2005)

*Re: The fix is IN!*



Moo Spot Prints said:


> You're right, I may have missed something obvious.


I'm not really suggesting that you did, just mentioned it in passing as a possibility (my paranoia urging caution again is all) - I think it's just as possible that the manufacturer missed something obvious, or that as you say it was a manufacturing variance with your press.


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Let's do some math!*

I've talked to some friends and I've come to the conclusion that this process is flawed. I am not taking into account the hardness of the rubber pad. The only real way to measure this is to put something under the platen and measure it directly (or in the path of the screw). I have some ideas in mind and when I get some time to tinker again I'll give them a shot. 


UPDATE: after using the press some more after my mods I can say with confidence that it definitely was worth it. I don't have hard lines on the bottom of my shirts and the pressure is noticeably more even.


----------



## MotoskinGraphix (Apr 28, 2006)

*Re: Let's do some math!*



Moo Spot Prints said:


> I've talked to some friends and I've come to the conclusion that this process is flawed. I am not taking into account the hardness of the rubber pad. The only real way to measure this is to put something under the platen and measure it directly (or in the path of the screw). I have some ideas in mind and when I get some time to tinker again I'll give them a shot.
> 
> 
> UPDATE: after using the press some more after my mods I can say with confidence that it definitely was worth it. I don't have hard lines on the bottom of my shirts and the pressure is noticeably more even.


How about a thin digital weight scale between platons? Probably work better on a swing away.


----------



## bobabuee (Dec 7, 2006)

how about dial indactor guage?onside platen attach strip of metal on lower platen so guage hits metal take some mesurements and then you would know 
soft, med , hard prussure record ho many times you turn knob to get to measure
ment?i dont have heat press yet but maybe next week?

you can get dial indictor from harbor freight ,think they digital ones too

this is my 2 cents on this subject


----------



## Moo Spot Prints (Jul 16, 2006)

*Re: Let's do some math!*



MotoskinGraphix said:


> How about a thin digital weight scale between platons? Probably work better on a swing away.


I tried that but ran into 2 problems: 

1. My kitchen scale (the thinnest I have) only goes up to 8 lbs or so.
2. It's way too thick to allow the press to lock down.

If anybody's got a 1/2 inch thick scale that goes to 100lbs in SoCal, let me know!


----------



## Moo Spot Prints (Jul 16, 2006)

*Math Update*

I've been sitting on this for months and it's finally time to revisit the problem. I've got some new math that I think will give me a reasonable answer. Here goes:

(Sorry for the bad ascii picture. My scanner is down and the php script is removing leading spaces.)

Picture a screw with a handle on it

|<---R--->|
__________ Q )
|/| /
|/| _ \/
|/| _R
|/|

| F
\/

2PI
F = Q ---- R
P
Where:

F = downward force (lbs)
R = length of arm (ft)
Q = force on arm (lbs)
P = Thread pitch (ft)

Clear as mud? Good.

From my earlier experimentation, I found that the thread pitch was 2mm, or .007 ft. I also determined that it took 10 ft lbs to go one full revolution.

Plugging the numbers leaves 

F = 1 ft * 2 * 3.1415 * 10 / .007 = 8976 lbs

My press is 16x16 so I need to divide by 256 to get the pounds per square inch.

F (psi) = 8976 / 256 =* 35 psi*

What this means is that when you rest the two platens together, you will get 35 pounds of pressure for ever turn you tighten the press. This *sounds* about right to me. 

Comments/corrections are always welcome!


----------



## raymondzachary (Jan 27, 2008)

Moo Spot Prints said:


> IMO, one of the greatest rock songs of all time, btw. As this isn't the proper forum for discussing the Merits of Queen or David Bowie, I'll focus on clamping pressure for heat presses.
> 
> I read yet another 'my transfers aren't coming out right' post and again there was more discussion about 'medium' vs 'heavy' pressure. Arrgh!
> 
> ...


We just bought a new Knight DK20S at the Long Beach ISS show which has the pressure indicator feature. This is not a pressure gauge but a platen height indicator which is supposed to correlate to pressure. I asked the Knight representative specifically about actual pressure measurement (using perhaps crush techniques) as many of the transfer paper sellers were specifying 80-90 psi. He said Knight would release just such a product Spring 2008.


----------



## Moo Spot Prints (Jul 16, 2006)

This is a pretty old thread. Since I posted, Hotronix has included a pressure gauge in their presses. I fiddled with the newer units and found that each indicator lever corresponded with a quarter turn on the dial. A '1' on the meter is the lowest pressure at which the auto release mechanism engages.

I still don't know if my initial math was right or not. I've since learned to do my pressing by feel.


----------



## ukracer (Feb 11, 2010)

Moo Spot Prints said:


> This is a pretty old thread. Since I posted, Hotronix has included a pressure gauge in their presses. I fiddled with the newer units and found that each indicator lever corresponded with a quarter turn on the dial. A '1' on the meter is the lowest pressure at which the auto release mechanism engages.
> 
> I still don't know if my initial math was right or not. I've since learned to do my pressing by feel.


Now that is a shame as I have followed this thread with interest...all be it in just an hour some 4 years late. 

But I still want to know how to measure pressure of a heat press................arrrrggggg.


----------



## signgeezer (Jan 7, 2011)

*Re: Under Pressure (cont)*

try a grilled cheese wrapped in alum. foil than a quesadilla to gauge it also.
;0


----------



## ukracer (Feb 11, 2010)

*Re: Under Pressure (cont)*



signgeezer said:


> try a grilled cheese wrapped in alum. foil than a quesadilla to gauge it also.
> ;0


very helpful.................thanks


----------



## inobu (Dec 29, 2010)

I'm sure you are wondering feel what? Feel that it hot? feel that it closed? Feel what?

Here is what you need to feel. As the press closed it applies heat and a downward force. The same concept when you hand iron a transfer. You want the heat to melt the transfer and the pressure to apply the transfer material to the shirt. 

Too much pressure and it smears/ghosts not enough and it peels off in spots. There are other factors that come into play material thickness, shirt quality, color and texture that dictated the required pressure needed to achieve a good transfer. The number that these companies give out is only a ball park. 

What I am finding out is we will learn as we go because every shop has its own variety of equipment and environment that makes it too different to call. 

Inobu


----------



## DosOkies (Dec 3, 2012)

What I do is place a piece of paper in the machine and close the lid. If it comes out fairly easy with a little resistance, that is light pressure n a shirt, Kinda hard to pull out, medium pressure and right at the point of not pulling out is heavy pressure. This works great and is consistent. No problems witht his method for standard shirts, hoodies is just a guessing game.


----------



## dkdesign (Apr 9, 2012)

What do others think about DosOkies way? sounds interesting


----------



## cbs1963 (May 31, 2007)

dkdesign said:


> What do others think about DosOkies way? sounds interesting


Most of the problems with heat transfers involves heavy pressure to insure the ink transfers completely. Most others that use medium or light pressure deal with less demanding types like vinyl or rhinestones. LIght pressure is just that.. light. Don't have to sweat this too much. Medium is solid pressure that does not require a lot of pushing on the handle to close, relative to what heavy requires. On heavy pressure closing the manual press requires actual effort for a grown man to close. Heavy needs two hands on the handle for most. The paper trick will allow you to make sure the platen is making solid contact on all sides as on heavy pressure the paper can not be pulled out. Hope this helps.


----------

