DAKE 10 Ton shop press

[ddewees]

Does anyone here own one of these, or know someone who does?

 

http://www.mscdirect.com/product/93143063

 

I'm trying to decide which press I should get, and the price for this one seems good. They will ship it for free too.

 

Thanks.

 

Oh, one other question...

 

If you own this unit, can you briefly explain how you use this pressure gauge?

[leedrill]

to me that looks like a good buy you would be able to do some 4lb motors on that i assume not sure about 6lb but that press is great with 16" of working room and 10 ton cant go wrong {thats my2cents for a first press }

 

my opinion is you will want some 90 degree brackets to fit the blast screen to the angle feet on the bottom

if you have a welder will be easy enough to extend the working height {not that youll need it }

it dosnt say if it is 10 metric tons and i always forget what ton you use in the states

 

my, what might be, confusing explanation of how to read the gauge :

 

obviously the gauge will read in mpa,kpa,psi, hopefully it will be the normal kind and be psi

to make this simple think of the piston in the jack as a square {which it is not and this is why you have to measure the surface area exposed to the pressure of the oil } you will not have to open it to do this just some jacks have a different size on the press stud rather than the actual ram

 

so picture you have 1000psi on your tooling you would have a 1 square inch ram in the jack and 1000psi on the gauge which means you are putting 1000 pounds of weight , mass , force , how ever you want to look at it but you need to do the pressure to force to understand it easily

 

so if your ram is round you need to figure out the surface area of it and multiply the gauge reading by that figure then you will know what weight / force you have on your tooling then you can figure out the surface area of your tooling

 

and to under stand this it is easier to think that if the tooling where the same as the surface area of the jack ram the pressure would be the same

 

so to keep it simple and rounded off using squares

 

8000psi on the gauge on a 1" square jack ram on a 1" square tooling the gauge should read 8000psi

for the same on 2" square jack ram and 1" square tooling 8000psi= 16000psi

for a 1" square jack ram and a 2" square tooling 8000= 4000psi

 

i hope this all makes sense and makes understanding it all much easier

Edited November 15, 2013 by leedrill

[ddewees]

Thanks.

[Varmint]

Leedrill:

 

I think you have some numbers mixed up.

 

First, forget about examples where you arbitrarilly change the ram size. The way this should work is you determine force by relating the pressure guage reading to the force on the ram.

 

The area of a circle is PI * R * R Where PI is 3.14.159265358979 and R is of course the radius of the ram.

 

OK, lets take a guage that reads to 20,000PSI, and a ram diameter of 1.12845, meaning exactly 1.000126 sq inches, close enough to exacly 1.

 

In this example, with the ram in contact with tooling or just bottomed out on the work plate, the guage reading is a direct indication of the force.

 

Now lets say you have 3/4 tooling for a rocket. Pump the jack to 5000 pounds indicated, and we have to MULTIPLY the force since we are putting that 5000 lbs on a smaller area.

 

So, PI * .75/2 * .75/2 = .441786467 square inches.

 

We grab the reciprocal (1/.441786467) = 2.263536968

 

So now with 5000 LBS on the guage, we multiply 5000 * 2.263536969 to end up with 11317.68484 lbs of pressure on the grain.

 

2nd example, tooling for a 1.0" rocket, ram force still 5000 LBS:

 

PI * 1/2 * 1/2 = .785398163 sq inches.

Reciprocal 1/.785398163= 1.273239545

Pressure on the grain = 5000 * 1.273239545 = 6366.197724 LBS

 

3rd example, tooling for a 1.5" rocket, ram force still 5000 LBS:

 

PI * 1.5/2 * 1.5/2 = 1.767145868 sq inches.

Reciprocal 1/1.767145868 = .565884242

Pressure on the grain = 5000 * .565884242 = 2829.421211 LBS

 

Key elements: The jack guage is only aware of the pressure in the cylinder, and the actual force delivered by the ram is soley dependant on the diameter of the ram (+ cyclinder internal clearance) and the pressure in the cylinder.

 

The composition (BP, Whistle mix) "sees" a different pressure than the gauge indication, and that pressure is the reciprocal of the tooling diameter times the force delivered by the ram.

 

DAS

[Varmint]

I have these calc embedded in an Excel spreadsheet.

 

You enter the ram diameter, the gauge reading, and the tooling diameter, the output values are the ram force and tooling (composition) force.

 

If anyone is interested in obtaining a copy, let me know and I'd be happy to figure out how to post it to the forum.

 

DAS

[dave321]

I would be interested in seeing the spreadsheet

 

any chance of posting it?

[Mumbles]

I'm fairly sure excel spreadsheets are allowed to be uploaded. If not, let me know and I can make it happen. I know I've sent a few through private message.

[Varmint]

Well, lets see if this works (attaching file).

 

Change values in column C rows 3 through 5 only, enter values taken from your press and tooling.

 

Values in column C rows 10 and 11 are formula based, so edit these only if you know how it works, and are aware of the effects of your changes.

 

If there is interest, I can make another tab to serve our members that utilize the metric system.

 

I might eventually offer a solver based version where you enter a target composition pressure, and it would solve for the jack pressure reading required to obtain that force so long as you input the ram and tooling diameters.

 

In the meantime, you can simply enter your ram and tooling diameters, and take educated guesses at the gauge PSI reading required to achieve a close match at the C 11 Composition PSI output data cell.

 

DAS

Pressing_Comps.xls

[marks265]

In the industrial world Dake is a good press. They've been around a while.

[leedrill]

thanks for your corrections marks i work with a p2f gauge and due to the speculation of the reason wolter and so on have p2f gauges with a 1" square piston in their gauges

 

can you explain

 

 

 

Key elements: The jack guage is only aware of the pressure in the cylinder, and the actual force delivered by the ram is soley dependant on the diameter of the ram (+ cyclinder internal clearance) and the pressure in the cylinder.

that says to me what ive already said that if the pressure on the gauge was 8000psi [The jack guage is only aware of the pressure in the cylinder]

[and the actual force delivered by the ram is soley dependant on the diameter of the ram] as it is with a p2f gauge I.E. if i have 8000psi and a 2" squared jack ram 1" square tooling and a p2f gauge with 2" squared piston then i should have 8000psi on both ends from my gauges but do i have 16000psi on the tooling which is what i was saying before

please correct me if im wrong

 

just so you know i left out the extra no.s because when ddewees asked to briefly explain so i was just making it simple as i can not sure what his understanding of it was and to be honest your understanding seems to be above mine

[Col]

Its useful to have dedicated cells that can calculate the effective area of hollow rammers. You can use the output values to churn out modified comp pressures for each rammer which takes account of the reduced area. It makes quite a difference with rocket tooling that consists of several hollow rammers.

 

leedrill, I think the confusion was probably in the wording (2 square inches and 2 inches square) mentioned in your post, the math looked ok to me but i work in metric so i may be wrong

Edited November 15, 2013 by Col

[Varmint]

This version is updated to include a "Solver" tab, where you enter your ram and tooling diameters, and the target composition pressure in PSI.

 

It also has reserved tabs for the metric versions of both calculators, I'll probably get the metric versions functional in the next few days. I need to study the most common metric gauging systems so my gauge input or output data works with the most common varieties overseas. Consider this a call for assistance as well, if you are familiar with the gauges in use, please drop a comment.

 

DAS

Pressing_Comps.xls

[Varmint]

Col,

 

Thanks for the info, and yes, you are spot on regarding my initial comments (inches square/square inches).

 

My tooling is home spun end burning, so I have no experience with the hollow sequential tooling used in core burners. I've always just ignored the small "nipple" in my bottom end tooling, and concentrated on the solid.

 

The problem going forward is knowing how many intermediate tools are used in the various tooling sets. If several kits offer 3 intermediates, when a another comes along and offer4 or 5, suddenly the SS is useless.

 

So, this is a call to arms to give me some sort of idea of how many total tools to expect.

 

Of course the other side of this is, the SS is a point of education, one meant to point out the PSI at the grain is either well above or well below the force provided by the jack depending on the rocket diameter. It also brings light to the jack gauging, (PtoF or jack mounted), I can't count the number of times I've discussed pressure with people who assumed that 5000 on the gauge was 5000 at the ram, when they had a 1-7/8" ram.

 

Anyway input is always appreciated, keep it coming.

 

DAS

[marks265]

If you have a P2F and you know what the piston diameter is you will be able to figure it out on your own easily enough. I will try to explain the best I can. My P2F has a 2.5" piston and I will use it for an example. I like my P2F because it is portable. If I end up using someone else's press at PGI or a club function I ignore all other gauges because I know what I have CONSISTENTLY when pressing any item. If you don't know what your piston size is you will need to call the manufacturer or take it apart to measure.

 

In this example I want to put 1000 psi of FORCE on the composition that is loaded into a 1/2" star plate that has 49 pins. The pressure gauge is on the P2F gauge and we need to know what this gauge should read to get 1000 psi of force on each star because someone told me that's what I gotta have.

 

To find the area of my P2F which has a 2.5" diameter piston. We use the radius multiplied by the radius multiplied by 3.1416 (PI). The radius of a circle is half of the diameter.

SO 1.25 X 1.25 X 3.1416 = 4.91 (I rounded up of course)

 

 

The star plate has 49 pins that are 1/2" in diameter

SO .25 X .25 X 3.1416 X 49 = 9.6

 

SO now we know:

The P2F has an area of 4.91

The star plate has an area of 9.6

We want 1000 psi of force on the composition in the star plate.

Now we can do the math to find what the gauge should read

1000 (wanted psi on the comp) X 9.6 (area of all 49 pins of star plate) = 9600

9600 divided by 4.91 (the area of the P2F) = 1955 psi

You should look for a reading of 1,955 psi on your P2F for this example.

What this means is that each of the 49 pins of the star plate will theoretically be pushing down with 1000 psi of force when compacting the composition.

Conversely, if you had a hydraulic jack that had a 2-1/2" piston and a pressure gauge installed to read the psi acting on the piston, you would be able to use the same formula. I've compared my P2F to other peoples presses and they are usually pretty close. If the piston of the hydraulic ram or P2F is 1 square inch the pressure gauge would read in a one to one relation ship between hydraulic oil pressure and force of the ram. When the piston is larger than 1 square inch (a piston diameter of about 1.13"), the force is multiplied (greater) making for an advantage to create more force with the same amount of oil pressure.

I did a little rounding of the numbers. When done carefully it won't be noticed because the increments of the pressure gauge will not be defined small enough to be that picky. We do want to be consistently close though so taking care in your numbers is still a good idea.

I hope this helps a bit

Mark

[Col]

Hi Varmint

I would just put a section in the spreadsheet to calculate the effective rammer area based on user input. All you need are two cells for entering the rammer size and the hole size, convert each to area, take one from the other and enter the result into the main calculator.

Most pyro`s will jott down the guage pressure needed for their various tooling, so they`d only need to do the calculations once for tools they own and when they buy something new.

Edited November 15, 2013 by Col

[leedrill]

cheers marks

i understand {not to seem like a smart ass} but damn you could not make it more complicated than using a large piston p2f gauge and a 49 pin starplate as an example

i now understand you where not saying i was wrong, you where just saying i was not concise enough to the mathematical method to be applied to the setup that was in question

ill say this for those that have minimal understanding of pressure to force your explanation will be misunderstood {unless they have good maths skills-in which case they can figure it out for them selves }

 

all i was trying to do was simplify it so people can see the change in force and pressure on different surface areas some people dont get it until they figure it out for themselves

 

can i say marks i am jealous of your p2f gauge i would love a load cell and the program to go with it like i use to use at work would be so grand to have everything all digital

but my wolter gauge will not be adequate for a 6lb motor and it is the largest they have on the website i think firesmith have a larger piston in theirs but not 2.5"

 

i was trying to figure out how much it would take to put 6500psi on an 8" comet and realised i would need a touch under a 150metric ton jack to achieve it i was wanting to experiment with large comets straight from the gun and was wondering how little binder could be used if high pressure was used during pressing

 

i know its off topic but anyone that could enlighten me to why {if there is a reason } lower pressures are used

[marks265]

Lee

 

It wouldn't be any fun unless I make 'em think a little about what they're trying to do so I just had to throw the plate in there.

 

My P2F is from Ben

 

I press 4" comets (3.5" actual) to about 1700 psi on the comp. These were C6 with 5 percent dextrin and I made quite a few with not one failure. A couple of them even had cracks. I made tooling for a 6" comet this year and never got to press any with it yet. I would probably still hold along that same amount of force or a little higher. Hard to say unless I actually was there to watch the P2F gauge. The biggest thing to watch is the dwell time. Put force on the tooling and watch the gauge. It will be easy to tell at first but as you press it will act a little different. Take the gauge to 2000 psi and watch it. At first the pressure will fade fast because there is still a lot of compacting to do. But it gets tricker when the comp gets compacted much more.

The amount of water used will also effects the compacting. I use 7 percent. You want to keep adding pressure until the pressure somewhat stabilizes. You can chase the "stabilizes" and why I say it is tricky. If I don't have to do a lot of pumping on my manual jack or I don't lose a lot of pressure I know I am getting close. Dwell time also prevents the comp from springing out too much after it gets ejected from the tooling.

 

To answer your question about "how little of binder could be used" would need some experimentation because of many variables from the manipulator and material used.

 

When I assembled my comets I did not use any discs under them or any other foreign objects. Just the wrapped comet and the lift and leader.

 

If I were to try an 8 I would shoot for 2000 on the comp. The binder will do a good portion of the work. I also do not make a doughnut comet, mine are solid.

 

Mark

[Col]

If the P2F can physically handle the hydraulic pressure from the press (ie 10 tons), just replace the original 3,5 or 10k gauge with a 15k. Full scale will give you around 8500psi on a 6lb. A 50 ton press maxxed out would put 2300psi on an 8" comet

[Varmint]

OK, a bit of a midset change on this version.

 

First, since the rocket builders main interest in pressure on the composition, the original versions first tab was essentially useless. Ergo, it has been deleted.

 

With thanks to Col, there is now a tooling area "workspace" which determines the frontal area of hollow (trans-spindle) and solid (above the spindle) tooling.

 

Once the tooling parameters have been entered, a button is available to move the calculated area from the results cell to the appropriate cell of the spreadsheet.

 

This was done to help prevent typos while anually entering the figure, but presents an issue with Excel which may warn the user that the spreadsheet has embedded macro code.

 

For this version of the file provided in this post only, I can guarantee the macro is harmless and presents no threat of any kind. If you get a copy from any other source I have no way of knowing what changes may have been made, and I will not be responsible for any changes they might have made.

 

Col, if you could take a look and give a quick review, I'd appreciate it.

 

DASPressing_Comps_V2.xls

[ddewees]

Varmint,

 

This is great, thanks.

[mikeee]

One of our club members uses a 10 ton drake press with an air over hydraulic pump.

The press works well and is light enough to be portable.

The shorter frame tends to stay level and not flex like some of the cheaper presses.

[Varmint]

This version gets rid of the macro, the calculated value from the tool area workspace is automatically copied to the main calculation area.

 

Still looking for assistance with non-US gauging so I can complete the metric version tab.

 

Thanks,

 

DAS

 

Pressing_Comps_V2a.xls

[Maserface]

Ddwees you will be raising all sorts of hell with this bad boy! Giving me a run for my money!!

[ddewees]

Heh...

 

I think you've got the "raising hell" part down to a science...

[Maserface]

Well you already got me running for my life so should be no problem !! - either way, gonna be a damn good time!!