# Bearings and Power Screw problems



## MikeR (Apr 1, 2009)

The MERM hardly touches on Bearings and Power Screws. There is a brief section on journal bearings and the practice book has a single 30 minute long Journal Bearing problem (nothing on roller bearings). There are no examples or practice problems on Power Screws.

Why has Lindeburg omitted these subjects? Is it because these are not big PE subjects? Or has he dropped the ball?


----------



## Shaggy (Apr 1, 2009)

My recollection is that there wasn't much on the test regarding bearings or power screws. My guess is at worst, there might be two problems in that area. Your best bet is to use Shigley for these problems. Machinery handbook may have adequate coverage too.


----------



## Sschell (Apr 1, 2009)

I dont recall anything like that coming up on the exam... I agree Shigley would be the thing to use if it does.


----------



## Capt Worley PE (Apr 1, 2009)

Third on Shigley...


----------



## MikeR (Apr 1, 2009)

Shigley... it shall be!


----------



## bph (Apr 2, 2009)

MikeR said:


> The MERM hardly touches on Bearings and Power Screws. There is a brief section on journal bearings and the practice book has a single 30 minute long Journal Bearing problem (nothing on roller bearings). There are no examples or practice problems on Power Screws.
> Why has Lindeburg omitted these subjects? Is it because these are not big PE subjects? Or has he dropped the ball?


Mike,

I just did the NCEES practice exam #1, and it had a power screw problem. I found the section in MERM and it had the identical drawing (must have copied it from the same source). I got the problem wrong, because the MERM did not define all the parameters (wth?) and although had the same image, the equation was incomplete and needed an modifier, which MERM gave later, but hard to pick up this as a look-up problem during simulated (or real) exam conditions. They should have a simple practice problem, but I bet they would have one with 3 simultaneous equations to solve with partial fractions!!!

I am extremely disappointed with the MERM practice problems (after doing the NCESS practice exam), they are way off base, requiring you to do a 30 minutes or more of calculations having nothing to do with the actual chapter you are working. IF I was doing it over, I would skip the MERM questions altogether, or maybe just do a few of the simple ones. The NCEES hammers away at fundamental knowledge and overall understanding, with very little calculation. If you have limited study time (which I do) the MERM question are a waste. Better to do both NCESS practice exams, maybe the one on-line, plus six minute solutions and lots of reading to understand the fundamentals. If you have extra time, then sure, do the MERM practice problems.

BPH


----------



## Shaggy (Apr 2, 2009)

bph,

I disagree, while the MERM Practice Problems are not representative of actual test questions, they do a great job of getting the rust off. It has been said before that a portion of a MERM problem is a typical test problem. So look at it this way, when you do a MERM problem, you are actually preparing for three or four exam problems.

Bottom line is to do as many problems as you can while preparing for the exam.


----------



## MikeR (Apr 2, 2009)

bph said:


> Mike,I just did the NCEES practice exam #1, and it had a power screw problem. I found the section in MERM and it had the identical drawing (must have copied it from the same source). I got the problem wrong, because the MERM did not define all the parameters (wth?) and although had the same image, the equation was incomplete and needed an modifier, which MERM gave later, but hard to pick up this as a look-up problem during simulated (or real) exam conditions. They should have a simple practice problem, but I bet they would have one with 3 simultaneous equations to solve with partial fractions!!!
> 
> I am extremely disappointed with the MERM practice problems (after doing the NCESS practice exam), they are way off base, requiring you to do a 30 minutes or more of calculations having nothing to do with the actual chapter you are working. IF I was doing it over, I would skip the MERM questions altogether, or maybe just do a few of the simple ones. The NCEES hammers away at fundamental knowledge and overall understanding, with very little calculation. If you have limited study time (which I do) the MERM question are a waste. Better to do both NCESS practice exams, maybe the one on-line, plus six minute solutions and lots of reading to understand the fundamentals. If you have extra time, then sure, do the MERM practice problems.
> 
> BPH


Isn't the online NCEES Test the same as the printed version?


----------



## bph (Apr 2, 2009)

MikeR said:


> Isn't the online NCEES Test the same as the printed version?


Mike,

I don't know? I have never done the on-line NCEES test.

BPH


----------



## bph (Apr 2, 2009)

Shaggy said:


> bph,I disagree, while the MERM Practice Problems are not representative of actual test questions, they do a great job of getting the rust off. It has been said before that a portion of a MERM problem is a typical test problem. So look at it this way, when you do a MERM problem, you are actually preparing for three or four exam problems.
> 
> Bottom line is to do as many problems as you can while preparing for the exam.


Shaggy,

To each his own. But for me a large amount of MERM problems were off base. I would not say that each MERM problem is 3 or 4 exam problems, they are very different on the exam, much less number crunching and more fundamental knowledge and the ability to simplify a problems quickly, apply judgment and cut away distracters. The MERM had very little of this, instead it had complex detailed answers that wasted study time with number crunching when you could be learning the material. I now realize that I wasted many hours doing MERM problems with simultaneous equations, complex vector graphics, and other long drawn out problems that are very unlikely to appear on the exam. What got me started was when MikeR noted that the MERM has no power screw examples or problems, but there was one on the NCESS sample exam, so I can't say MERM over prepared me for that. Maybe I am being a bit hard on the MERM sample problems, but I just don't feel they were good prep for the exam; however, they are very typical of what you find in college text books.

Any, as I said, if I had plenty of spare time (and I don't) then doing MERM problems is fine, just not as efficient as I would have liked.

The author of the MERM notes in the beginning, that the book in intended to go well beyond the PE exam. I would have preferred a book that was only directed at the PE exam.

I do think the MERM is a great text for the PE, in that it has everything under one roof and I would recommend it to anyone who will take the PE exam.

-BPH


----------



## MikeR (Apr 2, 2009)

bph,

I am sort of in your situation. The MERM is the best reference out there, but if you are short of time you need to know which areas to concentrate on. I am taking the PE for the first time and I have no idea what the NCEES might focus on. That's where this board comes in and some of the posters have been of tremendous help in pointing me in the right direction.

I am taking the MD depth section and will use the MERM and Shigley as the main reference materials.

The question I have is which areas I should focus on for the breath exam? Specifically which sections should I be concentrating within the MERM for Fluids, Thermo, Power Cycles, Heat Transfer and HVAC? There is a ton of material covered within these sections. I have Econ pretty much covered.


----------



## bph (Apr 2, 2009)

MikeR said:


> bph,
> I am sort of in your situation. The MERM is the best reference out there, but if you are short of time you need to know which areas to concentrate on. I am taking the PE for the first time and I have no idea what the NCEES might focus on. That's where this board comes in and some of the posters have been of tremendous help in pointing me in the right direction.
> 
> I am taking the MD depth section and will use the MERM and Shigley as the main reference materials.
> ...


Mike,

Yes, our situations appear very similar;

1. First time taking the exam.

2. I will be taking MD depth.

3. I have not studied anything but MD, I was notified late that I was approved (they misplaced my transcripts) plus life got in the way, so I started studying just a few weeks ago and I need to be very efficient.

4. I am just starting on the thermo, fluids, HVAC stuff and need to keep it super efficient.

The breadth section seems to focus on simple calculations, but true knowledge of what is going on. I will start tomorrow and think I will read the MERM (lots to read on this); maybe do a few of the simple home work problems, then do the six minute solutions breadth and possibly depth and NCEES breadth and possibly depth. If I don't get to the depth problems, I may just read them over.

I think this board is fantastic, and thank everyone who has contributed, a very worthwhile endeavor

BH


----------



## MikeR (Apr 2, 2009)

Be thankful for small mercy's... I live in Cali and I have yet to receive notification. I could be just wasting my time when I could be inhaling gallons of the "Amber Liquid" at the local watering-hole.


----------



## bph (Apr 2, 2009)

MikeR said:


> Be thankful for small mercy's... I live in Cali and I have yet to receive notification. I could be just wasting my time when I could be inhaling gallons of the "Amber Liquid" at the local watering-hole.


That's insane? How is that even possible, no notification 3 weeks before the exam?

Either way the exam goes, I definitely see "amber liquid" being a part of my post-exam recovery plan.


----------



## Shaggy (Apr 3, 2009)

bph,

Points taken. I do agree that there is probably an ideal path to follow to study for the PE. NCEES practice test and 6 min solutions are high on that list and MERM is near the bottom. So if limited on time, it would be best to stick with the better practice. I don't recall as much "number crunching" in the MERM problems as you described, but it was 2 years ago that I took the exam. It is amazing how quickly it all falls behind you. It doesn't seem so rough in retrospect. Also, there is the MERM sample exam. I remember that being more like the test... nonetheless do as many problems as you can and be familiar with your references and calculator.

Good Luck to both.


----------



## bph (Apr 3, 2009)

MikeR said:


> The MERM hardly touches on Bearings and Power Screws. There is a brief section on journal bearings and the practice book has a single 30 minute long Journal Bearing problem (nothing on roller bearings). There are no examples or practice problems on Power Screws.
> Why has Lindeburg omitted these subjects? Is it because these are not big PE subjects? Or has he dropped the ball?


Mike,

I just did the NCEES sample exam #2, and they had a ball bearing problem on it!

MERM has nothing on ball bearings. I looked the problem up in Mark's and they had the info needed.

BH


----------



## bph (Apr 3, 2009)

Shaggy said:


> .... but it was 2 years ago that I took the exam. It is amazing how quickly it all falls behind you. It doesn't seem so rough in retrospect. ...Good Luck to both.



Shaggy,

I hope I can look back 2 years from now and say the same!

Thanks for you comments.

BH


----------

