We typically use Ductile Iron 65-45-12 for spindle housings. This is a great material as it does not seem to get excited at a wide range of speeds (natural frequency). However, we have had a lot of requests for a much lighter solution for applications in robotics. There are other factors to...
Yes, tangential loading is always higher. But I’m trying to figure the moments and reactions on the shaft bearings. Radial loading and axial loading are what I need to figure bearing life. And if the shaft is going to bend, which would create chatter during machining, and may be catastrophic.
Anyone know of a program that calculates radial load? It is important in order for me to figure bearing life and shaft bending moments (we’re a spindle manufacturer). In my research, I have found this calc to be quite involved (merchants circle). Using a calc within Kennametal’s website, it...
I did a hand calc and I came up with a safety factor of 1.4 against the emergency stop torque. Apex gear states: emergency stop torque is 3x the nominal torque. And peak torque is 60% of the emergency torque.
When calculating shear Stress from the output of the shaft, should I use the emergency stop torque or peak torque (max acceleration torque)? Hopefully, it would be correct if I were to use peak torque in my calculation. That way I wouldn’t have to increase the size of our spindle, which is...
Hello, haven’t used FEA in quite some time.
Not sure how to interpret the results. I found in my hand calc, the max stress the broached shaft will see is 2830 psi. And the max/yield to be 4026 psi. Which matches the Von Mises result. The analysis is for torsion in the cross section of the...
You are correct used the full load torque. Breakdown torque is 103 lb-ft.
Sounds like I should’ve went with my original calc.. 2.57*motor torque of 103lb-ft
Wondering what the torque would be in a 2.5” dia. Spindle. Spindle speed=9,000 rpm. Spindle is driven by the motor, pulley ratio is 2.57:1. Shaft weighs 66 lbs.
Motor torque = 40.2 lb-ft
Motor hp = 15 hp
Motor speed = 3500 rpm
Motor shaft/rotor inertia = 0.474 LB-FT^2
I calculated the max...
OK... this is how I came up with the answer: Step 12 A - just add those 2 calcs together :)
see page 183 in Gates manual (your browser will say you're on page 185) https://files.engineering.com/getfile.aspx?folder=e57da752-7d7a-46af-8692-b9153af8f3a4&file=powergripdrivedesignmanual_17195_2014.pdf
So, I have moments created by belt pull, motor torque, axial and radial loads from tooling. I can consolidate it all and I get about 5,000 hrs. What I’m not sure of… is if I should exclude motor torque. If this was a sawing or machining operation, I believe I’d want to include it. Please let me...
Thanks for the reads, very interesting. I’d rather err on the side of caution and provide a robust solution. Moreover, I agree with you… 1k lbs in x and y. I am going to give the calcs to our senior engineer and see what he thinks.
New to this position, been designing tooling, fixtures before...
I believe I have the reactions right… for the motor and belt pull portion. What I can’t wrap my head around is the moments caused by the tooling. My colleague and I have been debating… he thinks there is an axial load of 707 N and radial load of 707 N because of the angle of the tool. The tool...
As a general rule… more parts = more cost. This is because there will be a lot more setups on machining centers. Let’s say your 4 parts take two setups each, now you you have 8 setups. That could equate to 4 hours of time. Not to mention, if you have them saw cut 4 pieces you can almost double...
It is a new spindle, not belt driven. Not sure what the application is (a senior engineer assigned me this so I can familiarize myself with how to arrive at the correct result). One set is fixed - these are the bearings I’m trying to calculate the L10 life for. The other set does float. We have...
I may have misspoke about the 25 lb load. So in the meantime, I would greatly appreciate help calculating the 100 lbs of thrust to start with. There are 2 sets of tandem bearings (in DB), the first set is subject to 100 lbs of thrust, which is more load bearing. If someone could show me how they...
