Lathes Flashcards
What factors determine feed rate and RPM?
The material being cut, the material of the cutting tool and the operation being performed
Complete the following: The harder the material that is being cut, the lower…..
The lower the cutting speed is
Complete the following: The Harder the cutting tool is, the faster……
The faster the cutting speed is
Use a what speed for roughing cuts?
A slower cutting speed
Use a what speed for finishing cuts?
Use a faster cutting speed
Why is it hard to give definitive answers on feed rates for lathes?
Because a lot of it depends on rigidity of cutting tools and the work piece
What is the approximate feed rate for roughing with a HSS tool on mild steel? What is that in MM
0.010-0.020 per rev or 0.25-0.5mm
What is the down side of high feed rates in regards to your cutting tool?
It dulls the tool quickly
What is the approximate feed rate for finishing?
0.002-0.005 inch per rev or 0.05-0.13 mm per rev
What do you set your cut depth on?
you set it on the cross feed dial
What is backlash?
Backlash is the play between the cross feed screw and the nut, It is unavoidable on standard machines and must always be taken into consideration. You must always be turning the screw clockwise to your final setting. You must turn it counterclockwise when boring.
What is a direct reading dial?
A direct reading dial is whatever you move the dial is exactly what will be taken off the diameter of your work piece. If you move the dial 0.001 thou is will take 0.001 off the OD of your work piece
What is a indirect reading dial?
An indirect reading dial shows you what you are taking off the radius of the work piece. So if you move the dial 0.001 it will take 0.002 off the diameter of the part.
What is a benefit of boring vs’s drilling or reaming?
Boring runs true to the axis of rotation of the center of the part. Drilling and reaming can drift from the true center.
What are some ways to reduce chatter while using a boring bar?
1- Have as little overhang as possible from the tool post
2-Have the set up as rigid as possible
3-Dampen the bar by holding a piece of wood on the boring bar
4- Use a boring bar with a carbide tip
For reaming holes under 1/2 inch what size should you pre drill be?
It should be 1/64th smaller
For reaming holes larger than 1/2 inch what size should your pre drill be?
It should be 1/32 smaller
What is one issue with you reamer being miss aligned in the tail stock?
It can ream a hole that is larger than your desired size
Where do you find the thread pitches that a lathe can cut?
It will be posted on the lathe so get familiar with the lathe you are using
How do you set the thread cutting tool against the work piece to cut threads?
You set the tool perpendicular to the work piece
What do you need to cut a thread on a lathe?
You need the thread depth, a center gauge, carbide threading insert, a feed rate
How do you calculate the strait depth of cut of a thread?
0.6134 x pitch
What are the three main types of cutting fluid?
Cutting oils, emulsifiable oils, and chemical cutting fluids
What is sintered metal?
It is when you cook the metal after adding the materials to steels to what you want.
Does carbide need lots of coolant?
No, it does not like the heating and cooling that can happen and leads to cracks. It only needs a very small amount of coolant
What is the difference of universal vs’s combination chucks for the lathe
universal has a scroll that moves all the jaws together and then micro adjustment screws that can adjust the scroll position. Combination has a scroll also but then each jaw can be moved individually also.
What does tail stock off set measure radial or diametral?
radial, it is measured off the centerline
Why is a lathe dangerous compared to newer designed machines?
It does not have safety guarding in place and has not adapted a lot of the new safety techniques in regards to the operator position and rotating equipment
How are lathes sized?
The largest piece that can turn in the lathe and the largest part that can fit between centers
What are the five main parts of a lathe?
-The bed
-The headstock (house’s quick change gears)
-The carriage
-The tailstock
-The tool post
Should the machine be locked out when working in the gear box?
Yes, always lock out the machine
What does the quick change gear box drive?
The lead screw or feed rod it is also known as
What does the split nut lever do?
It engages the split nut on the lead screw to rotate at the pre determined feed rate
Do compound rests have power feed?
No the do not have power feed
How much can a compound rest rotate?
It can rotate 360 degrees
What direction does the saddle move?
It moves parallel to the work piece
What direction does your cross slide move?
It moves perpendicular to the work piece
What does the apron comprise of?
It houses the drive gears, split nut mechanism, the feed change lever, automatic feed engage lever and the carriage hand wheel
Apron hand wheels move the carriage how?
Rack and pinion
