Graduated dials

Beone said:
I love the punch holder idea!
dave
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Thanks I was trying to come up with something quick easy to use and make and consistant it seems to fit the bill perfectly. Ray

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Nice work iron man. A bit suggestive criticism if you don’t mind. Might be a good idea to put a support under your work so all that hammering does not telegraph into your chuck and or head stock bearings. I know it’s not much hammer force but why risk it when you can avoid the possible damage/problem. Again, nice work and…Good Luck.
 
Glad you got around a problem that comes up, that's not always easy to do.
But.....stamping in the lathe is a huge nono. It will damage your nice tapered Timkin bearing races or rollers.
 
chips&more said:
Nice work iron man. A bit suggestive criticism if you don’t mind. Might be a good idea to put a support under your work so all that hammering does not telegraph into your chuck and or head stock bearings. I know it’s not much hammer force but why risk it when you can avoid the possible damage/problem. Again, nice work and…Good Luck.
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Thanks for the concern but that seems to me to be an old wives tale the hammer barely weighs an ounce the taps are very light and they are nothing compared to the abuse the bearings take as they get hammered when you machine something square or a welded up shaft or something out of round ect.. I worked in a machine shop for 25+ years where they use to straighten bent shafts in a lathe and in the 25+ years I never ever saw a broken, chiped or cracked timkin bearing and they where very hard on the machines. I would not recommend doing that but the stamps are only 1/16th really how hard do you have to strike them without damaging the stamp? not much, but after all they are just wheel bearings and look at the hammering a wheel bearing takes in a car or truck or off road vehicle much more force than a one ounce hammer..


I have had this lathe a long time and it had plenty of abuse before me I check the bearings every now and then they are the original bearings and show no sign of wear or cracks or chips.. Ray
 
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iron man said:
Thanks for the concern but that seems to me to be an old wives tale the hammer barley weighs an ounce the taps are very light and they are nothing compared to the abuse the bearings take as they get hammered when you machine something square or a welded up shaft or something out of round ect.. I worked in a machine shop for 25+ years where they use to straighten bent shafts in a lathe and in the 25+ years I never ever saw a broken, chiped or cracked timkin bearing and they where very hard on the machines. I would not recommend doing that but the stamps are only 1/16th really how hard do you have to strike them without damaging the stamp? not much, but after all they are just wheel bearings and look at the hammering a wheel bearing takes in a car or truck or off road vehicle much more force than a one ounce hammer..


I have had this lathe a long time and it had plenty of abuse before me I check the bearings every now and then they are the original bearings and show no sign of wear or cracks or chips.. Ray
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Hammer might weigh an ounce but your swinging it. Plus there is already downward preload from the chuck/work not helping.

Hammering on a spindle is never good.
 
I think its a mighty fin solution to you indexing problem and love the stamp holder setup. I have no idea if stamping with the dial in the spindle could damage the bearings but that was my first though and I try to stick to my instincts. I think you probably right though, an interrupted cut would probably put way more force on the bearing and your most likely not cranking out a few hundred dials a month.

Shawn
 
Hi. It is not obvious what the force multiplier of a hammer blow is, since it is short and sharp. There is an article in the latest California Blacksmith magazine that gives an estimate for the force multiplier for a hammer blow from a full swing, such as one carried out by a blacksmith. It is about 10000 X. In other words, a 2 lb hammer could potentially generate 20000 lbs of force, or 10 tons. This is entirely reasonable, since a hammer can exceed the yield stress of prehard 4140 in a small area. A lathe bearing should be able to handle a few thousand pounds, and that tiny hammer would be expected to generate substantially less. The small area over which the punch applies it, explains the ability to deform metal at its target. The area of the rollers should be quite a bit larger than the punch target, and made of substantially harder steel. But it surprising that the margin of safety is not as large as initially expected. That is the power of impact force.
 
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