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anybody use mandrels?
- Thread starter toag
- Start date
- Joined
- Feb 2, 2013
- Messages
- 3,627
yes, i still use mandrels.
the mandrels i have go from smallest of 1/4" ,5/16,3/8,7/16,1/2,9/16,5/8,11/16,3/4,7/8,1"largest
mine are very slightly tapered about .003" per length for the set. the 1" seems to have a slightly steeper taper,i didn't measure it
they range in length from 3 1/2" for 1/4" to about 8" for the 1"
i bought them couple years ago used for a song at a flea market cheap.
a couple blemishes, nothing steel wool and a little get'ner done couldn't solve.
pullies in aluminum are easily turned and can be made quite sturdy if you resist the urge to make them too thin or narrow.
they wear quicker than steel pullies, but sure can get you goin' when the SHTF... all you have is some 3" 6160 and an hour to get a machine running before the start loosing tens of thousands of dollars in spoilage.
last part was a true story, i'll leave the company nameless, operating a chicken production facility... a packaging machine had a timed outfeed operated by stainless steel timing pullies. the timing belt broke their production stopped, they didn't have a spare belt, i didn't have an OEM belt for the unit and was told when contacting the manufacturer that the belt was half the country away and couldn't even be shipped until the following morning.
Needless to say i got the Emergency phone call to go bail them out.
the call description reported a broken belt, not normally an emergency and rather unusual for this customer to call with a call of this nature:thinking:. it was at that point, i knew i was walking into some trouble...
i was able to quickly find out there was no timing belt to be had locally, but they stressed that the unit must run a quickly as possible to avoid loss of fresh product.
upon inspection of the machine, a failed bearing was the culprit of our belt problem.
the bearing was easy enough to change out with the factory issued tools, but we had no belts.
luckily the production was not going to be start and stop.
they were planning a continuous production until all the product was packed.
the normal belts are toothed and flat and ride on toothed timing pullies.
the shop was equipped with a lathe, they also had all kinds of materials as well.
i spoke to the shop foreman and asked if i could use their shop to fix the packaging machine.
he gave me permission to use whatever they had on hand to get them out of their pickle.
i was able to cut 2 3" OD aluminum v belt pullies, turn them on centers on their Clausing lathe, and replace their 4" timing pullies.
i used their bushings and broaches to finish the bore to 7/8".
i used an A48 belt over tightened slightly to eliminate any slippage .
i got them operational in an hour and a half, but had to return and remove my fix to install the OEM parts 2 days later.
the mandrels i have go from smallest of 1/4" ,5/16,3/8,7/16,1/2,9/16,5/8,11/16,3/4,7/8,1"largest
mine are very slightly tapered about .003" per length for the set. the 1" seems to have a slightly steeper taper,i didn't measure it
they range in length from 3 1/2" for 1/4" to about 8" for the 1"
i bought them couple years ago used for a song at a flea market cheap.
a couple blemishes, nothing steel wool and a little get'ner done couldn't solve.
pullies in aluminum are easily turned and can be made quite sturdy if you resist the urge to make them too thin or narrow.
they wear quicker than steel pullies, but sure can get you goin' when the SHTF... all you have is some 3" 6160 and an hour to get a machine running before the start loosing tens of thousands of dollars in spoilage.
last part was a true story, i'll leave the company nameless, operating a chicken production facility... a packaging machine had a timed outfeed operated by stainless steel timing pullies. the timing belt broke their production stopped, they didn't have a spare belt, i didn't have an OEM belt for the unit and was told when contacting the manufacturer that the belt was half the country away and couldn't even be shipped until the following morning.
Needless to say i got the Emergency phone call to go bail them out.
the call description reported a broken belt, not normally an emergency and rather unusual for this customer to call with a call of this nature:thinking:. it was at that point, i knew i was walking into some trouble...
i was able to quickly find out there was no timing belt to be had locally, but they stressed that the unit must run a quickly as possible to avoid loss of fresh product.
upon inspection of the machine, a failed bearing was the culprit of our belt problem.
the bearing was easy enough to change out with the factory issued tools, but we had no belts.
luckily the production was not going to be start and stop.
they were planning a continuous production until all the product was packed.
the normal belts are toothed and flat and ride on toothed timing pullies.
the shop was equipped with a lathe, they also had all kinds of materials as well.
i spoke to the shop foreman and asked if i could use their shop to fix the packaging machine.
he gave me permission to use whatever they had on hand to get them out of their pickle.
i was able to cut 2 3" OD aluminum v belt pullies, turn them on centers on their Clausing lathe, and replace their 4" timing pullies.
i used their bushings and broaches to finish the bore to 7/8".
i used an A48 belt over tightened slightly to eliminate any slippage .
i got them operational in an hour and a half, but had to return and remove my fix to install the OEM parts 2 days later.
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I use the expandable mandrels all the time. I have a set that goes from about 1/2 inch all the way to around 3 inches. very useful turning bushings etc that are already the correct bore but need the od turned down. One of the most useful things i use them for is to indicate irregular shaped pieces in the lathe. Just place the mandrel in the bore and indicate it in . I also have several different mandrels for turning impellers down.
so i am not too old fashioned.
I have a set of expanding mandrels that i use for anything that i cant easily grab in the chuck. I bought some cutters recently and the guy threw in about, and i kid you not, 50 some odd mandrels .250 to about 1"... i alomost hugged the guy.
I have a set of expanding mandrels that i use for anything that i cant easily grab in the chuck. I bought some cutters recently and the guy threw in about, and i kid you not, 50 some odd mandrels .250 to about 1"... i alomost hugged the guy.
- Joined
- Sep 22, 2010
- Messages
- 898
5C expanding mandrels, and a set of precision expanding mandrels for between centres.
Saved my bacon a few times.
Walter
Saved my bacon a few times.
Walter
- Joined
- Sep 20, 2012
- Messages
- 560
I'm a bit puzzled by this question, pardon my ignorance, but what other methods would do the same job?
Bernard
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BRIAN
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Turn up a length of steel betwen centre's to the size you want, then loctite the work to it . A little heat removes the finished work from the mandrel.
Brian.
- Joined
- Sep 20, 2012
- Messages
- 560
That is how I have done it myself, but surely that is just making a mandrel, or am I being too pedantic?
I assumed from the question there was some other more modern way..
Bernard
Another down and dirty trick for a stub mandrel is to turn a short mandrel to the size that you need in the lathe chuck. Without removing it from the chuck, file a flat on the mandrel so that a short section of nail can fit in between the work and the mandrel. The nail locks the work piece to the mandrel when you're turning.