Yet another Emco V10 owner and also a question

niedz · Post by **niedz** » Mon Nov 09, 2009 10:40 pm

greetings,

i recently purchased a used but in good condition Emco Maximat V10p!
im very excited by this.

i have been working in bicycle shops for the past 10 years, and from that i became interested in building bicycle frames and touring racks. from building bicycles and racks all by hand (files n hacksaws) i saw the need to machine parts, jigs, and fixtures. so i enrolled in the local vo-tech for night school in machining technology, and bought myself the V10.

there was one mishap to the machine during the move. the previous owner tried to remove the leadscrew crank handle, and broke the shear pin. i looked in the manual and it says to only replace with an original Emco aluminum shear pin. i was wondering if anyone had any recommendations on what i could use to replace this. i was thinking an aluminum trim nail might do it.

i look forward to asking many questions as i learn more!

daniel

spro · Post by **spro** » Tue Nov 10, 2009 9:29 pm

Yes welcome and that's a very nice machine. If the pin is a pin and not a key your filing experience makes it short work. There are slight other considerations as all alum isn't the same. You DO want soft at this point yet nails are generally emergency. What I'm thinking is something that won't slowly shear off and smear between the parts but either IS or isn't(because it sheared before damage). The little keys they sell everywhere for lawn mower flywheels might be something but they are only 1/2" long.
-would need some filing, in your sleep, blindfolded.

Jose Rivera · Post by **Jose Rivera** » Tue Nov 10, 2009 11:14 pm

I have owned a V10-P Mentor for about three years.
As fas as I know, the lead-screw handle (used when the mill head is used), does not have a pin. This would be at the right end as you stand in front of the lathe.

There is a shear/pin (material not specified on the parts catalog) at the left end, where it connects to the quick-change box.
This pin hold the output gear-box shaft to the clutch assembly case and to the lead-screw.

At one time I thought that I may have sheared this pin because in a jam the lead-screw stopped turning, but the gearbox kept turning.

Came to find out that that clutch assembly there is as a second safety devise to protect the whole gear-train.

These machines are built like a Swiss watch.
I am super happy with mine.

If this is the pin you are talking about, yes, is aluminum.
I would replace it the same material.
Aluminum has such a low shear that any type will do except pure aluminum that is extremely soft.

Never with any type of steel.

niedz · Post by **niedz** » Tue Nov 10, 2009 11:17 pm

Jose Rivera wrote:
There is a shear/pin (material not specified on the parts catalog) at the left end, where it connects to the quick-change box.
This pin hold the output gear-box shaft to the clutch assembly case and to the lead-screw.

that is precisely the pin i am speaking of. i do not know exactly how he broke it, i was loading the van at the time. i imagine he cranked hard on the handwheel to remove it, and broke the shear pin.

Jose Rivera · Post by **Jose Rivera** » Wed Nov 11, 2009 1:30 pm

I don't think that yo will find a replacement part easily or at all.

Make you own pin with your new lathe !!

Luckily that the pin did it's job and nothing else got damaged!

niedz · Post by **niedz** » Thu Nov 12, 2009 10:12 am

i plan to make one, im just curious as to what type of aluminum i should use...

Jose Rivera · Post by **Jose Rivera** » Thu Nov 12, 2009 12:53 pm

Your guess will as good as mine.

I think that the shear strengths of all types of aluminum are so close that it may not make a difference, except pure AL.

Post by **Harold_V** » Thu Nov 12, 2009 3:23 pm

Jose Rivera wrote:Your guess will as good as mine.

I think that the shear strengths of all types of aluminum are so close that it may not make a difference, except pure AL.

That's not quite true, Jose. 7075 T6 aluminum rivals mild steel in tensile (76,000 PSI), while 7075 0 has but 33,000 PSI tensile.

6063 0 has a tensile of 13,000 PSI, so there's a wide range of material strengths that can be used. Assuming the pin is intended to be sacrificial, to fail without damaging other components, material choice could be critical.

I wonder if anyone knows if that is the case?

Harold

Jose Rivera · Post by **Jose Rivera** » Thu Nov 12, 2009 4:51 pm

Tensile and shear are two different types of test. Fatigue is another different to the later two.

Though I could not find shear values on aluminum alloys on the internet (for free), it seem to me the shear value of any AL alloy will shear easy for it's use.

Not know what alloy is used I don't think that there many choices on this case Harold.