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Homemade Lathe?
Posted: Tue Jul 26, 2011 1:47 am
by Mr.Tallahassee
I thought about an idea for a homemade lathe attachment for a bench grinder. It's pretty much just threading the chuck onto the bench grinder and bolting the grinder to a very precisely cut mounting plate with the opposing chuck bolted down across from it.
Posted: Tue Jul 26, 2011 1:52 am
by jackssmirkingrevenge
Posted: Tue Jul 26, 2011 2:03 am
by jerome
wouldn't a bench grinder be too fast? maybe using a 90 degree twist belt from a pulley held in a bench or pedestal drill press. you'll have variable speed with the drill press and then you can also easily mount/remove the pulley( for other drilling operations.)
sure, eventually you'll bugger the bearings in the drill press from side load, but i'd rather chance that then slow spooling up speed of the grinder and also the risk of something spiting out at 2000 rpm.

Posted: Tue Jul 26, 2011 2:05 am
by Mr.Tallahassee
That's remarkable.

Blows mine out of the water. However, mine is more suited to a more budgeted and not so skilled builder. It'd take me weeks just to build that from plans.

Posted: Tue Jul 26, 2011 2:24 am
by Mr.Tallahassee
jerome wrote:wouldn't a bench grinder be too fast? maybe using a 90 degree twist belt from a pulley held in a bench or pedestal drill press. you'll have variable speed with the drill press and then you can also easily mount/remove the pulley( for other drilling operations.)
sure, eventually you'll bugger the bearings in the drill press from side load, but i'd rather chance that then slow spooling up speed of the grinder and also the risk of something spiting out at 2000 rpm.

That's understandable. Normally, lathes spin slower for harder materials but I guess you could throw in an CVT on a turn knob adjustment. That would give completely variable speeds. It would be expensive though and that kind of defeats the purpose.
EDIT: NO! Double post. Sorry!

Posted: Tue Jul 26, 2011 3:09 am
by Technician1002
One important safety item. DO NOT leave any screws extending out of the chuck. They were known for eating clothing and what ever was contained inside the clothing. Recess the adjustment screws and have the jaws move on screws that don't extend out.

Posted: Tue Jul 26, 2011 3:22 am
by Mr.Tallahassee

Good note. I myself only wear t-shirts but I will definitely do that. Don't want to lose a limb.
Posted: Tue Jul 26, 2011 11:07 am
by pipeboyswe
Mr.Tallahassee wrote:
Good note. I myself only wear t-shirts but I will definitely do that. Don't want to lose a limb.
Or more than a limb....
WARNING VERY GRAPHIC!
http://img1.uploadhouse.com/fileuploads ... 2773e1.jpg
Re: Homemade Lathe?
Posted: Tue Jul 26, 2011 11:56 am
by velocity3x
Mr.Tallahassee wrote:It's pretty much just threading the chuck onto the bench grinder and bolting the grinder to a very precisely cut mounting plate with the opposing chuck bolted down across from it.
I think mounting the motor and a "tail stock" is the easiest part of the project. What about a tool post, cross feed and screws? Why have bearings in the tail stock? Tail stocks are normally dead.
Posted: Tue Jul 26, 2011 12:54 pm
by mattyzip77
wow, not to get off topic, but that picture is un real!!! It will definatly make me think about safety next time I use a lathe, or anything else for that matter!!!!

Posted: Tue Jul 26, 2011 3:31 pm
by Mr.Tallahassee
Actually, they aren't "dead". They normally have small rollers on high speed bearings that run along the surface of the work material but this works essentially the same. I didn't include the tool rest but it just bolts along the edge of the mounting plate and will be adjustable. This was really meant for just machining pistons and o-ring grooves, nothing complicated. I probably should also do a diagram of the mount.
Posted: Tue Jul 26, 2011 6:52 pm
by Fnord
pipeboyswe wrote:
Or more than a limb....
That needs to be made into a "motivational poster" for shop safety.
-------
Anyway, thanks for mentioning the recessed adjustment screws. I was sketching up chuck ideas myself just the other day and would never have thought of that.
Also, in the sudden velocity change you experience when getting sucked into the "lathe" end, you're likely to grab on to something to push back against, which will probably be the "grinder" end

Posted: Wed Jul 27, 2011 12:52 pm
by velocity3x
Mr.Tallahassee wrote:Actually, they aren't "dead". They normally have small rollers on high speed bearings that run along the surface of the work material .......
Below is a pic of a typical tailstock on a manual lathe. It looks exactly like the tailstock on my lathe. I could be wrong but..............it sure looks dead to me.

Posted: Wed Jul 27, 2011 4:00 pm
by Mr.Tallahassee
The live tailstocks are becoming increasingly more common so why not upgrade?
Traditionally, a hard dead center is used together with suitable lubricant in the tailstock to support the workpiece. In modern practice the dead center is frequently replaced by a live center, as it turns freely with the workpiece — usually on ball bearings — reducing the frictional heat, especially important at high speeds. -Wikipedia
http://en.wikipedia.org/wiki/Lathe
Posted: Wed Jul 27, 2011 4:34 pm
by velocity3x
Mr.Tallahassee wrote:. In modern practice the dead center is frequently replaced by a live center..........
Correct but....... You are confusing the terms "Center" with "Tailstock". A Tailstock and Center are not the same thing. Tailstocks are DEAD........otherwise they couldn't be used for drilling. Whatever tool the operator chooses to insert into the tailstock (i.e. Live Center, Dead Center, Drill Chuck, etc.) is another matter but, the Tailstock does not turn ergo.....it's dead.