Building your own lathe?

[Ryaer]

Hi, This is my first post onto this forum so pardon me if this is in the wrong spot. I have a budget of 300~400 dollars and need a lathe to continue (read "start real rocketry) my rocketry hobby past cemented motors and basic motors. I would prefer to buy only one moderately sized lathe i.e. 10 x 20 in. Should I attempt to build one? I have access to a milling machine but not regular access to a lathe. (I plan on turning nozzles and motor casings) However the milling bits can only cut metals with a hardness of aluminum. I have a full design on autocad and a incomplete cost sheet. Is it a bad idea? Should I bite the bullet and buy a small but expensive one? Thanks for your time.

P.S. I can post screenshots of the lathe if need be

 

[Balor]

Hi Ryaer and welcome.

Go to Craigslist and check it out before you build a lathe, you just might find what you are looking for in your price range.

rngr1

 

[Boilerhouse]

I can't see how you could build a proper accurate lathe with multi-speed head stock, tailstock, accurate bed ways, fully functioning carriage, cross slide and compound, able to thread parts (if needed), cheaper than buying one. And that is ignoring the amount of time for such a project. I am sure others have built their own lathes from the ground up, but I suspect it is mainly for bragging rights.

 

[bdbecker]

Fun to read, never tried it...

https://www.amazon.com/dp/1878087010/?tag=atomicindus08-20

 

[baldredhead]

building a lathe will become your new hobby, and you'll be the only one able to service it, get parts for it, and when you've outgrown it you'll be the only one that wants(ed) it.

save more money, and get good at educating yourself on what a lathe is worth in your area.

check out used machinery dealers, they don't usually want the hobby level machines but sometimes get stuck with some. bring a wad of cash and make a crazy low offer if you find something you like.

a 10x lathe is pretty small in the grand scheme. they're fairly desirable for the garage tinkerer types and thus are disproportionately expensive for the size and features. if you can find a 12x or bigger machine and room for it, you'll likely be happier for longer.

 

[John in OH]

Fun to read, never tried it...

https://www.amazon.com/dp/1878087010/?tag=atomicindus08-20

Don't. You can try building the homemade lathe described in this booklet, but it is a massive, time consuming job. Ask yourself ... do you want to spend the limited free time you have available for hobby work building a lathe or building rockets??

As mentioned above, search CL for used lathes. Unfortunately, Missouri is probably not a hot-bed of used machine tools, but if you are willing to make a trip to, say Ohio or Chicago, there are lots of used machine tools available in the Rust Belt.

You probably don't need a super-accurate lathe, but you don't want to settle for a clunker either. Unfortunately, the smaller bench-size lathe that you want is also the most popular size for most home shops and, hence, command more money. You can actually find larger lathes for less money ... but watch motor size and power requirements. Also, there are a lot of junk boat anchors out there that are only worth scrap ... so be careful. Tooling for any lathe will usually cost nearly as much as the lathe itself.

I've actually found several decent machine tools at this place on the east side of Cleveland, OH:

https://hgrinc.com/

To machine odd shapes like nose cones you will probably have to design and build your own machining jig/tool holder. I have no idea how one would go about making such a device for cutting these curved cones, but I'll bet such a device, or a how-to-build instruction, can be found on internet rocket-hobby forums.

A lathe is a blast of a tool to use!! I love making things on my lathe.

Good luck in your search.

 

[DavidB]

Keep a look out on craigslist for used machinery. You can use something like searchtempest and quickly search for a lathe within *** distance from your location. Check daily and you'll probably find a few good candidates. Until then, read up on buying a used lathe so you can separate a good one from a worn out one. Also figure out how you'd move one. I've found several machines, including my lathe, using this approach.

I wouldn't pursue building my own. I think it'd take a long time, cost a lot, and you'd probably end up with a disappointing, limited machine.

 

[jfleisher]

I've got an older Atlas lathe that will be going up for sale soon...

 

[larry_g]

https://kansascity.craigslist.org/tls/d/craftsman-metal-lathe-hobby/6469467449.html

On a real tight budget something like the above would be a better starting point that starting from scratch. With the above you get a bed, headstock, carriage and part of the tailstock. Huge leaps above just a home made job and the precision is going to be much better.

https://springfield.craigslist.org/tld/d/central-machinery-7x10-mini/6470103849.html

Another that could get you going.

When I started playing with machine tools a friend said, remember this is just your first lathe. Get something and learn. while learning note what is lacking in the machine you have and make sure that you get what you want in the second or third purchase. The basic machines listed above will always return your investment and the tooling that you buy will work on the next one most of the time.

lg
no neat sig line

 

[7635tools]

I have to agree with looking on Craigslist. Also check local schools to see if they are discontinuing there shop programs. Good deals can be had there. I found a high school near me getting rid of the metalworking class and walked out of there with (3) 13” south bend lathes with tooling for $500. The machines were 1950 something but all worked great. I managed to get a lot of other tools too for pennies on the dollar.


Sent from my iPhone using Tapatalk

 

[matt_i]

Good advice. Don't build. It will divert you for a couple of years from what you are doing now.

Other advice (I adapt this from the legendary Forrest Addy) is to buy a lathe that's all there and has all functions working to be your first one. Not a project. Along the same lines if you can buy a "package" with chucks, post tooling, edge tooling can save you a lot of money over picking up the accessories separately.

Once you have a running lathe now you can get project machines because you have a way to make new parts and repairs.

 

[honcho]

If you want to read about a lathe being built under extraordinary conditions, check out this link. Prisoners of War, being held in a Japanese POW camp, built and used a lathe to to their benefit. These were incredibly resourceful and skilled men who put their talents to work under terrible conditions.

http://www.lathes.co.uk/bradley-pow-lathe/

 

[Ryaer]

Holy ****! Thanks for all the information! To respond to a few points, I realize as the armature machinist I am (to the extreme) I have a low probability of building an accurate and precise lathe. Thank you for bringing that to light. In terms of turning parts, nozzles and motor casings will be the only thing. Nozzles are basiclly two different sized cones carved into a piece of rod, and a motor casing is a fancy pipe. From what I've been reading (and my own experiences with imprecise concrete nozzles) high precision isn't needed and I can get a basic lathe. From what I've read it's possible to buy a small one, and then sell it off when it's too big?

Agian thank you for all the replies! If anyone has any offerings on a lathe that won't kill my feeble budget ( I know it will) I'll be looking into that. Also anyone know any excellent resources for high speed turning? (I'll be cutting steel at small diameters = lots of fpm = fast turning speed)

Please pardon any spelling mistakes, I'm typing this on the way to school on a phone.

I fear the screeching steel in the next months will make my dad mad

Additionally, you guys are so much help, I'm impressed! How do you guys find this stuff?

 

[VocaTexas]

I bought a really clean Central Machinery 9x20 lathe at an auction last year for $200. Deals are out there, you just have to keep your eyes open and be ready to jump. I let an unbelievably nice Atlas mill get away from me last weekend because I hesitated.

Go to this site and register: https://www.hobby-machinist.com/forums/

There are some really nice folks there and they will answer any question you have. They've been a big help to me. There's also a ton of interesting reading there, too.

 

[bdbecker]

Not sure how big you need it to be, but a mini lathe might do the trick. Lots of great info here:

http://www.mini-lathe.com/

 

[danb35]

Another possibility, if you can stretch the budget to the $500 range and don't really need 10" of swing, is one of the mini lathes. They're generally 7x10-12, weigh under 100 lb, and are available from a number of vendors. It would get you something new, but a bit smaller than you're talking about.

 

[matt_i]

I fear the screeching steel in the next months will make my dad mad

Ah, there really shouldn't be any screeching. As I was taught, if you are drawing attention to your machine you are probably doing something wrong.

I would just turn at normal rpms, 2000 is all you'd ever need on a lathe. Most chucks are pretty dangerous to operate even in that range. Collets are better for high rpm operation.

If you are on a budget learn to grind and use HSS tools. My free advice is to visualize in your mind how a moldboard plow works, that is roughly the same concept as a HSS tool bit.

 

[HoosierBuddy]

Ryaer,

Post a sketch of a typical nozzle design you want to make. I'm curious.

When it was me, I waited a year or two and found a South Bend Heavy 10 that I could afford on Craigslist...but it was more than your budget many years ago and didn't include any tooling.

If you're only wanting the occasional piece, maybe you could have a local machine shop or someone here on the board make parts for you? Just a thought.

Phil

 

[GarageGuy89]

I bought my mini lathe on CL for $50, some guy just wanting to clean out his shop. So the deals are out there. Anything larger and you really need a cherry picker or fork lift to take it home, so keep that in mind.

Also, I've found HSS tooling to be much more forgiving for the beginner. You can always go to the grinder and touch them up. I bought a couple carbide tools and ended up breaking them and dropping them within a couple days. On that note, search ebay for used HSS tooling, you can find a couple pounds of odd ball HSS blanks for the price of one 'new' blank.

As other have said. Building the lathe sounds really fun, but it will be a hobby. Sounds like your still in school so you may have the time to invest in a project like this. I would encourage you to watch some youtube videos of people rebuilding and building their lathes. You should be able to get a sense how/what it takes. Keep in mind, it takes a special set of tools just to build the lathe...

 

[Ryaer]

I'll post a screenshot of the nozzle when I get home. Having someone turn one for me is viable for the first one, but these things are gonna explode, melt, or get worn. Once I get a lathe I plan on cutting new nozzles every week and upping the bores and sizes of the motored every month to a rather large motor (3" bore x 6' long, basiclly a hvar but smaller) I'll look into hss tooling. The larger the lathe for a cheap price is better! (I would just prefer not to buy more than one, I'm not working yet...)

 

[Zewnten]

There are several examples on youtube, one even step by step with a few other cool ideas thrown in, guys handle is ratherbewelding, he based his on an I beam as did several others. But parts alone probably cost as much as your budget and he was getting his steel at scrap prices. I think if you posted a wanted ad and told everyone you meet you're looking for a lathe someone will remember where there is one sitting in a forgotten corner. (It's how I got my anvil.)

 

[larry_g]

Another form of metal shaping is Spinning. It is also done on a lathe and there are dedicated lathes for the job, but can be done on a regular lathe, or maybe a wood lathe.

lg
no neat sig line

 

[Ryaer]

I like the idea of spinning, but it can only work with sheet metals? A rocket nozzle has to be cooled through active cooling or ablative means. All of mine ( for simplicity's sake) are ablatively cooled, meaning every firing will erode the nozzle. I imagine a small 4 second burn motor would do just fine with 1/4 inch steel metal, but anything more would likely result in either the nozzle melting or destroying itself from pressure. I do have a wood lathe however.

 

[Ryaer]

Ryaer,

Post a sketch of a typical nozzle design you want to make. I'm curious.


Phil

Sorry it took so long, but here you go

 

[larry_g]

I like the idea of spinning, but it can only work with sheet metals? A rocket nozzle has to be cooled through active cooling or ablative means. All of mine ( for simplicity's sake) are ablatively cooled, meaning every firing will erode the nozzle. I imagine a small 4 second burn motor would do just fine with 1/4 inch steel metal, but anything more would likely result in either the nozzle melting or destroying itself from pressure. I do have a wood lathe however.

When I suggested metal spinning I was envisioning the nose-cone, not the nozzle. Sorry to mislead you. Your on the right track with regular cutting.

lg
no neat sig line

 

[Fretters]

Another form of metal shaping is Spinning. It is also done on a lathe and there are dedicated lathes for the job, but can be done on a regular lathe, or maybe a wood lathe.

There are also plenty of time served blokes missing digits due to spinning.

 

[Alchymist]

Easily done for a wood lathe, metal lathe not so much.

 

[2mJps]

I live in Mo and have a like new lathe for sale in your price range. Its a msc. Some one bought it and it wasnt what they needed i have others and dont need it.Its a 9"or 10" i dont remember the length.