efish

My Feedback: (5)

Hi, I'm not sure if this is the right forum, but I know that many of the members here are experienced machinists and since I mainly fly 1/2A, I would appreciate the perspective.

I've been given the opportunity to purchase a 1 month old lathe, mill and drill combo machine:-

http://www.sgtooling.com/product_inf...products_id=32

Pricing is pretty good - just over about 300 USD. Condition is reportedly excellent.

2 questions, perhaps related:

#1 Is this is a good idea (i.e. does it have enough travel and precision)?

and #2 With practice, will I be able to turn useful RC parts out of this thing? e.g. diesel conversion heads, small aluminium brackets, etc

I believe it can be converted to a CNC setup as well, so that might be the next step for me.

Thanks.

BMatthews

WIth care and skill you can turn model sized stuff on this machine. Depending on how much stuff you're going to use it for it may be all you'll ever need.

Concerning a CNC conversion. The biggest advantage of CNC is the ability to make multiple items. But for the most part model stuff is all one off's. And if you're not going to use it that often then is it really the best use of your time and money to go to the extent of doing the conversion?

efish

My Feedback: (5)

Hi Bruce, thanks. Model sized stuff would probably be about all I want to turn. One big attraction here is the price, plus I've always wanted to use a lathe and a mill.

Thought the CNC conversion was for precision and consistency (I've never used a lathe or a mill before). To be honest, I have no idea how much the conversion would cost, but if you think its unecessary, I'd just as soon put the time and money into material stock and practice. Afterall, that's part of the fun.

peter_gibbons

I have one... Its great. I highly disagree about the previous comment about CNC conversion. It took me three days to get everything calibrated (lash, speed, etc) but after that i have used it solid for 2 years and have never had a problem. The reason I disagree is, I sit down and draw the part on the computer. After that I always have it, and, when/if I ever need another one i just insert the stock, set zeros, run the program, and a new part is cut.. Don't get me wrong, there is a huge learning curve (Im old school) but the benefits of spending the 800 bux for the conversion, in my opinion, is a no brainer. Plus you learn things about machining that you never would have thought possible... plus when i run my programs (rc parts, injection molds, car parts) i never worry about ME making a mistake (unless i goofed up the code somewhere). The precision, and ability to run a constant feed speed so slow you cant even see it move, is well worth the investment. There are others that have differing opinions ("Buy an old Bridgeport!!", "Thats crap", etc.) just get what you want and learn how to use it.... This is just my opinion....

peter_gibbons

Oh, and not to mention, cutting a taper or a radius on the lathe is a piece of cake....

efish

My Feedback: (5)

Hi Peter, I take your point, and the reasons you set out are those that had me thinking about CNC, but Ack! if it's going to cost more than double the cost of the machine to go CNC, then I think I'm out for now....

Will talk to the importer of the machine (who happens to be a moderator on the local RC forum) to find out how much he paid to convert his.

Thanks for the second opinion though.

peter_gibbons

good idea, i just noticed you're in singapore... its probably a lot cheaper to do it over there... I went with a company out of California that has done these conversions for years... the benifit was the super high quality. When i opened the box I almost fell out of my chair looking at the quality... another reason it cost me more money was, I went with a 4 axis setup.. if you go with two... it costs a whole lot less... all depends on what you want to do with it...

ptulmer

My Feedback: (5)

efish, that looks like a nice machine. Keep in mind that a small machine limits your setup, etc. Since you specify 1/2a parts and a $300 price tag, I'd say you're nuts not to get it! Don't get in a rush to convert it to CNC because it can be hard enough to learn how to setup your machine! (and a little costly!) That said, CNC is definitely something to put on your agenda.
Peter, what company did you use? I've got a HF 9x20 that I want to start doing it to soon.

peterburford

Cnc is great, but remember that you will still need drills to drill holes.
I would firstly spend on measuring instruments, tools and attachments.
Peter

peter_gibbons

Agreed, spend your money on tooling first, unfortunately I had to do it all at once and it was costly. Ptulmer... the motion group in CA there website is kinda bad so just call them at 559-325-2727 All the folks i talked to there were awesome.

efish

My Feedback: (5)

Thanks all, knew there would be a great pool of wisdom here!

Peter G - yes, China made goods are generally cheaper over here, but unfortunately, quality is generally suspect or poor. When you said you had one, was that in reference to this particular machine, or to a CNC mill in general?

Spoke with the importer and it seems that he does not know of anyone who has converted one of these to CNC - guess that means that CNC will be off the cards for now.

Well, thanks again everyone for all the tips and info - I'm off to collect the machine in an hour. Can anyone suggest any sites/references I can look at to understand what further tools, instruments and attachements I will require? Would also be great if someone could point me in the direction of some basic guides on the use, care and feeding of a mill/lathe.

DICKEYBIRD

Definitely keep CNC in your plans...very difficult to make the contoured parts you'll no doubt be dreaming up in the future without it. Do learn the basic machining processes 1st though.

Here's my favorite machining links:

http://www.homeshopmachinist.net/bbs/
http://www.practicalmachinist.com/cg...ultimatebb.cgi
http://www.cnczone.com/forums/
http://www.gadgetbuilder.com/index.html
http://www.frets.com/FRETSPages/Machining/index.html
http://www.chaski.org/homemachinist/
http://homepage3.nifty.com/amigos/index-e.html

WARNING! I see a change in your spare time and money utilization habits!
(But you're gonna love it.)

BMatthews

I have to admit that I'm an old stick in the mud when it comes to CNC. For me a large part of my satisfaction with metal machining is to actually run the machine and do the setups and not just stick a wad of metal into the chuck or vise and let the computer have all the fun. So I tend to poo-poo CNC stuff for the home workshop where production is not involved.

So it pains me to admit that Peter has some good points about the CNC stuff.... JUST NOT IN MY SHOP!

peter_gibbons

Haha Bruce, I hear you and whats funny is, My uncle's name is Bruce and he doesn't do the CNC stuff either. He actually still uses a fantastic old Atlas 12. My machine is different than that one, I got mine from Grizzly, but, the company I mentioned (The motion group). all they do is retro-fits. When you go to pick it up ask them if the drive screws are metric thread or standard. Just keep it in the back of your mind, as the setup for this stuff is a little different between the two. You have to setup the 'resolutions' on the motors (digital steps) and the metric ones clock differently than the standard threads.


Tee Dee spinners, using cnc on a machine like yours, retro fit will cut in about 45 seconds if you have everything setup right And no more taper jigs!! hahhahahh sounds like a commercial... "Just Oxy Clean it"...

One more note, if you find charts for feeds and speeds, subtract almost 40% of those numbers when using as a mill. The spindle just isnt heavy duty enough to eat that much accurately. It still works fine, just takes a little longer. Its all about patience. Try to be patient while learning this stuff.. It takes a while, but its worth it.

One day maybe you will try the cnc stuff Bruce, nothing like being able to cut a gear on the mill without a bunch of mularky.

peter_gibbons

Oh! and after you cut your 45 second Tee Dee spinner, check out the home shop anodizing at http://www.caswellplating.com/ and make a gold and red spinner for that super killergoldenbeeblackwidowteedeepeewee.