Worth looking into? TOOLING-> Mini Mill drill lathe central machinery multi precision

[illcomm33]

Hello!

I was hoping to get some thoughts on this mini milling/lathe machine.

As a rookie builder (7 frames...) hand filing has been fine but I am really interested in purchasing some machining tools.

Anyone use one of these mini machines for mitering tubes? Good-bad-ugly?

The lathe seems like it would be a nice size for small parts...which is what I would need.

It is posted on Ebay (currently around $600).

Thanks in advance!

Here is the description: (specs)

I have for auction this hardly used central machinery mini mill lathe . I purchased it from a recent estate auction. It is just as you see it. It is in great working order. The Main flaw is the Gear housing cover is cracked. (see pictures 3 & 4). When you tighten the housing nut to keep the gear housing cover closed you almost don't realize there is a crack . (see picture #4). Other than this, damage, there is nothing else damaged. The mill works and the lathe works fine both in forwards and reverse. . Switching from lathe to mill is very easy. (see picture s (9 & 10). the knurled ring on the main gear shaft is how this change from lathe to mill is achieved, and it is easy. By grabbing the knurled ring and pushing it towards the headstock and it locks into place. To change back is just as easy. Pull the ring back. The chuck in the mill and the chuck on the lathe, are in fine condition and show literally no evidence of wear. the tray , at the bottom is in fine used shape. and is clean. The lathe has the capacity to cut threads. The lathe/mill is 19 1/2'' tall. the lenght of the tray is 18 1/4'' long. The only wear issue is the belt from the motor to the lathe is in need of being replaced. .It has deteriorated before my eyes, I think the owner put oil on it. the other belt on the lathe is fine. and the belt on the mill drill is fine as well. Please see pictures for condition. ask questions I know there is something I may of forgotten to mention. Buyer pays shipping and insurance UPS. thanks for looking

Model # 39743

Motor 115 volts, 60 HZ single phase

3500RPM 2.5 Amp load

MT #1 spindle taper

spindle speed drill/mill 500 rpm to 2500 rpm

Lathe 560 rpm to 2500 rpm

Travis
mill2.jpg
mill.jpg

[Jonathan]

It saddens me to think something of value might have been scrapped to make that.

[Dancingbear]

I won't be as blunt as Jonathan, but given the budget niche that Central Machinery products serve, I think you would end up frustrated with the limitations and quality of that particular machine. You would be better off looking for an older small South Bend for not much more money.

[Jonathan]

Yeah, that was blunt, and harsh. Before I ever built a frame I bought a little Chinese mini lathe for some other hobbyist metal working projects. It's long sold. I'm not sure i can think of anything I'd use that lathe mill combo for to build a frame.

[e-RICHIE]

As a rookie builder (7 frames...) hand filing has been fine but I am really interested in purchasing some machining tools.

Respectfully - why atmo?
Develop some tactile sense and intuition from working with hand tools, over and over - and over again.

[EricKeller]

It saddens me to think something of value might have been scrapped to make that.

I don't think this is overly harsh. I have often felt like renting a front end loader and a dump truck after shopping at Harbor Freight. The whole store would be better off at a metal recyclers. I have heard some peole call their tools parts kits, but their machine tools are really garbage and not worth working over to make them work. Some other companies sell similar machines that might actually do something, but they also charge for the fit and finish improvements.

[illcomm33]

Respectfully - why atmo?
Develop some tactile sense and intuition from working with hand tools, over and over - and over again.

This is a completely fair and appreciated question. My honest answer would be, based on my inconsistency and lack of speed and confidence with the files, I like the idea of perfect miters right up front. There is the honest answer! I will definitely take your guidance and continue to learn/practice/develop the tactile sense as I know I have seen improvement since day 1.

Thank you everyone for the honest, possibly harsh :), feedback on the machine. I had a feeling the Harbor Freight brand might be questionable but didn't have any backup which is why I had to ask the best!

[ToddFarr]

Travis,
I have a Smithy Combo lathe/mill at work that never gets used. I would steer clear from combo machines to begin with. As far as HF machine tools, if you've ever been in the store and looked/touched them, they are pretty poorly built. Tons of back lash, sloppy tolerances and super flexy in all the places where no flex is desired.

If you are looking to go the machine mitering route. Start trolling craigslist for a horizontal mill, lathe or milling machine that is built rigidly enough to handle the kind of loads associated with mitering tubes. You'd be surprised the deals that can be found if you are patient and troll craigslist often. I've also watched some good deals on local pickup on ebay (Southbend Heavy 10 perfect condition for $710)

Some brands to look for Atlas or older Craftsman, Southbend (be careful, I've seen a lot with way/bed wear) , Logan, Sheldon, Kearney & Trecker, Barker

Hope this helps if you decide to go this route.

[Dave Anderson]

This is a completely fair and appreciated question. My honest answer would be, based on my inconsistency and lack of speed and confidence with the files, I like the idea of perfect miters right up front. There is the honest answer! I will definitely take your guidance and continue to learn/practice/develop the tactile sense as I know I have seen improvement since day 1.

Thank you everyone for the honest, possibly harsh :), feedback on the machine. I had a feeling the Harbor Freight brand might be questionable but didn't have any backup which is why I had to ask the best!

Have you used templates? That's what I use. I can bang out a tight miter in minutes. In fact, I can do a front triangle faster than I could when having to set up the mill (That I used to have, but sold for lack of use) for each cut. For example:

(Note: I do not have anything against machine tools or using them. This method just works better for me personally. Plus there's a bonus: the cost is almost nothing and it takes up no space)

Note the center lines on the templates....makes it easy to keep the miters in phase


Rough cuts with a cut off wheel on an angle grinder


Rough miters on the bench grinder (this one is likely not OSHA approved...wear proper safety equipment!)


Final quick touch up with a file

[PCW]

Rough miters on the bench grinder (this one is likely not OSHA approved...wear proper safety equipment!)

Dave, I'm doing everything exactly like this now except for this step. Do you dress the wheel like that or does it just wear that way from grinding tubes? I'd like kind of like to add that step because the file on the cutoff wheel edges kind of sucks--not bad, but this step would save a minute or two per miter I'd think.

[Dave Anderson]

Dave, I'm doing everything exactly like this now except for this step. Do you dress the wheel like that or does it just wear that way from grinding tubes? I'd like kind of like to add that step because the file on the cutoff wheel edges kind of sucks--not bad, but this step would save a minute or two per miter I'd think.

Its an fine grit wheel that I dressed so that it had a rounded profile before I mitered the first tube. The grinder does 90% of the mitering. The photo below is what they look like right after the grinder step. You can take them down to the edges of the templates in a hurry. You don't want to overheat the steel though. The key is to keep rotating the tube. I sometimes also flip it end for end as I am grinding to let one end cool, etc. If the paper starts to turn brown from the heat you need to back off, etc.

Dave

[Kumo Cycles]

My honest answer would be, based on my inconsistency and lack of speed and confidence with the files

I would say there is only one real solution to this problem: Get in the shop and file file file some metal!

The learning curve is super steep down this end of the timeline, I learn bucket loads every day and muscle memory can only be taught by doing. keep persevering!

[dbohemian]

[QUOTE=Dave Anderson;466270]Have you used templates? That's what I use. I can bang out a tight miter in minutes. In fact, I can do a front triangle faster than I could when having to set up the mill (That I used to have, but sold for lack of use) for each cut. For example:

I am sorry Dave, only my opinion but at your stage (being a pro) that is ridiculous. If you want to use minimal tooling one can use two of the Paragon machine blocks, a bevel protractor and the right sized files and I will be done before you even print and cut those templates out. The blocks lock down on either side phase your miter and the bevel protractor (about $30 bucks) will be just as accurate while saving some trees. As far as machines are concerned, I am a machine guy. With a dedicated mill and a good setup you can punch out a miter in approximately 30 seconds. I rather spend my time filling a lug nicely or working on some other detail than something I know how to do in my sleep.

[Dave Anderson]

[QUOTE=dbohemian;466317]

Have you used templates? That's what I use. I can bang out a tight miter in minutes. In fact, I can do a front triangle faster than I could when having to set up the mill (That I used to have, but sold for lack of use) for each cut. For example:

I am sorry Dave, only my opinion but at your stage (being a pro) that is ridiculous. If you want to use minimal tooling one can use two of the Paragon machine blocks, a bevel protractor and the right sized files and I will be done before you even print and cut those templates out. The blocks lock down on either side phase your miter and the bevel protractor (about $30 bucks) will be just as accurate while saving some trees. As far as machines are concerned, I am a machine guy. With a dedicated mill and a good setup you can punch out a miter in approximately 30 seconds. I rather spend my time filling a lug nicely or working on some other detail than something I know how to do in my sleep.

Dave,

Never one to sit back and just tell folks about how you do stuff without attacking others are you? I would make a few counter points, but since you are always right, I don't see the point. You use your tubing blocks and bevel protractor and I'll do it my way.

Sincerely,

Dave

[dbohemian]

[QUOTE=Dave Anderson;466327]

Dave,

Never one to sit back and just tell folks about how you do stuff without attacking others are you? I would make a few counter points, but since you are always right, I don't see the point. You use your tubing blocks and bevel protractor and I'll do it my way.

Sincerely,

Dave

I am sorry if you felt I was attacking you. I have an opinion, I am not always right. If you would like me to document with pictures how it could be done better and easier for you, I will. I think we should all be open for some constructive criticism without getting hurt. I could say things more smoother tact if you like but we are all adults here eh? Make your counter points, I am interested in hearing them. Maybe another thread would be better.

[Rody]

Travis,

Congrats on your continued development in frame building, it's nice to see that you have enjoyed the process thus far and are looking toward the future.

Based on your anticipated needs, the mini mill/lathe combo you are looking at would be an excellent tool for developing frustration and dissapointment...not much else.

Here's my perspective. It is not necessary to have heavy machinery to build a simple bicycle frame. If your goal is a single frame at a time, custom designed for it's intended user and defined purpose, your money and time would be better spent as noted by the respondants above. Richard and Dave are two fine examples of folks who operate as professionals that fabricate their style of bicycle with minimal tools and loads of muscle experience. This maximizes their time and ultimately, their money. Low capital investment in machines and tooling allow them to pay themselves a living wage, actually surviving long term in this business.

Machinery becomes necessary when your desire moves beyond simply shaping a bicycle frame, one at a time. Machines allow two distinct advantages; the ability to miter multiple tubes with fantastic speed, accuracy, and repeatability for production runs, and allowing for the creation of fixtures, tooling, and the ability to fabricate your own unique products (bb's, dropouts, derailleur mounts, etc..) that solve either design or function issues, extending your ability as a builder to create custom products that go beyond just geometry. The trade off is that to do so means a substantial investment in not only money, but of time. Careful planning of time allocation and customer billing is required to insure that this business model not only pays for it's self, but pays you.

So, it comes down to what do you want? Will this continue to be a hobby or a career path?

If choosing this as a career, do you have the machining foundation and knowledge of fundamentals to put your purchases to use immediately, offsetting the cost with profitable fabrication?

If you choose to move forward with a machine purchase, take some time to come to Nahbs, talk to builders who utilize such equipment and learn the various methods they are employed. Then, research what type of tool (vertical mill, horizontal mills, lathes, etc...) will best fit your desired process, if a local resource is available for parts/service support, and then set your target and spend your hard saved cash on a tool that will serve you for your career.

Best wishes,

rody

[dbohemian]

Thank you Rody for bringing this back on track when I took it off course. Much better written and said than myself.

[liberacefanboy]

What?
You guys don't use lazer beams from your eyes to cope tubes?
Amateurs.
I use lazers . Yep I used a z in lazers. as in that works best for me , like as in I think Dave knows whats up for him, and David uses what works best for him.
Personally I use a Bridgeport, and let it cut slow and then do something else. It's all about efficiency and what works for you. I can get a lot of shit done when the mill is just turning away, and I am doing something else .
But, lazers.

[e-RICHIE]

Richard and Dave are two fine examples of folks who operate as professionals that fabricate their style of bicycle with minimal tools and loads of muscle experience.

Thanks - and to reiterate, we each had the machinery and subsequently jettisoned it atmo. I don't know or care enough to have the discussion from an engineering perspective but I will add that I think framebuilding, ensuring tubes feel and fit right, and knowing when to leave well enough alone OR go forward for more - all of these are very, very tactile tasks. If you are making a lot of frames, especially a lot of the same frame and in the same size, eventually you may concede to power. Or, if you simply like power, you may concede sooner. But I don't think your frames can get better unless you fully understand the material and how it works together. The assembly, what with different metals, different diameters and gauges, and infinite versions of interference fits all beg for a touch. Back to the original issue, mitering by hand enables the operator to develop a touch dot period. I know not everyone agrees and I accept that. But when I chime in and reply on threads like these, my motivation is to help someone become a better framebuilder and one who can have a chance at a career. If I were to be more agreeable when some folks on the left hand side of the evolutionary time-line want to know where to buy a granite table, or some of these power tools being cited in the last week or two, I'd be a hypocrite to sit on my hands. My inner e-RICHIE tells me that they wanna say they build frames far more than hey wanna be a framebuilder with a steady clientele and income.

You don't have to wanna spend a lifetime mitering by hand, or eschewing power tools and dial indicators (and the like...) but if you bypass part of the essentials and learning curve, you won't be in the game for too long atmo.

Anyway, maybe I am in a bad mood, or uncharacteristically confrontational. But I know what I know, and share it. No charge for this.

[ToddFarr]

Dave,
Are you resting the tool against anything when you push it against the wheel or is it just floating?
-Todd.