Chasing the true.

[alphatex]

Hello, I'm Jim from the Houston area. New to the hobby, crossed over from RC planes and engines. Just got a cheap mini mill off eBay and having lots of fun and frustrations chasing the true. Looking forward to learning from everyone here.

 

[428Bird]

Hey Jim, welcome to the site. I live in the Deer Park area.

 

[Naiveambition]

Friendswood area here. Just wondering what chasing the true means? And as for learning you are in the right place.

I read almost every post on this site for a year straight, and a few other sites as well. Was able to accomplish 4 engine builds and am on my fifth project now, with v8 s in the near future with no formal education in machining.

So I cannot stress enough to read , read, read, and ask questions to make this a worthwhile and fun hobby.

 

[428Bird]

Wow, we should create a local, southeast houston club!

 

[alphatex]

Hey fellas, although I live in Katy, I drive all over for work and I'm in the southeast area at least 2 to 3 times a week. "Chasing the true" is a phrase I picked up from one of my instructors years ago that I have found to be surprisingly appropriate in this situation as I am having all kinds of "fun" trying to reduce as much runout, backlash, wobble etc on my lathe and getting it to run as true as possible!

 

[428Bird]

What kind of lathe do you have? I've got a 16 inch Holbrook, and a Bridgeport I'm currently working on.

 

[alphatex]

A knockoff of a knockoff I would say, it's a Mingxi Industries 7 x 16 mini lathe I got off ebay.

 

[bazmak]

Thats the ideal lathe to mod/improve and all documented on lots
of sites.Please post your progress

 

[goldstar31]

In what little time that I have :-

1. Had the same-ish lathe
2. Had time to use it

I have been reasonably satisfied with my 'secundo mano' machine.

Going through my accounts, I am surprised to find just how much more money that has been spent in bringing it to what I expect in lathe- with almost 80 years of playing with the things mechanical.

What there is is the expected measurements in a model maker's 7 x 16 on the internet and perhaps more importantly, how to carry out these tests. I like Georg Schlesinger who sets an accepted standard on 'How to do it' As Baz suggests, there are lots of sources of advice on how to overhaul and modify a similar lathe. You'll be surprised to find just how different it is to actually have to put your hand into your pocket book which the college lecturer and the guy who stands at somebody else's purchase-- and makes his deliberations often out of the 'belly of abysmal ignorance'

Consequently, I bought what I consider the 'essentials' such as a 4 jaw independent chuck and a faceplate and ear marked the purchase of a new three jaw that hadn't been abused by a previous user. Again. I bought a fixed steady rather than make one. I'm a very cantankerous old so and so but before romping off to buy a qctp affair, I bought a set of collets and a collet holder. I can make a tool turret whilst the average three jaw chuck is not quite as accurate as one would want-; or eventually, aspire to..

You will notice that I have made no mention of lathes which are held vertically and called milling machines or such.
I recall, despite being just able to read, that the lathe was 'the King of Machine Tools' and my only alteration is to qualify that with the suggestion of adding the essentials mentioned above.

Have fun

Norm

 

[alphatex]

Hi Bazmak and goldstar, you guys are right. The main reason why I bought this lathe is because it is so well documented online. So I spent most of my free time last week cleaning and lapping all the important surfaces and adjusting to take out as much slop as possible and now I have a reliable 4 thou play on the compound and cross slide. I am going to call that good for now.

The biggest issue I'm having right now is I have about a 4 to 8 thou play each way on a test drill rod that I chucked up. The jaws of the chuck visually appears to meet in the middle, which is leading me to suspect how the chuck is mounted on the faceplate. Ran out of time tonight, will test more tomorrow.

Can't wait to get this resolved and make some metal curly fries.

 

[428Bird]

Good luck with it. I've found that there is no better way to get to know your machine than to tear into it with repairs/improvements.

 

[alphatex]

Thank you! Tearing into stuff is a great stress reliever for me.

 

[428Bird]

Same here. It took me six months to go through my lathe before I was satisfied. Now I know every bolt, nut, gear and bearing in the entire machine.

 

[alphatex]

Ok, finally figured out the cause of the wobble and it was starring at me right in the face. 2 of the bolts on the chuck were just a tad slanted and therefore the chuck is mounted on the faceplate with a very small offset. I enlarged the mounting holes on the faceplate slightly and remounted the chuck. To try to get it mated right, I used a piston ring compressor wrapped around the faceplate and chuck while tightening down the nuts.

Now the indicator needle just sits at 0 and trembles as I rotate the chuck with no discernible fluctuations. It's about as true as it is going to get I think. As a test, I turned down a 1/4" aluminum rod and I'm going to take it to my buddy's machine shop and have him check it with his high end instruments.

 

[428Bird]

Awesome! Always a good thing when it's something simple.

 

[alphatex]

Now I'm looking through the web for simple beginner lathe projects.

 

[428Bird]

My first project was a couple of drill and tap guides. 3/8 and 1/2 diameter. Pretty easy to make.

 

[alphatex]

Think I'm gonna make a simple manifold for my compressor. I need one anyways, getting tired of having to switch air hoses between the blasting cabinet and air gun.

 

[vederstein]

Think I'm gonna make a simple manifold for my compressor. I need one anyways, getting tired of having to switch air hoses between the blasting cabinet and air gun.

Making something that is actually useful. That's something not often mentioned here. Face it, this forum is essentially dedicated to complex and expensive toys.

...Ved.

 

[428Bird]

Hope you fellow Houston guys are weathering the storm well. So far, all is well at the casa Bettell.