Author Topic: Building a New Lathe (Read 533946 times)

S. Heslop · « **Reply #675 on:** July 16, 2018, 10:03:09 AM »

Quote from: vtsteam on July 15, 2018, 10:55:13 PM

I don't know of any pop-tech method that could compete for speed cost or simplicity or conservative use of materials and fuels than ordinary direct pattern making and casting.

I'm not trying to prove that one way is "better" than another, because this is all hobby stuff, and the interest and challenge are the most important products, not the objects we produce. But I do want people to understand the reasons for my personal choices -- many younger people do not actually understand them.

I do it this way because it gives me great joy to move that fast, that directly, and that easily from what I conceive, to what is there, ready to use. That personal choice comes from my own love of traditional skills and efficiencies. There is no intervening program, or computer or robotic tool. It's just me. That's my gas.

There's alot of marketing in the 3d printer world. Guys like this work tirelessly to steer discourse towards selling you stuff you dont need, and I think it's a conscious effort by some people to suppress smaller ideas and voices.

The local Maker society is currently in the process of fitting a rusted and faulty round column mill with stepper motors before fixing anything else with it, and they went for a laser cutter before even considering machine tools. I don't think it's stupidity or something on their part, it's just if you look up stuff online then you'll see mostly CNC, 3d printers, and lasers. There's alot of people who're just unaware of differing (and cheaper) methods, and if they do run into them they might disregard them. So I think it's important to put them in context and explain their value as you're doing.

Boy I talk about this stuff alot. Just imagine me pointing at one of those forensic string boards every time you read my posts. It's all connected!

Cool T bars by the way. And cool method of casting them! Can't wait to see them on the lathe.

vtsteam · « **Reply #676 on:** July 16, 2018, 09:24:33 PM »

Thanks Neubert, Simon.

Sorry to say there was no work on the lathe today. Worked on the bridge. Will have to do that tomorrow as well, unless it rains. Maybe I can get a little done in the evening.

Temps here were brutal again, but there's a night time thunderstorm right now, We need the water, so, no complaints..

Neubert1975 · « **Reply #677 on:** July 17, 2018, 04:54:58 PM »

no need to be sorry.
we have brutal heat here too, and today i have spend all day out in it, fixing my moms car, damn it was hot.
we sure could use some rain too, everything outsite is drying out.

Homebrewer · « **Reply #678 on:** July 17, 2018, 05:28:53 PM »

I've got both you beat, fellows. It's 106°F here in Texas with no rain or cool fronts in sight.

It's times like this that I feel blessed to have an indoor job!

Sent from my SM-G950U using Tapatalk

vtsteam · « **Reply #679 on:** July 17, 2018, 07:48:12 PM »

We got about 2 hours work on the bridge today before thunderstorms hit. They put down a couple inches of rain (badly needed) for the next 4 hours, and a flash flood hit the stream the bridge abutments are being built on. The water was over the coffer dams and about 3 feet up the new abutment. No damage or problems, but it sure did stop work.

I did get the the T-bars cleaned up some, shortened to length, and drilled them to take fastening to the cross slide. I was gratified to see all of the holes matched the slide's tapped holes perfectly -- not always an achievement for me. But they were all done on the mill, and my dial twiddling worked out.

Nothing much worth showing yet, They need to be countersunk, fastened, and then the whole surface milled together. But a little progress anyway.

awemawson · « **Reply #680 on:** July 18, 2018, 02:51:23 AM »

PekkaNF · « **Reply #681 on:** July 18, 2018, 03:21:41 AM »

I have a big interes on this latest T-slot construction.

I haven been planiing/doodling a new top slide for my small lathe. Original is that shitty that it is next to useless. I use it only when i can't avoid it, other times it is replaced with a rires block on the cross slide - much better and more stable. It also has two holes for mounting this riser, places are defined to maximize working envelope, original fixing point wast not even compromise, it had bad sides from the tool overhang and diameter capacity.

Milling the T-slots is the industrial practice, but not always easiest to do in HMS. And tou need a bigger piece on stock to start with.

Fabricating the pieces gives you more versatility and you can replace the parts. Also looks easier to make on small mill.

You planning to align the T-slots accurately with the top-slide I.E. nearly perpenticular to spinde axis?

Pekka

vtsteam · « **Reply #682 on:** July 18, 2018, 10:41:51 AM »

Sorry Andrew.

Pekka the holes in the cross slide and the T-bars were all done on the mill. Admission: unfortunately the first time I drilled the cross slide I hadn't checked the mill vise from the last time I'd used it, and it was slightly off perpendicular.

But, since I decided that 1-3/8" spacing between rows was smarter than 1-1/2" (because I could use 1" wide bars instead of 1-1/8), I plugged the old holes, indicated the vise in accurately, and re-drilled everything with the altered spacing. Because of the change in spacing, none of the newer accurate holes impinged on the old holes. so it was all in new material. Then I tapped them. So to answer your question, the T-slots should all be accurately parallel with the bed ways.

vtsteam · « **Reply #683 on:** July 18, 2018, 10:46:52 AM »

Pekka, you might recall I did a similar Tee-slot table before, though that time I just added the tops of the Tees:

https://madmodder.net/index.php/topic,8900.0.html

PekkaNF · « **Reply #684 on:** July 18, 2018, 12:09:33 PM »

Quote from: vtsteam on July 18, 2018, 10:46:52 AM

Pekka, you might recall I did a similar Tee-slot table before, though that time I just added the tops of the Tees:

https://madmodder.net/index.php/topic,8900.0.html

Thank you, I remember that one, but it was good to read again.

Pekka

vtsteam · « **Reply #685 on:** July 19, 2018, 06:08:21 PM »

Yesterday was a full day 8-7 on the bridge. Today we poured some of the blocks in the morning, but that left the afternoon free. So I was able to countersink and mount the T-bars, and then mill the surface flat.

We have to do what we can, when we can!

S. Heslop · « **Reply #686 on:** July 19, 2018, 06:19:07 PM »

Hell yeah, that looks awesome!

RotarySMP · « **Reply #687 on:** July 20, 2018, 05:56:50 AM »

Nice work. On the whole lathe project. When I made the built up, steel, T-slot table for my little 7x12 chinese lathe, I also epoxied the parts together, in case the screws work loose.

http://wrathall.com/Interests/machining/T-slot_cross_slide6.htm

Mark

vtsteam · « **Reply #688 on:** July 20, 2018, 06:24:32 PM »

Thanks Simon!

Hi Mark, I thought about that earlier, but decided I wanted to be able to change things around easily. I did epoxy and screw the way pieces to the lathe bed back two years and twenty some-odd pages ago.

We fastened our tee-bars differently I noticed -- it looks like yours are fastened only at the ends, while mine are fastened all the way across. Both make sense depending on whether there is or isn't a glue assist. Looks like you have a nice site. Thanks for letting me see that.

vtsteam · « **Reply #689 on:** July 28, 2018, 04:44:11 PM »

I took a short length of hot rolled 4" x 1/2" steel bar, cleaned it up, and bored a 1" hole 1-1/8" from one side. Then I turned a 1" dia. shoulder onto a 1-1/4" round bar. and deeply chamfered the end.

vtsteam · « **Reply #690 on:** July 28, 2018, 04:49:07 PM »

The rod was a tight slip fit into the plate. The shoulder was left a little short, and the chamfer turned because I wanted enough space for weld metal.

vtsteam · « **Reply #691 on:** July 28, 2018, 04:50:56 PM »

The shoulder and tight fit assured that the parts would be aligned square when welding.

vtsteam · « **Reply #692 on:** July 28, 2018, 04:57:18 PM »

I welded the post to the base, then milled the bottom flat again. I also put a hole in the top of the post for tapping, to take other accessories, if needed.

Here, checking the location of the tool block, and drilling locations for final mounting to the lathe.

That's all for today. Between the thunderstorms and the concrete bridge form pours, it's fairly slow going, lately.

Neubert1975 · « **Reply #693 on:** July 28, 2018, 05:37:19 PM »

looking good as always ;-)

We finaly got some rain today too, and thunder.
we havent had a drop of water the last 3-4 weeks and 30+ °c

krv3000 · « **Reply #694 on:** July 28, 2018, 08:38:59 PM »

as per a wondaful job

vtsteam · « **Reply #695 on:** July 29, 2018, 07:21:09 PM »

Thanks Neubert, Bob, always a pleasure to hear!

vtsteam · « **Reply #696 on:** July 29, 2018, 07:22:57 PM »

Another shake out:

vtsteam · « **Reply #697 on:** July 29, 2018, 07:23:28 PM »

Cleaned up:

vtsteam · « **Reply #698 on:** July 30, 2018, 06:54:09 PM »

And finally I used the lathe as a lathe (first time) to clean up the circular recess in the top slide base I cast yesterday.

I used the new fixed toolpost, which can either be mounted directly to the cross slide, or on top of the tee-bars. The hole spacing allows either.

The new top slide base will mount directly to the carriage.

I was very impressed with the solid feel of the lathe. No chatter with this difficult zamac piece. I had decided I wanted to move the recess back 1/8" so I was facing the hole sides eccentric. There was sand in the rough cast surface. And I needed to relieve to a sharp inside corner. The carbide insert I had was not ideal for the above, HSS would have been better, but quickly blunted. The lathe cut through without hesitation.

I was also impressed by the power of the motor and belt drive, even at 100 rpm with a heavy chunk of casting off center and out of balance there was no slowing down in a flat side profiling cut. Even though it doesn't have back gears.

And the mass of the new lathe and the new roller bearings, meant that though the flywheel load was un-balanced, there was no vibration or jumping around. I normally add weights to balance anything as off center and heavy as this casting was, but when I first tried out low speed operation, the lack of vibration (plus to my impatience level) had me trying a cut, without problem, and then I just kept going.

vtsteam · « **Reply #699 on:** July 30, 2018, 06:58:24 PM »

Relieving the center portion of the recess:

News:

Author Topic: Building a New Lathe (Read 533946 times)