Good stuff. Don't stress too much about it being the right way to rebuild a mini lathe spindle, we've all been there. Amazing how much it improves the way that it cuts.

Ambitious project! Well done. 👍 I cut 304 stainless on my minilathe all the time. The first thing I did was throw away all my insert tooling. Well, put it away in a box I never use lol. Then hand grind HSS cutting tools which are very sharp, and have a reasonably high rake angle. These cut the stainless with much lower deflection force. It is still NOT fast on a minilathe because you need to take small depth cuts, but it cuts really nice and you can get a nice finish and no chatter etc. And no tool costs because you can just re sharpen them. To cut your square sided grooves; i never use a parting tool for this. I have a HSS tool sharpened to an acute (pointy) angle about 40 degrees. I just use that as a turning operation back and forth to get some depth, then rotate the tool post and cut the square sides of the groove. That way there is no chatter and you can control the exact depth of cut and also the exact placement of each side (perfectnwidth and position of the groove etc). Basically you "sculpt" out the groove in 4 operations; rough depth, side1, side2, tweak the depth until perfect. That way of working is fairly quick and gives you a lot of options for weird projects.

I ran the same lathe for a couple of years on stainless. I found that carbide aluminium inserts gave me excellent finishes. Great work.

Razor sharp tools are your friend on a machine like this in order to reduce cutting pressure. Ground and honed HSS, polished aluminum inserts, or honed carbide. Nice work making it happen with the tools you’ve got!

Use HSS tools for tough materials on minilathe..

Watching you struggle with that hacksaw then with the stainless on that lathe made me want to cry. 4 years later I'm still recovering psychologically from experience of boring a stainless cylinder on my medium sizes lathe for the mirror holder on a custom telescope. The worst part was knowing that the part was deflecting away from the tool this precluding any attempts to do large passes. Nice job as you never gave up and you didn't surrender.

I was about to comment, “you need a solid tool post” right as you started making it. Don’t get lazy and keep it aluminum. I did the same exact thing, and just switched it from aluminum to 12L14 steel. The difference is just as night and day as from the compound to aluminum solid post. It’s amazing how much flex was actually in my aluminum tool post, and I’d never know if I would’ve just left it. You won’t regret remaking it. Especially if you want to cut 304 again.

Love your humor! 🙂

You have a strong character! 💪🏻 great video

While type 304 stainless steel has great corrosion resistance, it requires really sharp tools for successful & accurate machining. Rigid machinery doesn't hurt, either. For ease of machining I'd choose type 303 stainless steel. This is a very free machining stainless steel alloy with good corrosion resistance, too. I made all the ball handles for my Quorn T & C grinder from this steel, and it was a joy to use. Both of the above named steels are not very good in moving / sliding applications because of the galling properties of this alloy. For movable parts I'd use type 17-4 PH stainless steel. This steel is heat treatable for great strength and hardness making it wear resistant in moving applications. The heat treatment can be done after final machining because it is carried out at quite moderate temperatures such as 900 deg. F. Only a very slight discoloration occurs during this heat treatment. One last thought: All stainless steels are machined at much slower speed than say low carbon steels. Low carbon steels are typically machined at a cutting speed of 80 feet per minute, whereas stainless steels are machined at 60 feet per minute or less. On light machines I'd try 40 to 50 feet per minute and use high speed steel cutting tools with 15 deg. rake angles. It is a mistake to use tungsten carbide tooling on light weight machine tools. Learn to grind HSS tools and save a pile of money and aggravation. There are some excellent videos here on YT demonstrating this process. Try it you'll like it:-))

Right on, there is no such thing as a discontinued part.

Well done mate! Using what you have both in brainpower and tooling will always overcome any problem. And the humour wasn't too bad either.

Fantastic build

Was doing a job , my other lathe was down . I cut a steel bushing 3. In long 2.5 in. in Dia. 1.5 inch bore all with my little mini lathe . Had to let it cool offseveral times . But like a timex watch, Takes a lickin keeps on ticken . Nice save on that old bike . Better than the new ones .

This content is very well done for a channel with only 454 subs. Well done, mate. Great work all the way around!

for budget bandsaw a portaband or portable bandsaw is genrally the cheapest way to go (and the blade size is common among most brands) most people eventually make a stand for them. thanks for the lessons on stainless

The silence of that first cut of the thread was soo intense, perfect time for a jump scare

Nice work. To make the threaded pin I would have (and had previously and succesfully) started from a correct size grub screw and turned away all the unused material.

For stainless steel I recommend using lard as a lubricant, it improves a lot.

Great job and well done

Well done!

All you need to do to put a hex socket in the end is to bore and thread the end a tiny bit undersized. Then heat the the part, and put the set screw on the end of a impact driver. Freeze it in dry ice. Then drive it in. It will never come out. Another way would be to cut threads with a taper and then cut the threads down on a set screw with a matching taper. The put it in with an impact driver.

It's usually better to go with high speed steel tools when cutting harder materials, as those mini lathes can't reach the high speeds carbide tooling requires, especially when facing. You also want tools with as positive of a rake as possible, as those mini lathes don't have enough torque to push a neutral or negative rake tool properly.

Good job!

TNGG inserts works great on stainless..or any steel really, great video..

Howdy! Great job! A time counter would be sweet, if it is not too much work... Cheers!!

Like another poster, I've always had better luck machining stainless with hand ground HSS cutters. I used to do quite a bit of stainless turning on my little Sherline lathe making spear gun parts and accessories.

I had to make a brake piston the other day for an old RG500… it turned out perfect made from 316…

Well done considering the handicap of your equipment. If I may suggest a couple of things, when using abrasive tape it is best to pull up not push down. If the tape breaks pushing you will crash into the moving parts, but if you pull up and it breaks you move away from the lathe. A small thing but like using a spanner on car wheel nuts you pull up so you don't crash into the ground when it slips. Second, when hacksawing one hand is on the handle and provides forward motion and other hand is at the front to provide cutting pressure.

If you're turning a taper you may have a twist in the lathe bed. You can get that out if you bolt it down to something sturdy and carefully put some shims underneath one of the feet. That should help in pulling it straight. Use a test piece to check for taper or a known piece of straight bar with an indicator. The only downside is that this will probably make the lathe a lot less mobile but you'll gain in accuracy for it

Thers some great drill bits on amazon... M42 grade, brand name is Stroton. Not the M35, get the M42. They are very affordable and are phenomenal quality (M42 has high hot-hardness, high resistance to wear, basically an enhanced M35).

Hmmm... while saving the hex was clever, I'm not particularly fond of using glue. I would have cut some grooves on the hex insert and made it an interference/compression fit. Then I would have heated the stainless part enough to get some expansion, then tried to press the insert in. If that failed, I would have merely resorted to compression fitting that insert into the head of your fancy new bolt

Well done, often people give up too easily. Does your tailstock not have adjustment to help you adjust out taper?

Bolt the lathe down to something rigid! No wonder it's chattering.

The loctite will hold, but for how long, especially when exposed to heat? In this scenario, it might be worth reverse threading the hex plug.

Great video, but I'm a machinist and that was hard to watch you struggle with that POS lathe. I hope you can upgrade in the near future because it seems like you know what your doing.

Brilliant work! How got will those bolts get? As I recall, Loctite breaks down under heat; you could lose adhesion, friction, and grip between the hexagonal insert and the body of the bolt after a lot of heat cycling. You could stake the inserts in place...

Get ground finishing inserts, instead of moulded. These have much less tool pressure and you will have a much easier time in stainless (I have same machine with some significant mods)

Cool video, I think I would have chosen a different material to work with, but watching you struggle probably makes for better content :-)

If you made that plug a little bigger you could have gotten a much higher torque spec.

If you need to do stainless turning often, buy a more rigid lathe or make it more rigid. The latter costs almost as much if you count anything for working hours but the end result will still be a chinese lathe.

so much perseverance in this video

you definitely shoulda used the interference fit approach... brakes get hot, if you arent driving like you are disabled, hell, even then... And loctite, unless its the proper high heat locking compound, will not prove a great idea over time... I woulda machined those to interfere, the receiving end would be heated to around 300 celsius, the plug part would be blasted with gas refill bottle of butane to chill it down to around -30 celsius in a few seconds and drop... once it sets, its gonna hold until the end of times floral incandescent porpoises... if you get my meaning... and that 4cm inox rod... yikes mate, that must have hurt by the end...

You would be much better off without a QCTP as it moves the tool too far away from the area where it's better supported. (lot of leverage when it's 75mm or more away from center of mounting) Also, HSS and a much lower rpm works better on mini lathe as you can have things sharp instead of radiused edges designed for much heavier cuts. Nice to see older GS550, I ran workshop at a Suzuki dealers when they were a current model. Biggest issue was rectifier regulator, fiting something more modern fixes a lot of electrical issues. I also built a big bore GS550 which was faster than the 'brand new' Honda VF750

What size 4 jaw chuck is that?

If you had been using a lathe that was more up to the task I am sure this would have been somewhat easier to accomplish. So, that was not possible, Why not use material that would have been much easier to turn such as 12L14 or 1117. It would allow you to make a part that would worked. If it did last as long at least you could make a replacement without the trouble of using 304.

Great job I also have a mini lathe but do not have as much trouble with stainless as you did, also do not think the dome was all that important.

E bay

Your QCTP isn't helping you deal with stainless either. Wakodahatchee Chris

Get plunge EDM for the hex some Morlock dude on youtube has an EDM power supply for 500USD

Horrible lathe plus wrong inserts for this job