Making an indexing attachment for the lathe

smart design kudos

Jonesey can you post the manufacturer and part number of the chamfer tool you use on your mill? Thank you.

I wonder if the sector plates were larger in diameter, if that would reduce error. Great idea! I am going to check out my lathe now for that standoff point. Thanks for putting this together.

I was once helped in such a situation on an electrical erosion machine. The remnants of the tap were removed in this way from the blind hole in the aluminum part. Your situation is much simpler, the hole is through.
Good luck!

Jesus, either I'm deaf or you're narration sounds like your talkin through a mouthful a bangers n mash! Then again, I have been playin my guitars through a Marshall head and a Jackson 4-12 cabinet turned up to Sir Nigel Tufnel levels for the past 35 years so maybe it's just me. Carry on, pip pip cheerio and Bob's your Uncle whatsay!

Mr Pete says you only really need three or four threads and recommends over sizing the hole a bit for a percentage the holes depth so the tap only engages a portion equivalent to a common nut thickness therefore not to overwhelm your tap.

good video, ta.

That is a gorgeous surface on that aluminum. What RPM are you running?

Many years ago I saw a scheme for a military lathe where a indexing head was mounted on the spindle outboard and a powered spindle on the carriage could mill or use a slotter on the work piece.

Thus plastic and metal don't always work well together

I plan on doing your mandrel but attaching it to a 6cm 180 tooth cog belt with a 12mm 12tooth idler and a stepper motor. Thanks.👍🖖😇,jpk

I'm thinking of doing something similar, but mounting a rotary table on the back of the spindle, with the internal expanding collet mounted on the table and the rotary table housing stopped from rotating by a long arm attached to the headstock.

Wich program is is being used

Interesting
BUT WHERE IS THE HURRY TO SPEAK SO FAST ?
One receives more when what is being said has time to sink in
Too fast and not worth watching

When threading aluminium best cutting fluid is paraffin try it.

Dissolve Alum in hot water and soak the aluminum part in the solution. The aluminum will not be affected but the tap will be disintegrated.

This happens when you don't back off a half turn for every turn to break burrs and clear chips. This is a method of work taught in old school fabrication. In over fifty years of machine fabrication I broke only one tap. That was the first one, I learn quick. All I see now is keep turning and most don't even bother to lubricate the tap and they don't understand why it broke. I bought metric and S.A.E. tap and die sets when I became a machinist and replaced the one tap that broke, and four others over time that wore out. Both sets are almost as old as me!

nicely done! in the absence of a band saw, a Dremel Cutoff disc might be a good choice! :) For the tap, you might want to consider building an EDM tap remover and / or use an EZ-Out if the size of the tap allows for it.

I like the well designed attachment but as an American I cannot understand the speaker's rapid English accent.

Be sure you back out the frequently when tapping small features. If it starts to get really tight do not go further, back it out slowly. If it gets tight again, screw back in, then slowly back out. Forcing it like you did will ensure a broken tap.

You're much better off just re printing and using hole compensation values.

When needing a close fit with a 3D printed part, I will model just the section that needs to fit and print 2-3 at slightly different sizes to try out the fit. When I find the one that fits well, I update the actual model to match. Saves printing several complete larger parts.

Hi! In order to remove a piece of steel from aluminum, you can boil the part in water with citric acid - this will not harm the aluminum

It doesn't matter who snaps the Tap! It's still painful to watch ... and yes.. *FEEL*!
Wakodahatchee Chris

The Chinese girl who fixes lathes, pumps and whatnot, welds a piece of steel to a broken tap. Original and apparently it works. Uses tape and a sharpy to find center height, also original.

use a cordless drill for tapping

A boiling solution of alum, water with a bit of Sulfuric acid will dissolve the broken tap to the point where you can pick out the bits. May take a few reboils and an over night soak but the aluminum will be untouched.

Been looking at tools like the "broken tap removers" if you search on google or something, never used them but maybe something that would work .. dont know if they work with spiral taps =)

I know this is a little late, but to remove taps like that, I usually “drill” it out with a carbide endmill that’s the same size or smaller then the tap drill size. Then the rest usually breaks free. Every once in a while if it’s a really brittle tap you can hit it with a punch and break it out in pieces.

Great video. Thanks. I see that when you were hand tapping, you did not use a tap follower in the spindle. I saw the tap bending. Use a cheap spring loaded tap follower to keep the straight.

With tapped holes, the maximun strength achieved is 1.5 X screw diameter. With thick parts drill the clearance size hole for 2 to 4 threads, this achieves 3 things, location start for the screw and it gives a nice round hole to countersink and lastly any tendancy for the threads to pull upwards will not interfere with the mating parts. Car cylinder blocks and gearbox housings use this feature so nothing interferes with two flat mating parts. Drill the holes deeper than needed and do not let the tap bottom out. Regards from Australia.

Why not clean bore and make concentric the plastic parts to designed specs and a match to the metal.

Did you consider if the internal surface of the lathe drive shaft is an accurately milled tube running true!?!? Maybe bore it to be sure.

Chào bạn cảm ơn bạn đã chia sẻ rất là hay mình cũng làm về máy CNC

Never tap aluminum dry and use a tap guide. The easiest way to fix a broken tap is don’t break the tap.

You need to let the part cool before doing a fit. Thats why the part wouldnt fit. Usually FDM has a 0.2mm shrink. Do some test cirlces first to dial your printer.

You described how it works twice, but never actually said the name "Vernier scale".

Dear Jonesy, not pretending to be an expert but here is my advice. When hand tapping, for each few turns run complete reverse turns until you hear a crunch of the swarf tearing itself clean. You can then move forward and rinse & repeat. That way your swarf is progressively pushed back along the tap and doesn’t lock up which is what happened in your case. Touch wood, I have never broken a tap using this approach. Cheers.

TAPS. are just a pain. I'm sure you know most of the techniques to remove taps. Professional shops use spark erosion EDM using carbon electrodes in parrafin/petrol or just plain water but at home this is normally not an option. Larger taps might welded but in this case its too small and tight a spot. Then there's the brute force and drift it out with a punch and hammer and helicoil the hole ! That might be suitable in this case but not ideal. Or you could weld the hole up and re-drill it off course. A small pin punch or chisel and tappety tap tap for 6 hours and you might just wiggle it free is often the first thing people try. The real key tip is to persevere !

Only way i have ever got broken taps out is using a centre punch and a hammer.. it often shatters enough to start winding the fractured parts out, but at M3 you're not likely to achieve this.

Top tip for 3D printing. Print out the areas that are going to interface with the parts that you need to interface with just the interface area so you can get that size and correct and then print out the whole part

Get a pound of alum
saturate water with alum in a stove tolerant pan
heat the pan to 150ºF-180ºF
drop part in pan
add water occasionally (to compensate for boil off)
3-4 days later the iron stuff will have decomposed and the aluminum restored.

When the pan returns to normal temperatures you will have a pan full of crystalline alum
Add water and heat the next time you need to remove iron and preserve aluminum.

Use lard or candle wax to tap ally components so the tap doesn’t bind

Should have been using some kind of tapping oil when making those threads. Would have eliminated the breaking tap

I've had to remove taps from valuable parts before. Usually what I do is get a carbide end mill that is the size of the drill hole (smaller than the threads). Then set the spindle speed to about twice what you would normally run it. Use cutting oil or coolant to keep the end mill cool. Then you feather it in as gently as possible (.001-.003 of an inch at a time). It will be time consuming. It is the ultimate test of patience when it comes to machining but just go slow. The carbide end mill is trying to chew threw steel that is only slightly less hard. Listen for any crunching or snapping. Check the end mill occasionally. Keep dabbing it with oil or coolant. If everything goes right, the tap will basically be reduced to metal chips and will no longer be stuck in the hole. Don't know if you have access to carbide tooling but that's how I typically get broken taps out of parts that have a lot of time and effort invested in them.

Unsatisfying 😂

buy some cobalt drill bits and tap extractors, i’ve never snapped a tap bad enough for it not to have worked for me

It reminds me of a smaller Stanley Cup