Making a Custom Tap on the Proxxon PD 250/e Lathe 

Thanks for the tip!

Or just hold the wires vertically from above and the mic will hold then in place.

Thanks, good to know it is appreciated. :)

I know im randomly asking but does anyone know a way to log back into an instagram account..? I was dumb forgot my account password. I love any assistance you can give me

@Titan Dominik instablaster ;)

@Dean Korbin Thanks for your reply. I got to the site on google and im in the hacking process now. I see it takes a while so I will get back to you later with my results.

@Dean Korbin It worked and I now got access to my account again. Im so happy! Thanks so much you saved my account :D

@Titan Dominik glad I could help :D

Thanks! Clearly I need to channel my inner David Attenborough when making these videos. :)

@@AdventureswithaVerySmallLathe nah, you got him beat 🤣.

Already working on it, thanks for watching!

Toolmaking can be a really compelling hobby, and I've certainly been bitten. One of the first machining videos I watched was Myfordboy making a hob from silver steel, to free-hob a worm gear. I was almost immediately hooked!

@@AdventureswithaVerySmallLathe Yes I agree. Right now I am busy cutting MT0 and MT1 taper arbors for the Sherline. I have made a couple of MT1 slitting saw arbors, an MT0 extended dead center and an MT0 extended live center to be able to get the tool in with very small diameter work. I am almost reluctant to take the top slide off now, that the angle is set correctly.

lmao

right that person needs to read his comment 😂

@@bencesarosi7718 😍

That negative relief would certainly explain why my first attempt had no chance of cutting a thread at all. I haven't checked your math, but on a quick diagram I can see why that negative relief happens. A quick explanation of the grind I eventually did: I gound a flat relief just behind the cutting edge by carefully setting the angle of the grinding collet, then very gradually advancing toward the wheel, and checking carefully between each pass. It's not pretty, but it does work.

Veni, vidi, subscripta. Ego quoque.

I hope I'll always be able to find time to enter. Your competition has become a pillar of this community, and I'd hate to miss it. I'll see what I can do about getting some decent grinding footage.

I'd strongly recommend watching This Old Tony's tap making video. It's a very different kind of tap, but the principles are the same, and he knows what he's doing way better than I do.

Testing the limits of what a small lathe can do turns out to be great fun to make videos about, so I'm really glad people enjoy watching them too. Thanks!

Not quite infinite increments. It is a toothed belt, so can only be changed in units of one tooth pitch on the belt.

I wish I could do that too, but the tool post just doesn't have enough room to hold the single point tool upside down. I only get to do r/h threads away from the chuck if I don't need the tail stock.

Very useful they turned out to be, though they need a bit of training as a focus puller. ;)

Thanks, I'll do my best.

I'm certainly interested in learning to use that method at some point, but at the moment I don't think I have equipment that fits the job.

That's a huge compliment! I'm a big fan of This Old Tony, so this makes me think I must be doing something right. Thanks!

@@AdventureswithaVerySmallLathe All you're missing is a time machine or smthn of a kind. Sorry, i forgot, the no-nonsense english machining. Have been there, great (if boring) experience. (Boring is good).

This Old Tony regularly uses his Lathe for time travel, but I can never seem to find the right section in Machinery's Handbook on how to set it up.

Thanks for the tips! I've used Tracy Tools a couple of times looking for for BA taps and dies. They didn't have anything that matches this spec though.

I looked at Löwenherz thread during my research, and it's very close, but a 4mm nominal Löwenherz thread has a 0.7mm pitch, not 0.6mm. I spent a lot of time digging through the wikipedia page on old thread standards. :)

Thanks, useful to know!

On it!

Yep, you got it right. I set the compound in the wrong direction, and advanced it in a way that could contribute to chatter. I was going to talk about this a bit, but when the footage came out blurry I thought it would just get confusing. I'm going to do another video on left-hand thread cutting where I'll talk about setting the compound correctly.

Well spotted, by the way. :)

I welcome any comments that help me learn. For the compound, I worked out after I finished the project that I should have set the compound the other way, but it's really useful to me when more experienced machinists add comments highlighting my mistakes.

Adventures with a Very Small Lathe lol i am a bit experianced and i was gonna tell you to cut it from opposit direction but i saw your channel 6 hours late😂

This is spot on. I could listen to this man speak for hours.

So i think : a perfek job ! Now the question: did you produce & sell this watchmakerlathe sparepart ? Exactly this part a friend of my need this ...

I've used this technique too, which I learned from Joe Pieczynski's channel, but my toolpost doesn't have room for the tool upside down. Instead I get the right cutting direction by using a tool on the reverse side of the part. Look for the second thread in my Quick Change Tool Post Upgrade video for an example of the technique. I don't use it in all videos because it doesn't work with the tailstock.

That's certainly a benefit of using modern 60º threads, as they generally have flat topped profiles. The thread I was cutting in this video has a rounded top profile, like a number of older thread standards, so I was filing to try and match that profile.

It's speed change. Almost all of the video is sped up, but whenever I'm cutting metal I add an overlay to indicate how much it's sped up at that time.

@@AdventureswithaVerySmallLathe Thanks. I tried to notice if it was a speed change, but could not perceive it!

Thanks! I made quite a bit of use of the camera gear you donated to last years prize while making this video, so thanks for that too! :)

It's a rewarding project. I suggest watching videos from John Creasey and This Old Tony to get different perspectives on how it's done. Both are excellent.

@@AdventureswithaVerySmallLathe Thanks!

What went wrong? I'm genuinely curious.

That's true for many taps, but not all. I looked at a lot before settling on how to mill the flutes. The only real difference that makes is on the rake of the cutting edges, and I figured that on a tap this small, the rake wasn't incredibly important.

I think your Lego guys has a liquid lunch that day!!

My objective is not just to get the G Boley lathe working again, but to restore it to its original specification, with as much original parts and material as possible.

That's a good suggestion, but for me the whole restoration is an exercise, and the more I learn along the way the better. It's really important to me that I restore the Boley to as close to its original specification as possible. I hope you're not put off from making suggestions in the comments though. I've learned a lot from comments, as many viewers of this channel are smarter and a lot more experienced than I am. :)

@@AdventureswithaVerySmallLathe Point taken and more power to your elbow, I wish you well.

Thanks! Much appreciated. :D

It would change travel speed of the ways

@@bertjetolberg103 pitch would be the same on 55 and 60 degrees. .same amount of travel per rev.

@@albrolake7787 I suspect the pitch is as much a problem as the angle. I checked McMaster, and they have no 0.6mm pitch taps of any sort.

@@outputcoupler7819 3.5 x 0.6 standard size

Thanks Juan! I did quite a bit of reading on the lathe, and the thread standards of the time period it was made. There was a lot of variation in included angle, with many different angles proposed. In Germany (where the lathe was built) metric measurement was standard, but the modern 60 degree metric threads had not yet been standardised.

Interesting! Didn't know Germany was late to standardize on 60 deg threads

@@juanrivero8 I don't think Germany was any later than anyone else. These lathes were designed in the second half of the 19th century, but most thread standards didn't emerge until the later part of the century.

8x8mm lathe tools are really easy to get hold of from retail tool suppliers, eBay, Amazon, or the big Chinese sites which sell everything like Banggood and Aliexpress. Most of mine are from eBay.

Thanks Rustinox! I really appreciated your recent video about file safety on the lathe. Essential watching for every machinist.

It's a great technique if the setup allows for it, but my tool post isn't big enough to hold the tool upside down, and there isn't enough travel on the cross slide to hold the tool behind the work.

Adventures with a Very Small Lathe Sorry you have troubles here. I started doing this because my toy lathe did not have enough power at low RPM. Going backwards, so to speak, allowed full power. Have you tried making custom holders for your tool post? I have found running backwards when parting is also better on toy lathes. The lack of rigidity often caused the tool to dig in when running normally, running backwards allows it to just cut freely. Easily parting 1.5” diameter 17-4.

It's a SPZB63/85 DARMET. Very close, well spotted! The quality of the vice is really good for what I need, but I haven't checked the fine tolerences or tried to use it for grinding. I picked it because the German company I bought it through were recommended by a RU-vidr at some point, and I was looking for something smaller than the oversized milling vice I had. The Darmet is still quite big for my milling machine, so I've bought a pair of smaller grinding vices which also have the benefit of having clamping grooves at the side which the Darmet lacks.

@@AdventureswithaVerySmallLathe That's what I call a Quick reply! It seems these can be bought from their web shop now. I like the idea with the tightening force acting downwards. Don't know if it is an issue with Darmet, but in case it is, have you seen these improvements to the nut and cross axle? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JCmBFuGjtoM.html

@@paullehmor982 Partly luck that I was around, and partly that you had a nice simple question to answer. Thanks for the link to JohnSL's video! I like this stuff, and there's some good ideas in that video. I don't really have the first problem he describes, but I could definitely use that second mod. Too bad I have no 3D printer; I'll have to come up with another way to do that.

@@AdventureswithaVerySmallLathe Haha, I think ThisOldTony made a video about square holes.

Do you have a link to any information including the specific grade of silver steel? All the data sheets I can find for BS1407 Silver Steel say that it should be quenched in water.

Looking around online I guess the hardening process you are referring to is the one for DIN 1.2210 Silver steel, which has a diferent composition from BS1407 Silver Steel, and different hardening process.

@@AdventureswithaVerySmallLathe No, but I use 115CrV3, and read the instructions from one maker.

@@CandidZulu 115CrV3 is a different grade from BS1407. The British grade has less carbon, no vanadium, and differences to the other alloying metals. See the chart here for a comparison: en.wikipedia.org/wiki/Silver_steel

@@AdventureswithaVerySmallLathe Chromium increases hardenability, so oil quench is more suitable for 115CrV3. Oil is less likely to cause cracks. I've used a lot of "drill rod" in the past in the USA, and from memory that was also an oil quench steel. I would assume water quench will cause distortion more than oil.

Yeah, I think that might have worked, but it would have been really difficult to avoid making mistakes on such a small tool. It's only 4mm across. Using the mill gave me a lot of security and certainty, and was worth the time and effort it took to set it up.

I have to admit to knowing very little about endmill selection, beyond knowing that more flutes generally means more load. I'd love to hear if anyone has advice on chossing small diameter endmills for use on a very small mill, especially as I don't have the rpm that endmills like this really need.

@@AdventureswithaVerySmallLathe More flutes means more cutting load typically only because you increase the feed rate to reach the optimum cutting feed per flute (double the flutes ~double the feed rate~). For the odd job this is not really important slightly more tool wear isn’t the end of the day for a better cut and if your limited by a low RPM then a high number of flutes is a mean you can increase material removal rates if your setup can handle the increase feed rate and forces. I suggested an even number of flutes in this instance because if you think about how the cutting action happens over the course of 1 revolution you will find that only 2 of the 3 flutes are cutting at full depth some of the time (as 1 ball mill flute will be crossing the flute or “gap” of the tap), as it is an odd number of flutes this means the cutting forces are non-uniformed across the axis of rotation potentially resulting in chatter. A 2 flute cutter for example would have uniformed cutting forces but a non-uniformed cutting load over a full revolution (again as both flutes cross the gap in the middle) a 4 flute cutter would have both uniformed cutting load (almost) and uniformed cutting forces (across axis of rotation). I should point out that I’m only really basing this off of the reasoning I pointed out above. And all of this is really only because in this instance you have non-unformed cutting forces over 1 revolution (with a 3 flute cutter), now on an unformed cut (no gaps) cutting flutes directly opposing each other (such as 2 flutes of 4 flutes) actually creates oscillation => chatter but not as much as having a non-unformed cut would. I hope this explanation is helpful: as while I recognise in this instance it probably wouldn’t have made a huge amount of (if any) difference given the depth of cut and your feed rates I figured it might be useful to point out how you can think about the engagement of each flute when cutting on a per revolution basis as this might help with tool selection of other projects and generally help reduce chatter.

I don't have enough deep knowedge to know whether case hardening can work for making a tap. The amount of material I needed for this one-off tool was cheap enough that it wasn't a factor in choosing the material, so I chose a through-hardening tool steel that is easy to machine.

Most if not all lathes do that. That bit pulled to center, not away from it. The tail stock is usually slightly off no matter how hard you try to align it and that starter bit is designed to find center on a flat spinning surface all on its own. Tailstock mounted reamers are designed with a long shaft with slight flex so it can also compensate for this slight misalignment. No matter how accurately you try to level that lathe bed there will always be the slightest amount of twist in the bed which puts the tailstock slightly out of alignment, in addition a new lathe actually has the tailstock centerline sitting very slightly over center because the designers know that the way surfaces will wear over time. And the drill centerline will move down from slightly above center height to perfect center height to slightly below center height during the design life of the lathe. Chris

@@shadowdog500 thanks, I get what you're saying.

The tail stock is the weakest part of the Proxxon. It isn't perfectly central, isn't very rigid, and can't be adjusted. If I want to have really concentric hole, I have no choice but to use a boring bar. Thankfully for this project I didn't need the centre to be perfect.

A positive rake would probably be useful, but rake is not the same as relief. The tap would still need to have the relief ground in behind the cutting edge.

Which part do you mean? If you mean the tap, I'm afraid it isn't nearly good enough quality to sell. It only needs to be used once for my purposes, and it doesn't hold a sharp edge well.

@@AdventureswithaVerySmallLathe ... so you made your sparepart? Made another ...

@@GpunktHartman I'm not quite sure what you're asking me. Does your friend need a tap just like the one I made here? It's not really a spare part, but a tool I needed for my restoration. What does your friend need this for? Are they also restoring an old Boley lathe?

@@AdventureswithaVerySmallLathe ...no he not restore it, he use it ... but he need the part you made the tap for. I would like to get him in touch with you, if you like to do the part.

@@GpunktHartman I think perhaps you have misunderstood what I did in this video. I haven't made any parts using this tap, or the die which I made in the next video. Both were just used to restore damage to the original parts of the lathe. I think currently making parts for the Boley is too difficult for my skill level and equipment.

How would you achieve first few not fully formed threads if you turn the diameter smaller than minor diameter of the thread?

Grinding the taper is just the first step. The important part of the grind is the relief, which can't be turned as it's not round. I wasn't really able to record the relief grind, as the camera angles were very hard to set up, and I spent a lot of time experimenting.

Отрезаешь отрезным кругом на дремеле заборную часть метчика, занижаешь и затылуешь крайние зубчики, чтоб сформировался короткий заход - и станет можно. Ну или если не лень - сделать ещё один, но с короткой заборной частью для глухих отверстий.

Sure, here's an affiliate link, which supports this channel if you use it to make a purchase: rover.ebay.com/rover/1/710-53481-19255-0/1?icep_id=114&ipn=icep&toolid=20004&campid=5338559044&mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fitm%2FCutter-Tool-Grinder-Sharpens-Endmills-Lathe-Tools-Drills-From-Chronos%2F372533263837

Thanks Adam, and thanks for being a long time supporter! :D

All the videos I watched, and projects descriptions I read involved doing some kind of grind after hardening to form the cutting edge. Hardened steel is much less likely for form a burr, and holds an edge better, so it makes sense to me to form and sharpen the cutting edges after hardening.

@@AdventureswithaVerySmallLathe i know, but is this really how you sharpen a tap? feels to me like it needs more than grinding taper to be properly sharpened...

Oh, you're absolutely right. The taper turns out to be almost irrelevant compared to grinding the relief, which is what really allows the tap to cut properly. The step I did to add the pure taper, without any relief grind, was completely pointless. I should have ground the taper and relief at the same time, but had no idea how to go about it. I mentioned this in the voiceover, but I have no good video footage of grinding the relief, as it was very difficult to shoot, and I was clueless. :)