Making a 4-Jaw Chuck Backplate for the Proxxon PD 250/e Lathe

Making a backplate which fits a 4-jaw independent lathe chuck to the Proxxon PD 250/e using 42CrMo4 engineering steel.
A 4-jaw independent chuck is a vital piece of lathe equipment, but finding
the right chuck for this lathe took me a while. I finally found one light enough to be useable while still being extremely capable. To ensure the best possible performance the back plate needs to be very rigid, but on a small lathe like this it can't be too heavy.
Working on a part this big, made of tough material was a huge challenge on a Very Small Lathe. Check out the problems I faced, and how I overcame them in this video.
This video is part of Tool Fest 2021! Look for other videos with the #toolfest2021 hashtag, and post on other social media, all coming out today! Many thanks to Emma's Spareroom Machineshop for making this happen, and thanks to Chirpy's Tinkering for the teaser video.
Emmas Spareroom Machineshop
/ emmaritson
Chirpy's Tinkerings:
/ chirpystinkerings
00:00 Introduction
01:09 Cutting the Material
04:28 Facing the Disc
15:04 Boring the Through Hole
18:02 Boring the Spindle Pocket
23:39 The Spindle Hole Pattern
30:14 The Chuck Register
37:01 The Chuck Hole Pattern
47:13 Testing the Chuck
49:03 Next Video Preview
Materials:
80mm hot rolled 42CrMo4 engineering steel
Tools:
Proxxon PD250/e Lathe
Proxxon FF230 Milling Machine
Edited with:
Davinci Resolve 17.4.2
audacity 3.0.2
Music:
Easy Lemon by Kevin MacLeod is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Source: incompetech.com/music/royalty...
Artist: incompetech.com/

[@jmtx.]

Great project. Pushing the size limit made for an even more interesting watch!

[@CraigsWorkshop]

The backplate came out great! Tooling and machine improvements are my favourite kind of video. I am impressed with the idea for the wax lubricant on the bandsaw, I had not thought of that. I love how you battle on with the lathes low torque, people love seeing a story which has struggle along with a happy resolution! If you were to stick a bigger motor on there, or a gearbox or similar, you'd remove all of the challenge! :) Cheers, Craig

[@AdventureswithaVerySmallLathe]

Thanks Craig! I can't remember where I found out about the wax, but I ended up hunting it down because the bandsaw manual contains dire warnings about getting any kind of oil on the blade.

[@colincreedtattoomachines]

Alistair, that's another great example of how the PD 250/E can be pushed to its limits & still produce the desired goods. I can vouch for the expense of the Proxxon 4 jaw Chuck, it's even more so when buying in Aussie Dollars!! Contemplated doing similar to you utilising a Sherline 4 jaw given its size & quality but weighing up all the costs, the Proxxon Chuck worked out fractionally cheaper with much less potential of "introduced" problems. Concluded it was far quicker & easier buying the Proxxon 4 jaw Chuck, allowing me to get straight onto my projects. Like the old saying goes: "horses for courses".

[@AdventureswithaVerySmallLathe]

Thanks Colin! The real questions is whether the Proxxon 4-jaw's quality matches up to the price. I've heard from a couple of people that it's not up to the same standard as their 3-jaw stock chuck.

[@colincreedtattoomachines]

@@AdventureswithaVerySmallLathe Totally agree, their 4 jaw Chuck is NOT nearly the same quality as their (Rohm made) 3 jaw Chuck, yet they're about the same cost!! FWIW, I actually ended up having to make a set of replacement "jaw screws" out of M10 Grade 8 Grub Screws when the original 4 jaws started to fail & bind up within the jaw threads. IF I'd had the Mill before buying the 4 jaw Chuck then I'd probably followed your option.

[@michaelmayerhofer322]

I used the EMCO Unimat SL, EMCO Unimat 3 and PD 230 for many projects, but I never would have used any carbide insert cutters on these tiny lathes. I only use high-speed steel for lathes with motors rated less than 500W.

[@AdventureswithaVerySmallLathe]

That makes total sense, but there is a reason I didn't stick to the same principle. My lathe workbench was in a corner of my kitchen, and I had to keep the mess under control. Bench grinders are seriously messy, and really require their own bench space which I just didn't have.

[@624Dudley]

Good to see you again. Your videography and narration do not disappoint!

[@artisanmakes]

Props to that lathe for cutting through that steel.

[@hewlett-packardlovecraft2297]

Simply fascinating, watching you work through the problems and their solutions. Wish I could've been there for the live stream, but I just wasn't anywhere near a computer at the time- and I'm not someone who can look at their phone for longer than the time it takes to make a call. Outstanding video from start to finish, and while I understand they can't all be this duration, the near-hour length was a real treat. Hope you're as happy with the end result as I was watching you get there, and enjoy the rest of your week.

[@AdventureswithaVerySmallLathe]

Thanks HP! The original cut straight out of the workshop was over 2 hours, and it was quite a bit of work to get it down to 49 minutes. My principle is that my videos should be no longer than they need to be. I hope you can make the next premiere stream.

[@hewlett-packardlovecraft2297]

@@AdventureswithaVerySmallLathe Yeah, I can't imagine how much work must go into the editing of these videos. Stellar production values throughout, as always, though. You are a man of many hats, as my Dad would say. Absolutely will try to be there for the next live show, and thanks for the reply. Take care.

[@sambrose1]

Cutting big rounds like that if you stop a little before half way and turn it 90 towards the pivot it will cut much faster. Great video as always.

[@jadymulqueeney]

Thanks, very interesting. Your comments about basic machining fundamentals and potential problems are very helpful to a beginner like me. Cheers

[@hrishikeshb]

Nicely done! Looking forward to future videos.

[@andrewdolinskiatcarpathian]

Very interesting, informative and enjoyable. I am impressed what you have achieved using such small equipment. Well done. Hope the house move goes smoothly and that you are soon back in your workshop making more of your excellent videos. Take care. 👏👏👍😀

[@homemadetools]

Nice job. We shared this video on our homemade tools forum yesterday :)

[@samuraidriver4x4]

Its really time to get a new countersink, also deburring with the countersink the holes before tapping them makes it alot easier to get them started. Very Good end result from such a small machine with the trouble it can bring with the lack of rigidity and power.

[@AdventureswithaVerySmallLathe]

Good point about chamfering the holes before tapping. The order of operations on this project wasn't perfect, and there are a few ways I'd do it differently again.

[@BrilliantDesignOnline]

Great instructional video. I will be creating an intermediate plate to go from my 100mm G4000 oem chuck to a Bison 160mm 3-jaw, and your vid is encouraging.

[@YooProjects]

Interesting video dear man. I am glade you are come back :))

[@smallcnclathes]

Nicely Done! Dome head caps can be useful when you have limited depth for the head. Yes keeping a carbide insert cutting well can be difficult with limited power, my cnc has just 1/2 hp at the spindle, I tend to use ground edge inserts. Have even used aluminium type inserts on steel when required. My Hercus chucks have backplates but they are secured to the chuck from the back and long screws can pass right through the chuck to the spindle. Amazes me how you manage your commentary, you teach without it sounding like teaching.

[@daveys]

Great video, thanks for posting

[@jeffarmstrong1308]

Congratulations on doing a very tricky turning job turning job. These small lathes jam very easily. I have recently turned a 75mm form in steel beating a copper plate to the correct shape on my own Proxxon. Your videos decided me to get a Proxxon instead of another brand. Unlike you I had bought the Proxxon 4-jaw and I am now very glad I did!

[@tinker5349]

Well done, thanks for sharing your video and do keep up the good work

[@joeblochlinger]

The beginning of this video had me like "oh yea thats doable, easy enough, seems pretty strait forward"....then you went to the mill 😂😂😂😂

[@Rustinox]

And all this with very small machines. Good one, Al.

[@ianwhiteley964]

It is not often i can sit through a whole video of an item being made from scratch but the detail and my amazment that you managed to complete it on a mini lathe had me fixed from start to finish, well done sir, I may even one day get around to doing the other 3 i have been waiting about 5 years to do. thank you.

[@GoCreateHobbyMachineShop]

Very patient work , quite an achievement to machine large diameter high strength steel in such a small lathe. 7075-T6 aluminium alloy is a good high strength material and lovely to machine, might be a useful choice for some future large diameter projects on a small lathe where strength is required, though you do get more defection with this alloy as compared to steel.. A very engaging video.

[@T.Ackland]

Aluminium would be my choice and keeping the spacer as thin as possible.

[@matspatpc]

Nicely done!

[@6NBERLS]

Most excellent.

[@CreaseysWorkshop]

Lovely work Alister.

[@AdventureswithaVerySmallLathe]

Thanks John! I loved your video, though you never did show us what that ice did to your ice pick prongs.

[@Engineerd3d]

Man that backplate came out great.

[@CraigLYoung]

Thanks for sharing 👍

[@TechGorilla1987]

@22:19 - not to mention that most CNC machines can run a constant feed/speed by varying the spindle rotation as the cutter moves toward the center always keeping the insert in the optimal range for efficient operation. I found that fact fascinating.

[@AdventureswithaVerySmallLathe]

Yep, you can tell just from the audio of some CNC videos that the spindle rpm is varying, and it doesn't take long to work out it must be to keep the insert cutting optimally. On a machine that cost 6-7 figures time is money, so removing material as effeciently as possible without having to stop and change the insert too often can make the difference when it comes to staying in business.

[@TechGorilla1987]

@@AdventureswithaVerySmallLathe What amazes me about your work is the fact that even though you're working in the micro to those fancy, expensive machines, the accuracy, actions and tolerances are all the exact same. Frankly, I think working in the miniature must be more daunting.

[@Peter_Nottle]

always enjoy edge of the seat machining

[@stacysimon8864]

Nicely done sir. A quick check of tool height can be done with a small, thin steel rule. Place the rule on the OD of the bar, then gently bring your tool up to it until it makes contact and holds the rule. The rule will be square if on center. If tool is low, top of rule will be tilted towards you. I had very talented instructor 30 years ago, lol. Keep up the great work!

[@ferrumignis]

That gives a good approximation, but he was facing so that method wouldn't be possible without removing the work and putting a a round bar in the chuck.

[@AdventureswithaVerySmallLathe]

SkyWizardless: That's the trick. During a tricky bit of machining, quite often the accurate ways of getting the tool height right aren't available because they're too disruptive or would mess up the setup. In a better world I'd have a lot more toolholders, and could dedicate one to each tool I use. Then I could set every holder up to the right height well in advance, and just leave them all there.

[@bhoiiii]

Grim thoroughly impressed with your tenacity. There are so many challenges when you at the very edge of the machine’s capability. I can’t recommend polished inserts made for aluminum enough. They work very well on steel, cut more easily, and have very low tool pressure for small machines. Maybe $14 for 8 inserts on eBay.

[@AdventureswithaVerySmallLathe]

Thanks for the suggestion. There was quite a bit of discussion about that type of insert during the premiere chat, so I'm now thoroughly convinced to give them a try.

[@fna-wrightengineering]

@@AdventureswithaVerySmallLathe Honestly, I'm seriously considering going back to HSS tools on my mini lathe. I primarily use the aforementioned aluminum inserts on everything but brass/bronze... But recent experiments have shown me that a razor sharp 3/8" HSS tool, ground with exaggerated positive geometry, has far less trouble taking bigger cuts, without stalling the lathe.

[@bhoiiii]

@@fna-wrightengineering You may be right. I think that my challenge is “free hand” grinding a tool as sharp as the inserts. I respect your steady hand instead of my shaky old man hands!

[@fna-wrightengineering]

@@bhoiiii you can make a jig! Something that has a guide on the bottom that rides against the edge of the grinder rest, and a fence (either fixed or adjustable) on top to hold the tool blank at your desired angle. There's plenty of examples on YT. Alternately, a D-bit grinder with a CBN cup wheel does a great job of grinding tools to very precise angles and dimensions, but that's definitely not a cheap option.

[@bhoiiii]

@@fna-wrightengineering Great idea. I’ll think about that jig. Making a jig with the correct cutting/relief angles would be a fun exercise. What a sickness we have!

[@AlphaburnerAW]

Love these videos. I saw that you also purchased a “Seig” type lathe. Of the two which would you recommend for a novice just starting in machining. Any advice greatly appreciated thanks.

[@gvet47]

⭐⭐⭐⭐⭐ Great work!

[@lowwayoutubba]

Respect ❤️👍❤️

[@richardcooke9948]

Even though carbide tooling is readily available for mini and micro lathes, they just don’t have the power to use carbide. I have a 7x16 lathe and only use HSS tooling with good results.

[@TheRadioShop]

Fantastic job!. Really amazes me how you can do such great work with those small tools. I have the HF 7x16 lathe and the HF mini mill and struggle.

[@glennwright9747]

I used to have a Sears 6” lathe that had a back gear( planetary) and step pulleys. That arrangement allowed turning at low rpm with great torque. Not knowing your machine…could you use different pulleys to slow down the spindle?

[@kostasstamatakos1230]

well done sir! I remember your channel since its first days. you have gone a long way already! I can tell you love machine tools and machinists thinking as well. if I may be so bold, I would suggest you find a way and gain access to bigger machines, 1000 pounds or more. just so you know how they feel - if you don't know already that is! 42CrMo4 should be a joy to work with, not an odyssey... :) in any case, keep working on it!

[@makantahi3731]

i will have to do the same but i can not find chuck that mounting screws go from front side, just from backplate

[@user-nk8jq5km3s]

Очень рад вас витеть , и ваши новые видео, давно вас не видел. Спасибо

[@BedsitBob]

If you countersink the holes, before you tap them, it saves the second countersinking.

[@AdventureswithaVerySmallLathe]

Yep, that makes perfect sense. Thanks for the tip, I wish I'd thought of it that way.

[@TigerCarpenter]

very well executed I have self centering 4 jaw 125mm chuck with only 3 mounting holes, tightened with the regular nuts at the back of the back plate. I bought an independent 4 jaw chuck with 4 mounting holes. is it OK to just drill extra 3 holes ( + reuse 1 out of existing holes) in the original back plate, to match the new chuck? or do you think I need to make a dedicated back plate for the new chuck? or should I buy 125 mm universal back plate with mounting holes both for 3 and 4 holes chucks?

[@AdventureswithaVerySmallLathe]

I'd guess that would be ok, unless you' re really keen to perfectly balance the backplate to try and remove any trace of vibration. My chinese lathe spindle comes with the 3 and 4 hole patterns drilled into the same plate, with one hole in common between the two patterns just as you describe.

[@TigerCarpenter]

@@AdventureswithaVerySmallLathe the 4 jaw self centering chuck has a 3 bolt backplate the spindle might have 2 patterns but I need to open it up and see I saw some mini lathe back plates with both 3 + 4 patterns already drilled, I think I'll try that easy route first cheers!

[@TheKnacklersWorkshop]

Hello Al, Nice work and video production as always... sorry I'm a little late watching... Take care. Paul,,

[@AdventureswithaVerySmallLathe]

Thanks Paul, I really enjoyed your new machine video. A surface grinder is top of my own wishlist.

[@jamesgui3733]

Ok, the power up of your band saw sounds like a amplified harmonica

[@WeCanDoThatBetter]

Hi, is it possible for you to measure the bolt circle diameter of the proxxon three jaw chuck? I just can't find the info on the internet. For my new Emco lathe I'm looking for a new chuck. The proxxon seems to be identical to the original Emco if the mounting bolt circle fits. 29mm circle diameter would be great :) Would be very thankful if you can measure yours!

[@AdventureswithaVerySmallLathe]

Hi! I love your videos, and I'm delighted to be able to help. I've measured the 3-bolt circle as carefully as I can, and as far as I can tell it is a 29mm diameter circle.

[@WeCanDoThatBetter]

@@AdventureswithaVerySmallLathe Many many thanks for your quick reply! That is really good news. Nowhere I could find this measurements. Really thankful you checked this. Now I know the proxxon chuck should fit to my new Emco :) Thanks again ;)

[@bayopohan2294]

What lathe insert do you use, sir?, looks good

[@desertTooHot]

ooo nice editing work at 19:20

[@senorkasper]

Thank you for the great instructional videos. I am a beginer. At 21:36, what part exactly are you using to verify the correct diameter of the registration recess that you just cut? How do you get such part for any given spindle flange? Thank you in advance for the info.

[@hishampaqi6024]

We love you too.

[@AdventureswithaVerySmallLathe]

Awwww, thanks!

[@SK-eh4yf]

Good work. I do not understand why it is not possible to machine the face with a right handed tool. Did you do it in your first video ?

[@kikogarza6310]

Good video friend

[@marcoam2610]

23:43 Question about the proxxon dividing head TA250 (part no. 24044): Are you satisfied with it? Seems like Proxxon has superseded this with the UT250 (part no. 24046) - which one should i buy? i will mainly use it on the mill FF230 and am more interested in the more heavier, stable (all-steel) and precise device, that stepless feature of the rotary table 24046 isnt that important. maybe others can help me with their experience? i also wonder why 24044 is significantly more expensive than 24046. very good video btw thx

[@oliviersibaja2414]

Saludos desde Costa Rica

[@paullehmor982]

Just some speculations about the mounting holes: The Proxxon PD250 spindle has two sets of screw holes: four M4 for the 4-jaw chuck, and the collet chuck, and three M5 holes for the 3-jaw chuck. The cross section of three M5 screws is 17% larger then the cross section of four M4 screws. Also, a larger allen key can be used for M5. Is there any particular reason to use four M4 screws for the backplate instead of three M5? Could three screws for the backplate and four for the chuck cause more vibrations? It is clearly less symmetric. More, if using four M4 screws, would a radial line up of the M4 and M8 screws be better or worse than orienting them in angles in between? I believe any flex in the backplate would cause less vibrations if the screws were lined up.

[@AdventureswithaVerySmallLathe]

Obviously the two hole patterns are there so that the screw holes pass through the 3 and 4 jaw chucks without interfering with the jaws. When I came to make this back plate, I just used the 4 hole pattern for the 4-jaw chuck without really thinking about it any further. You're absolutely right that this backplate could have used either pattern without any issue, and could even have used both to get some extra holding at the expense of more effort. Of course using all 7 holes would mean the backplate only had one correct orientation, but that's actually an advantage when it comes to getting the best concentricity and balance. It would probably be better intuitively to line the M4s with the M8s I suspect. I avoided it because I thought the wall between the holes was a bit thin, but at 2mm that isn't small enough to be a concern. Thanks for your thoughts, it's interesting to think over what pattern would be better.

[@paullehmor982]

@@AdventureswithaVerySmallLathe You are right, the difference between the two bolt circle diameters is too small for the screws to be lined up safely. It would probably constitute a stress riser on the material. Yesterday I realized why the 3 hole screw circle is actually out of the question. It is smaller, less than 30 mm (the 4 hole circle is 34 mm). It would narrow the through hole in the backplate/chuck assembly. For a 80 mm chuck it is normally around 22 mm. It is very handy to have this wide through hole all the way up to the spindle, so the backplate should have a through hole mathcing the chuck. I have just received a 80 mm 4-jaw from Arc Eurotrade. It is backbolted of course, but with only three M6 screws on a 66 mm bolt circle! When I ordered the chuck I took for granted there should be four M6 holes. My plan was to drill 6 mm holes through them, all the way to the front. Now only one of them is located between two jaws, but the other two are too close to their nearest jaws to be drilled through the body. What to do? I drilled through the first and made three additional holes. Then countersunk them on the front side. I used a countersink mill intended for M5 to keep the holes on a safe distance from the outer chuck wall. Cast iron is surprisingly easy to machine. I used a 6.2 mm cobalt alloyed drill for this purpose. Then I made a backplate from aluminum. Not owning a bandsaw, cutting 80 mm aluminum round bar with a hacksaw was a bit tedious. I hope the backplate will stand the test. The motor is only rated 150 W so I don't think it has enough power to crash it. I spinned the chuck without the jaws and it runs smooth, without any obvious vibrations. Just finished a test run with some very hard and brittle 21 mm bronze round stock, and so far soo good. This chuck feels really solid. It was easy to dial in a workpiece in it. It is what I hoped to receive when I ordered the Proxxon 4-jaw a year ago. This new chuck is a magnitude better. The original Proxxon 4-jaw was probably designed for the previous PD230 lathe. The old 3-jaw chuck also had a similar skinny look.

[@pir869]

How much did the CRomolly bar cost,just a guestimate,i want to make plate for a 80mm 4 jaw and a 125mm 4 jaw for a clarke cl500.

[@MF175mp]

I use usually rivet drills for starting holes and for short holes. They're double end, short, super cheap and also have split point for easiest cutting and locating. Box of 10 in M35 cobalt HSS costs about 6€ and again they're double end

[@AdventureswithaVerySmallLathe]

I've never heard of rivet drills before, and a quick Google search isn't showing up much. Can you suggest a supplier or brand?

[@MF175mp]

@@AdventureswithaVerySmallLathe youtube doesn't allow me to post links, the comment just disappeared immediately. They're available on hardware stores, but I buy them from Aliexpress myself. The quality is no joke for a Chinese tool, they're all ground and I've drilled even 12.9 grade bolts with them in a pinch. Should appear if you search for example "double drill 70pcs" and hit cheapest first, there you can find a listing that has 7 different sizes of them and you can buy them either in a pack of 70 for all sizes which I did or individual sizes in 10 packs.

[@Boblebe]

Is it possible to replace the motor of this lathe with one with greater torque?

[@Roy_Tellason]

How much cross slide travel does that lathe have? I tried to look it up but the specs I'm seeing on that lathe don't seem to mention that for some reason...

[@ferrumignis]

Really nice job, it's a shame the 3 jaw mounts from the front when you can so easily move it between the lathe and dividing head. One thing I would say is that on these small machines sharp HSS tools work a lot better than indexed carbide, especially for very light cuts. Carbide inserts have a significant radius on the cutting edge so only works well when taking deeper cuts which these machines don't have the power or rigidity to exploit. Talking of rigidity, the amount of movement in the compound when you tightened up the tool clamp bolts was alarming, is that normal for the Proxxon?

[@AdventureswithaVerySmallLathe]

I'm certain you're right about HSS tools, but for many years I didn't use them simply because I didn't have anywhere I could set up a bench grinder. They need their own solid space, and somewhere where the grinding grit won't cause too much damage. For a long while I only had a few centimetres either end of the lathe, and had to be very careful about the amount of mess. I'm now learning a lot about the joys of hand ground HSS tools, especially how often they need re-sharpening, but also how beautifully a well made tool can cut. The think the compound movement was particularly bad because the compound gib had worked a little loost, and it took me a while to notice and tighten it. It's quite vulnerable to compound flexing which is why I'm hoping to fit a solid replacement toolpost soon.

[@3210gatorbite]

Love ya too!

[@Pushyhog]

can u link air canister spray bottle?

[@Infrared73]

Maybe it hasn’t come up yet in video. When you drill the 4 holes about 27 min in, you centre the chuck, but you never machined the outside of your material. Wouldn’t clamping on the un-machined outer surface potentially introduce an inaccuracy?

[@AdventureswithaVerySmallLathe]

Yeah, it definitely added some inaccuracy. I mentioned briefly that if I hadn't had to remove the part to get to the mounting screws, I would have avoided some re-chucking error. Unforauntely I just couldn't think of another way to do it.

[@Infrared73]

@@AdventureswithaVerySmallLathe Thinking on it as long as the surface is true the 4 jaw chuck will be fine.

[@jimsvideos7201]

Could you face one side, put the holes in for the spindle and do the rest from there? That seems like it could help with concentricity.

[@nightraidone9768]

Maybe you should try inserts for Aluminium, they are not coated but stikk Carbide and usually really sharp, so they should reduce the cutting force

[@AdventureswithaVerySmallLathe]

Quite a few people have suggested this, starting in the premiere chat stream. I'm definitely going to try it out; thanks for the tip.

[@ego73]

Agape! I love you too.

[@Smallathe]

All's well? Long time no see... (literally)...

[@AdventureswithaVerySmallLathe]

I'm good, but totally swamped by the process of moving into my new home and workshop. Updates as soon as I can sort them out! Thanks for checking in. :)

[@Smallathe]

@@AdventureswithaVerySmallLathe great to hear you are good! Congratulations on the new house and shop!

[@rodenreyes6320]

I noticed the steel shifted a little at the start of bandsaw cut...could that have caused the problem...no positive vise hold.

[@AdventureswithaVerySmallLathe]

Yeah, that almost certainly contributed, but honestly this bandsaw doesn't cut very straight, and I don't know how straight the end was when I started. There was always going to be quite a bit to clean up.

[@geoffwilson7572]

Hi, any information on the small bandsaw ?

[@AdventureswithaVerySmallLathe]

It's completely unbranded, but I really wouldn't recommend it. It was very hard to get it cutting acceptably, and it lacks many of the basic features which I would consider essential if I was buying again.

[@kundeleczek1]

Use brush to apply coolant. In my opinion, works better

[@AdventureswithaVerySmallLathe]

I used to use a brush, but I found it a bit sloppy. The needle tipped bottle let's me easily put exactly the amount of oil I want, where I want it.

[@kundeleczek1]

If you want to hit your dimensions by turning, use balance cutting.

[@AdventureswithaVerySmallLathe]

I would have to make quite a few serious mods to the lathe before that was practical.

[@joostgudde1989]

Nice video. What is the brand name of this 4-jaw independent chuck you made this adapter plate for?

[@AdventureswithaVerySmallLathe]

There is no brand name on it. It was listed on eBay as a 3.25" chuck with a low profile. The listing is no longer available.

[@joostgudde1989]

@@AdventureswithaVerySmallLathe Ok, thanks for your answer. I recently bought a Shobha 80 mm 4-jaw independent chuck (for sale at Hogetex and Chronos in Europe). I looks quite similar, however it has a DIN 6350 mounting at the back. Your chuck has 4 front facing holes/bolts. Or did you create those holes yourself?

[@AdventureswithaVerySmallLathe]

@@joostgudde1989 The chuck came exactly as I used it, with front facing bolt holes. I've found a similar listing from a similar named vendor. Try searching for '3.1/4" 4 Jaw Slim Steel Body Independent Chuck Light Type' from "fordeight_rotagrip_ltd" (KZbin deletes comments with links, even from the channel owner)

[@joostgudde1989]

@@AdventureswithaVerySmallLathe Thank you for the information and i have found the chuck with the given search description. I modified my Shobha low profile 4 jaw independent chuck by adding 4 extra front facing bolts. (See my youtube-video "Eps. 5: CNC EMCO Compact 5 Mill - Rotary Table & 4 Jaw Independent Chuck".) The chuck is now mounted with 2 circles of 4 bolts to the backplate. By tensioning the front bolts, I can control the backlash of the claws with respect to the chuck. This also increases the stiffness of the chuck, because a drawback of the light chucks is that they bend open when clamping a part.

[@raymondj8768]

Very cool lathe is it a jewelers lathe ?

[@AdventureswithaVerySmallLathe]

No, it's a light hobbyist engine lathe. It could certainly be used for some types of jewelery work.

[@RolfAnderssonLMY]

Love U 2

[@vukpesic1344]

when will you release a new video about chinese mini leathe or emco unimat?

[@AdventureswithaVerySmallLathe]

As soon as I've done making them. I have one of each in production. Bear with me; moving house is very tough, and I've done it twice in the last year already. Last move coming up, then I'll have a proper workshop and office again.

[@vukpesic1344]

@@AdventureswithaVerySmallLathe Oh thank you im so excited!

[@johnfritzel9833]

I am surprised you didn't opt for a smaller file at 32:10 ....Nick !

[@AdventureswithaVerySmallLathe]

The lathe is a long cut lathe file, which works well for parts running on a machine at a faster speed than you'd use when hand filing. I haven't been able to track down a lathe file in a smaller size.

[@colemine7008]

can't wait!

[@stockstergates4061]

proxxon pd250 four jaws chuck, not only expensive but also have lots of flaws, hole on the track and even on the screw

[@Mainswitch55]

46:17 that tool needs much less rpm!!

[@paullehmor982]

The Proxxon original four jaw for the PD250 is a real disappointment, don't by it! The jaws are too thin and dig into the material. It is poorly constructed overall. Normally the jaw lead screws have acme threads, but not on this. The lead screws are kept in place longitudinally by the jaws and follow them out. This makes it tricky to reinsert the jaws as they have to be fitted together with the screws. It is very easy to jam the ridge in the bottom of the jaw that grips into the groove in the lead screw. The usual method to lock the lead screws into place is by four guiding cylinders inserted from the back of the chuck body. With no lead threads in the bottom of the jaws, there is simply too little material to handle the tightening forces. I doubt any parts are hardened. IMHO, this product is ridiculously overpriced.

[@AdventureswithaVerySmallLathe]

Thanks for the advice! It's really disappointing that Proxxon didn't make sure the 4-jaw matched the quality of the 3-jaw, which is really good. Other comments have hinted similarly, but this is the most complete write-up of why it is to be avoided. Thanks again!

[@paullehmor982]

@@AdventureswithaVerySmallLathe Thanks to you too! I have learned a lot from your videos. The granite base plate is a great idea and works really well. I recently added 20 mm thick aluminum blocks to elevate the lathe a bit. Now it is much easier to clean up. I have tried a long list of improvements, including: Thrust ball bearings for the lead screw, pressure nuts (very tiny) for the lead screw and the cross slide, a new lockable knob for the lead screw engagement, ball bearings for the stepped belt drive in the gear box, wider nuts for the gear wheel screws, an round cap with through hole for the gear box door (so the door can be closed over the collet chuck drawbar screw head), packing the saddle cavity with shims and locking it together with the steel plate below (the stupid grub screws simply didn't do the job) ... and probably more coming. My main complaint about this lathe is it's "sandwich design". The saddle and compound base are made from cast Zamak (zink alloy), and in between some steel components. I wonder if any third party provider has considered to make an upgrade package? The whole machine lacks stability. One day it works perfectly well, the next something bad happens and it starts to chatter without any visible cause. The last weeks I got spiral groves when I faced a round stock, no matter which tools I use. I just don't get what the problem is. Maybe the main spindle bearings are loose? If I could host a bigger and heavier machine it would for sure be on it's way already! 😅

[@marcellofois6367]

Un tuo video di 28 secondi, per molti, sarà una istigazione al suicidio.. 😄

[@robertbutler8004]

To me that lathe is only good enough to work with plastic!!