For anyone doing this, It may be a lot easier to just use brass tapered pipe thread plugs like 1/4" or 3/8" NPT and tap then shallow, so they don't intrude deep into the case. If they do intrude at all, just file them down as much as needed. (If your in north America and don't have a mill to cut down the 5/8-18 plugs.) I just ordered the angular contact bearings for mine, and ran across your video. Thanks for putting it up. The speed control chart and dial control backplate is a excellent idea as well!

Dr. Jim. Great video ! I was going to purchase the roller bearings for my ( haven't received it yet } 7x12 from HF. Your video has better informed me of the better purchase . Thank you ! Also , the grease ports are great. Looking forward to watching all your vids. I like your style . Great work !

I’ve just purchased 2 angular sealed bearings from arc euro trade for £21. Thanks for you great update.

Nice video Jim - appreciate you taking the time and clear explanation for this MOD.

@francescozambuto1713

3 жыл бұрын

I have no idea why you would make such a reference to my comment, it's just an exchange of ideas, and I firmly state there is substance to what I express. Good day, Sir.P/S the solution is making a grease port.

@mlimey

3 жыл бұрын

francesco zambuto - I have no idea what you are referring to - I am simply complementing the producer of the video.

@francescozambuto1713

3 жыл бұрын

@@mlimey Please be so kind as to accept my sincerer apology for having misunderstood the intent behind "MOD". Please do have a nice day.

@mlimey

3 жыл бұрын

francesco zambuto - No worries - 😀 “MOD” is short for modification.

@francescozambuto1713

3 жыл бұрын

@@mlimey thank you

I fitted angular contact bearings to my lathe. The headstock is the same as yours. I no longer use the gears as i run the lathe vi a 3/4hp 3 phase motor and vfd. The gears are still in the headstock, but are locked in Neutral as the spindle is now driven directly by the motor. The bearings have stood up well and have been in about 3 years and still seem fine. I check the preload occasionally but they have not needed adjustment so far. I have a lot of projects awaiting my attention, but lack of time and cold weather means i am not spending a lot of time in my mini workshop at the moment. I have the same mill as you as well and the larger x2.7 mill as well, also a slightly larger lathe than yours, All of which get used. Keep up the good work you have a good channel.

much easier if you put the shaft in the freezer for an hour , doing field service we use dry ice

Very Nice Job! I am copying your design, Implementation. I too had bought the tapered roller bearings from Timken and realised the same and then bought the angular contact bearings. I just wasnt happy running the tapered rollers without an oil bath or way to grease them. Nery nice work sir. Now I am off to find 5/8 x 1/2" fine thread headless allen bolts.

5:34 i did the same holes with my WEN 7"X12" mini lathe to lubricate the new steel gears with liquid grease WURTH LPC200, and works very very good.

It sounded like you ended up like me with the metal gears. Not only are they noisier they seem to have more backlash that makes it even noisier yet. LMS sent me another set and still a lot of backlash. I used the same sealed bearings and did worry they seemed to press in harder. In the end I had to add a steel washer before the first nut because I ran out of threads to preload. Bearing seats may just have been a little deeper in my lathe. The bigger grease plugs look like a better idea than oiler ports I've seen that oil just runs out of the bottom of the headstock. I found it easier just to install a tach with digital readout. The last fix I need is a better way to keep the tailstock in alignment than the original flat plate keeper.

Excelent video. Thanks

Very informative. Thanks

There different types of grease, just thought like to help and works very very well, motor bike chain have this spray that it's very stick as motorbike chains need this type of grease. There great on the gearing as it doesn't fly off the gears and bearings and for shore no mess.

Wise choice on the bearings.

I installed a set of sealed angular contact bearings but replaced the plastic spacer between the bearing and the nuts. The plastic spacer will deform over time and increase the backlash in the spindle. Now that you have the lathe back together it would be an easy task to make a steel spacer and install it in place of the plastic one. I tried the steel gears in drive train and had the same excruciating noise your lathe has from them...very poorly made gears...went back to the plastic gears and have not had any trouble with them (lathe is 39 years old).

@tomt9543

Ай бұрын

My feelings exactly on the metal gears! Would never do it again! I put them in a Grizzly G0765, and was greatly disappointed by the increase in noise. I quickly decided that if I ever took the headstock off, plastic gears would be put back in! After buying a Harbor Freight 7X12 (online order only) mini lathe and happy with the quieter operation, I sold the Grizzly! Lesson learned!

Wonder where you got your metal gears I got mine at LMS and even after a second set they had way more backlash than rhe nylon originals. Just a lot of noise and affect cuts more. The weak part is the belt and plastic motor pulley. Such a pain to keep the belt tight. Tear everything down to get to the motor bolts.

Great Video! Thank you for putting this up! I have been wanting to do the same to my mini lathe, with the bearings. The pressing scenes are making me a tiny bit nervous about it now, though. Was the pressing on and/or off very difficult or tight? It sounds like it might be on the video. I don't even have a press. In comparison, installing tapered roller bearings looked much easier on some other videos that I have found. But I really wanted to go with the sealed angular contact ones.

@DrJim-zh8je

3 жыл бұрын

It is easy as pie with a press. But be sure to press on the races, NOT on the seals. You can see how I built a press in my first video about the mini mill. It is true that freezing the shaft (as suggested by gary above) to shrink it will make it easier. But if the inner race is properly made, it should go on and off easily with a press. You will only need something like a 20 ton press to work on something like an automotive differential. Years ago I actually rigged up one of those to do just that.

@francescozambuto1713

3 жыл бұрын

I think the other is better this way Dr. Jim added ports can be used to maintain the gears bearing and keep things a-okay. However, as food for thought, I would consider a waist port used when cleaning the inside out the old grease can be liquified and it will come out of the lower port; the positioning of the waist port is most important, under the box is a good place. What you think Dr. Jim.

@ET-cj8jo

2 жыл бұрын

@@francescozambuto1713 you mean waste, not waist.

Put a hose clamp on your grease gun coupler, adjust it so it will hit the case and not allow the coupler to contact the gears. Then pump away.

@DrJim-zh8je

3 жыл бұрын

As I showed, It is better to let the gun contact the gears while they are not moving so that you can really get the grease in between the teeth all around. You will find that if you try to do it while they are turning the grease really doesn't stick well and ends up at the bottom on the bed. Squirting oil will get all over the gears, but it won't stick as well as grease.

if you taper tapped the thread then it would get tighter and make a seal to :)

@DrJim-zh8je

3 жыл бұрын

They haven't budged yet.

Could you share the name and/or where you purchased them so I could try this mod? Thanks, excellent video!

@DrJim-zh8je

3 жыл бұрын

The only decent price I found was with a British company. I don't remember the name. Try to look there.

@charliedaniels5575

3 жыл бұрын

Arc Eurotrade in the uk sell the angular contact bearings. Part number sc3-1-ac. Web site arceurotrade.co.uk

Sealed angular would be nice, a small rat tail file made quick work of the thickness difference on the plastic spacer making about 3/32 room for the key. felt goes a long way to seal the bearings and some aero shell clayed grease. Not to mention a 5000lb vehicle goes 100k miles on a single lube session so It’s highly unlikely it would ever be an issue. But we’ll see. YMMV. Now to get some gib strips that don’t suck…lol

I would like a little advice, out of all the 7x14 mini-lathe, keeping in mind precision and no Teflon gears, which lathe would be the best one to buy with your hard-earned money?

@DrJim-zh8je

3 жыл бұрын

I would suggest going right to Little Machine Shop .com . Or maybe Grizzly. LMS will cost a little more, but it would probably cost as much to bring the cheaper stuff up to snuff. If I had known about LMS, I would have avoided Harbor Freight tools. I have had the mini mill teeth on the gib levers crumble on me and the Z axiz column stop snap apart on me. Those levers were the first things I had to replace with my own mild steel design (an allen cap screw with a lock nut allows adjustment for routine use). I am convinced that the steel castings "they" make are NOT done with metal properly fluxed, so the metal is too oxidized and therefore weak and or crumbly when strained. Getting something better is worth the cost.

@francescozambuto1713

3 жыл бұрын

@@DrJim-zh8je I am grateful for your advice and will look into it. Your right, one gets what they pay for. I also believe that even when one pays extra nowadays with things as bad as they are in the end they still get shortchanged. As a personal note, please do not be offended by anything thing I had said (only an expression of good faith thoughts on probabilities) I can assure you. I am most grateful to you for taking the time to create your videos and share them with us, thank you, Dr. Jim.

@ET-cj8jo

2 жыл бұрын

@@francescozambuto1713 "Your right, one gets waht they pay for" .... should be : "You're right, one gets what one pays for." Just trying to help ...

@kendonahve924

Жыл бұрын

@@ET-cj8jo give us a break! Take your lectures to some other forum.

im sure the bearings are 'better' considering the inherent other shortcomings of a small lathe anyway.. the regular bearings will 'preload' also, it just has to be precise, bet you didnt know that ... and metal gears in likely most situations for the hobbiest have exactly zero to do with strength or wear characteristics and are not an 'upgrade' per-se.. plastic is actually preferred so your entire drivetrain isnt nuked by a user error, but no, the 'advantage' of a metal gear set are the odd tooth count gears in the set allowing approximation for threads your leadscrew isnt cut for ...

@ricksweetser1683

3 ай бұрын

Standard ball bearings are not designed for axial loads...

7:01 looks like the main shaft has had some hammer getting the old bearings off!

@DrJim-zh8je

3 жыл бұрын

Wrong. No hammer was used, only the press and an appropriate fixture. See the previous video on the mini mill to see the fixture used for the chuck-end bearing.

@leaflee2066

3 жыл бұрын

@@DrJim-zh8je LOL, okay I guess all that galling was there from the factory! and just so you know in the UK "had some hammer" is a colloquialism for been treated rough, not always the literal meaning hit with a hammer!

@DrJim-zh8je

3 жыл бұрын

@@leaflee2066 Thanks. Next time I stub my toe, I'll say that it had some hammer.

Did you notice any improvement? Thanks

@DrJim-zh8je

3 жыл бұрын

No detectable side play for the chuck. But real cutting improvement would have been hard to detect without first tightening up the saddle and slides, which I have done. See the next video on how I did that.

I have a question I was hope you may have answered regarding the bearings (pressure) I am thinking to myself what if the sealed ones won't take the pressure produced by the speed of the axial attached to the chuck, I am assuming it will turn at about 2, 500 a minute or so that would create a lot of pressure within the housing of the sealed bearing and perhaps that's why sealed ones were not installed of course this is just coming out of someone who is not certified speaking (writing). Could you fill me in on this issue? can anyone give me an answer, will the seal bearings leak once the chuck is turning at a high speed are they made for taking high speed?

@DrJim-zh8je

3 жыл бұрын

I don't think 2500 RPM is so great a demand on these bearings. An online search may find data to answer your question. They already are going to have a preload, for which they are designed. I assume that what you mean by "axial attached to the chuck" is applying pressure from the front of the chuck, not a side load. I think that applying enough pressure in that way to damage the bearings would be abuse of the machine. Cutting a piece with that much pressure should not be necessary. Do I understand you correctly? If you have chucked something lopsidedly, (perhaps in a 4-jaw chuck) you will have to go slower. In my opinion, if the seals leak, the manufacturer has failed.

@francescozambuto1713

3 жыл бұрын

@@DrJim-zh8je What I am trying to say is that spinning of axel may produce pressure within the sealed bearing; the bearings will cause the grease or lubricant to expand creating excessive pressure it was not designed to withstand therefore cause the seal to leak and dry out. This may cause severer damage to the bearing, axel, and so on. I would like to remind everyone, I am not a certified engineer, machinic, and so forth, I just had a similar problem and so I am sharing my thoughts.

@francescozambuto1713

3 жыл бұрын

@@DrJim-zh8je No Sir, I did not explain myself precisely, no undue force from the side, high speed will eventually dry out the packing and the bearing will have to be changed, that's the way I see it. It's like the Teflon gears, they will crack and have to be changed not unless you can make your own before they crack and do an upgrade. Perhaps the solution may have been to create a grease port. In any event, I think the bearing the lathe came with are low grad ones they would have had to be changed with time, how long don't really know. Let's face it the Lathe is not first quality and the buyer gets what he/she pays for, so that's the bottom line. Thank you for sharing your video with me and for giving me a response, it was nice of you.

@DrJim-zh8je

3 жыл бұрын

@@francescozambuto1713 Thank you for clarifying. Have you seen a case where heating of the grease caused this to happen? Or centrifugal force? Was your "similar problem" with angular contact bearings?

@francescozambuto1713

3 жыл бұрын

@@DrJim-zh8je Seen it in a Grinder, the ball bearings are pre-packed and specifically sealed to take the heat and a load of pressure. But, what happens is that the packing gets dirty, dry, and harden and with that each bearing begins to wear down, causing damage to the housing. This is what I believe may happen with the sealed bearings, and if a bearing pops out and flies around in the gearbox it may cause a problem, imagen that. Of course, I could be wrong, the lathe is not a grinder and there is more space in there which will allow the bearings to cool down better. Ho, wait, they are sealed bearings which will contain the heat and with time the packing may dry as I suggested and you may have to change them. Only time will tell. What say you?

The interference between the shaft and bearing should be reduced, otherwise there is no way for a right preload on the bearings if they are too tight with the shaft.

@DrJim-zh8je

3 жыл бұрын

Are you saying that the inner race stretched that much? It went on with typical pressure for a bearing.

@Rheasound

3 жыл бұрын

@@DrJim-zh8je no, stretch the race probably but is not the issue here. This is like a car wheel. The bearing should slice on the shaft snugly, so when you preload, the force applied by the nut is the same force on the bearing. If the bearing are too tight with the shaft there is not control of how much preload you are applying. Hope this help, and I really like your videos, thank you for your time and knowledge.

@DrJim-zh8je

3 жыл бұрын

@@Rheasound Tightening the nut did take up initial slop, so the preload DID work. No undue force was needed. I got no sense that the bearing was "too tight" on the shaft.

Do you have the model or part number on the bearings? Thanks

@DrJim-zh8je

3 жыл бұрын

see below. 7206 RS .

@DrJim-zh8je

3 жыл бұрын

Oops, 7206 2RS. Sorry.

@rupertsuzuki3376

3 жыл бұрын

I ordered FAG 7206-B-XL-2RS-TVP

Where can I buy those metal gears friend?

@JohnBrown-hx5oy

3 ай бұрын

Little machine shop in California

like the vid can you tell me the angular contact bearing number please

@tomt9543

4 жыл бұрын

Go to “Little Machine Shop” site. They have all the stuff to maintain & upgrade these Chinese mini lathes regardless of what brand they are.

@williamcombs6560

4 жыл бұрын

@@tomt9543 look and called them do not have the bearing what is the # on the bearing? i like the seal part of it

@DrJim-zh8je

4 жыл бұрын

@@williamcombs6560 The bearing number is 7206 2RS. The 2RS means that they are sealed. It is 30 x 62 x 16 mm. LMS only has regular ball bearings for this lathe, or else I would have gotten them from them. I had to order them from the UK and ... WAIT ... to get them at a reasonable price. From the USA they may be high $. BTW, to set the preload, pull up and down on the chuck. If there is any play, tighten the lock nuts. When the play stops you are there.

@williamcombs6560

4 жыл бұрын

@@DrJim-zh8je thanks i see waht you mean just got a set for england just have to wait now

@jimmyhawkins7696

3 жыл бұрын

Thanks for your video im buying this model used helpful in knowing ahead how to upgrade and parts to do it.

You're right Jim only time and regular use will tell if the sealed bearings will last without maintenance. In my opinion they will not last and you will have to take them out again to install new ones.

The grease ports wont do much for the sealed bearings.

@DrJim-zh8je

3 жыл бұрын

They were not meant to.

@francescozambuto1713

3 жыл бұрын

@@DrJim-zh8je Hi, but I do think the sealed bearing will slow it down, adding workload to the engine. The least resistance is the best enjoy your lathe Jim, I think you put a lot of work in making your videos to share with us, thanks.

@PatriotPaulUSA

3 жыл бұрын

@@francescozambuto1713 You know these lathes came from the factory with cheap sealed ball bearings. He is replacing them with Angular Contact ball bearings, which are designed to take some side load. Regular ball bearings (like the factory ones) are Not made to do this, but, they are very inexpensive. Communist China manufacturers don't care if these last more than 30 days so the ball bearings are used! They are only made to take a radial load. The angular contact bearings can take a fair bit of Axial Load. You can look up those terms to see what I am saying. Tapered roller bearings are also designed for radial and axial load force but they must be kept constantly greased. That is near impossible in this machine without disassembling it. I doubt there is much difference in these angular contact bearings, versus the regular ball bearings it came with, as far as resistance is concerned.

Сверху надо было вырезать квадрат

Way too much woffle .......Get to the point !