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Are 125mm Diameter Chucks Too Large For The Myford ML7? 

Steve Jordan
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In this video I prove that the larger diameter full length chucks are not so good as the 100mm chucks on my Myford ML7. I have found that I get a lot of chatter or vibration when using the larger chucks most probably caused by radial free-play overhang, combines with movement on the spindle thread. I show some tests plus a bit of turning to show what is happening.

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22 июн 2021

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Комментарии : 64   
@grahameblankley3813
@grahameblankley3813 3 года назад
Isn't it good to see Steve Jordan back!
@79_air-arms-shooter29
@79_air-arms-shooter29 3 года назад
I give the thumbs up before I’ve even watched Steve’s vids. Always very interesting
@JohnsOrganWorks
@JohnsOrganWorks 3 года назад
Great to see you back again Steve. I don't see how the modest additional overhang could explain the movement increasing that much (2 thou to 7 thou). Can only conclude that the larger backplate must be a looser fit on the spindle.
@johnrussell6620
@johnrussell6620 3 года назад
I might offer that if the plate was made of A36 steel vs AR400 steel vs cast iron vs plastic, there would be a different amount of flexure due to the various material strengths. Can you see and measure your chatter marks? If they measure 0.007, then this may be your problem. Also #1, the cutter is further from the center of the main bearing, creating a longer torque arm, as the cutter applies force to that bearing through the work, it bends/twists the spindle more easily. Also #2, How is the chatter if the work is supported by the tailstock or a steady rest? Extra support at that distance may resist spindle flexing resulting in less chatter. Also #3, How is the chatter of the 4" chuck if the work is being cut at the same distance from the main bearing? Also #4, the extra weight of the 5" chuck should create additional vibrational dampening effects, unless it's own "out of balance" characteristic may be causing minute variations in cutter speed/progress through the work...as the out of balance causes the work to flex down, and then flex up, the actual cutting speed minutely increases and decreases as well. Good luck on your research!
@plang42
@plang42 2 года назад
It's also the weight of the bigger chuck, it's probably also making the whole spindle flex and vibrate 🤔
@MrLukealbanese
@MrLukealbanese 3 года назад
Lovely to see you back Steve. Another great video.
@robbishop2694
@robbishop2694 3 года назад
Hi Steve Good to see you back as always a very interesting video
@ianpendlebury3704
@ianpendlebury3704 3 года назад
Good to see you back - it's been a while.
@TheKnacklersWorkshop
@TheKnacklersWorkshop 3 года назад
Hello Steve, Firstly good to have you back on our screens.... An interesting video, Burnerd made a 6" SLIM 4 jaw chuck for the Myford to reduce the overhang and weight so clearly they thought there was a problem with bigger chucks... I will check back in a few days to see the other comments from your viewers... Take care. Paul,,
@donaldnaymon3270
@donaldnaymon3270 3 года назад
Great video. Good demonstration. Definitely found the issue. Thank you for sharing.
@hansslagter5366
@hansslagter5366 3 года назад
I suspect that the spindle is flexing. My sugestion is make a tight fitting mandrel to Place in the bore to make this spindle more rigid.
@SteveJordan
@SteveJordan 3 года назад
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@reamer1363
@reamer1363 3 года назад
Great explaination, I have found that jaw flex can do the same thing and I use a small narrow slip of paper towards the end of the jaws to fix this , pretty crude I know but works for me. I will now check my boxford as you discribed . Thanks.
@BartolomeoPestalozzi444
@BartolomeoPestalozzi444 3 года назад
Nice to hear (and indeed to see!) from you, it's been a while from your last video 😉
@stephenmale4492
@stephenmale4492 3 года назад
Hi Steve. Good food for thought. I get a lot of chatter on my 9a southbend. The 3 jaw that came with it is significantly bigger than the 4 jaw. I’ll look into this. Thank you👍
@pickwizard-aka-Stevie
@pickwizard-aka-Stevie 3 года назад
Well worked out Steve
@neelsscheepers8841
@neelsscheepers8841 2 года назад
Thank you Steve now i Know why my Myford ML7 chatter on deep cuts even after rebuilding the lathe.
@JHowell-kt5gx
@JHowell-kt5gx 3 года назад
Good to see another video from you Steve. I’ve copied a number of your ideas for my Myford and I was debating getting a 5” chuck and I think I’ll just stick with my 4” now.
@SteveJordan
@SteveJordan 3 года назад
Hi Thanks, I still use mine a lot but only when turning with a live centre up. Plus if I'm doing milling or drilling ops, but if you don't need a bigger chuck it is best to stay with the 4" like you say. Regards Steve
@petemacrae5982
@petemacrae5982 3 года назад
The Chuck might need a balance. I've noticed most factory supplied chucks with a lathe, have balancing holes drilled in the rear of them.
@bmotowerks
@bmotowerks 3 года назад
I found the same! Thought it was a bearing/spindle issue. I found different tool tips can improve or make it worse.
@MrArray1967
@MrArray1967 3 года назад
Long time no see 🙈 I wonder just a little bit, have you compared the play or movement of the chucks relative to their back plates? Or the runout of the 125 mm chuck vs. its backplate? Any misalignment combined with the longer hang out could be the cause and not the hangout itself?
@MegaLostOne
@MegaLostOne 3 года назад
I'm going to go another route with this, it was mentioned that the self centering 4 jaws maybe out by another comment and this may be the case HOWEVER I would try the exact same cut with a live center also and see if the chatter ends or lessons a large degree, if it does my theory would be an out of balance chuck and that the bearings in the Myford ML7 don't have the ability to control the chuck that far out of balance and would only worsen at higher rpm's, like using a 4 jaw independent chuck and having the object off center you would have to drop the rpm in order to keep the centrifugal forces from taking over. You could test the chuck for out of balance easy enough (do a search on balancing a watch staff) and make something up of your own to test (ground bar and two parallels), it doesn't have to be exact since you are just trying to see if the same side always drops and you know you have a heavy side on the chuck. IF the chuck ends up being out I would probably try to see if there was a local shop that balances drive shafts that could try and bring the balance in a little closer on the chuck for a reasonable price. I have a 6" Atlas lathe and am all to familiar with the weaknesses of the smaller lathe and I have actually ordered a larger lathe now that my skills have grown, BUT having to work around the limitations of having a smaller lathe has taught me how to improvise so there are pro's and cons.
@jmunozar
@jmunozar Год назад
Hello Steve, many thanks for these videos!, I am learning a lot; what quick tool change is the one you are using in this video?
@Telectronics
@Telectronics 2 года назад
Oh nice content ! I guess you saved me some problems with this video. My lathe also comes with a 100mm chuck and I wanted to use a 125mm 4 jaw chuck but I went with the 100mm. They are pretty cheap on banggood :) I have a question thou. Does it make a difference how I mount my chuck at the backplate ? Because then I have to remember/mark how it was on there before.
@johnsmith-wl8dp
@johnsmith-wl8dp 2 года назад
hi Steve, i have the same problem with the 4 jaw selfcentering 5" chuck which i bought from RDG few years back on my myford S7. when i use 6" dia. 4 jaw none selfcentering Burnard chuck i have no issues at all. i enjoy watching your vids.
@wk7060
@wk7060 2 года назад
Many people say no to the idea, but I thought about trying aluminum for a chuck backplate, just seem like the softer material could act as a cushion to stop the vibration/chatter transfer. Any thoughts?
@andrewbird3691
@andrewbird3691 3 года назад
Are you sure that your 5" chuck is seating properly on the backplate? I'm thinking that perhaps you have a sharp corner contacting an internal radius or suchlike. I thought the 2 thou play at the rear didn't scale up linearly to 7 thou at the front indicated that there was some flexing in the chuck mounting.Hope it helps, Andrew
@shaunwhiteley3544
@shaunwhiteley3544 3 года назад
Have you tried the 125 mm Chuck on the Chinese mini lathe? Was going to get one but funds dried up. With me measuring it, it should fit. Cheers
@john2478
@john2478 3 года назад
Steve I have just tested 2 lathes I have that have 125mm 3 jaw chucks. One is on a Boxford Lathe and the other on a very old Lorch 5" lathe I have just finished renovating. The Boxford lathe has taper roller bearings at the front and the Lorch has polished hard steel bearings running in cast iron. If I take a cut over 2.2mm deep i.e. 4.4 mm measured on the diameter on the Boxford lathe it is fine and cuts ok. If I make the cut deeper it chatters. I tried the same on the old Lorch lathe and with more overhang and a much thinner spindle I was surprised that would cut 2.2mm deep without chatter if the feed rate was low. The spindle in the Lorch has cone bearings at the front and a ball thrust race at the rear bearing. I suspect the problems with the ML7 chattering is more to do with the plain bearing at the front and the difficulty in adjusting it. The 'Better' Myford 7 lathes have angular contact bearings I believe as the front bearing. I am sure I saw somewhere on the Internet that a ML7 has been converted to such bearings but I cannot find it. John
@SteveJordan
@SteveJordan 3 года назад
Hi John, yes the Myford Super 7 has much better bearings than the ML7. I put a brand new spindle and bearings in mine a few years ago. Although I don't like the type of split bush bearings. Also I don't particularly like the screw on chucks either. It is a nice lathe though. I put heavy duty angular contact bearings in my Chinese Mini lathe which are excellent, although it is let down by the weak carriage and compound slide type. It's all very interesting though. I have learnt so much about both lathes having them both. Regards Steve
@eoinm0nvk110
@eoinm0nvk110 3 года назад
I see exactly the same.. Haven't used the 100mm for years, much better thank you
@paulklasmann1218
@paulklasmann1218 3 месяца назад
What would be the best recommended 3 or 4 jaw non chinese chuck to use on a Super 7 Small Bore lathe?
@kevinmartin7760
@kevinmartin7760 3 года назад
I think there is something else going on here besides the larger stickout, though I can't really be sure what. All else being equal, the deflection you see with that static lateral load test should be proportional to the distance between the front bearing and the measurement point (there will also be deflection due to rear bearing play, that would be proportional to the distance to the rear bearing and so would vary less with position). Yet with the larger chuck you are seeing more deflection even when you measure at pretty much the same location as you did with the smaller chuck. Also, due to the dead weight of the chuck I would expect to see most of the deflection when you pull up on the rod, and that its unloaded position would be at the bottom of the range of play, yet it seems to deflect more with downward force that with upward force. It is difficult to tell from your test what is play in the system and what is elastic flexing of the system.
@reaper060670
@reaper060670 5 месяцев назад
The Myford ML7. Is it hard to get one of these in Europe? I like the look of these Lathes and I'm trying to get a decent sized lathe but thee would really only be for lighter work?? Ok so they could always do certain types of jobs I know and they're a well thought of Lathe from what I have seen online but my main question is are they expensive to buy even with a fair bit of work needing doing to one??
@ctrlaltdude
@ctrlaltdude 3 года назад
Hey Steve, good to see you're back! I was afraid you were slain by the virus.
@SteveJordan
@SteveJordan 3 года назад
Hi Hans, Thanks....No it wasn't the virus, I like a rest from engineering sometimes. Regards Steve
@dickmick5517
@dickmick5517 Год назад
I would like to see on test on the spindle and another set on the chuck as close to the inner diameter as you can get. May prove if the issue is in the spindle fit or the movement is all in the bearing clearance.
@SteveJordan
@SteveJordan Год назад
Hi Dick, I found out in the end it is the chuck mount only. The original Myford chucks are fine, though. The spindle is perfect as well, without any noticeable movement.
@davidbawden6567
@davidbawden6567 3 года назад
The back plate I think is the problem, given you the extra lenght. Just measurded my 150mm adjustable 4 jaw chuck, from the back of the chuck to the tip of the jaws= 67mm. The 100mm = 74mm.
@davedunn4285
@davedunn4285 2 года назад
I am interested in your oil cup nozzle on your oil can mate
@gvet47
@gvet47 3 года назад
Interesting you did not use the long bar on the smaller chuck and measure it's movement. I assume the larger chuck seats well on the spindle? Larger chuck just magnifies the bearing clearance.
@stuartself19
@stuartself19 2 месяца назад
Can you compare your results with someone who has a newer model ?
@stevec8064
@stevec8064 2 года назад
I find the opposite to be the case. I get chatter with my 4 inch 3 jaw Chinese chuck but not with my 5 inch Burnerd 3jaw or my 6 inch Burnerd 4 jaw. I assume it is the quality of the chucks that makes the difference.
@Steviegtr52
@Steviegtr52 2 года назад
Hi Steve. Not sure if you have seen any of my video's. I have the Super 7B. The 3 jaw is a pratt 4" griptru. Superb chuck & very accurate. The 4 jaw as supplied with the lathe is a pratt, independant. But it is only 4 1/2" dia & 2" deep. I have had no such problems with either chuck. The one you have looks awfully deep. I guess much heavier than the ones supplied new. Regards
@SteveJordan
@SteveJordan 2 года назад
Hi yes they are deep and heavy. I have the original Pratt independent chuck as well so I use that mainly now plus the 4 inch three jaw chuck. I have subscribed to your channel.
@Steviegtr52
@Steviegtr52 2 года назад
@@SteveJordan Thank for the Sub Steve.I subscribed to your a long time ago. Keep up the good work. Regards. Steve.
@maxwinfield8388
@maxwinfield8388 3 года назад
I agree with John Barber. The increase in deflection of the 5” chuck is not proportional to the small increase in overhang. I suspect there is an issue with the chuck mounting, ie it is not solidly registering and there is some clearance at the joint.
@SteveJordan
@SteveJordan 3 года назад
Hi Max yes I think you are both right. I will only use them when I have a live center up from now on. Regards Steve
@reaper060670
@reaper060670 5 месяцев назад
your lathe was bouncing when u were bringing the bed away from the piece in the chuck. What type of bench or surface do u have the Lathe up on pal? Maybe some type of concrete blocks under a strong table top so u could somehow screw or bolt the Lathe to it might help also. The Lathe was flexing like mad when u ere moving the tool bed/rest/bed back along the ways.. Sorry if I am sounding stupid man but I saw ur Lathe bouncing up and down like it was on a load of springs.
@rpmunlimited397
@rpmunlimited397 2 года назад
If the chuck adapter is cast iron, you may want to make a steel replacement and see if the adapter is flexing. If the unit you are using is of unknown mystery metal, it may just not be ridged enough
@65cj55
@65cj55 3 года назад
I never thought it was a thing until i seen Winky's Workshop done videos on it, it's amazing, quite the opposite to what you would think, i would of thought, bigger Chuck more mass etc, but no.
@shane5809
@shane5809 3 года назад
You're comparing a 4 jaw self centering with a 3 jaw self centering, two different animals. If you compare the run out visually at 7:30 (4 jaw) and 10:23 ( 3 jaw) , You'll see the 4 jaw is way off center. I never use 4 jaw self centering chucks. Not saying that's your problem at all and doesn't explain your runout when indicating it, but well it's a thing to be aware of. The 4 jaw self centering will always find an axis when clamping down. You could also be experiencing runout in your backplate, maybe there's a burr in there or the register is off? The amount of movement you are getting when you indicate it just seems really extreme to me. You can visually see the whole thing move were the backplate meets the spindle, which seems like a fitment thing? I know the larger chucks have more weight and stickout and that's definitely something to be aware of as well, but I use a 5" 3 jaw self centering bison on my ML7 and don't get chatter or runout like you are getting. Maybe's it's a fit and finish thing as well? HBM VS Sanjou. I've never tried either of those before.
@ronbianca1975
@ronbianca1975 2 года назад
I swear I heard an Owl hooting in the background, do you start that early in the day?
@gillian9178
@gillian9178 3 года назад
This is why the likes of Sieg on their mini lathe only fit an 80mm chuck still, they say a 100mm chuck is to big & to heavy for those size lathes. Where as other Chinese mini lathe suppliers are now fitting 100mm chucks as standard now.
@darkcrusade5785
@darkcrusade5785 2 года назад
et si vous serrer plus fort votre plaque arrière sur la broche ? même résultat ?
@davedunn4285
@davedunn4285 2 года назад
Any recommendations on a quick change tool post Steve
@SteveJordan
@SteveJordan 2 года назад
Hi Dave The Dixon type are very good or the Chinese gib type, the AXA 250-000. I have both types. The Dixon is probably the best to go for as Myford even sell them. They are cheaper on eBay though. Regards Steve
@davidforbes6250
@davidforbes6250 2 года назад
Interesting.
@frederickbowdler8169
@frederickbowdler8169 Год назад
The chuck is bigger than the headstock no wonder.
@JohnDoe-pg7gt
@JohnDoe-pg7gt 3 года назад
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@malcolmtill
@malcolmtill 3 года назад
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@adamsblanchard836
@adamsblanchard836 Год назад
I'd try different types/size belt set up
@glennmoreland6457
@glennmoreland6457 3 года назад
Mass V diameter Weigh both chucks Steve... I bet 1" increase in ∅ returns an over 50% increase in weight...
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