#MT40

Making a 125mm chuck backplate for a Sieg SC4 lathe.......
I hope you find this video of interest.
If you can offer me any help or advice, please leave a comment.
I hope some of my videos help inspire others to venture into model engineering.
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Backing track credits......
Music: (intro) Water Lily by the 126ers - KZbin Audio Library
WARNING: Metal turning can be dangerous! I am not sure whether the methods I use are established ones, and I do not recommend them.
Please do not copy me without doing your own risk assessments!
You are responsible for your safety - not me!

[@jonsworkshop]

Hi Andrew, great result. Your hole won't really have been eccentric by 0.004, your issue will be squareness. As the drill went through it will have run off square slightly, the reamer will just follow the drilled hole axis. A tip to avoid this is either an endmill/slotdrill just under the reamer size following the drill, failing that, a boring head (as you dit it in the mill) assuming you have one, this squares the hole up prior to reaming. I would personally whip the chuck back off and bore it out to your headstock tube diameter so you can slide stock through. This will square up the hole, (still got your insurance policy) and allow you more freedom. Hope this helps. Excellent work. Cheers, Jon

[@learningturningmetal]

Hi Jon - many thanks for the advice. I must try to remember the endmill/slotdrill tip. I'll open up the hole today. Cheers Andrew

[@johnfox4691]

Great result and thank you for the video.

[@learningturningmetal]

Cheers John!

[@Mister_G]

A very pleasing result - well done. :) It looks like the adaptor moved after you started facing it off - you can see the centre hole running dead true when you start the spindle before facing at 12:28, but the hole is visibly running out when you start the spindle to cut the OD at 13:20. No harm done in any case. Thanks for the video.

[@learningturningmetal]

Well spotted mate.

[@markvenables4804]

Hi Andrew, might want to open up the central hole in the backplate to accommodate larger bar stock..... Nice well presented informative video... Thank you. M

[@learningturningmetal]

Thanks Mark - yeah there always seems to be another job! I''ll have a go at finishing it today. Cheers Andrew

[@rpmunlimited397]

I would agree with mark to open up the inside bore as large as possable, you will find a need for the extra room

[@CraigLYoung]

Thanks for sharing! Good job😊

[@learningturningmetal]

Cheers Craig!

[@mauserkk98]

Practice makes perfect, nice job .

[@learningturningmetal]

Thanks Nicholas!

[@daniellindholm]

Fantastic job! Got me really inspired!

[@learningturningmetal]

Thanks Daniel. Onwards and upwards! Cheers Andrew

[@TheKnacklersWorkshop]

Very nice wok Andrew, a pleasure to watch...

[@learningturningmetal]

Thanks mate!

[@ruftime]

Thank you Andrew! Waiting on my 8x16 mini-lathe to arrive, learning alot following your projects. Greetings from SoCal😎

[@learningturningmetal]

Thanks mate! I hope you have lots of fun with your new toy. Those mini lathes are quite capable little machines. All the best. Andrew

[@lwizzit]

Which one did you order? I’ve begun looking about myself.

[@garymucher9590]

Very nice fit in my book. You did that machining on the plate perfect. Thumbs Up!

[@learningturningmetal]

👍😀

[@MattysWorkshop]

Gday Andrew, great results, 3 tenths is as good as perfect mate, beautiful finish as well, throughly enjoyed watching, cheers Matty

[@learningturningmetal]

Thanks Matty - yeah I'm happy with the runout. I just hope the aluminium holds! Time will tell! Cheers Andrew

[@OL6162.]

Andrew As always good job.

[@learningturningmetal]

Thanks mate! 👍

[@daveswain8295]

Quality job & video as usual Andrew, I'm sure it will last you a good while with the amount if use it will get.

[@richardmeyer418]

Stunning work, Andrew. I have to admit, my stomach dropped when I saw the 3-4 thou runout with the centre rod, but it seems to have come out really well.

[@learningturningmetal]

Thanks Richard - yeah I just don't understand how that happened - especially when everything else looked spot on. Anyway, the end result seems OK. All the best. Andrew

[@jdmccorful]

Experience is a great teacher, likwise failure. I enjoyed your video, thanks.

[@learningturningmetal]

Thanks John - best way to learn is by your mistakes. Though it can be very frustrating when you think you have a rock solid method and the result ends up in the scrap bin! All the best. Andrew

[@pauls5745]

well done! I'll have to go back thru this when I get a 5" chuck. the Sanou 100mm 4 jaw upgrade was a bolt on from the 3" factory part. doing me well and I love it but turning bigger flywheels is a problem

[@pgs8597]

G’day Andrew. Well done, thanks for sharing Cheers Peter

[@learningturningmetal]

Thanks Peter! All the best. Andrew

[@daveticehurst4191]

Turned out great again Andrew. I see that you are still Fixated with 0.010" cuts, that seems to be your favourite number LOL. BEWARE next time, when you tried the first bore and the gauge fitted, you rotated it and it went TIGHT, that was because the aluminium was "Picking Up" and was galling and starting to seize. Apply oil film next time. You will probably encounter similar problems putting the plate on an off the spindle, with it wanting to grab, especially after running due to temperature changes. Apply a bit of Anti Scuffing Paste to the Ally recess or Copper Kote if you have any ( used on car brake parts ). Regards from Australia.

[@learningturningmetal]

Hi Dave - many thanks for the great advice as always. All the best. Andrew

[@2WHEELSor2WINGS]

Nice one. Strange but I have been doing something very similar this week for my rotary table. 😎

[@learningturningmetal]

Thanks Graham. I seem to recall I made one a while back for the rotary table. It definitely opens up more options for workholding. All the best. Andrew

[@richardboucher6904]

Andrew, I was just over at MrCrispin's channel reading the comments on his piston ring saga and I thought I would let you know that George Tremble's article was published in Strictlyic Magazine in 1989 in issues 7,8 and 9. The copyright is still in effect but the publisher can supply all issues of the magazine for $8.00 each US. Their website is @t. I used his methods to make the piston rings for my Friends Models "Tom Thumb" which is now totally worn out from running and is on loan in the current owner of Friends Models Live Steam museum in Beverly Massachusetts USA

[@learningturningmetal]

Hi Richard - many thanks for spending the time to provide me with the info. I did actually find that info last week. The payment information on the website looks really out of date, so I tried emailing them to see if they would take PayPal payments. I've not received a reply, so I guess that the publisher is no longer in business. I understand that the owner passed away a while back. If I get a reply I will let you know. I'm in contact with a few folk in the US and one of them offered to get the magazines for me and post them on. He didn't get a reply from the publisher either. I notice that the magazine content is copyrighted to Robert A. Washburn 1988 - 2001. Interesting that it stops at 2001. Wow - I've just looked up some pictures of the Tom Thumb. What a fantastic looking engine. You must be really proud that it's now on show in a museum. All the best Andrew

[@andrewdolinskiatcarpathian]

Job’s a good’en! 👏👏👍😀

[@ParsMaker]

nice work

[@learningturningmetal]

Thanks mate!

[@rallymax2]

Hi Andrew. If you want to dial out the runout you can turn down the aluminum boss register so it is 1 thou large. Then tap 4 holes around the perimeter with fine thread. You can then slightly loosen the m8 bolts, adjust the opposing grub screws and tighten it down again. Works a treat for dead nuts centering 3 jaw. If you’re interested I’ll find you the video of Robin Renzetti dialing in his for 10th work or some photos of mine. Edward.

[@learningturningmetal]

Hi Edward. Thanks for the tip. I checked out Robin Renzetti's channel but couldn't find the video. However I think I understand the solution based on your description. For now I think I will leave it as is, but at least I now know how to improve it if I need to. All the best. Andrew

[@richardboucher6904]

Another relaxing afternoon video for coffee time . I probably will never need to make a backplate for my 7x14 lathe because if the part is to big for the chucks I have on the machine I can go to my 10 inch South Bend lathe to work on bigger things but as I said your video's are so relaxing for my afternoon coffee break. Please keep them coming. Do you have a secret for getting the bolts in and out of the small space between the flange on the spindle and the headstock of the machine ? I also like your 4X editing with the whale swimming around.

[@learningturningmetal]

Thanks for the feedback Richard. I'll try to keep the videos under 30 minutes to fit in with your coffee break ha ha. Sounds like you have a cracking setup! Cheers Andrew

[@Stefan_Boerjesson]

Really well done! Great footage and editing. What was Your goal for interfacing and using a 125 mm chuck? Reversed jaws do give quite some range on the 100 mm chuck? The torque of a small lathe... will it be enough? I've also got a 125 mm chuck that fits my rotary table.. Face milling and reclamping gave me more of a roller coaster as I remember. Why not drill holes, counter sink and bolt directly to the mill table? To me it looks like several critical steps on the way but You clearly mastered them well.

[@learningturningmetal]

Thanks Stefan. In the past I've occasionally encountered limitations with the 100mm chuck - hence getting a 125mm one. I've not got any specific plans for it yet though. It should also open up some work holding options on the mill. Cheers Andrew

[@gb_engineer]

Good job and top tip using aluminium, I made an adapter plate for my collet chuck, I brought some really nasty high carbon steel, broke lots of index tips, lost of very hot chips but turned out ok in the end. You have to be very careful what and where you purchase stock - but found Noggin good.

[@learningturningmetal]

Thanks Andy. I'm not sure if aluminium is good for the long term, but time will tell. Cast iron is most likely a better bet. Thanks for the info regarding Noggin. Looks interesting and good value cast iron billets. Added to my bookmarks! Cheers Andrew

[@robertoswalt319]

Concerning the runout of the rod in the chuck, you might take another light cut on the back plate on the chuck side to open up the register. There may be enough play in the chuck mounting holes to allow you to zero out the chuck. I also agree with others that boring out the center hole will allow you to chuck up longer items

[@learningturningmetal]

Thanks for the advice Robert. I'll open up the centre hole today. However, I dare not touch the register again because I think I would make a real mess of it. All the best. Andrew

[@miketherefurbisher8000]

Hi Andrew Great Video!! Alloy should be OK on a small chuck, I have the next size up lathe to you,slightly different arrangement for attaching the back plate but basically the same, Like you I use a dummy to get the register But I never drill the fixing holes for the new chuck until I have a perfect fit to the register this makes for greater accuracy. But well done keep it up!!!

[@learningturningmetal]

Hi Mike - thanks for the tip. Fingers crossed the aluminium will last. Time will tell. Cheers Andrew

[@TorteTS]

Nice work. Did you grind a lot on the lathe? Because of the fine dust.

[@learningturningmetal]

I machine a lot of cast iron on the lathe. Just need the clean up well afterwards.

[@gtcollection6933]

Hi, just got myself a C4 too and wondering if you've taken to time to look into bearing radial load & mass for a double-weight chuck. If so can you share your calculation?

[@learningturningmetal]

Hi, that is way over my head. All I can say is that the 125mm chuck is a real bonus and the lathe handles it well. Cheers Andrew

[@timjoinson7232]

Turned out very well and amazingly accurate. Was it just the video, but the lathe seemed to be running fast for some of the cuts near the outer circumference. No real problem with Aluminium but you wouldnt get away with it using a harder material. Possibly the reason for the run out on the cast iron version? So, do we deduce that the next project is going to be something big requiring a larger chuck? 😜

[@learningturningmetal]

Thanks Tim. I think I ran the lathe a little faster than when I tried machining the cast iron one. Not sure why that one didn't work out so well. On the odd occasion I could have done with larger chuck capacity. I didn't think my next project will need it though 😉 Cheers Andrew

[@kimjeppesen2172]

Good job Andrew. I really enjoy You videos. I bought a back plate from Arc Eurotrade for my mini lathe, and also an independant and self centering Ø100mm 4 jaw chuck, as my lathe came with an Ø80 3 jaw chuck and Ø11 through bore. But I am very dissapointed with the runout of both the chucks and the back plate! It's terrible, the whole lathe is almost jumping off the table! Perfect runout on the spindle itself. Do You have any pointers? I tried to turn the bolt attachment pattern 120 degrees at the time for all of them but still terrible. Have a nice week-end.

[@learningturningmetal]

Hi Kim - assuming your 80mm chuck has minimal runout, I think your problem points towards a bad backplate. I would use a micrometer to check that the thickness of the backplate is the same all round. Also take your chuck off and put a gauge on the face of the spindle register to make sure that is running true with the lathe bed. If all good so far, bolt the backplate onto the spindle without a chuck attached and put a micrometer against the face of the backplate to ensure that runs true with the lathe bed. You could put the original chuck on and put a test bar in to see if that shows runout. Do the same with the other chucks. If you turn the bolt pattern 120 degrees, does the problem follow it? If so, it seems like a duff backplate to me. It should be a process of elimination, but I appreciate that it's sometimes difficult to get to the bottom of problems. Try to take a step back and try working through it starting at the headstock spindle. Hope that helps. Cheers Andrew

[@kimjeppesen2172]

@@learningturningmetal Thanks a lot for Your comments Andrew. I'll give that ¤#%&"#¤ backplate one more try or it will end up as a door stopper.

[@ettoredicarlo1679]

Very nice work Andrew, however I not sure alluminium it’s the right choice for a 125 mm backplate... also if may I say I would have done first the front register previous to the 3 fixing holes on the front . But you got a very good result anyway, so wel done, and thanks for sharing

[@learningturningmetal]

Thanks for the advice. I hope aluminium will be OK - time will tell. Fingers and toes crossed! Cheers Andrew

[@Fubar12341]

Hi Andrew I know its off topic but do you have a link to where you obtained your vice from on your miller ? Thanks

[@learningturningmetal]

Hi Chris The first vice I purchased for my mini mill was a 70mm Precision Tool Vice Type 2 from arceurotrade. They are a great vice and when I got the larger mill I purchased the 90mm version and the 120mm version. The 90mm is a good size for the warco wm18 mill. The 120mm is a bit too large for what I do. Cheers Andrew

[@Fubar12341]

@@learningturningmetal Many Thanks I can feel an early Birthday present coming on !

[@georgefleetwood7740]

Hi Andrew what is your opinion of the SEIG SC4 Lathe are your happy with it. Thanks George

[@learningturningmetal]

Hi George, I've found the SC4 to be a very good lathe. Power cross feed is good for finishing, but I like manual control when parting off. The only problem I've had was the Emergency Stop switch failing - this is covered in one of my videos. I think it's a fairly common issue. I got mine fixed, but I've since added my own NVR between the lathes power plug and my mains socket (belt and braces). That wouldn't put me off buying another. Like all these types of lathes, changing gears for cutting threads is a pain. There is no thread dial indicator either on this lathe. I might at some stage buy an additional lathe with a gear box, specifically for thread cutting. That said I definitely recommend the SC4. Cheers Andrew

[@georgefleetwood7740]

Thanks for the info on the Lathe Andrew l have been following you videos and you have done some nice work with it.

[@stevebosun7410]

Hi Andrew, a few tenths runout on a 3 jaw is pretty good in my book. Why not try the other two positions just to see if it improves. I would be a shame not to try. You never know.

[@learningturningmetal]

That's a great idea Steve. I'll give it a try 😀 Cheers Andrew

[@stevewilliams1054]

Hi Andrew: Just some thoughts on using aluminium as a backplate. Not saying it is a mistake to use aluminium only time will tell, but the inherent properties of any material used must be taken into consideration as its suitability for the duty it is to perform. There is a rule that aluminium has 1/3 of the tensile of steel. Its lower Young's modulus may reduce the overall rigidity, but provide a bit more spring between chuck and lathe. There is also the consideration of differential expansion problem between aluminium and steel or cast iron. The rigidity of the system is dependent upon the rigidity of all the parts, it does not matter how rigid the rest of the system is if you have something softer in there. This may cause vibration and chatter at a lower speed then CI or steel would. It may not cause any problems in your application, but if you find rigidity problems, this could be the cause. Keep on producing your videos always interesting and provide food for thought.

[@learningturningmetal]

Hi Steve - many thanks for the advice. All valid points. I will have to see how it goes. I don't do much (if any) heavy duty work - but like you say, time will tell. If I end up making another one in cast iron, I will at least have a decent process to follow. All the best. Andrew

[@semyil751]

Hey nice video! I have the same lathe with a different name which it is jetco jml-3s. They are exact same lathes. However, I have a problem on my lathe nowadays. I made lathe work a couple days ago and turn off the lathe and then turn it on again about half hour later but the fuse that on the front panel which is above the green light pops out. I replaced the fuse with same one but pops out again. I tried 5-6 times but each time it just blew. So I've checked the control board, servo motor, screen boards etc. I didnt see any damage on them, and even the fuse on the control board was working. So, do you have any idea what's going on my lathe? Thank you.

[@learningturningmetal]

Hi. I am no electrician but my guess would be either your front switch is faulty or the spindle is stuck causing it to stall. My manual has a section on troubleshooting but it doesn't refer to this specific problem. However it might help you fault find. Email me at [e-mail] and I will send you a copy of those pages. Cheers Andrew

[@semyil751]

@@learningturningmetal Thank you so much for the reply Andrew. I'm gonna send an email right now, may be it'll usefull for me. Thanks

[@learningturningmetal]

@@semyil751 No problem. I've scanned the trouble shooting section and emailed it to you. I hope it helps you out. Cheers Andrew

[@nikhilbhale79]

I think you didn't show it but you opened the hole at centre too. Same dimensions as spindle bore.

[@learningturningmetal]

Hi mate. Unfortunately I forgot to open up the hole. I've done it now though ☺️ Cheers Andrew