7x12MiniLathe

Group Guidelines

@... — Tue, 01 Apr 2025 05:30:45 -0700

TERMS OF USE -- How the 7x12 Group Operates

The 7x12 Minilathe forum was founded as a way for machinists, both expert and novice, to help each other learn about our machines and to inspire each other to try new things. Here you can ask machining questions and expect to get knowledgeable answers. You can ask for help in finding just the right technique or design for a particular project.

The files and archives can be searched for helpful hints and ideas to improve your knowledge and the quality of your work.

In return we ask that you confine your discussions to machining related topics,聽 that you treat each other as you would want to be treated, that you write your messages with a sense of camaraderie, and that you honor the rights of those who willingly give of their time by sharing their knowledge and ideas with you.

Over time a group personality emerges, shaped by the people and personalities who comprise the group.聽 We would like this group to be friendly and welcoming, a place where machinists of all skill levels come to teach and to learn and we ask your cooperation in meeting these goals.

To help achieve those goals, the following rules govern operation of this group:
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* On-Topic posts only. Posts are not normally moderated, except those from relatively new members. But posts which are clearly off-topic will be deleted; 聽 the member's email status may be changed plus their posting status may be changed so their future messages are moderated.聽 To avoid this, please refrain from responding to OT posts. Leave decisions as to whether a subject is OT to the moderators. Give them a little time to deal with聽 the matter, and some latitude in judging what is off-topic.

聽 Experience has shown that some topics can drift into off-topic areas; for example,聽 posts about using a lathe to make angling equipment can degenerate into fishing聽 reminiscences and those about making car parts into the merits of member's past vehicles. Posts on making gun parts are a particular problem, as they can end up as general discussions about firearms and ballistics, or worse still as sterile arguments about the merits or demerits of gun control, where no-one is ever likely to persuade anyone else to change their views.
聽聽聽 Think before you post聽 - is what you will be saying really on the subject of lathes and machining?

* CNC, ELS and 3D Printer topics are handled in the /g/digitalhobbyist聽 which is dedicated to these and similar topics. Or, /g/3D-Printing-for-Metal-Hobbyists

* Please avoid religious or political asides or references in your messages, and likewise quotations, slogans etc at the end of them.聽 Limit signatures to 2 lines maximum.
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* Be civil to your fellow members; derogatory or combatively worded posts will be deleted, and offenders placed on moderation.

* Pictures: Following our move to 开云体育 we would like to allow members to post pictures. 聽 We ask that only machining related pictures of lasting interest be posted. When appropriate include mention of the message number concerning the topic covered in the picture(s).
聽 Members who expect to post a number聽 of pictures should make an album containing their name to hold their pictures.聽聽
聽 Pictures of passing interest should be posted in messages or on public servers like Flickr.

* Files: Members may post machining related files.聽 Again, these should be of lasting interest.

* LINKS are found in the left menu of the Forum under Databases.

Moderators may remove pictures or files judged not to meet the above stated criteria.

聽Moderators are currently:聽
John = GadgetBuilder = John@...
Mike = DrMico60
Trevor = Trevor_Rymell聽

Maximum size of pictures should be 800x600. Pictures may be cropped and/or resized using Irfanview (free) or any other photo processing program.
One criterion for inclusion is that the photo should be of lasting interest, like a lathe modification or accessory, rather than something which will only be of interest while a question is being asked about it. This avoids "Photos" getting too cluttered with pictures relating to long-forgotten threads.聽
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*** Moderators reserve the right to determine what is and what is not聽
appropriate for this group as well as the right to delete messages and/or聽
remove members. This is not up for discussion or debate. ***
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Suggestions to members:
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When quoting previous posts, eliminate non-pertinent text, but keep enough so your response has some context.
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If you want to delete one of your posts: view your message on the forum and then click on the trash can at the bottom. Though you may receive copies of posts in your email, they can only be deleted by visiting the Group.
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Members may post "For Sale" info for their personal lathe or related item but we don't allow advertising by vendors; when posting, ensure your email via the Group is correct so members may contact you. Members wishing more info or wanting to
purchase an offered item MUST use email to contact the seller; responses sent via the group will be deleted.
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Members may use the group to connect with other members when they need machining done that they cannot do themselves. Responses and further refinement of details should be done via email rather than by posting to the group. See "Helping Hands" in the Files section for 7x12 Group members who will machine items for others at reasonable cost.
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New members please look at the files (especially FAQminilathe) and Search the archive for answers to common questions.
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Thank you for joining!

Re: dril a scp 486

ajsmith1968@... (Tony Smith) — Sun, 23 Mar 2025 18:43:44 -0700

Drilling a 486 CPU is like drilling glass, the 486 is probably harder.聽 Same technique would be needed, diamond drill, water, patience etc.

聽

Here鈥檚 an old page for making a keychain from a 486, basically solder a wire to the back.聽

聽

https://web.archive.org/web/20010410093643/http://www2.apex.net/users/timwhita/keychain.html

聽

Not sure why they took a Dremel to the pins, you can unsolder those.聽 Note that the metal plate on the back of the chip is soldered on, unsolder that and fill it with resin so you can see the actual CPU.

聽

Tony

聽

Re: dril a scp 486

gfeldman2904@... (Gerald Feldman) — Sun, 23 Mar 2025 17:10:05 -0700

It also reduces the heat generated in the tooth and washes away the swarf from the operation.聽 Ultrasonic drills also use a mist spray for these same reasons (but they don鈥檛 utilize diamonds bonded on the 鈥渂it鈥�.

聽

Jerry F.

聽

Re: dril a scp 486

roylowenthal@... (Roy) — Sun, 23 Mar 2025 16:32:40 -0700

Diamond abrasive bits are actually diamond powder mechanically attached, not chemically bonded, to the bit body with nickel plating. When your dentist uses them, notice there's always a cooling water mist involved to protect the integrity of the bit.

聽

Roy

Re: dril a scp 486

jacquessavard@... (Jacques Savard) — Sun, 23 Mar 2025 12:32:01 -0700

HEURELA聽聽TONY聽

聽

JUST聽 WELDING聽 SOME聽 HOICK聽聽

聽

AND聽 THAT聽 IT聽 THANK聽

聽

JACK 47 71

聽

Re: dril a scp 486

ajsmith1968@... (Tony Smith) — Sun, 23 Mar 2025 01:35:12 -0700

Depends on the age on the CPU.聽

聽

Most CPUs up to the first Pentiums were all ceramic 鈥� have fun drilling thru that.聽 Later ones shrunk the ceramic bit and have a 鈥渕oat鈥� of maybe 5-15mm of PCB that you can more easily drill thru.聽 These are the ones that tend to be made into keyrings.

聽

Modern CPUs drop the ceramic cover and instead have a metal cover over the entire chip, you can drill the edge of those.

聽

Depending on usage might be easier soldering a plate to the back of the chip.

聽

Tony

聽

Re: dril a scp 486

animal@... (mike allen) — Sat, 22 Mar 2025 21:58:20 -0700

maybe a 44 mag

animal

On 3/22/25 9:30 PM, Charles Kinzer wrote:

Re: dril a scp 486

ckinzer@... (Charles Kinzer) — Sat, 22 Mar 2025 21:30:51 -0700

I thought the hole was to be through the circuit board, not the chip itself.聽 The substrate is silicon which is rather hard.聽 It has a Mohs hardness of about 7.聽 Titanium is less hard at 5 to 6 as a comparison.聽 Tungsten carbide 9.聽 The silicon wafer is also much harder than regular glass.

You probably not only need something like a diamond drill as mentioned, but perhaps even a means to cool it.

One other thing.聽 The silicon wafer at the beginning of the semiconductor manufacturing process is about 1 mm thick.聽 Many wafers, after the devices have been deposited on them, go through a "backgrinding" process to remove much of the silicon wafer to make it thinner.聽 Then it is sliced up into individual chips and then packaged.聽 Thinning helps with heat distribution.聽 (I know this stuff because I was involved in designing semiconducting manufacturing equipment).聽 Therefore, the substrate might actually be quite thin.

Charles E. "Chuck" Kinzer

On Saturday, March 22, 2025 at 09:15:44 PM PDT, Jon Rus via groups.io <byghtn5@...> wrote:

Perforate the chip with a LASER!

聽in a CNC to run a circle pattern round-and-round to achieve the desired hole size.

On 3/22/2025 2:27 PM, Jacques Savard via groups.io wrote:

399聽/聽5鈥�000

聽

R茅sultats de traduction

R茅sultat de traduction

I have some cpu 486 or pentium vintage version

聽

But impossible to drill a ho;e in the material

Normal drill for Metll Nothing Drill Diamand for glass or stained glass Nothing

barely trace

Probably epoxy tre

Do you have an idea please Jack 47 71 it is exposy proly but very hard stouf Any Advise Please

Re: dril a scp 486

byghtn5@... (Jon Rus) — Sat, 22 Mar 2025 21:15:39 -0700

Perforate the chip with a LASER!

聽in a CNC to run a circle pattern round-and-round to achieve the desired hole size.

On 3/22/2025 2:27 PM, Jacques Savard via groups.io wrote:

Re: dril a scp 486

ajsmith1968@... (Tony Smith) — Sat, 22 Mar 2025 21:07:27 -0700

Keychain or similar I guess, maybe drawer pulls for a nerd cabinet.

聽

Never tried drilling one, but yeah diamond would be the go.聽 Maybe masonry or glass bits.聽 It鈥檚 a pretty common craft item.

聽

Another way to make a keychain was you鈥檇 unsolder all the pins and then solder a loop of wire back on.聽

聽

Thinking about it, a cabinet with big chunky ICs as drawer pulls does sound pretty cool.

聽

Tony

聽

Re: dril a scp 486

gfeldman2904@... (Gerald Feldman) — Sat, 22 Mar 2025 18:43:09 -0700

1) I am curious as to why you want to drill a hole through a scrap 486 microprocessor.

聽

2) The substrate for the microprocessor is very likely some type of ceramic material, so it is expected to be very hard and brittle.

聽

3) Carbide 鈥減rinted circuit鈥� drills are meant for drilling holes in glass-epoxy circuit boards, not the ICs themselves.聽 Glass-fiber reinforced epoxy is very abrasive and will quickly dull a steel drill bit.聽 And yes, carbide is very brittle and will snap if there is any radial pressure on them.

聽

4)聽 If you really want to make a hole through a 486, I suggest that you use a diamond encrusted burr of the same type that dentists use to grind (not drill) through tooth enamel.聽 If you cannot find one, ask your dentist if he will give you one that is not completely used up.聽聽

聽

Good luck,

聽

Jerry F.

聽

Re: dril a scp 486

gary.ag5tx@... (Gary Anderson) — Sat, 22 Mar 2025 18:36:08 -0700

I don't think we are talking Cu/FR4 PCB drilling here, rather drilling through a ceramic microprocessor package.聽

Re: dril a scp 486

ifly172@... (Ryan H) — Sat, 22 Mar 2025 18:31:23 -0700

I started with a .6 to 1.5mm set and then bought 10 pack replacements for some I did break, all from eBay.聽 I was drilling lots of small holes and was dulling them before I broke too many.聽 They probably would have been fine in a high RPM CNC machine but I could tell when they were getting a little dull in the lathe.聽 They were pretty affordable shipped from China, in the fifty to seventy five cents a piece range.聽 Several came with Chinese manufacture stickers over other stickers which revealed them to have originally been labeled as made in Japan.馃し鈥嶁檪锔徛�

Ryan

On Saturday, March 22, 2025 at 07:14:05 PM EDT, Roy via groups.io <roylowenthal@...> wrote:

There are also re-sharpened ones that are even cheaper. Unfortunately, one of the batches I bought were packaged with a piece of聽 plastic foam with the drills stuck into it, quite a few of them broke when the foam was removed. OTOH, I now have a lifetime supply of 1/8" carbide rods 馃槖

聽

Roy

Re: dril a scp 486

roylowenthal@... (Roy) — Sat, 22 Mar 2025 16:14:02 -0700

聽

Roy

Re: dril a scp 486

ifly172@... (Ryan H) — Sat, 22 Mar 2025 12:32:20 -0700

Yes, try the carbide PCB drills. They're sharp and hard and will cut stuff that just laughs at high speed steel or even cobalt drills. BUT they are fragile and will break if you look at them sideways. You want to use them in a well centered chuck if you're using them on your lathe or a drill press with the part fixed so it can't move. I've drilled down to 0.6mm with them on my lathe.聽

On Mar 22, 2025 at 2:41鈥疨M -0400, Charles Kinzer <ckinzer@...>, wrote:

Re: dril a scp 486

Claremont5@... (Charles Devore) — Sat, 22 Mar 2025 11:45:46 -0700

Yep, the PC drilling machines I have seen were branded DAK they used high speed electric drive spindles, 10K rpm?聽 and we used small collet held carbide drill bits, they were CNC聽

Re: dril a scp 486

ckinzer@... (Charles Kinzer) — Sat, 22 Mar 2025 11:41:25 -0700

There are "printed circuit board drills" that I believe are carbide.

Amazon has inexpensive ones.聽 Professional industrial ones cost more.聽 The are all quite brittle and easy to break.聽 They are usually used in CNC machines with multiple heads doing multiple boards at one time.

Amazon.com : printed circuit board drills

Charles E. "Chuck" Kinzer

On Saturday, March 22, 2025 at 11:27:37 AM PDT, Jacques Savard via groups.io <jacquessavard@...> wrote:

399聽/聽5鈥�000

聽

R茅sultats de traduction

R茅sultat de traduction

I have some cpu 486 or pentium vintage version

聽

But impossible to drill a ho;e in the material

Normal drill for Metll Nothing
Drill Diamand for glass or stained glass Nothing

barely trace

Probably epoxy
tre

Do you have an idea please
Jack 47 71
it is exposy proly but very hard stouf
Any Advise Please

cpu drill

jacquessavard@... (Jacques Savard) — Sat, 22 Mar 2025 11:30:38 -0700

聽

I have some cpu 486 or pentium vintage version

聽

But impossible to drill a ho;e in the material

Normal drill for Metll Nothing
Drill Diamand for glass or stained glass Nothing

barely trace

Probably epoxy
tre

Do you have an idea please
Jack 47 71
it is exposy proly but very hard stouf
Any Advise Please

Re: FC350BJ/110V Controller Transformer and Switch Failure.

gary.ag5tx@... (Gary Anderson) — Thu, 20 Mar 2025 16:42:17 -0700

I still have no real idea on what caused the failure of the transformer and switch.聽 I just replaced the parts and hope for the best, with the lurking feeling that it will happen again.聽 I now do have a better delta connected surge protector installed at the AC mains plug.聽 No issues so far with very limited use.

聽

Before power-up, I checked that the fuse was the proper rating.聽聽I didn't check when I bought the used machine.

聽

I tore down the faulty switch.聽 The copper colored stud contact is damaged where the brass colored spring loaded tab makes contact.聽 It looks like there was arcing in the switch as the 'copper' has migrated.

聽

I cut away the faulty transformer's insulation tape, and it did not have a thermal fuse.聽 None of the visible magnet wires showed sign of damage.聽 I have not yet unwrapped it to see if there was a possible arc over on the primary before becoming an open.聽

聽

One idea I had was to not switch any 120V AC through the pot/switch.聽 Rather switch low voltage DC as the control input to an optically isolated relay (low voltage, low current through the pot/switch).聽 This circuit could use either the unusual as-built pot/switch which is closed when CCW, or the much more common open when CCW.聽聽The 12V fan circuit _might_ be able to supply enough extra current to power a relay.聽 I've used relays such as https://www.amazon.com/dp/B095YFJ69T in the past.聽 Had LMS not had the pot/switch in stock in a reasonable time, I would have done this.聽聽I mention this alternative in case someone else is having issues with their pot/switch and can't find a suitable replacement.聽 As much of this post is only in the spirit of sharing my findings for others to find, and if someone has more insight... I'd be happy for them to share with me.

聽

Regards,

Gary

聽

Converting cross slide screw to ball bearing

davesmith1@... (davesmith1800) — Sun, 16 Mar 2025 14:22:12 -0700

Here working next is converting my cross slide to ball bearing.

Very easy tooy

. Using a motor grade 6201 seal聽

Thd pdf is clearer than screw shot.

I did not put here so did use space here if see pdf goto聽

ball_bearing_cross_slide_covertion

聽

Dave聽