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Re: Lathe motor controller
¿ªÔÆÌåÓýI looked over the listing on Ebay.? The specs are poorly written and difficult to make sense of.? Where is the information that this drive is reversible? Wilfred ? From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of LJG
Sent: Thursday, November 22, 2012 8:32 PM To: 7x12minilathe@... Subject: [7x12minilathe] Lathe motor controller ? ? Anyone looking for a pwm motor controller to replace a failed motor control on the 7x lathe or the small milling machine, might want to look at this. Copy the link and paste into ebay search. |
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Re: My New 7x14 Micro Mark lathe
¿ªÔÆÌåÓýThanks for the threads on this subject.
I joined this list exactly because I was considering a MicroMark
lathe but had heard that there were issues with all of these "7
by" lathes but also that they could be made usable by tuneup.
Interesting that some people have no trouble while some people
have terrible issues. I'd really like something I could use out of
the box without tuning up, but cost is also a factor. I'll mostly
just listen in, but thanks for this list and its focus.
Mark On 11/22/12 3:59 PM, Michael Jablonski wrote: ? |
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Lathe motor controller
Anyone looking for a pwm motor controller to replace a failed motor control on the 7x lathe or the small milling machine, might want to look at this. Copy the link and paste into ebay search.
5V-110V Max 10A DC Motor Speed Control PWM MACH3 Speed Control 12v 24v 36v 96v It doesn't have the reset to zero voltage when reversing. But it looks like a good replacement at $15.00 shipping included. The true replacement controls are vastly overpriced. Larry |
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Re: My New 7x14 Micro Mark lathe
MERTON B BAKER
¿ªÔÆÌåÓýAnd; if you buy a used machine, you don't know what
the former owner, or owners, may have done to it in an attempt to improve
it.? Not all changes are actually improvements.
?
Mert
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Re: My New 7x14 Micro Mark lathe
¿ªÔÆÌåÓýHello
and welcome to the forum.
?
Your
subject line indicates that you have a Micromark 7x14 lathe. I take it that you
recently purchased this lathe used since Micromark hasn't sold their 7x14 lathe
in well over a year now.
?
Many
of these?mini lathes sold under various brand names have problems with
the?gibs. It appears that it is hit or miss on whether you get a lathe with
gibs that are easily adjusted, or one that is practically impossible to adjust
and hold the adjustment?without modifications. There are plenty of messages
here that discuss modifications to the gibs to make them better but it sounds
like you have already made the necessary improvements to your
lathe.
?
Michael -
USA
Micro-Mark MicroLux
7x16 ?
?
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Re: My New 7x14 Micro Mark lathe
MERTON B BAKER
All my 7x (I have 4 of 'em) lathes were bought on sale, different vendors,
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and have worked fine just as they arrived, after a little cleanup of the preservative off the sliding parts. I have never bought one of MMs lathes, presumably checked out by the vendor and made much better than the common run, and priced much higher in consequence, because I'm a registered cheapskate. Your story tells me that this idea of mine is not so, or maybe yours was checked out and set up early on a Tuesday after a 3 day weekend. Now any new machine will wear in a bit and require re setting after few hours' use, but your woes sound as though you should complain to MM. Most of my complaint experience is with HF, which is not the priciest outfit, especially when their stuff is on sale. I had three 4x6 bandsaws delivered and sent back, bought on sale, before I got one without a broken casting, but HF did not complain, and saw to it that I got a useable machine, despite what it cost 'em in shipping. I had no problems with my HF 7x10, the first of my 7xs, bought for less than $300. That was back in the days when HF had free shipping, too. It did need a new circuit board after 3 year's use, however. That was over 20 years ago , though, and no trouble since. Evidently, mileage varies. Mert -----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...]On Behalf Of freejoshua42 Sent: Thursday, November 22, 2012 11:50 AM To: 7x12minilathe@... Subject: [7x12minilathe] My New 7x14 Micro Mark lathe Hi, Guy's I'm new to this forum, I recently purchased a Digital 7x14 mini lathe, and found the machining to be absolutely horrible, my cross slide not only has to big a gap in the dove tail gib side, but also had a ridge on the undercut of the opposite dove tail, which I removed so the cross slide would site flat on the machined surfaces, using an indicator I found the cross slide had a tilt of 10 thou because of the ridge . Also the gib is to thin for pocket area of dove tail, I'm currently making as larger gib from amco bronze about .370 wide, the gib tends to twist in the pocket and makes the adjustment difficult. Now about the tail stock, also does not have enough room to line up to the head stock, so I made a design change in the lower portion with the key I reversed the retainer screw and added a steel bushing to help guide the hold down bolt, now in the top portion I machined a angle relief to left and right of the center line of the spindle, leaving a 1/4" land area on the center line of the spindle, also I added side adjusting plates to line up the tail stock from laeft to right. now the it lines up real easy and also in the angular as well. The apron gibs required readjusting. Now it's a real lathe not a Joke. ------------------------------------ Yahoo! Groups Links |
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My New 7x14 Micro Mark lathe
Hi, Guy's I'm new to this forum, I recently purchased a Digital 7x14
mini lathe, and found the machining to be absolutely horrible, my cross slide not only has to big a gap in the dove tail gib side, but also had a ridge on the undercut of the opposite dove tail, which I removed so the cross slide would site flat on the machined surfaces, using an indicator I found the cross slide had a tilt of 10 thou because of the ridge . Also the gib is to thin for pocket area of dove tail, I'm currently making as larger gib from amco bronze about .370 wide, the gib tends to twist in the pocket and makes the adjustment difficult. Now about the tail stock, also does not have enough room to line up to the head stock, so I made a design change in the lower portion with the key I reversed the retainer screw and added a steel bushing to help guide the hold down bolt, now in the top portion I machined a angle relief to left and right of the center line of the spindle, leaving a 1/4" land area on the center line of the spindle, also I added side adjusting plates to line up the tail stock from laeft to right. now the it lines up real easy and also in the angular as well. The apron gibs required readjusting. Now it's a real lathe not a Joke. |
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Re: Centering large stock
John Lindo
How close do you want the concentricity.? The group can help from there. John L Spain
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Re: Centering large stock
Is it a three or four jaw chuck?? If it is a three jaw, you will
only get it centered to within a few thou just by tightening.?
Tighten the jaws evenly.? If you need closer, you can put shims
under the jaws.? (A beverage can is good for thin metal but the
thickness is not constant.)? If you have a four jaw, you can get it
as close as you need.? Centering stuff is a bit fiddly but
definitely gets easier with practice.
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At 03:07 PM 11/22/2012 +0000, you wrote: ? |
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Re: Centering large stock
¿ªÔÆÌåÓýI am assuming you are?using a 3-jaw
chuck?? It would then be normal to be off a little.? This is due to
the accuracy of how well the chuck can work.? (Mainly, the scroll in these
chucks just isn't all that precise.)
?
If you need accurate centering, you should consider
a 4-jaw independent jaw chuck.? You can move each jaw independently and,
while measuring with an indicator, adjust opposite jaws until it runs
true.
?
With only a 3-jaw, you can usually get pretty close
by putting very thin shim material between a jaw(s) and the work piece as
needed.
?
Chuck K.
?
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Centering large stock
I am working on a 3/4 SS 303 rod and trying to get it centered in the chuck of my HF 7x
mini lathe, and it seems to always be off a little. I used my mag base dial caliper and can get it close but not close enough. Any ideas on this? The rod is 4". I have a QCTP, steady rest, and follower rest on the way from littlemachineshop but need ideas until they get here please. Thanks Mark |
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Centering large stock
I am working on a 3/4 SS 303 rod and trying to get it centered in the chuck of my HF 7x
mini lathe, and it seems to always be off a little. I used my mag base dial caliper and can get it close but not close enough. Any ideas on this? The rod is 4". I have a QCTP, steady rest, and follower rest on the way from littlemachineshop but need ideas until they get here please. Thanks Mark |
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Re: problem with gibs...
The gib on my cross slide had conical dimples, no doubt made with a drill bit. The ends of the adjusting screws weren't pointed or turned down in any way; they were just plain screws, threaded right up to the end. A Sharpie pen showed that the dimples only roughly coincided with the screws. I could see the gib twisting as I tried to adjust it. No wonder adjustment had always been a compromise between no tight spots on the one hand and no looseness on the other.
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To cure this, I used a 4mm slot drill to flat-bottom the dimples, repositioning two of then slightly. I also faced the ends of the screws and turned the last 1/16" of thread from their ends (happily, I have another lathe available). This may have had the same effect as mooring the gib with a pin. There is now no detectable looseness on the slide, which moves smoothly all the way. If working on the dimples, make sure you end up with a little clearance between the bottom of the gib and the top of the saddle. Speaking of clearance, there should be some between the top of the male dovetail on the saddle and the roof of the female dovetail on the slide. When I got my lathe, I found these two areas were fouling slightly, making the cross slide very stiff over the last ?" of outward travel. That was soon fixed by reducing the height of the male dovetail slightly at one end with a file. Andy --- In 7x12minilathe@..., "DAVID C HUTCHINS" <dchutchins@...> wrote:
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Re: problem with gibs...
Give me a few days to find it & then I¡¯ll e-mail to you personally off
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thread. Dave -----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of dennis Sent: Wednesday, November 21, 2012 8:10 PM To: 7x12minilathe@... Subject: [7x12minilathe] Re: problem with gibs... dc if you could email it to me too. I have a micromark 7x16. cant keep gibs tight and want to be able to fix it. Thanks,Dennis --- In 7x12minilathe@... <mailto:7x12minilathe%40yahoogroups.com> , "DAVID C HUTCHINS" <dchutchins@...> wrote: also going to do the same with my 7X12. I took the advice of Geo Thomas (Ithave is the gib is sliding ever so slightly back & forth & with the setscrew points riding the dimple pockets in the side of the gib, it slidesuntil it rides up the point of the set screw & tightens up. Once I pinnedit, I've lost that problem. I used a 1/8" spring pin. I drilled the holeon the saddle. You will need to disassemble it all once done & de-bur it& email you a scan of it.<mailto:7x12minilathe%40yahoogroups.com> [mailto:7x12minilathe@...<mailto:7x12minilathe%40yahoogroups.com> ] On Behalf Of Exibar Sent: Wednesday, November 21, 2012 4:58 PM<mailto:7x12minilathe%40yahoogroups.com> Subject: [7x12minilathe] problem with gibs... |
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Re: problem with gibs...
on my mm 7x16 i'm working on using shims.
mine were so bad and soooo loose it was rediculous.
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george
From: dennis To: 7x12minilathe@... Sent: Wed, November 21, 2012 5:10:09 PM Subject: [7x12minilathe] Re: problem with gibs... ? dc if you could email it to me too. I have a micromark 7x16. cant keep gibs tight and want to be able to fix it. |
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Re: problem with gibs...
dennis
dc if you could email it to me too. I have a micromark 7x16. cant keep gibs tight and want to be able to fix it.
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Thanks,Dennis --- In 7x12minilathe@..., "DAVID C HUTCHINS" <dchutchins@...> wrote:
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Re: problem with gibs...
MERTON B BAKER
When you adjust the gibs, you need a box end wrench for the locknut and an
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Allen one for the screw. Make the screw a bit too tight, holding it immobile with the Allen wrench, and then snug the locknut down, which relieves the pressure the screw put on the gib. Mert -----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...]On Behalf Of Exibar Sent: Wednesday, November 21, 2012 4:58 PM To: 7x12minilathe@... Subject: [7x12minilathe] problem with gibs... my cross slide is either too tight to move (more or less) or too loose.... I can't seem to get the right combination using the set screws.... I'm thinking that maybe there is a tweak or two that I can do? anyone have any thoughts or guidance? thanks! Mike B ------------------------------------ Yahoo! Groups Links |
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Re: problem with gibs...
I had the same problem with my cross slide of my South Bend 9¡±, I¡¯m also
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going to do the same with my 7X12. I took the advice of Geo Thomas (It was either him or Guy Lutard) & drilled & pinned the gib. What you have is the gib is sliding ever so slightly back & forth & with the set screw points riding the dimple pockets in the side of the gib, it slides until it rides up the point of the set screw & tightens up. Once I pinned it, I¡¯ve lost that problem. I used a 1/8¡± spring pin. I drilled the hole completely through the right side of my cross slide & through the gib about ?¡± in from the front. Make sure to back your cross slide out toward you so it sticks out enough that you don¡¯t drill into the part on the saddle. You will need to disassemble it all once done & de-bur it all. If you need more info I can look in the books & find the article & email you a scan of it. Dave -----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of Exibar Sent: Wednesday, November 21, 2012 4:58 PM To: 7x12minilathe@... Subject: [7x12minilathe] problem with gibs... my cross slide is either too tight to move (more or less) or too loose.... I can't seem to get the right combination using the set screws.... I'm thinking that maybe there is a tweak or two that I can do? anyone have any thoughts or guidance? thanks! Mike B |
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