The low cost diamond wheels are typically about 4" resin bonded, meant for cutter grinders. See Shars or CTC Tools. You could make an adapter and use a 4" wheel on your present grinder, or rig something else up. 6" diamond wheels are available on eBay but price is considerably higher.

One caution in grinding carbide: the dust is toxic so take appropriate precautions.

John

Any recommendations? My grinder takes 6" x 3/4" wheels.

On 10/10/2011 02:33 PM, GadgetBuilder wrote:

The consensus on green wheels for carbide is that they work but cause micro cracks leading to early failure of the edge.

Better to use diamond -- diamond wheels are reasonably priced now and should last a long while in a home shop.

John

--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand

-----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of lathe_7x14
Sent: Monday, October 10, 2011 3:04 AM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: 7X14 mini-lathe

?

I think it is really a matter of getting what one pays for and that it would be unfair to blame the supplier. It is generally understood that between the Chinese factory and the buyer the box get's transshipped many times and bounced about, and things do come loose. Usually the first time the box gets opened is when it reaches the buyer and he does the 'quality check' at this end. I have seen one supplier who for ?100 offers to open the box and 'prepare' the lathe, but whether that includes a full functional test, I don't know. When I first looked at the Chinese lathes it was suggested that the best way of looking at them was as a 'kit of parts' and one has to be prepared to do some work on them. The fact that I, an 'expert' after one whole days experience, managed to clear all the problems, shows that they were fairly simple to resolve.

I think the best approach is to examine the box on the pallet for any external signs of damage, before signing the carriers paperwork. The polystyrene packing is very thin, but bruises should show up on the outside of the cardboard box. After unpacking photograph anything you don't like and immediately inform the supplier.

In this case the supplier was really on the ball and helpful and I would recommend them to anyone. They even told me to keep the two undersized tool holders and immediately sent me the correct replacements. So I have nothing but praise for the supplier and do not think it would be fair to penalise them in any way. I am a happy customer.

--- In 7x12minilathe@..., "Michael Jablonski" wrote:
>
> Sounds like a lot of problems right out of the box.(Snip}.

The consensus on green wheels for carbide is that they work but cause micro cracks leading to early failure of the edge.

Better to use diamond -- diamond wheels are reasonably priced now and should last a long while in a home shop.

John

Dunno, myself, I just bought the ones HF sells with its tool grinder, and
they've worked OK. They never said what the grit size was, but it's worked
just fine for me. Mert

I'm thinking of getting a green wheel for my bench grinder for carbide
cutters since I'm getting more of them. Which grit is the best for tool
sharpening, I see Enco has them in 60, 80, and 120. I'm guessing 120
but figured it's best to ask.

--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand

I was doing some general turning under power feed yesterday, nothing elaborate, and all of a sudden the lathe stalled. After much investigation I finally diagnosed the problem: the B/C gear bushing has somehow fused or stuck itself to the B/C gear shaft on which it rides. Seems absolutely welded. Right now I have it soaking in wd40.
Anyone had a similar problem and can give any advice?
Thanks,
Paul

Bushing and Key <>

Replacement Bushing and key <> is only $3.84
from LittleMachineShop <>.

I'd say to just think of the replacement part as a kind of reverse
Murpy's Law: If it no longer matters whether or not you can get the old
bushing off without mangling it all up, it will of course come off with
no real drama. /Only if there is no replacement easily available/ does
Murphy's Law apply. Similar to the "butter-side-down" rule for dropping
your toast or the fact that it is exceedingly rare for your car to
conveniently break down right in your driveway, or perhaps in front of
your favorite local garage.

When mine seized up I used two flat screwdrivers to force it off, then
I lightly round filed the ends to clean up the prying marks, and
wetsanded the shaft down a bit until it was a sliding fit again. Since
then I have made a point of using lots of white lithium there ever
since. This isMurphy's Law <>
exception to the /mostly/ true opinion from those you may have read
about here who have decided those plastic gears need no lubricant...
except for that metal on metal bushing you discovered, that too is only
/mostly/ true... :-)

Good Luck!
John Z. Of York, Pa.

On 10/9/2011 12:47 PM, jaspercan7 wrote:

I should be more specific. In addition to suggestions to keep it from
happening again, are there any recommendations for non-destructive
ways of separating the stuck bushing from the shaft?


--- In 7x12minilathe@...
<mailto:7x12minilathe%40yahoogroups.com>, Jerry Durand <jdurand@>
wrote:

polish shaft and use more lithium grease?

On 10/09/2011 09:17 AM, jaspercan7 wrote:

I was doing some general turning under power feed yesterday,

nothing elaborate, and all of a sudden the lathe stalled. After much
investigation I finally diagnosed the problem: the B/C gear bushing
has somehow fused or stuck itself to the B/C gear shaft on which it
rides. Seems absolutely welded. Right now I have it soaking in wd40.

Anyone had a similar problem and can give any advice?
Thanks,
Paul

--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand

Dunno what others experience, except for the complaints I read about here,
but the experience I've had with the Chinese 7x lathes, one 7x10 from HF,
One 7x12 from Homier (RB), and one 7x12 from Grizzly, is that they all
worked much better that I expected from the amount of money I paid, and
continue to do so. I was especially pleased to find out that the 7x12s are

?

Dunno what others experience, except for the complaints I read about here,
but the experience I've had with the Chinese 7x lathes, one 7x10 from HF,
One 7x12 from Homier (RB), and one 7x12 from Grizzly, is that they all
worked much better that I expected from the amount of money I paid, and
continue to do so. I was especially pleased to find out that the 7x12s are
really 7x14s. Difference of opinion is what horse racing is all about,
however. I don't know how many of these machines are in use in this country,
let alone others, but adding up all the complaints would seem to indicate a
very small percentage, and surely some of that would be from some who do not
realize that they are looking in the mirror. To expect less than half a
tenth runout from a $400 7x12 lathe seems unrealistic to me. Paying what a
machine with guaranteed half-a-tenth runout would cost, is equally
unrealistic, I'm a retired small town schoolteacher. Rejoice & learn.

Mert

Sounds like a lot of problems right out of the box.(Snip}.

Sounds like a lot of problems right out of the box.(Snip}.

Hi,

You could try gently heating the stud/gear combination in the hopes
that the thermal expansion will break the bond.

Ian.

--- On Sun, 9/10/11, jaspercan7 <jaspercan7@...> wrote:

From: jaspercan7 <jaspercan7@...>
Subject: [7x12minilathe] Re: shaft and bushing for the B/C
change gears
To: 7x12minilathe@...
Date: Sunday, 9 October, 2011, 17:47


I should be more specific. In addition to suggestions to keep
it from happening again, are there any recommendations for
non-destructive ways of separating the stuck bushing from the
shaft?


--- In 7x12minilathe@..., Jerry Durand
<jdurand@...> wrote:
>
> polish shaft and use more lithium grease?
>
> On 10/09/2011 09:17 AM, jaspercan7 wrote:
> > I was doing some general turning under power feed
yesterday, nothing elaborate, and all of a sudden the lathe
stalled. After much investigation I finally diagnosed the
problem: the B/C gear bushing has somehow fused or stuck
itself to the B/C gear shaft on which it rides. Seems
absolutely welded. Right now I have it soaking in wd40.
> > Anyone had a similar problem and can give any advice?
> > Thanks,
> > Paul
> >
> >
>
> --
> Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
> tel: +1 408 356-3886, USA toll free: 1 866 356-3886
> Skype: jerrydurand
>

I was doing some general turning under power feed yesterday, nothing elaborate, and all of a sudden the lathe stalled. After much investigation I finally diagnosed the problem: the B/C gear bushing has somehow fused or stuck itself to the B/C gear shaft on which it rides. Seems absolutely welded. Right now I have it soaking in wd40.
Anyone had a similar problem and can give any advice?
Thanks,
Paul

I was doing some general turning under power feed yesterday, nothing
elaborate, and all of a sudden the lathe stalled. After much
investigation I finally diagnosed the problem: the B/C gear bushing
has somehow fused or stuck itself to the B/C gear shaft on which it
rides. Seems absolutely welded. Right now I have it soaking in wd40.
Anyone had a similar problem and can give any advice?
Thanks,
Paul

-----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of lathe_7x14
Sent: Sunday, October 09, 2011 10:21 AM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: 7X14 mini-lathe

?

--- In 7x12minilathe@..., "copascetic1" wrote:
>
>
> Would enjoy hearing opinions from owners of the Micromark 7X14
>

I have had my new 7 x 14 for a week now. There were several faults when it arrived (as I had expected). The DRO wasn't working and that turned out to be an intermittant connection on the Display board. The usual fault is the sensor plug working loose during transit. The speed sensor had been maladjusted and the interrupter vanes almost touching one side of the opto switch. The mounting for the sensor has adjustment holes, so that wasn't a big problem, to center the switch gap around the vane.

The power to the spindle was also intermittent and that was because a connector had worked loose on the main PCB board, next to the sensor plug.

The MT2 hole in the tail stock had not been bored deep enough and it was ejecting the centre, effectively losing a good 20.0mm of travel. I had read about this problem elsewhere and cut about 20.0 mm off the end of the Morse adapter sleeve for my chuck and that fixed it. One could gain about another 15.0mm of travel with a smaller diameter Morse taper, but I am happy with it as it is.

I also ordered two spare tool holders for the quick change tool post, making a total of five. The two spare ones would not fit on the dove tail of the QRTP and the supplier changed them for me. When the tool holders are set to the correct height, they foul the QRTP clamping lever, so at some stage I need to find some shorter socket headed screws, for tool height adjustment. I found it a bit finiky pushing the sling dovetail out of the block each time I wanted to change a tool holder, so I have fitted a spring on the plunger so it always pushes the dovetail out when taking off the tension.

That is about it for the moment. I did some real turning on it yesterday and today and I am well pleased with the lathe and find it excellent value for money.