# PM-25MV delivery and setup pictures, power feed issue.



## erikmannie (Sep 22, 2019)

So I received the PM-25MV with no serious shipping damage. The only problem was scratches and scuffing on the blue paint which I am fine to touch up. The freight driver was willing to wheel it up into the garage so that was appreciated.

*The only problem I had was installing the power feed*. I am quite sure that they sent me the wrong limit switch. Worse yet, I cracked a small gray bracket which appears to be cast aluminum. I will contact PM to ask about the limit switch issue and see if I can obtain a replacement bracket. I was not tightening the screw terribly hard, but it cracked while I was tightening it so I will accept responsibility. I should have been more aware that cast iron is more brittle (or, more to the point, less ductile) than the materials that I am used to working with.

So here is a ridiculous amount of photos. I had considered putting the mill on casters, but I was actually out of money so I just used two 1/2" anchor bolts. I left *plenty* of room to walk around the back of the mill as well as roll welding carts back there.

I cleaned all of the shipping grease with denatured alcohol, and I put on a thin layer of 3-in-1 oil. Hopefully that oil is okay.

At some point, I will touch up the white paint on the castings. A lot of it flaked off, which I am not worried about.

I put back on the hand wheel, and I will pursue the power feed installation when I get a limit switch that fits I will report here how I did obtaining the replacement bracket. My backup plan is to fab a replacement bracket out of 6061 aluminum plate.


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## erikmannie (Sep 22, 2019)

I rented a beam lifter to raise it up. This made it very easy for two guys. Lining up the bolts to get through the base casting, chip tray and stand took awhile.


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## erikmannie (Sep 22, 2019)

The friend who helped me is a generation older than me, and he always teaches me a great deal. Working with him is like being in school (in a good way!).


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## erikmannie (Sep 22, 2019)

If you are ever going to install a power feed, you need to have NLGI No. 2 grease. I did not find it at the hardware store, but I found some at the auto supply store. This is graphite based lubricant.


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## erikmannie (Sep 22, 2019)

Some of the pictures appear to be the same, but upon closer inspection you will see that they were taken before and after the cleaning.

I thought the mill had a power vertical feed, but I don't see one.

Also, I learned that you engage the precision ("fine") vertical (spindle) feed by engaging it with the circular knurled knob located at the center of the three handled spindle control (like you have on your drill press). Also, there is a z-stop lever on the left side of the head.

I was happy that everything works on the mill. The action is smooth enough.

I am actually still trying to master the use of the x- and y-axes table locks. These are levers located at the front of the machine.


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## erikmannie (Sep 22, 2019)

The T-nuts that came with the PM vise are too large for the dovetails in the table. I am planning on using the T-nuts in my PM 58 piece steel clamping kit and a quality bolt and washer (Grade 8) from the hardware store.


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## mikey (Sep 22, 2019)

Congrats on the new toy - looks like a nice little mill.


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## erikmannie (Sep 22, 2019)

mikey said:


> Congrats on the new toy - looks like a nice little mill.


Thanks. I didn’t ever think about buying a mill or lathe until I went to school 18 months ago for bicycle frame building. Using a mill for the tube coping is a quick way to get to a great fit up.

As you know, great fit up makes the welding job easier.

My buddy and I were disappointed that we failed to get the power feed installed. It is not often when a project ends in defeat.

I have yet to compose my email to PM regarding the power feed issue. I am curious if a replacement bracket is available. Hopefully somebody who is installing this power feed will read this and go easy on the mounting bolt for this cast aluminum bracket.

I am also perplexed why the limit switch didn’t fit. The limit switch was marked “New Limit Switch”.


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## mikey (Sep 23, 2019)

Not sure what went wrong with the power feed bracket. I have an Align power feed on my RF-31 and it went on without a hitch. However, the Align units are made in Taiwan so fitment is possibly better? When a casting cracks, its often because there is someplace on the casting that is not flat. I hope PM is able to help with this. Otherwise, you have to machine one from flat stock ... luckily you have a mill now!


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## pontiac428 (Sep 23, 2019)

I read a few posts about people overdoing the effort on the mounting bolts and breaking the bracket on these power feeds.  Luckily, I read those before I installed mine.  I torqued them softer than I was inclined to, knowing they were fine thread clamp bolts, and it hasn't moved at all.  This is a case where going easy on the spinach before grabbing the wrench is the thing to do.


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## erikmannie (Sep 23, 2019)

I could make my own bracket and mount, but I have 12 months worth of projects in line now. I am sending off the email to PM now. I will upload the pictures that I sent them.


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## pontiac428 (Sep 23, 2019)

No worries, you're not alone and you bought from a good company!


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## erikmannie (Sep 23, 2019)

Thanks. If I was to have a problem, this is the one that I would want to have! I was so happy that everything on the mill worked.

In the photos you will see the cracked bracket, T-nuts that are so large that grinding them would require grinding away part of the bolt hole, and that the limit switch is too tall.

The mounting bolts for the limit switch would have the limit switch an inch above the table.

Also, the T-nuts aren't tapped.


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## erikmannie (Sep 23, 2019)

Also, the limit switch is hard wired into the main compartment for the power feed, so if they do send a limit switch that fits then I will have to reconnect the wires inside the new switch.


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## pontiac428 (Sep 23, 2019)

Looks like you will have to make/modify your bracketry for the limit switch.  I chose not to use mine at all after failing to make it fit on the back side of the table on my RF-31.  It's imprecise, awfully bulky, and I'm not sure if I understand it's purpose.  But that could just be my phonetic reading level.


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## erikmannie (Sep 23, 2019)

We had it running. It can go quite fast to really slow or anywhere in between. It is a little noisy, but that doesn’t bother me.

If I used this limit switch, the locking levers for the x and y axes would have very little room to maneuver. Putting a limit switch there really illuminates how short the distance is between these two levers.

It seems like the limit switch I received is made for a larger mill.

Yes, I could make a custom mounting plate for the back of the limit switch. I will post what PM says as soon as I hear back from them.

I bought the power feed to save time, reduce operator fatigue and hopefully get a more consistent surface finish.


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## pontiac428 (Sep 23, 2019)

erikmannie said:


> I bought the power feed to save time, reduce operator fatigue and hopefully get a more consistent surface finish.



Then you won't be disappointed.  It definitely does all of those things.  I don't regret ditching the limit switch.  If the spindle is turning, I'm at the helm.  Most machines have a crash point, so not having stops is not new.  Power feed is a fantastic mod and well worth any effort it takes to fit a unit from Xiangzhao onto a machine from Guangdong using a parts kit from Xaimen.


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## mikey (Sep 23, 2019)

I don't use the limit switches, either.


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## jsh (Sep 23, 2019)

Looking forward to more of your progress. 
I am planning on a mill by next summer. Have a few wood working projects to do to move lumber out of the way for the mills spot.


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## erikmannie (Sep 23, 2019)

mikey said:


> I don't use the limit switches, either.


I would always be at the helm, too. If not using the limit switch is a practical option, I would be amenable to that choice, primarily for the purpose of providing plenty of room for my x-and y-axes stop levers.  

This would be a matter of the mill operator ALWAYS being mindful of the setup. I understand that the power feed crashing into the mill would be a terrible development.


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## erikmannie (Sep 23, 2019)

I called PM, and they said that they may have a spare bracket at their facility. If not, then we will see how to move forward.

More interesting yet is that as of Sept. 2019 there is only one limit switch used for all power feed kits. The limit kit bracket (or mounting plate), however, may vary. As such, the customer may need to trim the mounting plate provided.

It would also be very easy to machine a limit switch bracket to the desired specs. This would be a steel plate with six holes in it. One could use the oversized mounting plate provided as a template for these bolt holes.

They also said that the T-nuts should have been tapped, but any T-nuts would work (of course).

I am starting to ask myself why I didn’t just machine the replacement part for the cast aluminum bracket that I broke.

PM also said that not using the limit switch is too risky to consider.


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## WyoGreen (Sep 23, 2019)

Your PM25 power feed setup looks just like my Pm30 setup. I didn't like how the supplied mounting plate clamped over the existing end plate, so I made a new replacement end plate that the power feed bolts to. The power feed seems to run much smoother and quieter now. If I remember right, my limit bracket didn't fit right either. I seem to remember turning the bracket over or some such thing. I'll have to go look. I think I posted some pictures of my new end bracket on here, so a search should turn that up.

Oops, gotta go to lunch, Steve


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## mikey (Sep 23, 2019)

erikmannie said:


> PM also said that not using the limit switch is too risky to consider.



They might be looking at it from a liability standpoint, their liability. I assure you that your mill will not blow up if you use power feed without a limit switch. You will find the hard stops to be far more useful.


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## erikmannie (Sep 23, 2019)

PM is sending me the cast aluminum power feed bracket that *I* cracked, free of charge. It already shipped out, and they provided me a tracking number. Very nice of them. PM said that those do, in fact, crack if one overtightens them.

PM confirmed that they sent me the right limit switch with the power feed kit. Again, I was informed that they use the same limit switch for all of their power feed models, regardless of what milling machine it will go on. I will make a custom limit switch mounting plate which maximizes the area for the x- and y-axes stop levers and keeps the limit switch under my vise.

I am also leaving my mind open to not even using the limit switch (again, so that I have plenty of room for the x- and y-axes stop levers). I understand that PM was mostly thinking about safety and liability; I will probably make the conservative choice and put the limit switch on there.

I bought some extra T-nuts for a 1/2" slot on eBay. The T-nuts that I bought accept 3/8" studs. The 52 piece clamping kit that I got from PM (when I bought my PM-25MV) included *3/8"* studs and nuts, so I am trying to have 3/8" female threads on all of the T-nuts in the shop.

I wonder if I will have to grind down the 1/2" T-nuts to fit in the 12mm T-slots in the PM-25MV. Most of the T-nuts that I saw online were for metric fasteners. I saw a lot of 12mm T-slot nuts in M8 and M10. I will report back here how the 1/2" T-nuts fit in the 12mm dovetail slot.

I had to grind down all of the T-slot nuts that were provided with the power feed kit; the instructions said that one often has to do so.

I bought a 20 piece TiN coated end mill set from Little Machine Shop. I followed the recommendation of Blondihacks on YouTube. She chose the exact same mill and lathe that I did.


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## erikmannie (Sep 23, 2019)

Just for the record, the thread pitch in the PM 52 piece clamping kit is 3/8"-16.

I took my T-nut down to the hardware store, and of course neither an M8 or M10 would thread in.


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## erikmannie (Sep 23, 2019)

WyoGreen said:


> Your PM25 power feed setup looks just like my Pm30 setup. I didn't like how the supplied mounting plate clamped over the existing end plate, so I made a new replacement end plate that the power feed bolts to. The power feed seems to run much smoother and quieter now. If I remember right, my limit bracket didn't fit right either. I seem to remember turning the bracket over or some such thing. I'll have to go look. I think I posted some pictures of my new end bracket on here, so a search should turn that up.
> 
> Oops, gotta go to lunch, Steve


Steve here nailed it. The limit switch mounting plate needed to be taken off, rotated 180 degrees and reinstalled. So it was the correct part, but the factory installed it incorrectly. All good now...


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## mcdanlj (Sep 23, 2019)

Like @WyoGreen, I have the PM-30.



erikmannie said:


> If I used this limit switch, the locking levers for the x and y axes would have very little room to maneuver



That's spot on. I have the limit switch in place, adjusted to just barely allow full X travel, but it definitely cramps my style with the X gib locks.

I have not found a great way to route the limit switch cable. In practice, it occasionally snags.

I used the mill to cut down the T-nuts rather than filing or grinding them. They weren't hardened steel...

You'll find that a lot of folks have made power lifts for the PM-25 and a few for the PM-30. I used a drill on the nut in the Z wheel to lift the head before I made my Z power feed out of lots of re-purposed bits.

Using a drill:








						PM-30 Z-axis power feed?
					

That video shows lower left for PM-727, as does the site for the PM-727, PM-932, and PM-940. The PM-833T has lower right. PM-25 and PM-30 are upper right. I don't see any PM bench mills that have Z crank on upper left; that seems to be the only option that is not used! ☺    I'm guessing that the...




					www.hobby-machinist.com
				




You can buy a pre-made PM-25 Z power feed:








						Pm25 power z axis
					

Welcome!  Little Machine Shop sells a power lift for their bench mill that might work.  The LMS 5500 and PM-25 share very similar column and crank layouts.  https://littlemachineshop.com/products/product_view.php?ProductID=5657&category=2122081966




					www.hobby-machinist.com
				




My recycled hack:








						PM-30MV for mcdanlj
					

The nylon locking ring in the nut didn't quite engage the threads, so I bored out another 0.1" and now the nut now tightens securely:    While I was at it, I added some bevels. The innermost bevel makes threading the nut more comfortable. The large outer bevel just makes it a slightly better...




					www.hobby-machinist.com
				




Enjoy the mill! ☺


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## erikmannie (Sep 24, 2019)

So after I talked to PM I forgot that we didn't resolve the matter of the wedge nuts supplied not being tapped (for what needs to be M8 X 1.25 (M8 coarse)).

M8 wedge nuts are readily available in the UK and India, but I definitely couldn't find any in the US. These are also called Vee Nuts, V-Nuts or Vee Wedge Nuts. I guess they are common over there, but not here.

Here is a picture of what one would use to mount something (e.g. a limit switch or stop of some kind) in the front dovetail slot of a PM-25MV milling machine.







If anybody knows where to get these in the US, I would be interested to know.

Looks like a good beginning milling project!

A lot of people would probably just grind down a T-nut. 

Anyway, I found it odd that these were not readily available.


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## erikmannie (Sep 24, 2019)

The closest that I could find was the items pictured below, and I will grind them to fit. I would have also expected to grind the one pictured above.


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## mcdanlj (Sep 24, 2019)

erikmannie said:


> So after I talked to PM I forgot that we didn't resolve the matter of the wedge nuts supplied not being tapped (for what needs to be M8 X 1.25 (M8 coarse)).



In one of your earlier pictures, it looks like a bolt is threaded into the v-nuts.






How are they not tapped? Is it that they aren't tapped through? I would expect PM to be happy to drop some replacements into the mail if so. (Also, and incidentally, an M8 tap isn't that expensive, and I'd think that for bike frame building you'd want a metric tap set anyway?)


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## shooter123456 (Sep 24, 2019)

erikmannie said:


> So after I talked to PM I forgot that we didn't resolve the matter of the wedge nuts supplied not being tapped (for what needs to be M8 X 1.25 (M8 coarse)).
> 
> M8 wedge nuts are readily available in the UK and India, but I definitely couldn't find any in the US. These are also called Vee Nuts, V-Nuts or Vee Wedge Nuts. I guess they are common over there, but not here.
> 
> ...


It looks like the parts diagram has "M6 Square Nut" listed for mounting the stops in that dovetail slot.  I don't recall having any nuts similar to those you show on my machine.


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## wrmiller (Sep 24, 2019)

mikey said:


> They might be looking at it from a liability standpoint, their liability. I assure you that your mill will not blow up if you use power feed without a limit switch. You will find the hard stops to be far more useful.



Agreed. I have never installed/used limit switches. Actually, one of the first things I do when getting a power feed is to take a pair of dikes to the cable for the limit switch.


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## erikmannie (Sep 24, 2019)

The power feed kit comes with four Vee nuts. Two of these nuts were tapped, and the other two were not. I may as well buy an M8 X 1.25 tap and tap those two.


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## erikmannie (Sep 24, 2019)

shooter123456 said:


> It looks like the parts diagram has "M6 Square Nut" listed for mounting the stops in that dovetail slot.  I don't recall having any nuts similar to those you show on my machine.


When my mill came, there were two round markers set on either end of the x-scale. These markers are anchored to Vee nuts. 

I think these markers need to be removed to make room for the limit switch,


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## erikmannie (Sep 24, 2019)

Here are the x-axis "stops" that I referred to above:


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## erikmannie (Sep 24, 2019)

wrmiller said:


> Agreed. I have never installed/used limit switches. Actually, one of the first things I do when getting a power feed is to take a pair of dikes to the cable for the limit switch.


I wonder what percentage of people do this. If I am unable to use my x- and y-axes levers, I will be one of them.


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## mikey (Sep 24, 2019)

Erik, those round X-axis stops in your picture are important. They allow you to positively stop a cutter at a precise location for repeated cuts, like the end of a slot in a thick work piece that requires you to take several passes to fully cut through. Limit switches do not stop the table precisely; the table travels a little before actually stopping. You cannot use them to limit the dimensions of a cut, which is what stops are supposed to be for. You can either use the hard stops or the limit switches; you cannot do both. My vote is for the former.

Just to be very clear, the X-axis stops allow you to stop a cut precisely. As you approach the end of the cut with your power feed but before you hit the stop, you disengage the power feed and then manually feed until you gently hit the stop. This is how they are used, and you can do this to precisely begin and end a cut. You cannot do this with limit switches.

As for the nuts, you can drill and tap them for whatever you wish. A 10-32 thread will work fine and you probably already have the tap and the hex wrench to fit it.


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## erikmannie (Sep 24, 2019)

mikey said:


> Erik, those round X-axis stops in your picture are important. They allow you to positively stop a cutter at a precise location for repeated cuts, like the end of a slot in a thick work piece that requires you to take several passes to fully cut through. Limit switches do not stop the table precisely; the table travels a little before actually stopping. You cannot use them to limit the dimensions of a cut, which is what stops are supposed to be for. You can either use the hard stops or the limit switches; you cannot do both. My vote is for the former.
> 
> Just to be very clear, the X-axis stops allow you to stop a cut precisely. As you approach the end of the cut with your power feed but before you hit the stop, you disengage the power feed and then manually feed until you gently hit the stop. This is how they are used, and you can do this to precisely begin and end a cut. You cannot do this with limit switches.
> 
> As for the nuts, you can drill and tap them for whatever you wish. A 10-32 thread will work fine and you probably already have the tap and the hex wrench to fit it.


I really appreciate your help. I just did a test install of the limit switch and I am 99% sure that I will not be using it.

Firstly, I have been saying "x- and y-axes stop levers". I just learned that there are *two* x-axis stop levers in the front, and the two y-axis stop levers are on the lower right.

*Huge development*: as seen in the photos, the limit switch appears to require removing the x-axis stop levers! I must be missing something, but I think that the limit switch interferes with these levers (see photos). With the limit switch in place, I would only be able to move the table about 3 inches in either direction before the lever and the body of the limit switch collided.

So now I am looking at solving this problem by not using my limit switch and being very mindful of the situation.


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## erikmannie (Sep 24, 2019)

Regarding taps, I have always wanted some, but I always spent my money on other tools. I have a few loose taps that I got from my Dad, but I don't even have a tap handle yet.

My next purchase is parallels, V-blocks and metrology equipment (e.g. micrometers, dial indicators).


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## mikey (Sep 24, 2019)

There should be a simple bracket that looks like an inverted "T". Use that with the hard stops.


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## mikey (Sep 24, 2019)

erikmannie said:


> Regarding taps, I have always wanted some, but I always spent my money on other tools. I have a few loose taps that I got from my Dad, but I don't even have a tap handle yet.
> 
> My next purchase is parallels, V-blocks and metrology equipment (e.g. micrometers, dial indicators).



Okay, you really are starting from scratch ... enjoy the ride!


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## erikmannie (Sep 24, 2019)

mikey said:


> There should be a simple bracket that looks like an inverted "T". Use that with the hard stops.


A bracket that I fabricate? I am just sending an email to PM about whether or not one needs to remove the x-axis stop levers.

Honestly, at this point I am mostly curious about what percentage of people that buy an x-axis power feed don't use the limit switch.


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## higgite (Sep 24, 2019)

Something about the pics in post #38 doesn’t look right. I don’t have a PM mill, but on my mill, the limit switch doesn’t travel with the table. The LS is mounted to the table base, not to the table, and the stops hit the limit switch to stop movement. In other words, the way yours  appears to be mounted, the LS travels to the stops while on mine, the stops travel to the limit switch. Are you sure you have it mounted in the right place?

I found the instruction sheet for the PM-25MV from PM’s website. If you look at Figs. 5 & 6 of this link, I think you’ll see what I’m talking about.


			https://www.precisionmatthews.com/wp-content/uploads/2017/10/Power-feed-Install-Bench-mill-V1-4-29-2018.pdf
		


Tom


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## erikmannie (Sep 24, 2019)

higgite said:


> Something about the pics in post #38 doesn’t look right. I don’t have a PM mill, but on my mill, the limit switch doesn’t travel with the table. The LS is mounted to the table base, not to the table, and the stops hit the limit switch to stop movement. In other words, the way yours  appears to be mounted, the LS travels to the stops while on mine, the stops travel to the limit switch. Are you sure you have it mounted in the right place?
> 
> I found the instruction sheet for the PM-25MV from PM’s website. If you look at Figs. 5 & 6 of this link, I think you’ll see what I’m talking about.
> 
> ...


You make a very good point.  I’m sure that you are right.  There are no holes there in the mill. I will email Precision Matthews and ask if I should drill and tap the mill there for mounting holes. 

So what is the general consensus about not even using the limit switch?


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## mikey (Sep 24, 2019)

You might want to post your question about limit switch use as a separate thread. It is buried here and folks who are not following your thread will not see it.


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## erikmannie (Sep 24, 2019)

I will start another thread soon when I can get some time.

I called PM about this. They said that you do have to either (1) drill and tap holes in the saddle, _*or*_ (2) make a custom mounting plate and use the two holes that are already there where the silver "zero" indicator is.

The tech at PM said that the best way to go was the drill and tap route.


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## mcdanlj (Sep 24, 2019)

mikey said:


> Erik, those round X-axis stops in your picture are important. They allow you to positively stop a cutter at a precise location for repeated cuts, like the end of a slot in a thick work piece that requires you to take several passes to fully cut through.



I think it may have become clear in the intervening conversation, but just to be certain: the limit switch block _replaces_ the index key against which those round stops would run to index a precise location, as @higgite mentions. Following PM's install instructions, and unless I'm missing something that I want to learn for my own PM-30, you have to choose between limit switches and the hard index stops.



erikmannie said:


> Regarding taps, I have always wanted some, but I always spent my money on other tools.



Not to tell you how to spend your money, but only as information... A cheap set of common sizes of metric taps should set you back $10 or less. At least if you are tapping aluminum or plastic, spiral flute taps are nice in my opinion. You can chuck them in the mill and rotate it by hand instead of a handle, in many cases.


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## AlanB (Sep 25, 2019)

When I needed some unusual T nuts for my rotary table (to mount a chuck on it) I made them out of 6061-T6. Much easier to fabricate than steel and they work fine. If I was changing configurations every day perhaps they would be problematic but I don't remove that chuck often enough to be an issue.

Having an assortment of 6061 has been very handy for lots of things.


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