# Power Feed on a SIEG X2 style large table from LMS?



## SwarfMuncher (Aug 31, 2015)

Little Machine Shop sells an oversized base and XY table for the SIEG X2 style mini mills. Their part number for it is 3677.

I am interested in upgrading my Homier X2 style mini mill with that table, but rather than spend an additional $300 to get the power feed kit that is made for that table, I would like to use the existing power feed I have on my Homier, which is also sold by LMS as part number 2501 (the one with the 0.050" per turn lead screw).

I asked LMS about it and Chris told me the way the 3677 power feed is a bolt on accessory is quite different than how the 2501 connects, so he doesn't think this is possible. But one thing I have learned in over a decade in this hobby is that these little machines have great potential, and many things are possible simply by designing and building what they need to achieve a goal. Indeed, I have a second 2501 power feed box that I just installed as a belt fed drive for my Y axis on this mill.  I should be able to move it to the larger 3677 with minimal fuss. 

So I think it is just a matter of making the right adapter interface between my 2501 power feed and a new 3677 table. I am wondering if anyone has done this already, or has devised any other custom power feed for the X axis on the 3677? 

Any advice will be appreciated.


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## XD351 (Aug 31, 2015)

Hi swarfmuncher ,
I have the same power feed unit on my x2 and found it wanting in power so with the extra surface areas of the larger table dovetails it may struggle .
The  way it mounts onto the table looks like it is just a matter of an adapter plate in place of the end plate on the table and maybe have to extend the drive coupling.
I suspect the mounting holes in the end of the table will be further apart on the larger table so a simple 3/8 thick adapter plate drilled and counter bored for the holes in the end of the table and drilled and tapped for the holes in the drive unit housing which are the same as the  holes in the end of the x2 table .
The only issue could be if there is not such a significant difference in the spacing of the holes in the end of the larger table versus the old small table to allow you to make the adapter plate fit 
the coupling is just some round bar drilled one end for the drive shaft on the drive unit and has some grub screws holding it on the shaft , the other end is drilled and has a drive pin fitted through the coupling to mate up to a slot in the end of the feed screw . 
Check out a youtube video by stefan gotteswinter as he makes a very nice clutch unit for his optimum mill that may give you some inspiration .

Ian.


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## SwarfMuncher (Aug 31, 2015)

Hi XD351,

I am curious if you have one of those power feeds that has been tweaked for added power?

Initially, I had a terrible time getting mine to work, as it kept bogging down and stalling out, simply moving the table at its extremes, especially on the RH end as you face the mill, even when not milling anything I even went so far as to add an ammeter to my power feed box, to watch the current being drawn by the motor, so I could try to adjust the gibs a little to add a bit of slop (unhappily) so it moved easier. 

Eventually I did some research online and discovered that LMS had a procedure in which, if I remember correctly, a resistor was removed from the control board and replaced with a different value. I have all the original paperwork from the process in my cabinet, but I don't remember if that was all we had to do. Anyway, the result is that the motor can now draw more power before the controller shuts it down. I seem to recall the internal power allowance being boosted from perhaps .75A up to 1.2A? On my meter it typically pulls about 200ma when things are freshly adjusted, and about 400ma through most of a milling load across the table. On the right end it climbs to over 800ma and eventually bogs down, but it usually makes it all the way now before it stops from the built in overload circuit. 

If you have not done this mod, it is easy if you are comfortable with soldering electronics, and well worth the time spent. 

I ordered the large table, and hope that the quality of gib and leadscrew nut machining has seriously improved since I got the mill about 11 years ago. 

Thanks for the tips! As long as the screw holes don't try to reside partially overlapping, your ideas sound like the way to go. On another forum someone suggested I add a sliding dog clutch engagement device in the adapter. I've never really minded the direct connection on my existing power feed and table when hand cranking. It turns pretty easy. And if I'm going any distance I use the power feed to get close anyway. 

If the screw locations do become a problem, I know there is some room behind the mounting plate inside the drive units we have. So I could probably move its mounting holes elsewhere to make it mount up to the large table, or an adapter plate, if needed.. 

I know the drive made for that table is a bolt on accessory accessing the end of the leadscrew through an existing plug in the end pate of those tables. I just don't yet know how it is configured behind that plug. But there should be some way to connect things. 

Thanks!


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## XD351 (Aug 31, 2015)

Hi SwarfMuncher,
I haven't really looked into the problem yet and i didn't know of the procedure from LMS but will have a look on their website for it.
I would suspect the resistor change could raise the output voltage of the internal power supply in the PWM unit so it is pulsing the motor with a higher voltage.
I only briefly looked at the circuit board from memory just a simple controller using a switch mode driver IC to switch a transistor or scr etc.
I would also like to add a jog button for fast feed ,once i strip it down and sort out the circuit i will know more
Thanks for the tips etc and the lead for the LMS conversion !

Ian.


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## SwarfMuncher (Sep 1, 2015)

Hi XD351,

If you can't locate the info on the power feed resistor change, I'll dig through my paperwork and see if I can find it. I was just looking on the LMS site and didn't see any mention of it anywhere. It is possible that newer versions of the power feed box being sold now already have the modification installed. If I ever need to dig into the new power feed box I had just bought for my Y axis belt drive project, I plan to look and see if it has the conversion. It does seem to have enough power to move the Y axis OK. I used a 1:1 pulley ratio between its motor and the handwheel. 

When the new larger table arrives, I plan to use the new power feed for my belt drive as a stand in power feed for it, while I engineer how to connect one of them to the table. That way I will still have a powered X axis to use on the mill while making whatever parts I'll need to make.


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## SwarfMuncher (Sep 1, 2015)

I've been watching the Clutch videos on You Tube by Stefan Gotteswinter, and I have to say it must be nice to be able to make the aggressive kind of milling and boring cuts he is making on the full sized mill.  Weight and mass sure make a difference. He does nice work and has some very nice tools. 

When I added a handwheel to the leadscrew on my 7x10 mini lathe I made a clutch similar to his, but it doesn't use dog teeth. It uses a roll pin through a shaft, with a slotted tube collar on the mating shaft. I can use it to engage or disengage the leadscrew from the gear drive just by sliding the collar back and forth. Something similar may come in handy on the power feed for the larger table.


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## XD351 (Sep 2, 2015)

Ok thanks i will have a look over the next few days ,might even send them an e-mail .
I'm also interested in your lathe mods as i have the same machine , i have seen a few ways of doing this but they seemed to me to be too much work for something like this mostly modifying the gear train brackets etc but something that can just slide along a shaft sounds much easier any chance of a few pictures ?
My lathe has a 3ph conversion , mainly because it was just as cheap to do than purchasing a new motor and controller , i ended up doing a v belt set up with a layshaft etc and steel gears in the head .
I intend to re visit this set up as the gears are too noisy and i will convert to direct drive and get rid of those noisy gears !
So many mods so little time !
Just found the torque mods to the board on the LMS website , it is in the chris's  tips section at the bottom of the page for the power feed unit and it is r23 that gets changed you can also increase the motor load trip setting using the potentiometer on the board .
By changing r23 to 2k it gives a 30% increase in power .

Ian


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