[ChrisAttebery]

I've decided that it's time for a couple upgrades on my mill. I bought the material to make column and head spacers. The column will be moved back 2". That will give me an extra 1" of Y travel and leave 1" for the Y axis way cover. I have some 12" wide by .060" sheet rubber to make a new cover with. I'm going to move the head back out 1.5". That will center it up on table and give me a usable Y travel of 7".

My new treadmill motor has been working pretty well, but I think realistically it's about 3/8 HP at 6000rpm. If I try to push it any harder than that it starts to arc the brushes.

The chip shield I installed in April worked out great. I haven't had any more chips on the front of the Y screw. Once I get the new rear cover on I shouldn't have any more trouble with chips on it. I still get an occasional click on the X screw. I think I need to pull the ball nuts and replace the balls.

I've made about 300 parts so far this year. I've only had to scrap about 4% of those.

[ChrisAttebery]

I got my column spacer done over the weekend. I used the mill to drill a 1" deep pilot for each of the holes. Then I milled a pocket 5/8" deep. I finished the 5/8" diameter holes on my drill press. With the motor geared 1:1 it just doesn't have enough torque to drill anything bigger than 1/4" in steel. I think it came out pretty well though. The picture is deceiving, the finish is smooth to the touch. Kind of like a scraped surface.

I used a 4F 1/4" carbide end mill at 3000RPM and 12IPM. I took a .050" x .050" cut.

Now to start on the head spacer. The only 5" round stock available at the local supplier was 4140 so I'm hoping that it doesn't become a PITA.

[Fastest1]

Cool that is 1 of my next projects.

[ChrisAttebery]

Get er done son. :^)

[ChrisAttebery]

Well, apparently I cursed myself, that 4140 WAS a PITA to work with. :tired: I had to turn the RPM down to ~1200. At that speed the motor doesn't have much torque. I wound up snapping a couple drill bits and a 1/4" carbide end mill. So, I decided that 6061 should be fine for the head spacer. I bought a 2" slice of 5" diameter on my way to work this morning. I'll get it done sooner or later.

The only 5" round stock available at the local supplier was 4140 so I'm hoping that it doesn't become a PITA.

[Aaron5Bend]

The only 5" round stock available at the local supplier was 4140 so I'm hoping that it doesn't become a PITA.

[ChrisAttebery]

Well, I seem to have smoked another treadmill motor. I'm not 100% sure why. I have a couple theories though. First, I looked at the output of the KBMM and with the MAX speed adjustment all the way down I'm still getting 120VDC on the output. I could have sworn that I had this down to 90VDC when I put the motor on. I think the pot on the board may be bad. I'll add an external pot to adjust the max speed. I also did a 2-3 hour program with the motor running around 1000rpm which may have caused it to overheat.

I put the stock motor back on the machine yesterday and started making a head spacer out of aluminum. I've got one side done and I need to flip it over and finish the other side the next time I get out in the shop.

[luv2ride]

That's too bad about your motor troubles. Hopefully the stock motor will do what you need it to.

[ChrisAttebery]

I finished my head and column spacers. I wound up getting about .5" more travel on the Y and mow the way covers don't get pinched when the table is all the way back. I need to readjust my home switch for the Y axis to account for the extra throw. I also need to look at moving the bracket the holds the Z bellows and Y cover to the column. As it is now the bellows runs out of travel before the spindle hits the table by about 1.5". That's going to interfere with the automatic tool length offset touch plate with some of the smaller tools I use.

[ChrisAttebery]

BTW: I figured out why the voltage was so high on my KBMM. The manual states that the MAX and MIN are interdependent, but never mentions the fact that the ACCEL setting also affects the MAX setting. So I had turned the ACCEL setting up to get the spindle up to speed faster and it turned the max voltage up to 120V. I set it back to 3-4 seconds and the max voltage is back down to 100V.

I was never that happy with the treadmill motor. It was noisy and didn't seem to have that much more power than the stock motor. I found one of the 1100W motors like Hoss uses for a reasonable price, so that will be my next purchase/upgrade.

[Fastest1]

I bought one of those 1100 watt motors too. What a PIA it was to actually receive it. It took an incredibly long time ( 2 months ) even though I paid for direct shipment from China. It was thru a stateside supplier who will go unmentioned as they were going out of their way to try and help me. The owner finally called and it was remedied almost immediately after he became involved.

[gcofieldd]

BTW: I figured out why the voltage was so high on my KBMM. The manual states that the MAX and MIN are interdependent, but never mentions the fact that the ACCEL setting also affects the MAX setting. So I had turned the ACCEL setting up to get the spindle up to speed faster and it turned the max voltage up to 120V. I set it back to 3-4 seconds and the max voltage is back down to 100V.

I was never that happy with the treadmill motor. It was noisy and didn't seem to have that much more power than the stock motor. I found one of the 1100W motors like Hoss uses for a reasonable price, so that will be my next purchase/upgrade.

I have been thinking about getting a BLDC and driver from Skyfire when he gets his website up.

Also, I found a 1.13 HP three phase motor that is about 4 inches square that you could use a VFD with. The info is in my thread "Graham's BF20 Conversion"

[ChrisAttebery]

That's more than I want to sink into this machine right now. The 1100W motor should be more than enough power for my use. I'll save the 3 phase route for a bigger machine.

[COMachineist]

That's more than I want to sink into this machine right now. The 1100W motor should be more than enough power for my use. I'll save the 3 phase route for a bigger machine.

Hi Chris
Can you post the info where and how you got 1100W motor? I am looking to do the same thing with my 0704. I have toasted 2 treadmill motors also, I thing they just get hot and die. I have been in contact with the Chinese supplier about one of the 1.5kw 6000 rpm motors but they want a lot of money to get one. I can get a 3ph and VFD for less. I may still do that any way.
CH

[ChrisAttebery]

Once I have one ordered, sure.

[COMachineist]

Oh, sorry I thought you had already ordered and was getting it soon, My bad. I have tried to contact Weiss Machinery in china but so far no reply. Just wondering how to get a response from them.
Thanks Chris
CH

[ChrisAttebery]

OK, I got the motor from machinetoolonline.com importers of the Precision Matthews machines. They had ONE motor off the older style PM-30 mill and I got it for $115 shipped. From what I recall the difference between the older and newer motors was the motor mount was changed but it won't matter for my purposes. It should be a decent upgrade from the stock 700W motor. I'm only getting about 1/4HP from that motor before it starts lugging down.

[COMachineist]

Hi Chris
Ok, I saw that web site maybe I'll check with them as I can't get Weiss to replay to my e-mails. I have a Belt drive from Hoss's plans and all I need do is make a mount to fit the larger motor. So I guess I will keep looking. I still like the 3ph/VFD better really. You get a lot more power and speed from it than a DC bush motor. you can gear it for a lot of speed if needed because of the increase in torque. Let us know What you think of the 1100w motor when you get it going.
Thanks
CH

[ChrisAttebery]

Well, I did my first cuts with the mill since I added the head and column spacers. I wasn't pushing it that hard, but I was getting chatter. I swapped tools but it didn't improve much. I noticed that when the tool touched off to measure offset that the head was flexing upward. I'm wondering if it's because I used aluminum for the head spacer, if I need to torque down the bolts down more, or if it's because there is a lot less surface area between the head and Z slide. I'll look into it a bit more tonight if I get a chance. Otherwise it's going to be Sunday night before I can look at is again.

[SCzEngrgGroup]

Well, I did my first cuts with the mill since I added the head and column spacers. I wasn't pushing it that hard, but I was getting chatter. I swapped tools but it didn't improve much. I noticed that when the tool touched off to measure offset that the head was flexing upward. I'm wondering if it's because I used aluminum for the head spacer, if I need to torque down the bolts down more, or if it's because there is a lot less surface area between the head and Z slide. I'll look into it a bit more tonight if I get a chance. Otherwise it's going to be Sunday night before I can look at is again.

The answer is most likely "D) All of the above." Plus the head spacer increases the leverage of the tool in flexing/moving everything. And, any existing slop in the gibs, etc., will also be magnified. A head spacer is pretty much guaranteed to measurably reduce overall machine stiffness and precision. Making it out of aluminum, unless it's *really* badly made, will not be a factor at all.

Regards,
Ray L.