[mrcodewiz]

Haven't made too many updates to my machine lately. I picked up an air cylinder off of ebay cheap a couple weeks ago in order to add a pneumatic drawbar. There have been a lot of good ideas flying around here lately on that topic and it has motivated me to put one on the mill. The cylinder was supposed to be NOS. It may be but I cracked it open to find that the shaft is pretty rusted. First step after the holidays will be to replace the shaft. I'm just going with a manual lever... no plans for an ATC any time soon. I am probably going to redesign the treadmill mount while I'm at it or at least the tooth count on the gears. Once I wired the spindle control to the BOB I found that I lost about 750 RPM or so. I want to get my max RPMs back up to 5500 to 6000. I never drew it up the first time so I will try to do that this time and add it to my cnc plans thread.

[dugpits]

Is that an MP3x1-4-1?

Looks just like the one I got recently - glad I read your post.

I should open mine up. Bet the shaft is rusted on mine too.

[mrcodewiz]

Is that an MP3x1-4-1?

Looks just like the one I got recently - glad I read your post.

I should open mine up. Bet the shaft is rusted on mine too.

Yes, it's an mp3-1-4-1. I could see rust on the mounting bolts in the photo but the ad said something like 'new old stock. Dust from sitting on shelf' or something like that. I submitted a low best offer and they accepted.

The rest of the internals look fine. I had to spray down the nut in liquid wrench and let it soak a couple days to get it off. I'm soaking the ram now. I think that shaft is just 7/16-14 allthread.

[mrcodewiz]

Finally spent some time at home so I made a little progress on the drawbar. I don't have a picture but I got the cylinder cleaned up. There were little bits of rust in each cylinder that had flaked off of the rusted shaft and stuck to the grease so I disassembled the whole thing and cleaned it out. I replaced the rusty shaft with some 7/16-14 allthread.

dugpits - if you end up doing the same thing, the shaft is red loctited into the ram so it needs heat to come out.

I modeled my PDB after the one gd.marsh posted in his 45 thread (which I think was based off of Hoss'). I first made a new drawbar. I made it a little long so I could trim it up once I worked out all of the details.



Here is the general idea. My cylinder came with mounting bases that were only 3.5" square so I just replaced the through bolts with some longer 3/8-16 allthread to mount to the floating plate.



I am using the 9712K437 bellevilles from McMaster. They are rated at 900 lbs with .019 of deflection. I stacked them like (())(())(( for double the load (1800 lbs) and 5 times the deflection.





I still need to add the alignment pins. I just mounted it up to see if there was enough deflection which there appears to be. The tool doesn't drop free though. I have to pull it out so I may add some more deflection in the future should I ever go to automated tool changes.

Once I get the pins in and mount the RPM sensor back up, I will draw it up and put everything in my cnc plans thread along with the various parts I used. I will just draw up the entire system - PDB, motor mounts for the treadmill motor, pullies for the belts, etc, etc. I used Hoss' spindle sleeve for the pulley spindle mount though so I won't be posting that. You could just direct mount the pulley to the spindle. I went with his design for that because I wanted to keep the quill useable but this PDB sort of cancels that out anyway.

Oh, I'm also eventually planning on making the spindle pulley a little bigger. Once I went to spindle control on the C11, I lost about 1000 RPM on the treadmill motor. with the manual control I could get a little over 5K out of it and now it maxes out at 4000. If anyone knows some way to fix that I would like to know. Maybe the manual control lets you send through more voltage? I don't know much about the electronics side.

[mrcodewiz]

I haven't drawn everything up yet. I was having some parts powdercoated so I threw in all of my drawbar parts along with them. Hopefully I get them back this week.

I ended up finding my lost RPM so I should be back up to the 7K or so that I wanted to be at without having to make another pulley (and without having to underpower the motor)

I also noticed that even though the cylinder is fairly heavy, it doesn't always release the collet. I have a vague idea as to how to make it do it consistently but I need to try it out.

[mrcodewiz]

Parts came back from the powdercoater and re-attached to the mill. I used the mounting bolts from the safety shield to mount the air lever to.



Also, I did this a while ago but I cut off the end of the Shars vise in the bandsaw and cleaned it up on the mill. I don't run into the column with it now.

[Connor]

Parts came back from the powdercoater and re-attached to the mill. I used the mounting bolts from the safety shield to mount the air lever to.



Also, I did this a while ago but I cut off the end of the Shars vise in the bandsaw and cleaned it up on the mill. I don't run into the column with it now.

Is that the 5" or the 6"?

[mrcodewiz]

It's the 5" (550V)

[Connor]

It's the 5" (550V)

OKay, yea, was going to say that looks like what i have.. Little nervous about cutting off the back lip though, and I don't think my bandsaw is up for it..

[mrcodewiz]

I just have a sorry old worn out Harbor Freight 4X6 bandsaw. I just cut through halfway on one side, flipped it over to do the other, then cleaned it up on the mill.

[mrcodewiz]

I picked up a spare motor. It isn't the exact model I already have but it is the same style - just a higher HP. I expected it to be a little bigger but it is quite a bit bigger. It is about as big of a motor as will dimensionally fit on the head and not interfere with the column or the power draw bar. Hopefully it isn't too heavy. The stock motor is about 10 pounds, the current treadmill motor is about 11 and this one is about 22. I will probably mount it up temporarily just so I can move the head around and see how it does. Coming up with a mounting bracket will be a little trickier than the smaller one too since it doesn't fit between the supports.

Here is the backup next to the existing treadmill motor.



and mocked up on top of the head

[DRock]

Is that one of the 425 Oz Nema23s motors? It looks like a lot of weight, I hope it works out because I plan on using a similar motor.

[mrcodewiz]

Is that one of the 425 Oz Nema23s motors? It looks like a lot of weight, I hope it works out because I plan on using a similar motor.

That stepper is a nema 34 640 oz.

[mrcodewiz]

I made one of those work stops for my X2 that bolts to the back of the vise but I hadn't made one for the G0704 yet. I didn't want to do it like the X2 since I already had issues with clearance between the column and the vise so I looked around the web and found some that just bolt to the table. Here is my quick and dirty version.

[mrcodewiz]

I hooked up the larger backup motor. I was hoping it would cure some issues I am having with surface finish using a 3" facemill which I was attributing to vibration from my motor/pulley setup. It did help quite a bit but it still isn't perfect. It runs considerably quiet now, though.





Here is the motor running at 1000 RPM

G0704 :: 269ee101.mp4 video by mrcodewiz - Photobucket

Running at 3000 RPM

G0704 :: 3e250ee6.mp4 video by mrcodewiz - Photobucket

Running at 6000 RPM

G0704 :: 05cb1cd7.mp4 video by mrcodewiz - Photobucket

[mrcodewiz]

I haven't posted to this thread in a while - mainly because I haven't done anything to the machine. I have just been busy making stuff which is nice.

I have to say, adding the PDB has been the best thing I have ever done to either of my mills. The time saved in not having to remove and insert a new collet and re-zero at every tool change is ENORMOUS. I used to plan my parts to minimize tool changes but now I worry more about jigs and part placement. I could use a lot more holders but even what I have now is a huge help. I just need enough to fill up my tray.



I have been trying to follow along on some of the ATC threads. I would like to see someone come up with a real simple setup for the bf20.

[Fastest1]

Why can't Hoss or similar be mounted on any table?

[mrcodewiz]

I'm sure it can. I guess I was hoping to leave the ends of the table free but for the small number of tools i need, maybe I will end up going that route. I'll have to dig back through that thread and see how it worked.