First Milling Machine Choice: PM 833T or 835S?

ACHiPo

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I'd really like to get a mill. After thinking about getting a better drill press to replace my Atlas bench-top, I looked at drill presses. Then started looking at the bench-top models from Weiss, and the WMD30 looked like it it would be a great drill press and get me started on machining. Then I read about the PM833T and THAT seemed like the bees knees. Along comes the 835S and I'm thinking it's perfect for me. (See a trend?)

So, why do I want a mill?
1) So I can drill big holes in stuff (the Atlas belt slips or motor stalls when trying to drill holes approaching 1")
2) To learn about milling: to make faces of things flat and square
3) To repair and/or make parts for my Cobra replica

I have limited space in my shop (a good sized 2-car garage), and multiple hobbies (woodworking, auto repair, metal working), so I decided on a strategy of putting everything on mobile bases. This is working very well for me, and I plan to put the mill on wheels as well.

My plan for the WMD30 or PM833T was to get a sturdy steel cabinet with drawers that I could augment with a steel frame with casters--voila a mobile mill with storage space for tooling. I still like this idea, although have pretty much dismissed the WM25 as too small. ThePM833 would be about 1100 lbs on cabinet full of tooling, which I figure is about as massive as I want to try to wheel around.

The new 835S appears to have all the feature of a Bridgeport clone, but at 3/4 size (and weight). The weight's about the same as the 833, but instead of extra storage, I get 17" of Z travel.

I've read the multiple recommendations to just buck-up and get a Bridgeport. Given my interests, I just don't want to make that much of a commitment to a mill.

I'm not in any hurry, so I'm not terribly concerned that Matt only has a drawing of the 835 at this point.

Thoughts? Comments? I definitely want 3 axis DRO, but how many axis auto-feed? What about chuck choice? Collets? Vise?
 
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Man, every time I look at the PM site I get to drooling!

I would seriously consider that 835S. What I especially like is that it has a real knee on it. That allows you to keep the quill retracted for maximum rigidity/accuracy and raise the work like a real mill. The tilt and nod is not usually used all that much but it makes tramming a whole lot easier than trying to shim a column. Very importantly, it looks like the spindle runs in a cartridge, as opposed to running in bearings held in the head casting. This is a more rigid and precise arrangement and just on this basis and the knee, I would opt for the 835S. 2HP is enough for most jobs you'll do on this size mill; if it had VS, that would be awesome and I have to wonder if the model to follow will have this option - might ask Matt. It gets up to 2720 rpm - very useful for small cutters and carbide tooling.

This mill has an R8 spindle taper so all the common stuff will fit it - collet chucks, collets, drill chucks, etc. The table looks just about right for a 5" vise but I bet even a 6" will fit okay - you have 9" of Y-axis travel. I would probably opt for the 5" vise, though.

If you can swing the DRO, that would be awesome. You want (as opposed to need) at least an X-axis power feed. I'm not so sure you need power on the other axes but will let others who have it chime in. To my thinking, I would get the X-axis feed and use the money that would have gone to a power feed on the other axes to accessorize the mill. It would be nice if it had power down feed on the quill for boring or power tapping but you can live without it.

Brother, this ain't no drill press! This is one of them wet-your-pants benchtop milling machines and now you got me thinking!
 
Mike,
Great feedback as always. I'll give Matt a call next week and ask about availability, power downfeed, and variable speed.
Evan
 
I'll agree with mikey here, in that if you can afford it and have the space a knee mill of whatever size has advantages over a bench/bed mill. Both can do good work, but the knee makes most things easier.

And I'm very jealous. My dream was to get a decent garage shop set up and build a FF5 replica. Things didn't turn out the way I planned (do they ever?) so the only way I'll ever own a replica is for me to build a plastic model of a Cobra.

I did manage to get the lathe and mill I wanted so at least I accomplished something. :)

EDIT: Went back and read the description on that new 835, and it says "full featured head". So I'll bet my lunch money it has PDF just like my 935TS.

SECOND EDIT: At the bottom of the page for the 835 (or any of his machines for that matter) there is a 'specification' tab. There Matt specs the 3 speeds for the PDF and says there are 8 speeds for the spindle (belt). So the head is basically like mine on the 935TS. Wouldn't be surprised if he's sourcing the head from the same factory.

Put a VFD on that thing like I did my 935 and you have variable speed belt drive without all the mechanical contrivances of a Reeves drive. :)
 
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Bill,
I hear you regarding the Cobra bug. I came very close to starting a project 17 years ago--in fact if I'd had my checkbook with me when I visited ERA I would have written a down-payment check. After one ride in an ERA I was hooked. Well, life happened, and it's just as well I didn't go through with it as I would have had to sell it 3 years later due to a divorce (and it likely wouldn't have been completed so that woulda been expensive and difficult, although come to think of it if I HAD pulled the trigger, the divorce would have come much earlier, so a guy never knows :confused:). Fast-forward 13 years and I get relocated to CA from OR and end up with a 3-car garage AND a 2-car former guest cottage aka shop (with flowered wallpaper and ugly vinyl), so after getting settled and somewhat set up, I began restarting previous passions like audio, woodworking, cars, and now metal working. At some point I hope to get rid of the vinyl and walls and turn it into a proper man cave, but I digress. Hope you can figure out a way to at least some time with a Cobra--there's an active community of enthusiasts in AZ, and I know I love giving someone a ride whenever I can. (By the way my daughter's boyfriend's parents are in Sierra Vista just up the road from you).

I suspect you're right about the head--it sounds like a standard set of pulleys with a belt (not a fan of that or the mechanical variable speed Reeves drive).
By the way, what does the "spindle down feed in 3 steps" mean? Does it have a powered downfeed? Edit: Now that I re-read your post above I realize that PDF means power down feed not an adobe document. :confused 3: The 835S is looking better and better!
 
Bill,
I hear you regarding the Cobra bug. I came very close to starting a project 17 years ago--in fact if I'd had my checkbook with me when I visited ERA I would have written a down-payment check. After one ride in an ERA I was hooked. Well, life happened, and it's just as well I didn't go through with it as I would have had to sell it 3 years later due to a divorce (and it likely wouldn't have been completed so that woulda been expensive and difficult, although come to think of it if I HAD pulled the trigger, the divorce would have come much earlier, so a guy never knows :confused:). Fast-forward 13 years and I get relocated to CA from OR and end up with a 3-car garage AND a 2-car former guest cottage aka shop (with flowered wallpaper and ugly vinyl), so after getting settled and somewhat set up, I began restarting previous passions like audio, woodworking, cars, and now metal working. At some point I hope to get rid of the vinyl and walls and turn it into a proper man cave, but I digress. Hope you can figure out a way to at least some time with a Cobra--there's an active community of enthusiasts in AZ, and I know I love giving someone a ride whenever I can. (By the way my daughter's boyfriend's parents are in Sierra Vista just up the road from you).

I suspect you're right about the head--it sounds like a standard set of pulleys with a belt (not a fan of that or the mechanical variable speed Reeves drive).
By the way, what does the "spindle down feed in 3 steps" mean? Does it have a powered downfeed? Edit: Now that I re-read your post above I realize that PDF means power down feed not an adobe document. :confused 3: The 835S is looking better and better!

When I moved from SoCal to the Bay Area (Mission Hills, SJ 1991-2000) I quickly got into track events. Built a nasty little gen3 RX-7 that could smoke the M3 tube-framed race cars at Laguna Seca. Then started playing with my Saleen and started doing time trials (Solo 1) at the various tracks in the area. The RX-7 was like a surgeon's scalpel on the track. Smooth was the trick to fast lap times in that thing. The Saleen on the other hand was like a bull-in-a-china-shop on steroids. The Saleen would post faster lap times everywhere except Laguna (more technical track), but man, hustling that thing around for a few laps was very tiring.

At one Solo 1 event I was given the opportunity to do some test laps in a Factory Five race car. Didn't stop grinning for days. Wanted one REAL bad. Won't happen now, but that's OK. Not everything turns out the way we'd like them to. :)

I read the specification sheet on that 835 and it does indeed have power down feed. With three different feed rates, just like my 935TS. It has a 2hp motor (according to the spec sheet). I don't see a 3-phase offering on the motor which would allow you to install a VFD and have the best of both worlds. You may be stuck with the stock 8-step spindle speeds. Not that this is a bad thing.
 
When I moved from SoCal to the Bay Area (Mission Hills, SJ 1991-2000) I quickly got into track events. Built a nasty little gen3 RX-7 that could smoke the M3 tube-framed race cars at Laguna Seca. Then started playing with my Saleen and started doing time trials (Solo 1) at the various tracks in the area. The RX-7 was like a surgeon's scalpel on the track. Smooth was the trick to fast lap times in that thing. The Saleen on the other hand was like a bull-in-a-china-shop on steroids. The Saleen would post faster lap times everywhere except Laguna (more technical track), but man, hustling that thing around for a few laps was very tiring.

At one Solo 1 event I was given the opportunity to do some test laps in a Factory Five race car. Didn't stop grinning for days. Wanted one REAL bad. Won't happen now, but that's OK. Not everything turns out the way we'd like them to. :)

I read the specification sheet on that 835 and it does indeed have power down feed. With three different feed rates, just like my 935TS. It has a 2hp motor (according to the spec sheet). I don't see a 3-phase offering on the motor which would allow you to install a VFD and have the best of both worlds. You may be stuck with the stock 8-step spindle speeds. Not that this is a bad thing.
Bill,
You've got a lot more experience with these things than I do. The only race track I've been on was running Rotax go karts. I hope to take my "starter" Superformance Cobra up to Thunder Hill for a beginner's class this fall just to test its (and my) limits in a relatively safe environment. My "final" Cobra will start construction in September and plan to have it completed and on the road by May of 2018.

I checked out your new digs--looks like you've still got a nice set up. I wouldn't be surprised if you couldn't generate a build a nice little business--it seems there's always a need for machining, although I'm not sure how willing folks are to pay a fair price for it.

I was wondering how to do variable speed with a single phase motor--I guess I don't. It will be interesting to see what Matt has to say next week.
Evan
 
Many people are too greedy, in that they want top shelf quality for Harbor Freight prices. Had a 'gentleman' ask me to basically build him a $6000 full-on custom pistol with months of work involved, but he wanted it for $2k. My first impulse was to kill the idiot and put his head on a pike out front as a warning to other idiots, but then I realized that we've not been allowed to do that since the medieval days... ;)

Never drove a Rotax. I did scare myself silly on the front straight at Willow Springs in a 250cc shifter cart. Something about doing triple digits, a few inches off the pavement, and looking between your feet to see where you're going. Right then I decided those guys are nuttier than the guys road racing on two wheels and dragging a knee in the corners (did that too for a bit).

If the 835 has a 2 hp single-phase A/C motor, then you're pretty much stuck with what you get, unless you decide to change motors. Which depending on personal preferences, may or may not be worth it. :)

Let us know what Matt says about the new mill?
 
Put a VFD on that thing like I did my 935 and you have variable speed belt drive without all the mechanical contrivances of a Reeves drive. :)

Hey Bill, did your 935 originally come with 8-speed pulleys? If so, how well did that work for you? Was it restrictive enough that it made you go to a 3ph VS setup?

I ask because this mill looks to be almost the ideal hobby class mill. In my mind, the only thing that it lacks is a VS motor but that might be an issue only in my mind, hence my questions. If a VS model is forthcoming, it might be worth the wait because while you can add VS later, it isn't that cheap to do if you use quality components, and it won't be covered under a warranty. Optionally, if Matt agrees to upgrade the motor at a reasonable cost if it becomes available later then no waiting is required.

It is not fun living vicariously through your experiences ... :(. Let's see - Evan, Bill, @Ulma Doctor, @darkzero - I hate all you guys!
 
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