New PM-25MV Mill

I think it's a killer idea. Honestly, I would offer up different levels of kits... Keep a hardware set on hand and have it ready to ship, just in case some one wants a more complete kit... Assuming you have the financial and storage means to carry some inventory. You could also provide a hardware list, so they can just order it themselves.

The parts themselves look pretty dang good. The only criticisms I have is (A) I would try to use a fly cutter, or face mill on the flat surfaces you get a super smooth finish. (B) come up with a logo/name, and etch it into the big parts. That's really just aesthetics though.

Last I would say find someone on the board here that would be willing to give it a try. Hopefully someone that is willing to help you out with pictures of install so you can build some good instructions (if you want to take it that far). Once that mill is up and running have him take a bunch of vids to send you so that you can post them, some with the thing just chewing the some Al.

I could see this being a nice little side business, and with your skills I bet you could build some cool fixturing to really save you time and make nice parts. If it works, you could branch out to other machines... A kit for a PM-833T would be killer. (https://www.precisionmatthews.com/shop/pm-833t/)

As always, solid work!

PZ
 
I appreciate the feedback!

Honestly, I would offer up different levels of kits... Keep a hardware set on hand and have it ready to ship, just in case some one wants a more complete kit... Assuming you have the financial and storage means to carry some inventory.

There are a few reasons I wanted to offer only the machined hardware and not the ballscrews and bearings.
1. I couldn't buy anything in enough quantity to get a wholesale discount, so I would be paying the same price anyone else would, except I would need to pay for shipping twice.
2. I would need to support the ballscrews and bearings and make sure they were decent quality for a decent price. If a set is bad, then the purchaser has to ship them back to me, then I would need to ship them back. Again, paying for extra shipping.
3. I wouldn't be offering anything different than everyone else selling kits. Competing directly would be tougher than offering something different.
4. People can re-use ballscrews they already have, purchase used ones, or take advantage of any sales or discounts.
5. I don't really have the extra money and space to buy a few sets and store them.

The only criticisms I have is (A) I would try to use a fly cutter, or face mill on the flat surfaces you get a super smooth finish. (B) come up with a logo/name, and etch it into the big parts.

More good feedback, thank you. I have a face mill that creates fantastic finishes, but they are not perfectly flat. I figured the part being flatter would be better compared to looking nicer. Though for most of the parts, it doesn't matter how flat they are, so it looking better could be the better way to go. I have been thinking about a logo, but I am not the creative type. That is good advice though, I will try to come up with something.

Last I would say find someone on the board here that would be willing to give it a try. Hopefully someone that is willing to help you out with pictures of install so you can build some good instructions (if you want to take it that far). Once that mill is up and running have him take a bunch of vids to send you so that you can post them, some with the thing just chewing the some Al.

Is there any reason you would find someone else to do it, instead of just putting it on my machine and taking the pictures/videos with that?

Again thank you for the feedback!
 
Those are 5 good reasons not to get into the hardware business lol. You have obviously thought this out! In this case I would say just provide a drawing of what the ball screw needs to be... MAYBE go so far as to provide some part numbers for ball screws you know will work.

As for flatness vs finish... As a general rule I tend to pick function over form each and every time, however if you can make it look significantly nicer and not detract from the function, or add significant cost... make stuff shinny. I would challenge you to evaluate your parts, and make drawings with realistic tolerances. Like you said, some of those surfaces don't need a flatness on them at all... better to make them look nice. Remember people on the interwebs make decisions based on pics they see... It's marketing really.

As for a logo... Start with just a name, and etch it, or an abbreviation into a few parts. More marketing really, you just need to make sure that if someone sees some pics of it on the interwebs they know how to find you.

Last, I was thinking that you would keep yours up and running, but if you're going to tear it down, DEFINITELY write the instructions as you are assembling (IMO no instructions is not an option). MUCH easier to do it all yourself. HOWEVER... I would still find a guinea pig and have them install and post all about it. Again, marketing.

PZ
 
Great thread!

I had similar issues with my ball screws, but they work ... for now.
 
With all the photos of a dis-assembled mill in this post, how difficult is it to remove the head and table and then re-assemble? I have a basement workshop but there is no room on the basement stairs to take down a complete mill. I have restored a '40s Logan lathe but I have never worked with milling machines before. I do have a knock down engine hoist that can be used. Thanks for the help.
 
Its not hard at all. The head is very easy to remove, but I would remove the spindle motor first, otherwise it is very top heavy and has a tendancy to swing around hard when you loosen it up.

To remove the head, there are just three nuts that need to be removed and it pops right off. It weighs around 60 lbs, so be ready for it. There is also a little spike at the bottom to point to the head angle, and its a bit hazardous.

The table is about 55 lbs if I remember right and also comes off pretty easy. You just need to run the table to the end of its travels, remove the end blocks and loosen the gib up and it slides right off. Be careful when it is at the end of the travel because it may tip a little, especially if the head is already off.

Reassembly isnt too bad. The tough parts are getting the X axis gib back in place. I needs to be wiggles and nudged to get it to sit right. The head can be a pain in the butt to get the screws lined back up, but that is the hardest part. Then it just needs to be trammed back in.
 
Trying to make a lot of parts gave me a chance to push the machine harder and try to get even more out of it. I am making motor risers and at first it was taking about 10 minutes for the first operation for each part. I sped things up and got it down to about 5. I posted a video of it moving pretty quick if anyone wants to see.

 
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What is your max RPM right now? Looks like she was cooking!

Also, consider ditching the drill op... Looks like your pretty much machining it out with the end mill anyway.

PZ
 
What is your max RPM right now? Looks like she was cooking!

Also, consider ditching the drill op... Looks like your pretty much machining it out with the end mill anyway.

PZ
Holding steady at 7500. Can't really push it higher without a good deal of spindle work.

I didn't really want the drilling operation in there, but without it, there was trouble getting into the corners. The 1/4" end mill doing and adaptive cut would leave a lot of material. Then doing a 2d contour to finish it, there would be a lot of chatter when it got to the corner. When I used a 1/8 end mill to do the adaptive, it got into the corners just fine, but took 4x as long to do it. The drill time for that operation is 32 seconds (and I have been running 2 parts at once and the other part needs holes drilled, so the drill will be in the spindle anyway) and so far is the best way I have been able to figure out how to do it. I think if I spent some time figuring out ideal feeds and speeds for drilling, I can speed it way up.
 
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