What's new
What's new

Newbie Scraping a mini Mill

radiocontrolhead

Aluminum
Joined
Jan 8, 2018
Hey all.

Quick question. Am I out of my mind for trying to bring the 4 raised blocks on the base down to the same level by means of filing? I do not have access to a mill or a grinder at this time (will grind the other 3 blocks using a powered grinder).

My real questions, without a mill to bring all 4 blocks to within a scraping tolerance (say a thou) am I in over my head to rough scrape to where i need to be or will i be chasing my tail.

I'm really new to this whole thing and I wanted to get started on the project and may have jumped the gun a bit too early.

The idea was to great a much more uniform and even bearing surface instead of just the 4 tiny blocks that the column sits on.


Thank you all for your help.

Again, I'm a newbie and appreciate your patience and input!

image1.jpg
 
Hey all.

Quick question. Am I out of my mind for trying to bring the 4 raised blocks on the base down to the same level by means of filing? I do not have access to a mill or a grinder at this time (will grind the other 3 blocks using a powered grinder).

My real questions, without a mill to bring all 4 blocks to within a scraping tolerance (say a thou) am I in over my head to rough scrape to where i need to be or will i be chasing my tail.

I'm really new to this whole thing and I wanted to get started on the project and may have jumped the gun a bit too early.

The idea was to great a much more uniform and even bearing surface instead of just the 4 tiny blocks that the column sits on.


Thank you all for your help.

Again, I'm a newbie and appreciate your patience and input!

View attachment 217393

?? Are you expecting to cray-glue that toy to a surface plate a foot or more THICK?

Masturbatory, 'coz otherwise what you do is SHIM those feet.

Even if they had arrived perfectly flat and in-plane the surface you mount them to cannot reasonably be expected to be anywhere CLOSE to flat. Nor remain so.
 
Ouch!!!

Firstly, this forum usually prohibits hobby-only machines, so don't mention the name, the thread may get locked. Try to speak in generalities.

The carriage is about a mile in front of the horse.

It isn't clear that you would have gained much rigidity by this process anyway, but now that you are there, there are a few options.

1) Leave the other three pads alone, and make up a block of metal to fit.

2) Buy another baseplate.

3) Continue what you are doing till it is done.

All of these have a common problem. Geometric alignment. How are you going to know that everything is in order?

You needed a plan BEFORE you started filing.

Do you have the inspection equipment/knowledge to measure/test the squareness of the column to the base.

It isn't enough to just be level. It has to leave the column square in two dimensions to the x-ways.

Monarchist;

This isn't about mounting the base of the mill, these I think are the pads that the mill column rests on.

Folks may offer better suggestions, but be prepared for a drubbing.

p.s. There are other forums where these machines are permitted/encouraged. You will find more info there.


regards,

Jon P.
 
Yes thank you gentlemen for the help. I am quickly realizing that this isn't the place to be posting these questions and will move over to a different forum.

For the sake of continuing the discussion. I have a inspection equipment including a surface plate, dial indicators, blocks, etc. and have picked up scraping equipment as well. I am fairly confident with enough patience and persistence (the only way i really learn) I can get it relatively geometrically correct and the reaeson for the post was to see if it was even possible with enough persistence. I was intending on using a straight edge across the each outer legs in the short direction to test geometric relationships. The mill column does in fact sit on these 4 pedestals. I intend to get the column baseplate flat and geometrically square to the z axis ways but the real reason for grinding down these pegs was to increase rigidity
 
Monarchist;

This isn't about mounting the base of the mill, these I think are the pads that the mill column rests on.
Sad, given it is every bit as easy to manufacture them in-plane and actually harder work to NOT do. But probably true as it would be in keeping with the general character of the a(ny) MMSO the factory in question sees branded under so very many names.

Oh wait. On-edit.. he ruint it himself?
 
The mill column does in fact sit on these 4 pedestals. I intend to get the column baseplate flat and geometrically square to the z axis ways but the real reason for grinding down these pegs was to increase rigidity

Bet you will plan ahead better NEXT time before damaging alignment?

'Coz it won't increase rigidity, only change stress transfer, probably distort the flimsy base differently than the factory planned for.

Metals MOVE, y'know. Even when they have two or three more zeros on their mass than this toy. Just not as much, nor as easily.
 
Don't worry too much your learning you will get a lot more lessons as you go.

Everyone started with no much knowledge and built on it as they went along in life just like the people who give harsh feedback.
Maybe you could do with some lessons from Richard King that would help you along a bit.

i.e. take one of his courses when he runs one next.
 
I hate to admit it I have helped work on some of those crap made machines. New to the trade people buy them and have no clue how screwed up they are. Some probably run them and think they are amazing until they buy a real machine not made in that unmentionable place.

I have seen them out .020" and .012", ways ground with what looks like a angle grinder with a course wheel. The pads are bolted to the stand even when they are not the same height. One of the forum member bought one and brought it to the Boston class explaining he bought it for the castings and figured he would have to re-machine and scrape it. What's sad about those "things" I won't call it a machine as they are things not even a toy. But it's hard to measure them like you would on a well built conventional mill.

The 4 feet that bolt to the sheet metal frame are not the same height, the frame crap welded and the place the 4 feet bolt on are not the same height. The top flats of the base that is above the 4 feet is not parallel. So my advice to you on this is to buy a surface plate. Granite B grade would be amazing compared to that thing. The plate would be bigger then the base. Then grind, file or sand and then scrape the 4 feet the same height or planar to each other. No sense in screwing around without a surface plate. Hell a kitchen counter top would probably work for that thing.

Thing base on Bridgeport milling after we scraped 4 feet to a plate, Crap factory machining of ways

DSC01955.jpgDSC01976.jpg
Then do yourself a BIG favor take it to a machine shop and have them mill the top flat's and dovetails parallel and planar before trying to assemble it. It amazes me they haven't closed this thread but this is a warning for anyone even considering buying on of those things. Don't and save yourself some headaches.

Table on plate, scraping thing to make it a machine, measuring bottom feet or base to plate using a feeler gage.
 

Attachments

  • 20160824_134126_resized.jpg
    20160824_134126_resized.jpg
    99.6 KB · Views: 730
  • DSC01975.jpg
    DSC01975.jpg
    43.7 KB · Views: 716
  • DSC01956.jpg
    DSC01956.jpg
    56.2 KB · Views: 739
i have one and its a good drill press for the home shop but i also have a bridgeport for milling. i saw a you tube vide that shows bedding the base with some sort of steel bedding compound but that was just to help with tramming it out

have to add what better thing to learn how to scrap on after all it will teach you many things and if you mess up you have not really hurt any good old iron i may work on my mini before tring to rehab my bridge port
 
Milling steel and the like is tough machining...but for such as grinding the likes of the smaller KO Lee have sharpened many cutters and can even do a fair job of surface grinding..I see nothing wrong with truing up a small mill. I do agree with Monarchist and Richard ..better start from the the bottom and then up if you intend to bolt it to any base. And the base need be flat.
A solid base would give a small frame machine more resistance to to bending or the like with machining pressure. Likely an old iron surface plate might be good.
 
Thank you all for the comments. This was going to be an exercise for me to learn to true up a machine. i know how bad they are coming out of the factory as I have already indicated many of the surfaces.

The base wasn't surprisingly terrible. The worst part about the base IMO were the 4 pegs which was done by hand to get it to just bolt up (I agree it was terrible) which prompted me to cut them down to depth such that the column will have the most surface area to bolt up onto. The space that I have currently allows for a mill of this size, and frankly this was the heaviest benchtop rig I could find (with the intentions of major calibration)
 
Thank you all for the comments. This was going to be an exercise for me to learn to true up a machine. i know how bad they are coming out of the factory as I have already indicated many of the surfaces.

The base wasn't surprisingly terrible. The worst part about the base IMO were the 4 pegs which was done by hand to get it to just bolt up (I agree it was terrible) which prompted me to cut them down to depth such that the column will have the most surface area to bolt up onto. The space that I have currently allows for a mill of this size, and frankly this was the heaviest benchtop rig I could find (with the intentions of major calibration)

Might be a worthwhile project but with no tools and no previous experience it's going to be mistake prone. Get a 24"x18" granite surface plate, an ACCURATE square ( granite too ) and a some sort of height gage. Watch some scraping videos. Always bear in mind that while the machine's geometry might be rubbish, within the actual envelope you are using it might be good enough. It's not a jig borer, needs not be within a tenth corner to corner. Needs to be marginally better than a drill press.
 
I hate to admit it I have helped work on some of those crap made machines. New to the trade people buy them and have no clue how screwed up they are. Some probably run them and think they are amazing until they buy a real machine not made in that unmentionable place.

I have seen them out .020" and .012", ways ground with what looks like a angle grinder with a course wheel. The pads are bolted to the stand even when they are not the same height. One of the forum member bought one and brought it to the Boston class explaining he bought it for the castings and figured he would have to re-machine and scrape it. What's sad about those "things" I won't call it a machine as they are things not even a toy. But it's hard to measure them like you would on a well built conventional mill.

The 4 feet that bolt to the sheet metal frame are not the same height, the frame crap welded and the place the 4 feet bolt on are not the same height. The top flats of the base that is above the 4 feet is not parallel. So my advice to you on this is to buy a surface plate. Granite B grade would be amazing compared to that thing. The plate would be bigger then the base. Then grind, file or sand and then scrape the 4 feet the same height or planar to each other. No sense in screwing around without a surface plate. Hell a kitchen counter top would probably work for that thing.

Thing base on Bridgeport milling after we scraped 4 feet to a plate, Crap factory machining of ways

View attachment 217432View attachment 217433
Then do yourself a BIG favor take it to a machine shop and have them mill the top flat's and dovetails parallel and planar before trying to assemble it. It amazes me they haven't closed this thread but this is a warning for anyone even considering buying on of those things. Don't and save yourself some headaches.

Table on plate, scraping thing to make it a machine, measuring bottom feet or base to plate using a feeler gage.

Thank you for sharing the details of WHY these .."things" are.. no more than what they are.. Richard.

I hope this thread does NOT get "locked". Or IF locked, at least left searchable.

Now and then it is useful to be able to point to a link carrying the specific reasons PM doesn't want to waste the time even discussing these.. "things".
 
Might be a worthwhile project but with no tools and no previous experience it's going to be mistake prone. Get a 24"x18" granite surface plate, an ACCURATE square ( granite too ) and a some sort of height gage. Watch some scraping videos. Always bear in mind that while the machine's geometry might be rubbish, within the actual envelope you are using it might be good enough. It's not a jig borer, needs not be within a tenth corner to corner. Needs to be marginally better than a drill press.

surface plate has been acquired, tools are being purchased. scraping videos are being watched. lots of research occurring on the back end. I learn from mistakes and I am not scared or worried about that. Worst case i'll buy a new base but I want to take this seriously with the resources I have.

the main two points: I really had was if bringing those 4 tabs down using a file was doable or should I just have it milled to within a thou before scraping. I understand the surface plate and indicator concept and where/how to checks things for geometry/flatness which is relatively trival for this part of the mill. There are places i would rather alter more than others to generate less work in the end. For example I plan to adjust the base geometry before scraping in the base ways because it's easier to adjust those than to change a relatively flat base ways.


I have a plan, just not written down which i plan to do soon. attached is my plan for the column pegs.View attachment JLA_YYYYMMDD010.pdf
 
I hate to admit it I have helped work on some of those crap made machines. New to the trade people buy them and have no clue how screwed up they are. Some probably run them and think they are amazing until they buy a real machine not made in that unmentionable place.

I have seen them out .020" and .012", ways ground with what looks like a angle grinder with a course wheel. The pads are bolted to the stand even when they are not the same height. One of the forum member bought one and brought it to the Boston class explaining he bought it for the castings and figured he would have to re-machine and scrape it. What's sad about those "things" I won't call it a machine as they are things not even a toy. But it's hard to measure them like you would on a well built conventional mill.

The 4 feet that bolt to the sheet metal frame are not the same height, the frame crap welded and the place the 4 feet bolt on are not the same height. The top flats of the base that is above the 4 feet is not parallel. So my advice to you on this is to buy a surface plate. Granite B grade would be amazing compared to that thing. The plate would be bigger then the base. Then grind, file or sand and then scrape the 4 feet the same height or planar to each other. No sense in screwing around without a surface plate. Hell a kitchen counter top would probably work for that thing.

Thing base on Bridgeport milling after we scraped 4 feet to a plate, Crap factory machining of ways

View attachment 217432View attachment 217433
Then do yourself a BIG favor take it to a machine shop and have them mill the top flat's and dovetails parallel and planar before trying to assemble it. It amazes me they haven't closed this thread but this is a warning for anyone even considering buying on of those things. Don't and save yourself some headaches.

Table on plate, scraping thing to make it a machine, measuring bottom feet or base to plate using a feeler gage.

OMG :).....I have "things" I cannot talk about (not that one, but others that i am slowly replacing)...but i leave them at home. In any case yes you can scrape anything and make them a 100 times better. BTW good parts can be made on crap machines, it is just much harder.

Quick addition: One thing for sure, if you mess up one of those "things" one of two, or both, outcomes are likely. 1.) The thing will be no worse than started. 2.) You have a perfect example what not to do when you get a real machine to restore.


dee
;-D
 
surface plate has been acquired, tools are being purchased. scraping videos are being watched. lots of research occurring on the back end. I learn from mistakes and I am not scared or worried about that. Worst case i'll buy a new base but I want to take this seriously with the resources I have.

the main two points: I really had was if bringing those 4 tabs down using a file was doable or should I just have it milled to within a thou before scraping. I understand the surface plate and indicator concept and where/how to checks things for geometry/flatness which is relatively trival for this part of the mill. There are places i would rather alter more than others to generate less work in the end. For example I plan to adjust the base geometry before scraping in the base ways because it's easier to adjust those than to change a relatively flat base ways.


I have a plan, just not written down which i plan to do soon. attached is my plan for the column pegs.View attachment 217445

Excellent ! As far as I understand you'll gain nothing by making larger pads - just complicates the problem. Again, as far as I understand ( good pics of the machine would help ) you should flatten the base until it somehow sits on a plane and then scrape the pads to equal height using a height gage to test for coincidence. I used a very stout dial indicator with a long arm. A file might seem quick but it does too much and you can quickly drive a surface into the ditch. Use a scraper. Most of the time ( I do small surfaces ) I use a 6" long 1/2" wide HSS parting blade well covered in masking tape. HSS can take a vicious edge and that helps. Once dull, it takes 30 secs to have it back where it was. I'm not fond of carbide for my limited purposes. A BIAX IS NOT NEEDED HERE ! :) :) :)

This is not rocket science - almost impossible to go wrong.
 
Hey all.

Quick question. Am I out of my mind for trying to bring the 4 raised blocks on the base down to the same level by means of filing? I do not have access to a mill or a grinder at this time (will grind the other 3 blocks using a powered grinder).

My real questions, without a mill to bring all 4 blocks to within a scraping tolerance (say a thou) am I in over my head to rough scrape to where i need to be or will i be chasing my tail.

I'm really new to this whole thing and I wanted to get started on the project and may have jumped the gun a bit too early.

The idea was to great a much more uniform and even bearing surface instead of just the 4 tiny blocks that the column sits on.


Thank you all for your help.

Again, I'm a newbie and appreciate your patience and input!

View attachment 217393

Feel free to DM me any of your questions, im the fellow in the 3rd photo Rich posted, testing my machine base with feeler gages. I reached excellent results with my machine, its very capable in my home shop doing weekend jobs for people, and after rebuilding, its accurate and feels fantastic. Even better than my Bridgeport at work when held within the capabilities of the machine. I definitely does take a lot of work and time, but there's no question that your machine can be made to be tight, smooth, and accurate, and you will indeed gain a great learning experience. To my understanding, bringing those 4 bosses down to a solid plane would not be beneficial, and if you were to scrape that surface, you'd probably want to scrap a "+" in between the areas of the 4 holes slightly lower anyway, making good contact at the bolt locations, essentially, giving you what you started with.
Corey
 








 
Back
Top