Looking forward to seeing the completed XY table once it is operational.
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Looking forward to seeing the completed XY table once it is operational.
Hi Guys,
Since there is not going to be any more done on this project until I come back from holiday, and all the parts except for the leadscrew assembly are done ready for putting together, I thought that a picture of the parts currently done was in order.
Attachment 379061 Attachment 379062
The large slab of steel on the right of the second picture next to the motor support column is going to become the top slide, the one that all the other, yet to be made, parts will ride on. The black pieces of bar are the end plates for the slide and they will support the bearings. Those black pieces of plate are glued together using super glue ! That was done in order to make sure that both pieces were exactly the same.
Surprisingly there is over 20 Kg in weight of steel there, far more than I expected. It will be interesting to discover how much more weight will be added when the motor and the tool holder is made.
Talking about the motor, I've already got the metal for the motor support bracket and I'm looking for a suitable motor. I've not yet decided whether to make a spindle or to come straight off the motor shaft.
Thanks for looking Guys.
Hi Guys,
Just got back from a seven and a half week holiday in France including a week at Euro Disney. Looking forward to getting back into the workshop. Spent part of the day unloading the camper and sorting various things.
I've also managed to spend some time measuring various parts, mainly to make sure that the table had parallel sides and also checking the saddle width. For some reason the plate for the saddle is 14 thou out of square on one edge, making it spot on for the width at one end and 14 thou small at the other. So much so that I can see the difference with a set square. Not sure why that should be ? I think that I may either remake the saddle plate or use a shim to square it up. I need to machine the grooves on either side of the base plate for the bearings first though.
I've also managed to strip the teeth off the plastic mill table drive gear this afternoon, I had forgotten that I had locked the table ! My own fault :C. So I have now got to set to and repair that before I can start to machine the grooves in the table sides. I don't want to go back to winding the table by hand, its a right royal pain.
More later. Thanks for looking. Comments welcome.
Hi Guys,
Well I've got some more work done on the three major parts for the base, saddle and top slide, that is after fitting a new mill table drive gear. Luckily I had a second one, so it was just a matter of taking the motor assembly off the end of the table and swapping the damaged one with the new one and putting it back together.
Anyway I machined the top slide to the right width and measured the other parts to ensure that they were the right size.
Attachment 379853
This first picture shows the set up that I used to check that all three parts were the right size and the sides were parallel to each other. The part on the left has one end that is lower than the other by 14 thou, although the other sides are the right width and are parallel within the limits of the Mitutoyo gauge that I used. I did discover that the last digit only shows zero or a five. So the resolution of this instrument is half a thou.
Attachment 379849
This is the saddle piece that has one end lower than the other. I suspect that there must have been a bit of swarf under one end when I machined it, since all the other parts that I've machined are within half a thou of being parallel.
Attachment 379851 Attachment 379852
These are the gauge readings at either end of the longest piece of material, the top slide, which is 240 mm long. I cross checked each piece by turning it through 180 degrees just to make sure that the zero and half thou readings were valid. The surface plate is a porcelain floor tile 13 mm thick and was selected because it was flat. I also have a large granite tile 24" by 36", 40 mm thick but I can no longer lift it up to use it. That one came from a local monumental mason.
Attachment 379850
This is the saddle plate and the top slide stood together.
More later: Thanks for looking.
Hi Guys,
Today has been a mixture of questions !
One of the things that I needed to do was to set up the work piece in the mill vise so that it was as square as possible. I had already made sure that the mill vise was square to the table and needed to ensure that the work was as well.
Attachment 379925
This first picture shows the set up that I used to make the measurements. The premise being that if the work was exactly the same distance away from the spindle at both ends then the slot that will be cut into the work piece will be parallel to the work piece surface.
Initially I used my Mercer 1/2 thou dial gauge, but the readings were all over the place. I thought that the Mercer gauge had become faulty. So not having a suitable clamp for the Mitutoyo gauge, I had to make one.
It turns out that the Mercer is fine and that I hadn't understood what it was telling me.
Attachment 379921 Attachment 379919 Attachment 379920 Attachment 379918
This is what I came up with. A bit of aluminium scrap, an M6 cap screw and a four inch length of 1/4" inch diameter aluminium rod. I drilled 3/8" inch hole right through and drilled and threaded a hole for a clamp screw and one at the back for the support rod. It can be seen in the pictures below holding the gauge.
Attachment 379922 Attachment 379924 Attachment 379923
Now using the set up as described I proceeded to re-make the mesurements to ensure that the work was square. Note that the last digit on the Mitutoyo gauge can only be a zero or a five
Initally a big failure ! Every time I wound the table from one end to the other the readings changed. I wasn't until I leant on the table and the gauge readings changed that I realised that there was something wrong with the table movement.
I'd adjusted the gib strip previously and found that the table bound up, so I'd just set it so that the table moved easily. On removing the gib strip I found that it was bent and had burrs on the edges. Filing off the burrs and harage I refitted it. The difference was remarkable, much better but not perfect. I managed to get the readings at each end of the workpiece a consistant zero difference. However pushing and pulling on the table still gives a a one thou change. If I adjust it any further the table becomes hard to move, so I've backed it off enough so that it moves without undue force. So I'm hopeing that when I machine the slot it stays square to the work piece edges.
Tomorrow I hope to be able to start cutting the slots for the roller bearings to fit into.
More to come: Thanks for looking.
Hi Guys,
I finally managed to get around to cutting the first slot in one side of the base plate. Having spent a considerable amount of time making sure that the setup on the mill was as good as I could get it. I took the long, 240 mm long plate out of the mill vise and replaced it with the shorter base plate that requires a 13 mm slot cut into both edges.
Attachment 379954 Attachment 379953
I set the cutter in the centre of the width of the workpiece so that I had an equal amount of material on both sides. The idea was that I would have a 4 mm (160 thou) wide edge on both sides and would only have to move the table 1 mm forward to give me a 13 mm wide slot by making a cut on only one side.
I used a 12 mm diameter slot drill running at 650 rpm and an indicated 1 mm depth of cut with a table traverse speed of 1 inch per minute. I did three passes at 1 mm and ended up with a total cut depth of 3.25 mm. Another discovery here, the flex on the depth gauge arm because of slight misalignment causes the cut to be deeper than that indicated. To avoid climb milling I ran the table back to the other end of the workpiece and then took a full depth cut of 1 mm off the front edge. You can see the differences in slot edge thickness in the pictures below.
In practice I ended up with a slot exactly the same width as the bearing diameter and 3.25 mm deep.
Attachment 379952 Attachment 379951 Attachment 379950
These pictures show the finished slot on one side of the base. The other side still has to be done.
I made a scraper from a 1/2" inch HSS tool blank and scraped out the thin edge enough for the bearings to just drop into the slot. After deburring and breaking the edges it went back into the mill vise ready for the other slot to be machined.
Before putting it back in the mill vise I made measurements of the thickness of the slot walls at either end and in the middle, three places on both edges. The measurements taken with a M&W 1" inch micrometer and depth gauge are as follows:-
The thick edge measures 163.0 thou at one end, 163. 2 in the middle and 164.1 at the other.
The thin edge measures 123.0 at one end, 123.1 in the middle and 123.8 at the other.
The slot depth goes up and down by about 10 thou, probably because the bottom of the slot is quite rough but averages 3.25 mm or 132 thou deep.
I'm hoping that the other side comes out the same as this one did. I do wonder if I could have done the cut at full depth, but I don't think my mill is rigid enough to do this.
Thanks for looking: Comments welcome.
You seem to be enjoying your return to work on the grinder project, it seems to be coming along nicely.
From your comments on the depth of cut I would say you drive your mill harder than I do, I sometimes wonder what sort of depth of cut others are using - my average depth of cut in steel for a 1/2 inch cutter would be around 1/3mm to 1/2mm which is quite a bit less than you, possibly my mill is not as rigid as yours, I have an Arboga which has seen a lot of use. I don't have power feed - a bit of a pain to crank the handle and also a bit hard to judge the feed rate but on the plus side so I can usually feel if the cutter is getting dull by the increase in effort needed to crank the handle.
Hi Familyguy,
Yes its nice to get back into the workshop !
I don't know the Arboga mill. I'll post a picture of mine below.
Attachment 379955
I've made a couple or three changes since this picture was taken.
You may have noticed that the bottom of the slot is quite rough ! This I think is due to the lack of rigidity in the mill column, even though I lock everything up, the head vibrates as its cutting. I think that using a four or five flute end milling cutter would reduce the vibration. I might try that when I do the very long top table.
But for now I need to get the slot in the other edge machined then I can start to fit the saddle.
That mill looks like a BF20 or copy, I guess you know your machine but I would think that if the head vibrates at all then you are asking too much of it, any vibrating/shaking in the head would translate to vibration at the cutter and would probably affect the finish of the work, I would be trying less depth of cut, I know it will take a bit longer to machine but it may repay you with a nicer finish . Your pics are not real clear on how you have setup the plate vertically in the mill - it looks as if the bottom of it clamped in the mill vice and the rest of it just stuck up in air with no support, thick plate may look and feel quite rigid but if you put your dial gauge against it near the top and give it a push with you hand I'm sure will see some deflection. If I was doing that job I would find a way of clamping it with a heavy angle plate or something so as little as possible is unsupported.
In my experience also having the milling cutter run over it's own swarfe in not good, it just gives the cutter and the machine extra work to do chopping up metal that it has already removed, do you blow the swarfe away with light blow of compressed air while it is cutting or brush it away with a small brush? I've setup a water soluble flood coolant which is good as it washes the swarfe away and keeps the cutter cool but is also not very convenient, messy and I can't just leave the machine after the machining operation has been completed as the coolant that is trapped under the vice will stain the mill table after 3 or 4 days standing, so the vice needs to be removed and all the coolant cleaned up.
Bear in mind I'm not a trained machinist these are just my observations you may have a lot more experience than me, my original training was electronics and a my first working years were spent in industrial electronics until changes to the laws made me unqualified to disconnect a machine from the mains supply.
Hi Familyguy,
Yes it is ! Its the one with the extra long table.
Yes I agree that there is 2/3 thirds of that plate stuck up above the vise ! I believe that the real problem is that the head of the mill is very high up the column and the quill sticks out a long way, and it flexes the column. A while ago I made the Norman toolpost and cut a 1/2" by 1/2" slot in it for the tool to sit in. I machined that in 1 mm cuts without any vibration issues, but that only protruded about 1/2" inch above the top of the vise and the mill head was well down the column.Quote:
I guess you know your machine but I would think that if the head vibrates at all then you are asking too much of it, any vibrating/shaking in the head would translate to vibration at the cutter and would probably affect the finish of the work, I would be trying less depth of cut, I know it will take a bit longer to machine but it may repay you with a nicer finish.
At the moment I using a Rocol Foam cut sample, as both lubricant and coolant. I just brush the swarf away. Like you I've tried flood coolant and found it very messy. I've also tried spray and mist, but neither of those is particularly good with steel, works fine with aluminium.Quote:
Your pics are not real clear on how you have setup the plate vertically in the mill - it looks as if the bottom of it clamped in the mill vice and the rest of it just stuck up in air with no support, thick plate may look and feel quite rigid but if you put your dial gauge against it near the top and give it a push with you hand I'm sure will see some deflection. If I was doing that job I would find a way of clamping it with a heavy angle plate or something so as little as possible is unsupported.
In my experience also having the milling cutter run over it's own swarf is not good, it just gives the cutter and the machine extra work to do chopping up metal that it has already removed, do you blow the swarf away with light blow of compressed air while it is cutting or brush it away with a small brush? I've setup a water soluble flood coolant which is good as it washes the swarf away and keeps the cutter cool but is also not very convenient, messy and I can't just leave the machine after the machining operation has been completed as the coolant that is trapped under the vice will stain the mill table after 3 or 4 days standing, so the vice needs to be removed and all the coolant cleaned up.
Haha ! Neither am I ! :U I've spent 40 years in the electrical, electronics and computing technologies fields. I've had a lathe for years but only been able to get into machining since I retired. My wife bought me the mill for our 45th wedding anniversary, so I've had it for nearly six years. The only formal machining education I've had was at school, where we weren’t allowed to touch the metal lathe and the school didn't have a mill only a shaper. About the only thing that I learnt in there, was how to use a hacksaw and a file. I soon dropped metal work for woodworking, at least you got to use the wood turning lathe and power sanding wheel. I later dropped that in favour of chemistry and physics.Quote:
Bear in mind I'm not a trained machinist these are just my observations you may have a lot more experience than me, my original training was electronics and a my first working years were spent in industrial electronics until changes to the laws made me unqualified to disconnect a machine from the mains supply.
Ahh well back to the TCG project. :)
Hi Guys,
Well I've now got both slots machined in the base plate.
Attachment 379957 Attachment 379956
The first picture is one where the cutter is moving from left to right on the last of the three 1 mm cuts. The white foam you can see is Rocol Foam Cut. A sample tin was given to me by a tool supplier representative whilst I was visiting one of the engineering companies that I go to in order to raid their scrap pile.
The second picture is a general shot of the mill whilst cutting the second slot.
Not much else to report at the moment ! But work continues...
Thanks for looking: Comments welcome :)
Hi Guys,
I've got the slot cut in the other edge and now need to clean then up and remove the harrage before marking the hole positions for drilling and threading the ends of the saddle plate. The bottom of the slots was quite rough, so a used some 600 grit emery paper to take some of the roughness off. The bearings fit very nicely in those slots now.
Attachment 380022 Attachment 380021
I spent a little time making sure that the saddle and base plates were square to each other and clamped them together ready for marking out prior to drilling. I used a 30 thou shim between the plates to ensure that I had some clearance between them. I didn't want grinding dust getting under there without some way of being able to wipe it clean. I might fit some felt wipers later on. Not sure about that yet,
Attachment 380019 Attachment 380018 Attachment 380017
These two plates have already been drilled and the holes for the bearing spindles threaded. I fitted up a couple of the bearings in the still glued together side plates and spotted through the mounting holes to mark the drilling points on the saddle plate. If you look closely at picture (002) you can see the 30 thou shim that I placed under the saddle plate, between it and the base plate. I did this to ensure that there was a small clearance between the two when they were assembled.
Attachment 380020
I placed the two parts on the drill press X-Y table in order to drill the holes in the ends of the saddle.
Attachment 380016
First I used a centre drill to ensure that I got the hole positions accurately positioned in the pop marks,
Attachment 380015
Then I used a 5 mm drill to drill 20 mm deep holes ready for tapping M6.
Attachment 380023 Attachment 380014
I used the drill press as a tapping stand to ensure that I got the tap started dead straight. You only need to thread two or three turns. After starting the other hole, I finished tapping with the work pieces secured in the bench vise. A nice blob of "Temaxol" cutting paste on the tap.
Thanks for looking: More to come.
Slightly off topic but not quite...
How do you find Temaxol is for clearing chips away when tapping? I use an apparently similar sort of paste called Trefolex for tapping and while it works well, the chips from tapping don't clear, leaving a mix of paste and chips in the flutes. I'm wondering whether for taps that are not self clearing, I'd be better off using a thick oil (even something like way oil) if it lets the chips clear better.
Michael
Hi Michael,
Thanks for your response !
I use both and as far as tapping is concerned they are both the same. I was given a tin of Rocol Foam Cut and that recommends itself for tapping. Quite frankly its better used as a cutting fluid on the mill. It doesn't smoke as much as Temaxol or Trefolex does. I also use both on the lathe, either is a good drilling lubricant as well. At least if the chips stay in the flutes they don't get recut and cause binding, which on small 6BA, 8BA and 10BA taps can be fatal. :)
Hi Guys,
I've now assembled the saddle to the base plate. Apart from having to shim one of the end bearing support plates it all fits together nicely.
Attachment 380121Attachment 380118 Attachment 380122 Attachment 380119
These pictures show the saddle fitted onto the baseplate. Surprisingly there is no rocking or twisting of the saddle. Its a little tight, but moves smoothly from one end to the other without any problem. I did expect that I would have to make some fine adjustments but no. :o
Attachment 380120 Attachment 380115 Attachment 380114
These pictures show the underside of the saddle and the 30 thou clearance between it and the baseplate. Actually one of the most difficult things was making the spindle pins for the bearings. The slightest burr prevented the bearing pushing onto the pin. However a little spin in the lathe and some 600 grit emery paper sorted the burrs out. You can see some oil on those parts. I did lubricate the slots in anticipation of any sticking or jamming.
Attachment 380116
Because the saddle plate was high at one end, I squared it up by taking a 20 thou fly cut across it. This made the saddle 20 thou narrower than the baseplate. So I put a 25 thou shim in between the end of the saddle and bearing support plate. You can see the gap produced in this picture. Actually it didn't seem to make any difference which side I put the shim on. So I'm very happy that things are as square as I could get them.
Attachment 380113
Fortunately the roughness at the bottom of the slot doesn't interfere with the smooth running of the bearings. I did however give the slot a good rub with 600 grit emery to remove any high spots that might have caused a problem.
Next its time to machine the slots in the top slide.
Thanks for looking: Comments welcome.