8 Attachment(s)
More work on the motor mounting !
Hi Guys,
I've been doing some more on the motor mounting block and motor support plate.
Attachment 388957
I marked out the column side of the motor mounting block and drilled the four 5 mm holes 15 mm deep, M6 tapping size and proceeded the to tap the threads in them being careful not to break the tap by hitting the bottom of the blind holes. I took the sharp edge of the threaded holes with a countersink tool.
Attachment 388956 Attachment 388958
After drilling and threading the motor mounting block, I marked out and drilled the aluminium plate with the four 1/4" diameter holes and counter sunk them to suit M6 hex countersunk screws. The four holes in the corners of the plate are sized to suit the mounting holes in the Parvalux motor feet.
Attachment 388955
This picture shows the assembly of the mounting block and the motor mounting plate.
I need to work out the fastening details for the grinding spindle mountings that will be on the other side to the motor. I'll post those details later.
Now onto the next job !
Attachment 388960 Attachment 388959
One of the items that is needed is the split cotter that will be used to lock the motor mounting block to the column. The second picture shows how the split collet will grip the column when it is in place inside the motor mounting block.
As you will have seen in the previous pictures, the 12 mm diameter steel pin was placed in the hole in the motor mounting block before the hole for the column was machined. In order to do this the pin was drilled right through with a 5 mm drill and the ends threaded M6 to enable cap screws to be fitted to secure it.
After machining the 20 mm hole for the column the pin for the split cotter was removed and cut in half so that the scallop was equal on both sides. Then one half of the pin had the threads completed all the way through the pin. The other half of the pin was drilled 6 mm all the way through to clear the M6 by 30 mm cap screw used to pull both half’s together when in place thus locking the motor mounting block to the column.
I drilled the flat end of the non threaded pin using a 10 mm slot drill, to get a flat bottomed hole that the head of the cap screw would sit in without protruding.
Attachment 388962 Attachment 388961
These two pictures show the motor mounting block along with the column, threaded rod and the split collet in place. The second picture shows how it will look when set up on the grinder base.
That is all for now, there is still lots to do before I can call this project done !
Thanks for looking Guys.
10 Attachment(s)
More work on the Grindling Spindle !
Hi Guys,
Thanks for all the likes and thanks given, I do appreciate them !
I've been looking around for a few weeks for some suitable thick wall steel tube that I could machine to make some collars 20.80 mm in diameter, that would fit into the 21 mm bore of the spindle housing and go between the outers of the end bearing races.
I found a piece the other day, about 100 mm long. I put it in the three jaw chuck and turned the diameter down by just over 1/2 a mm. After which I then bored it out to give me a 2 mm thick wall, these are the two large bits of tube that you can see in the family picture at the bottom of this post..
Attachment 389105 Attachment 389104
Here you can see the piece of tube in the lathe after turning to size. It machined extremely well with an excellent surface finish. I needed two collars of about 20 mm in length, so I just cut two pieces off this tube using the bandsaw and then cleaned up and deburred the ends on the lathe.
Attachment 389108 Attachment 389107 Attachment 389106
These pictures show the reason that I needed the two collars !
Assembling the spindle cartridge with the bearings held on their outer edges meant that when the end caps were screwed in the bearing outer races would be trapped against the internal collar and the end caps. This meant that the spindle was free to move in the bearing inner races. By holding one end of the spindle in the lathe three jaw chuck the cartridge outer was free to move end wise. By setting up a dial gauge in the tool holder, I could now measure the amount of end float in the spindle. As can be seen, this end play amounted to 3 thou. So I now knew that I needed to shim the spindle by three thou to remove the end float.
Attachment 389110 Attachment 389111 Attachment 389109
I had some paper that was two thou thick ! So I made a punch to knock a 12 mm diameter hole in some and then cut it to form a round washer whilst it was on the spindle pressed against the shoulder.
The pictures show the washers on the spindle and the first picture is of the practice one. Whilst the two paper washers amount to four thou thickness, the one thou difference doesn’t cause the bearings to tighten up. This also allows me to measure by how much material I need to remove to adjust the length of inner collars, these are the small ones in the family picture, to allow for the clamping force by the pulleys mounted on the ends of the spindle.
Attachment 389113 Attachment 389112
These are the family pictures. The spindle cartridge can be seen at the top with the spindle below it. The ends of the spindle are symmetrical so from the ends. The threaded end cap, the outer bearing, the two collars, inner and outer ones, the inner bearing.
The end caps are threaded one right hand and the other left hand threads. These end caps contain the pair of Teflon labyrinth seals and the sleeve that bears against the bearing inner race that the Teflon seals run on.
Thanks for looking Guys.
8 Attachment(s)
Spindle mounting plates !
Hi Guys,
I've been busy cutting pieces of 15 mm aluminium plate and machining to size as per drawing in previous post.
Attachment 389223 Attachment 389221
This picture is the central block that is intended to support the motor and the grinding spindle cartridge. The two side plates are secured to the motor mounting plate by M6 hex countersunk screws. At the moment I haven't done the countersinks on the holes but that is a a job for later.
Attachment 389220
In order to allow access to the split collet clamp screw each side plate required a hole drilling in it. In order to make sure that these holes were in the right place, I used a transfer punch. This consisted of a piece of 6 mm diameter rod with a point turned on one end. By using the drilled out half of the split collet the hole centres were marked on the side plates. You can see the 6 mm diameter rod in this picture.
Attachment 389222
The other end of the side plates were marked and drilled with a 5 mm drill to a depth of 40 mm. After which I cut the top section off using the bandsaw. This allowed me access to thread the holes in the side plates M6, and drill out the 5 mm holes in the top pieces to 6 mm. This makes the M6 cap screws a close fit in the holes allowing the cut off piece to be accurately refitted and clamped to the side plates.
Attachment 389219 Attachment 389218
This picture shows the side plates along with the cut off pieces. The coloured marker has been used to identify which end piece belongs to which side plate.
Attachment 389217 Attachment 389216
Now that I have the side plates drilled for the split clamp screw access, I've prepared them for boring out by putting a 10 thou shim between them and clamped them together with 30 mm long M6 cap screws. You can just see the shims between the side plate and the top part. They still have to be counter bored so that the cap screw head will be below the surface of the top part.
The shims will allow the grinding spindle cartridge to be securely clamped when the side plates are bored out.
I was originally going to use the four jaw chuck on the lathe, but have discovered that my chuck isn't big enough to hold them. Unfortunately the 9 inch face plate will only allow one piece to be held without the work fastenings hitting the lathe bed. So the fall back position is to drill and bore each side plate using the mill and boring head.
So that is the next job. More later.
Thanks for looking Guys.
13 Attachment(s)
Motor and cartridge mount !
Hi Guys,
I've almost finished the work on the motor and grinding cartridge mountings. I finished boring the other side plate this morning then counter sunk the cap screw heads into the clamping pieces. I've put the whole lot together and it all fits very nicely.
Attachment 389251
I promised a picture of boring out the mounting hole for the cartridge.
Sorry if this looks as if the picture was taken by candle light. I did try flash but it just burnt everything out, so this is just with the ring light and the adjustable one.
Attachment 389252
A view of the bottom of the motor mounting plate with all the holes now countersunk and the side plates fastened to it with Pozidrive M6 counter sink screws. I've run out of hex drive ones.
Attachment 389253 Attachment 389254
These two views are of the main support block screwed onto the motor mounting plate and with the side plates fastened on.
Attachment 389260
These are the two cartridge securing caps now that I've counter bored them for the screw heads.
I used a 10 mm drill to a depth of 6 mm and then a 10 mm slot drill to get a flat bottomed hole rather than use commercial counter bores.
Attachment 389259
Here I've just rested the cartridge in the side plates basically to check the alignment more than anything else prior to fitting the securing caps in place.
Attachment 389263 Attachment 389261 Attachment 389262
Securing caps fitted and tightened down ! I can just get a 1 thou feeler gauge blade under each end of the caps without over tightening the screws. The spindle cartridge is as near as I can tell square to the mountings.
I'll find out how square when the whole thing is assembled onto its cross slides.
Attachment 389258 Attachment 389257
Attachment 389256 Attachment 389255
Last few pictures with the motor mounted. I still need to drill and put a grub screw into the driving pulley on the motor shaft and find a suitable drive belt. The piece of 20 mm bar where the support column will be is there to prevent the split collet from falling out and the long piece of threaded rod will be used to adjust the grinding head height. Even though I've used aluminium for the bulk of this assembly its far heavier than I expected it to be.
That all for now folks, I'll post some more later as I get on with some of the other bits and pieces for this project.
Thanks for looking Guys.
8 Attachment(s)
Bearing for height adjuster !
Hi Guys,
I've started getting on with the height adjustment for the motor and grinding spindle assembly. The threaded rod that will be used to adjust the position of the grinding wheel on the support column sits in a bearing supported by a movable bracket that either sits on the bottom of the column or can be positioned anywhere on it secured by a split clamp.
Attachment 389356 Attachment 389353 Attachment 389357
These pictures show the aluminium bracket and the threaded rod that will be used for height adjustment. The thirteen mm diameter bearing sits in a recess bored in one side of the bracket. In the second picture the split clamp is visible. In the third picture the threaded rod is located in the 5 mm bore of the bearing.
Attachment 389355
This is the split clamp that will be used to secure the bracket on the column. Its made from a short piece of 12 mm diameter printer shaft with an M6 cap screw used to close the clamp onto the column.
Attachment 389350 Attachment 389351
Attachment 389352 Attachment 389354
These pictures show the general arrangement. Note the grinding spindle cartridge and supports have been removed so that the general layout can be seen.
More later !
Thanks for looking.
4 Attachment(s)
Starting on the Electrics !
Hi Guys,
I've purchased a suitable ABS plastic box that I intend to use to house the electrical items for the grinder work head.
Attachment 389371
This is the plastic box. It is 105 X 80 X 38 mm and is deep enough to get all the parts need in it.
Attachment 389370 Attachment 389369
I've cut a piece of 1 mm thick aluminium plate to make a bracket to fit the box onto. The plate is intended to fit under the motor mounting bolts and will be bent at 90 degrees so the it will sit over the motor body.
Attachment 389368
In this picture there are three of the four items that the box will have fitted to it, the other item is the motor start & run capacitor. The IEC mains input connector is at the top with the on/off switch to its left. The small slide switch to the right will be used to change the motor's direction of rotation. I intend to position it so that it indicates the direction of rotation.
More about this part later !
Thanks for looking.