Another Tool & Cutter Grinder

With the grinding head mostly machined, I now need to fasten the motor mount to the head. I was going to use a shoulder bolt but opted for a brass bushing.
IMG_0663.JPG Here you can see a 1/2" bolt which is a good slip fit into the bushing I made. The bushing is a couple thousandths longer than the distance of the motor swivel and the recess in the grinding head. when assembled and tightened, the bushing is captured by the bolt and the swivel rotates on the brass bushing easily but with no detectable end play. The swivel only has .001" clearance all the way around its circumference. this assembly is very precision and has no play anywhere. This is why it was important to be precise on sizes and everything had to be very concentric to have no binding. The assembly works great.
IMG_0664.JPG The swivel is mounted in this photo and works extremely well.
IMG_0665.JPG The motor plat mounts and covers the bolt. There will be 4 holes in this plate for the motor to bolt to. Next is the split cotters to lock the motor in position.
Split Cotter.jpg
This is the print for the brass split cotters. I chose to use two for security although one probably would do the job.

IMG_0667.JPG The split cotters are in place and work perfectly. If you look at t he print there is a spring pocket in one half of the cotter. I put a spring in between the two halves so when loosened they separate and release the motor swivel.

IMG_0666.JPG I tapped the one side of the head and the other side is clearanced for a 5/16" bolt. The top and bottom bolts are tightened just enough to give a nice sliding head with no slop. the center bolt will be tightened to lock the head in place. this takes a maximum of a quarter turn because the other two hold it so close. I will make a special bolt with a handle for the center bolt later on. The heavy steel washer are close fit and prevent the bolt from digging into the aluminum.
IMG_0669.JPG The grinding head is mounted to the 2" column. Everything came out perfect so far.

IMG_0674.JPG I made a brass pointer that will be somewhat adjustable for indicating the position of the motor tilt. I will not fasten this until the complete grinder is assembled so it will read zero with the motor and grinding wheel mounted. ( It will also get polished to a nice shine.

IMG_0673.JPG The anti back lash lead screw nut is mounted on the head. It is as close as possible to the column to make the elevating easier. ( it has to work harder the farther out it is.)
The next step here will be to make the upper and lower lead screw brackets. One at the top of the column and one at the lowest travel point on the column. Once they are mounted the head will not be able to rotate . The whole column assembly will rotate to change the angle. The head will retain its position because the acme lead screw will prevent it from rotating. I found this worked very well when I built the Bonelle grinder. The precision nut keeps the head from having any play in the rotational axis.
The reason for the massive size of the head is because the 48 frame motor weighs 13 pounds and I wanted a lot of rigidity in this machine.

I was thinking of painting the head with black wrinkle finish, but first I am going to polish the aluminum to a mirror finish and see if I like that better. The head is complete to where it is time to polish it
 
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I mocked up the motor assembly today and tested it. This is the 1/2 HP split phase motor I got from the Chinese water pump. Originally it was for the Bonelle grinder but didn't have enough starting torque, so I got a bigger motor for it. This motor has plenty of power once it is up to speed so will be ideal for this setup because it is small and light. It will be good for this direct drive setup. I also mounted the pointer for the degree markings.
IMG_0680.JPG

IMG_0678.JPG The motor is mounted on the head. Everything is working out quite well. That switch box will be removed from the motor and mounted remotely. I painted the head black wrinkle finish but polished the top , bottom, and front. It looks nice. Once the grinder is built, the motor will be aligned so the wheel will be level and square with the table when all dials are at zero, then the motor will be pinned in this location so it cannot move out of alignment.
I also got the hand wheels mounted on the table. They are great. I will make the spinner handles to go on the hand wheels.
IMG_0675.JPG Y axis hand wheel.
IMG_0676.JPG X axis hand wheel.
IMG_0682.JPG I am using a 3/4" thick aluminum plate for the base for this grinder. I have the parts setting in place to see how they will fit. I still have to make the swivel base for the column.
I have made an arbor for the motor shaft to adapt different grinding wheels. I will be posting these details soon.
 
An excellent write up and a good design! I can see the Quorn ancestry every once in a while and this looks a lot less fidgety.
The first of last year , I built a Bonelle grinder which is basically an over engineered Quorn. It is a great grinder but requires a lot of setup. This grinder is more like a Cutter Master and will be much simpler and easier to setup and operate. It will also do everything the Bonelle and Quorn will do but easier.
 
Hi Mark.
Your work is first class! Thank you for sharing. Could you please supply me with the dimensions of the x-y table with movement range figures aswell. I want to start getting materials together for that and to start making something similar. Thanks in advance
 
Hi Mark.
Your work is first class! Thank you for sharing. Could you please supply me with the dimensions of the x-y table with movement range figures aswell. I want to start getting materials together for that and to start making something similar. Thanks in advance

The table I am using is a Phase II , X Y table. there are several brands less expensive. ( I happen to get this one given to me by a friend :grin: ). Enco has one and there are a couple on eBay. The table is about 5 1/2" wide and around 12 inches long. There is 4" of X movement and 6 1/2" of Y movement. I just looked it up and it is on eBay for $150 new. The table and the motor are the most expensive parts. you need a small motor at least 1/3 hp or more with a 42 or 48 frame mounting, 3450 rpm and it needs to have ball bearings. I got the lead screw and anti back lash nut on eBay. the screw was around $12 and the nut was about $17. Pretty much everything else is made from aluminum and steel. My prints will specify. If you want, I can send you the prints for everything I have done so far.

A NOTE: I disassembled the table, cleaned everything up, made new large dials and hanged the cranks to 4" diameter hand wheels ( got the hand wheels off eBay. They are about $15 each now but really nice ones). I tried to eliminate as much backlash as possible in the table and installed a lock handle in place of one of the gib set screws on each axis. I make most everything I need. It is important to have the best quality table you can find even if it costs a little more because the accuracy is important.
 
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Thanks for the info Mark. Ebay is somewhat of a myth in my part of the world. I will have to make a table from scratch if i cannot find one somewhere. I have someone who has promised me a 200mm long set of linear ball bearings , which i have planned to use as the y-axis. For the x-axis i plan to make a wide dovetail setup with the leftover cast iron tractor weights from my Tom Senior/Maho vertical mill head conversion.
Would you mind sending me the prints please.
Thank you once a again for sharing
 
Thanks for the info Mark. Ebay is somewhat of a myth in my part of the world. I will have to make a table from scratch if i cannot find one somewhere. I have someone who has promised me a 200mm long set of linear ball bearings , which i have planned to use as the y-axis. For the x-axis i plan to make a wide dovetail setup with the leftover cast iron tractor weights from my Tom Senior/Maho vertical mill head conversion.
Would you mind sending me the prints please.
Thank you once a again for sharing
I couldn't figure out how to send the prints to you directly so I will put them here. you can save them. It is possible I make a few errors so watch them closely and ask if something doesn't look right. These are what I have done so far. There will be more to follow.
Elevation Screw Bracket.jpg Grinding Head (2).jpg Grinding Head.jpg Motor Arbor.jpg Motor Mount and Swivel.jpg Split Cotter.jpg
 
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