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Adding power feed to a surface grinder

Wlodek

Aluminum
Joined
Nov 15, 2018
I am used to run a Jones & Shipman 540X hydraulic surface grinder and when recently getting a used manual Ingar 618 I found it rather tedious to run the two drives manually - especially the longitudinal one. Since I was going to rebuilt the machine anyway, I've decided on adding a simple power drive and I just have happened to have the right type of Bodine DC gear-motor to do it. The motor is coupled to the drive via a timing belt, and the timing belt pulley connects to the motor shaft by a toothed clutch to disengage it when working manually. The motor speed is adjustable as are the timings of the reverse cycles (0-1 second). This allows for a comfortable manual advance of the Y slide at the end of each transverse.
Other work on the grinder included adding a DRO (with the scales mounted inside the castings), replacing the lead-screws rubber boots and spindle and motor bearings, making new splash guards and the coolant circulation setup.
Ingar is a Spanish machine and when dismantling it I was surprised by how much its design is similar the Boyar-Schultz, including even the use of inch fasteners that are not common in Spanish products. The major difference is a multi-V belt drive for the longitudinal drive - the Boyar-Schultz grinders I have seen are using rack and pinion. The belt drive is surprisingly smooth and light to operate.

I realize that a project like this is not exactly an economical proposition. But at this, my semi-retired stage, it is not only a "fun" project that did altogether cost me very little, but one that allows me to do small grinding jobs while the Jones & Shipman is busy or set up for other work.

I've made a short video showing the conversion and the operation:
YouTube


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Very nicely done Wlodek.

What are the details on the clutch, I assume disengaging clutch restores easy use of manual table movement?

Thanks for sharing.
I hope you are able to create additional youtube videos!
Dan
 
Looking at the OP's design it's quite straightforward. The pulley nearest the motor is free to rotate on the shaft,like a keyed pulley on a shaft with the key missing. The gold coloured part is connected to the drive shaft probably by a keyway but can slide. When disengaged the gold part rotates with the motor but the silver pulley stays stationary. When the gold part is slid to engage with the radial teeth on the free silver pulley They are locked together and drive is transmitted to the othe pulley movingbthe table. The teeth are a nice touch but a simpler drive dog would work, th teeth mean the clutch cam be engaged in many more positions.

I like this design and will use some of the elements. I have a non-geared BLDC Bodine motor, its control board has speed and direction inputs that I'm planning to control by Arduino. My table drive is rack & pinion and there is a fair amount of backlash so I can use the Arduino to slow the drive down before reversing direction to minimise shock on direction change. I have considered converting to cable drive but the helical gear meets the task at approx 45 degrees so Imdont know if I can cut a helix for the cable groove and if the cable with grip sufficiently.
 
Very nicely done Wlodek.

What are the details on the clutch, I assume disengaging clutch restores easy use of manual table movement?

Thanks for sharing.
I hope you are able to create additional youtube videos!
Dan

Thank you. The clutch is a simple device. The timing belt pulley, with the clutch face gear riveted to it, is free on the motor shaft (it runs in a ball bearing pressed on the shaft and pressed inside the pulley.) The other face gear is attached to the red knob and slide together on a 12 groove spline cut in the motor shaft (and a matching female spline in the face gear). On the red knob you can the see the threaded hole where a ball detent is inserted and clicks in two grooves on the motor shaft - one engaged and one free. All parts (except the aluminum knob) are hardened steel. The idea is to decouple the motor for manual operation. There are, of course, other ways of doing this.
As for the operation of the motor, it is very simple. The 24V power supply voltage can be adjusted to suit the speed. The travel limit switch switches one time-delay- relay at a time to change the direction with an adjustable on time delay. This works quite well as the table has some inertia to come to a soft stop and start. The only "programming" is setting the time delays to suit (the knobs on the relays).
I really like the Ingar multi V flat belt drive for the transverse table as it has zero backlash (the tension is adjustable) and a very smooth operation. I have not seen this arrangement in other machines I know.
 
Nice work Wlodek, enjoyed the video. Do you have any images of the DRO scale mountings? I’d like to add a vertical scale to my surface grinder, and I like the elegance (and cleanliness) of putting it inside the casting.
 
Unfortunately I did not take any photos while working on the machine. I've used narrow scales (1 micron resolution) that have smaller cross section and can be fitted inside(with some difficulty). The vertical column leaves very little space inside and placing the scale required a little bit of grinding of the casting and making custom spacer for the scale to sit next and parallel to the sliding part.
On the vertical my scale is bolted to the casting and the sensor to the back side of the moving part.
On the X the scale is moving and the slider bolted to the casting. As well, to get the right fit and the full travel I had to order longer scales and to cut them to the exact length that will fit the space and not restrict the travel.
By the way the DRO and scales were an inexpensive Chinese product, but are working well. The total accuracy is not that good even after calibration. I get random errors of up 5-8 microns over the full travel. However, and especially on a surface grinder unlike on a mill or lathe, one seldom needs accurate long travel. The incremental accuracy of the scales is quite good, probably in the 1-2 micron range. So if I need to take 5 microns from a part I am really limited by the overall accuracy of the machine which is likely about 2 microns as well. But I can always bring the last micron by lapping....
 
I was using slim scales, the cross section of the housing is only 17mm x20mm - considerably less than regular scales. In the column of my machine I just had to file off 3mm from the tops of the two inside ribs to bring the scale close enough to the slide. Tight fit, but the scale clears all and I was able to install the back guard in place.
 
Wlodek,who is clutch producer? I am planning something similar for grinding machine.

The clutch was shop made. The two face gears were cut out of A2 steel and heat treated and the spline cut on the shaft and in a steel insert in the aluminum knob. The knob assembly locks in the engaged and disengaged position by the the ball in the two grooves in the main shaft.

X-drive-mk2.jpg
 

I am familiar with commercial toothed-jaw clutches and in fact did base my design on those (initially I was going to make a single "dog" coupling or one with four slots). But since this whole project was more of the "fun" nature (I would not embark on anything like this while working full time) and I did use the existing motor shaft to cut into it the splines, it was easier to design and make all the parts to suit.
 








 
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