Author Topic: surface grindy type project (Read 41435 times)

shipto · « **Reply #50 on:** July 15, 2014, 04:26:12 PM »

Bit off topic but since I dont have anything constructive to do with grinder I decided to put the wheel arch on the camper.. finally.

Brass_Machine · « **Reply #51 on:** July 15, 2014, 08:03:56 PM »

How did I miss this thread?? Very cool!

Eric

shipto · « **Reply #52 on:** July 23, 2014, 03:12:18 PM »

Been a bit quiet last few days as I have had to take a crash course in ladder logic to operate the plc, actually its not too bad once you get your head around it.
To start my main problem was I kept thinking of it like basic computer programming but afterwards I started thinking about it like a live rail and earth rail.

awemawson · « **Reply #53 on:** July 23, 2014, 03:33:25 PM »

Just remember that ladder logic developed to replace umpteen relays, so yes, think of two power rails with contacts and coils between them in intriguing combinations

shipto · « **Reply #54 on:** August 04, 2014, 03:23:54 PM »

Been busy making power supplies need 24v for the plc and controls 12v at about 3amp for the y axis motor. Took a little time to work out the panel too (pic). From top left it is Grinder start/stop, X axis start/stop, then Y axis start and Y axis stop and the final 2 yellow are to bring Y axis backwards and forwards. Need to get some nice labels now.

shipto · « **Reply #55 on:** August 07, 2014, 03:20:33 PM »

wiring or the beginnings of it anyway. Knew the wiring harness from my old fridge freezer would come in handy

shipto · « **Reply #56 on:** August 08, 2014, 06:29:33 AM »

kept looking at the panel and thinking theres something missing but dismissed the idea as me being daft, Then last night it dawned on me I havent put the speed pot for the X axis on there. Going to have to decide on a resonable position for it but think its probably going to look out of place wherever I put it now.

nel2lar · « **Reply #57 on:** August 18, 2014, 12:21:24 AM »

Shipto
I drew up a working that I said I would try to get to you. Well here it is and I hope you can understand my scribbling.
Nelson Collar

shipto · « **Reply #58 on:** August 20, 2014, 05:10:54 PM »

Thanks nel2lar I think I understand what you have drawn and its worth filing for future use.
The machine is getting so close now but all the wiring is taking me some time not to mention that i finally got the welding on the camper done just need to put it all back together then gather a few thing and I will be ready to mot it (fingers crossed).

shipto · « **Reply #59 on:** August 25, 2014, 05:23:36 PM »

Managed to get a fair bit done this weekend, I have put the rail for the y axis limits which will allow me to set the travel. The wiring for these limit switches and the power for the motor driving the table travels up the arm.
However there is a problem with my plc programming the grinder and Y axis is fine but I cant get the X to perform as expected and I am not sure why. Is there anyone who knows about easy logic on the board?

shipto · « **Reply #60 on:** August 30, 2014, 02:08:58 PM »

The plc programming has been a bit of a headache but I have finally sorted it and everything is working as expected now

shipto · « **Reply #61 on:** August 31, 2014, 02:44:40 PM »

Decided to give it a little test by grinding the table top I am quite pleased. About the straightest thing i have in the shop is the ruler off my set square which I wouldnt guarantee but its probably close enough for my needs and the red area in second picture marks a place where I can slide a rizla paper under the ruler. everywhere else is too close to get it under.

Stilldrillin · « **Reply #62 on:** August 31, 2014, 03:53:04 PM »

That's great Shipto!

I think the wheel needs racing, for an improved finish.

By the way...... I'm sure, it's your rule which is bent.......

Love it!

David D

shipto · « **Reply #63 on:** September 01, 2014, 02:59:08 PM »

Thanks Stilldrillin the wheel definatly needs changing the one on there is pretty bad but I will get another one once I have mounted magnets and made a jig to true it up. still have much to do like the mentioned magnets and guards which will include wipers and brushes to keep the guide rail clean. need to figure out how I am going to keep the muck from going under the table too, The linear bearings have wipers of their own but I still want to stop as much as possible going onto rails.

nel2lar · « **Reply #64 on:** September 11, 2014, 09:36:46 PM »

A good vacuum system will do the trick.

shipto · « **Reply #65 on:** September 12, 2014, 05:00:34 PM »

Quote from: nel2lar on September 11, 2014, 09:36:46 PM

A good vacuum system will do the trick.

Thought about that but the noise would be horrible.
However I have been thinking about a canvas cover for the ways which I will try to describe because I would like opinions,
where the canvas is protecting the way it will fold around it but when off it will fold around the backsomething like this (see pic)

chipenter · « **Reply #66 on:** September 13, 2014, 02:30:31 AM »

Have you looked a bellows http://www.arceurotrade.co.uk/Catalogue/Machine-Spares/Machine-Bellows , I have the rubber ones and they squash down well .

PekkaNF · « **Reply #67 on:** September 13, 2014, 03:39:40 AM »

I have a little experience on dust issues on round quides.

I would start from two ideas:
* Prevent excessive fallout on quide rods, a little shield on top, maybe an ash vacumcleaner or something (you don't want to set shopvack on fire).
* keep quides dry and clean.

We had one system with plenty of abrassive dust, few hardened quide rods and plenty of ball bearing bushes. When lubricated regularry, the bushes wore out no time. They lasted about as long if they were never lubricated or lubricated with "dry" lubricant. But they life was varied even more (like factor of five) depending how often the ways were cleaned on shopvack. Claning with pressurized air was worse than no cleaning at all!

It's rally hard to prevent ingress of fine dust. IMHO non pressurized belows are not worth of it. If you get any dust/grinding paste in, it's really hard to get it out.

Commercial manual grinders seem to trust on design, that minimizes dust fall out on quides. Labyrinth seals with pressurized air purge are pretty involved.

On that type of machine I would put some shields and some wipers/lipseals to prevent any bigger that rodent size particled entering into linear bearings.

Pekka

shipto · « **Reply #68 on:** September 13, 2014, 06:33:18 PM »

I am less worried about the linear bearings they have rubber wipers fitted and I plan to fit brushes to sweep them as the table moves along, with that I am looking into a method to block the majority of the dust even getting there in the first place. The main problem is the top of the way at the back, I am worried about a build up of dust which the bearings there will run over thus making the whole thing less accurate by whatever thickness the dust is.
Here again I am planning to use brushes the sweep the rail. the canvas Idea if I can get it to work would stop most of the dust getting there making the job of keeping the rail clean easier for the brushes.

Manxmodder · « **Reply #69 on:** September 14, 2014, 08:19:29 AM »

The canvas sounds a good idea to prevent the majority of grime getting in.

I just wondered if you had also considered placing a couple of neodymium magnets in a location where they would capture a lot of the metallic dust produced while grinding is taking place......OZ.

shipto · « **Reply #70 on:** September 15, 2014, 12:49:59 PM »

Funny you should say that, I have yet to take photo's but I have fixed the magnets to the bed and tried a bit of grinding and the magnets did seem to be catching most of the grindings.
editted to include pics.

shipto · « **Reply #71 on:** September 21, 2014, 03:10:13 PM »

Have moved on a little, brought the rod ends to replace the temporary arm and made a start on the guards.

shipto · « **Reply #72 on:** September 27, 2014, 06:24:06 PM »

I have been testing the grinder out a little over the past week and come to some conclusions:
The grinder itself is too slow, too under powered and not sutable for prolonged use it overheats quite a lot.
It will suffice to allow me to make the parts to improve it, I am going to reamake that part using a .55kw motor and shaft with a variable pulley to set the speed between 3000rpm up to about 6000rpm. I also intend to make some adapters to hold the grinding disks I need to buy so they can be balanced before being placed on the machine. hopefully this will mean I can have a variety of grits.
Also something needs to happen with the main slide the bearing are digging in a lot quicker than I thought so I am thinking that if I can get some straight thin hardened material that I could fix to the areas where the bearings run that should do the job.

shipto · « **Reply #73 on:** November 04, 2014, 02:31:34 PM »

Been busy working in the house keeping the treasurer (wife) happy but had a day off today and made some progress. The grinder has been stripped of its electrics and is ready to be mounted on new slide mechanism. Also made a start on the balancing adapters for the wheels.

shipto · « **Reply #74 on:** November 10, 2014, 02:39:32 PM »

Bit more done

Over the weekend I knocked up a couple of slide rails and got the motor plate mounted on the slide rails.
pic one shows the slide rails and on the floor is the motor thats going to be mounted (along with the evidence of my bad smoking habit

) and pic two with the motor mounting plate in place.

News:

Author Topic: surface grindy type project (Read 41435 times)