herb
spending too much on rocks
Member since November 2011
Posts: 470
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Post by herb on Oct 8, 2014 15:31:09 GMT -5
Hi, Not a home made equipment question, but an equipment question just the same... I have an 18 inch Highland Park slab saw model J3. While slabbing a rock the other day, I had the blade jammed on me. I didn't notice until probably something like 10 minutes later (This is exactly why they tell you to never leave your saw unattended!). Fortunately, the drive belt was loose enough so that the motor kept turning while the belt and the blade staid still. This prevented the motor from burning out, but it caused the motor pulley to burn about half way through the drive belt. Replacing this belt is simple enough, but while I was taking it off, I noticed that the other belt, the one that drives the carriage forward has a small split in it. I figured while I am replacing one belt, I might as well do the other one too. The question I have is how does one change the belt? It looks like you basically have to remove the saw from the arbor and then unbolt the pillow block bearings and then maybe slide the whole assembly out the side of the saw case in order to put the belt on. Before I do all that, I just wanted to confirm that I am doing it correctly. Here is an overview picture. The pulley on the left is what holds the damaged drive belt. The belt that is shown is what I am wondering how to replace. The pulley on the right is the tension pulley and out of frame further to the right is the step pulley that controls the feed rate.  Here is a detailed top view. I am thinking I have to remove the 4 bolts holding the pillow block bearings (red arrows). The blue arrows point to the set screws that are used to align the arbor shaft and blade with the carriage. Do you think I will have to realign the blade after the new belt is in place?  Finally, here is another top view that also shows inside the saw case the arbor shaft, collar and blade. I am thinking after I remove the bolts for the pillow blocks I will have to remove the blade and collars and then (hopefully) be able to slide the whole assembly out of the saw (to the left). I am not sure what is preventing oil from leaking out where the arbor shaft goes out the side of the case? There must be some sort of collar there that I am not seeing. I guess I will end up checking the blade alignment anyway, just to be safe. Do I need to worry about the blade no longer being perpendicular to carriage in the vertical direction (eg: would have to shim under the pillow block bearings to correct) or just in the horizontal direction (eg: adjust the set screw with the blue arrows). Are there any other things I should be thinking about?  Thanks for your advice! Herb |
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zarguy
fully equipped rock polisher
Cedar City, Utah - rockhound heaven!
Member since December 2005
Posts: 1,791
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Post by zarguy on Oct 8, 2014 16:00:14 GMT -5
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Post by captbob on Oct 8, 2014 16:03:07 GMT -5
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Post by parfive on Oct 8, 2014 16:04:06 GMT -5
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Post by kap on Oct 8, 2014 16:08:46 GMT -5
Mine has a link belt. Most mechanical supply houses has them.
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herb
spending too much on rocks
Member since November 2011
Posts: 470
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Post by herb on Oct 8, 2014 16:48:40 GMT -5
captbob said: Couldn't ya just use an adjustable link belt?
parfive said: Link belt
kap said: Mine has a link belt
A link belt! Duh! (Sound of palm hitting forehead!) Of course! A link belt would be about 10000 times easier! Thanks everyone! Sometimes it really pays to ask questions :-)
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Post by captbob on Oct 8, 2014 16:51:00 GMT -5
Here ya go Herb, you can borrow this --->  |
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Post by johnjsgems on Oct 22, 2014 19:03:02 GMT -5
Link belt would be easiest. You could possibly unbolt the outer bearing from frame (maybe both bearings) and get enough play to slip a belt over. Cases like this buy the best quality belt you can. Or the link belt and spend time cutting.
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rhoward
off to a rocking start
Member since March 2020
Posts: 2
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Post by rhoward on Mar 27, 2020 18:28:30 GMT -5
Herb what did you end up doing with regard to replacing the carriage belt on your HP J-3? I have a J-2 with the same arbor/bearing setup and need to replace the carriage drive belt?
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herb
spending too much on rocks
Member since November 2011
Posts: 470
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Post by herb on Mar 29, 2020 19:20:55 GMT -5
Herb what did you end up doing with regard to replacing the carriage belt on your HP J-3? I have a J-2 with the same arbor/bearing setup and need to replace the carriage drive belt? You have good timing with your question! I am in the process of replacing the inner pillow block bearing so I now know what needs to be done to replace the carriage drive belt. I ended up sticking with the damaged belt. I temporarily took the damaged belt off the pulleys and had it held out of the way as I tried out the link belt. The link belt worked ok, but it was quite noisy. Also seemed to cause a lot of vibration. Didn't have any negative effects on the quality of the cuts, but I decided to go back to the damaged belt and wait for it to break before going to the link belt. Maybe the link belt was noisy because I had the wrong width or profile shape, I don't know. It was the only one the local store I got it from had, so I didn't have any other options. But now that I need to replace the bearing, I know how to replace the carriage drive belt. It is kind of involved, but not too bad. Here are the steps: First, remove the belt guard at the front of the saw that covers the step pulley. Slip the damaged belt off the pulley. Next, slip the belt from the motor off its pulley. Here is a modified pic from my original post to help explain the next steps:  saw_top by Shiny Objects, on Flickr Next you'll have to remove the outer pillow block bearing. There are 2 bolts (red arrows) that need to be removed. On the under side is a nut, a lock washer, and another washer. Make sure you don't let any of them drop to the floor and spend 15 minutes looking for them like I did! There are 2 set screws on the bearing that have to be loosened (green circle shows 1 of them) You will probably also have to loosen the 2 bolts that hold the pillow block in place (blue arrows) Now try pulling the bearing off the arbor shaft. I got lucky with mine coming off pretty easily. I just gently pried with a screw driver against the large pulley and the bearing slid off. Next, the 2 belt pulleys (black arrows) each have a set screw that needs to be loosened. Clean off the arbor shaft between the small pulley and the inner pillow block to get rid of any gunk that will make moving the pulleys difficult. Push both pulleys in towards the inner pillow block. (Might have to do 1 at a time) Make a mental note or measure where the pulleys are on the shaft before you move them so you know where they should go back to later with out having to adjust them multiple times. With the pulleys pushed inward, there is now enough clearance to remove the carriage drive belt. Take the damaged belt to an auto parts store or where ever your favorite place to get drive belts from and have them use your old belt to figure out what size new one you need. Keep in mind your old belt is probably stretched a little, so if you have to choose between a slightly larger belt and a slightly smaller one, pick the smaller one. To reassemble everything, push the pulleys back where they belong and tighten the set screws. Put the bearing back on, install the bolts (red arrows) tighten the other bolts (blue arrows), tighten the bearing set screws (green circle). Slip the belts back on the pulleys, put the belt guard back on over the step pulley and hopefully you are back in business. Good luck! -Herb |
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rhoward
off to a rocking start
Member since March 2020
Posts: 2
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Post by rhoward on Mar 31, 2020 13:35:55 GMT -5
Thank You Herb, I have done all you described to loosen the pillow block bearings but probably need to get a gear puller to remove the pillow block bearing from the shaft as it is not moving with minimal force.
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herb
spending too much on rocks
Member since November 2011
Posts: 470
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Post by herb on Mar 31, 2020 16:34:01 GMT -5
Thank You Herb, I have done all you described to loosen the pillow block bearings but probably need to get a gear puller to remove the pillow block bearing from the shaft as it is not moving with minimal force. Bummer! Are you sure you loosened all the set screws golding the bearing on the shaft? Maybe the bolts pointed to by my blue arrows need more loosening? I was surprised I got lucky and my bearing came off with out much force. Sorry you weren't so lucky |
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Post by catmandewe on Mar 31, 2020 17:36:25 GMT -5
Thank You Herb, I have done all you described to loosen the pillow block bearings but probably need to get a gear puller to remove the pillow block bearing from the shaft as it is not moving with minimal force. Bummer! Are you sure you loosened all the set screws golding the bearing on the shaft? Maybe the bolts pointed to by my blue arrows need more loosening? I was surprised I got lucky and my bearing came off with out much force. Sorry you weren't so lucky Sometimes those are concentric bearings. If so then there will only be one set screw and the other hole is to put a punch into to turn the collar counterclockwise to unlock it. Check to make sure it is not that before you go to pulling it off with a puller. Good Luck! Tony |
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Post by woodman on Mar 31, 2020 17:42:33 GMT -5
Link belts are known to reduce vibrations not cause more. they are sold as an ant vibration belt. I like them'
are the colors the cam lock type that you have to rotate after you loosen the set screws, can't tell from your photo?
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herb
spending too much on rocks
Member since November 2011
Posts: 470
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Post by herb on Mar 31, 2020 19:55:41 GMT -5
catmandewe, woodman I dont know alot about bearings or their terminology, but with my bearing they are definitely 2 set screws. I'm not entirely sure what a concentric or cam lock bearing would look like but I dont think that's what I have. rhoward has a different model saw than mine so maybe his bearings are different. If it helps, my bearings are SKF SY100. Maybe rhoward could tell us his bearing model number so those who know more about bearings can offer additional advise.
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Post by catmandewe on Mar 31, 2020 20:42:49 GMT -5
If there were 2 set screws then it is not a concentric bearing.
Tony
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Post by woodman on Mar 31, 2020 21:17:36 GMT -5
Take your time and use lots of pb blaster or other good penetrating oil. they will come off but take your time and do no more damage.
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Post by catmandewe on Apr 1, 2020 12:08:28 GMT -5
If you can find it get some Kroil, its a miracle in a can!!
Tony
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Post by toiv0 on Apr 1, 2020 15:11:03 GMT -5
If you can find it get some Kroil, its a miracle in a can!! Tony I love Kroil. |
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Post by woodman on Apr 1, 2020 15:41:40 GMT -5
If you can find it get some Kroil, its a miracle in a can!! Tony I love Kroil. i like the smell also! |
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