HELP!!!!!
I made a crosscut sled and everything seemed okay until I put the runners in the miter slots on my table saw. Now, it wants to stick. It will go so far and then it becomes hard to push. I pulled it back out and tried again and it does the same thing. I checked the underneath side of the sled and it seems fine. I checked the top of my table saw and there doesn’t seem to be anything on it that would hold it up. I put butchers wax on the runners and in the miter slots and that seemed to help a little but it still sticks. The sled is also very hard to push.
Anybody have any ideas that I could try to remedy these problems. I would appreciate any insight anyone might have.
Thanks, Steve.
Replies
Most likely either the miter slots are not precisely parallel to each other or when attaching the runners, one or both got slightly tweaked.
You can identify the tight spots by looking at the runners after trying to push it through. There should be rub marks from binding. If so, you should be able to make a sandblock and with some judicious sanding remove the rub points until it fits. Just sand a little, try it again, repeat as necessary.
If the slots are not parallel...you'll need to build in a little slop in the runners to account for the problem. Again, a little sanding may well be the ticket.
Take care, Mike
Steve
Mike gave you good advice.
You can also purchase the correct size of cold rolled steel (it is a stock size) to work as runners, and eliminate the swelling and shrinking of wooden runners.
I do not know the way you built your sleds, but when I build mine, I first attach the runners to the plywood, which is oversized. Once the assembly is adjusted and slides smoothly, I cut the plywood to size on the blade side by pushing it through the saw. Then I layout and attach the fence temporarily, and do test cuts until the adjustment is perfectly square. Only then is the fence fully attached. The same holds true for the 45 degree fences on another sled. There I build both LH and RH fences on the same sled. JL
I thought cold rolled steel was too hard for the cast iron miter slots?I have been looking for aluminum in that size but can't find it. Steel is common.
CJH
Not to worry. The table is not iron, it is steel. Cold rolled steel works VERY well and causes no problems. The reason that table saw slots are the size they are is because they were created to match the stock cold rolled sizes. Hardwood works fine, but, being wood, is not as efficient. Aluminum, on the other hand, is too soft for this kind of application. It will work, but... JL
CJH
Addendum to the previous post I made to you:
Look at the mitre gauges that come with the table saws. The guides are all cold rolled steel. JL
Hi,
I had a simialar problem with my runners. My miter slots aren't exactly 3/4". So I had to make minor adjustments. Try using a chisel to scrape the sides of the runners. Much faster than sanding. I think it's more effective. Especially when using oak runners. My sled now slides nicely over the saw table with no slop. Not too tight not too loose.
Wanda
I had thought steel would be okay since miter guages are steel, but had read on more than one forum that it was too hard. I'll give it a try. Thanks for the input.
Steel is OK; if it works for the miter why not the sled........same difference.
Aluminum, wood or phenolic might be easier to work with, that's all. The complications come into play because of the approach taken when installing and lining up the runners. You have got to incorporate runner adjustability in your design then be able to hold the runner in place after lining it up so it runs without binding.
Thanks. I was going to use Rich24's method for building the sled (build it in two halves) which addresses the concern of lining up the runners.At least that's the plan...
CJH
It will work well for you. JL
My first thought is either the runners are not parallel, or if you screwed them to the sled, the screws "expanded" the thin wood strips causing tight spots when in the miter track.
To check parallelism, measure a diagonal from the outside front edge of the right runner to the outside BACK edge of the left runner. Then do the same for the other diagonal and see if the numbers match exactly.
The other thing I recommend is to loosen one runner and see if one runner slides smoothly. Then slowly tighten the other runner by leaving the sled in the slots and sliding the sled until the last screw is visible under the back edge of the saw. Then slowly tighten this screw. Pull the sled past the front of the saw and slowly tighten the front most screw. If the sled moves smoothly, then slowly tighten the remaining screws.
HTH.
Regards,
Cincinnati
Chief, instead of sandpaper to remove the high spots of the runners, try using the corner of a scraper. I am buiding a sled for a box joint jig and had the same problem that you describe yesterday.
I saw this advice from John White, the FWW shop manager, in a response to another post a couple of months ago. Anyway, it works great and is quicker than using the sandpaper.
Steve
Don't the scrapers come in handy?! I bought these mini-scrapers from Lee Valley, and they're great for problems like the one described here.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
forestgirl, they sure do.
I had not see the mini scrapers before. Thanks for the link.
Steve
Check your local hardware store and see if they have aluminum stock that would fit the miter slots. If you find something that is a tad oversize it is a minor task to mill it with sandpaper till it fits the miter slot. When attaching the slides to the cutoff sled board you should first put the glides in the miter slots and make sure they are snug and with no slop in the miter slot. With the glides in the miter slots then place your board on top of it. Extend the assembly past the front edge and screw it in the nearest hole, back the assembly to the rear of the saw top and attach with another screw. Before taking it off the saw slide this back and forth to make sure it glides smoothly. You should have a minimum of 5 screw attachment holes in each guide bar. With the assembly still on the top repeat the process of extending the cutoff assembly to attach the next screw toward the front and back. After this you can take the sled off and attach the middle screw. This is the way I have done mine and it takes the frustration out of binding in the miter slot. All this takes time, but it is time well spent so you don't have to second guess why it isn't sliding properly. When looking for aluminum square stock, make sure it is chamfered on the corners so it glides easier in the miter slots. Best of luck
The method you describe is the best way to fit sled runners to the sliding bed, in my opinion. It eliminates a lot of the "squirm" that can happen when screws enter a piece of wood (the sled's runners). Since the runners are pretty much locked in place by the cast iron tabletop, they're aligned perfectly with where they need to go. This is the way I build all my sleds. Yes, it might take slightly more time, but the end results are worth it..
And, wood is perfectly fine material to use for sled runners. It's not like you're going to wear something like this out in a hurry. A sled is not something you use all day, every day. I use maple for sled runners and have never had to replace one. Some of my sleds are 15+ years old. Plus, wood is the easier material to adjust to end up with that perfect sliding fit.
Zolton
Steve, since the bottom of the table slots are not fully square, why not plane off a chamfer on the sled runner's bottom edges? Next, (using a charcoal pencil,) rub the suspected strip lightly with the dull point of the pencil. Work on one strip at a time. Work the sled fore and aft in the groove.
Any tight spots will show as a worn spot Sand only this spot.
Try for fit... if not better, work on the other strip... sand if wear occurs. Pretty soon it should slide effortlessly.
Steinmetz .
Is your shop located in a damp location? If yes, you might want to substitute phenolic runners (also chamfered)
Edited 4/2/2007 2:42 pm ET by Steinmetz
Edited 4/7/2007 12:21 am ET by Steinmetz
Incra makes a fine slider that is adjustable. Made of aluminum and comes with plans/instructions for the sled. Available in 18" and 24".
Available at http://www.eagleamerica.com In the search section type in part Number 434-0900 for the 18" or 434-0924 for the 24"
Work Safe, Count to 10 when your done for the day !!
Bruce S.
dirt and or dust in the miter track, double miter runners not square, miter runner(s) bottoming out.????
American Woodworker, this issue, has an excellent article on building a sled. It should still be on the News Stand.
Wood runners quarter sawn do a good job; especially if your follow the example mentioned above.
Careful of aluminum runners you might purchase at the big box. They are not truly 3/4" wide. Check T-track sections at the wood working supply dealers, they make excellent runners and can be screwed from the bottom with sloppy holes until the adjustment is complete then permanent screws can be installed in tighter fitting predrilled hole.
Also be careful about using flathead screw in the top, which would be the logical place to screw the runners, this installation has a tendency to pull and/or push the runner, when tightened by virtue of the "V" countersink , if the holes are not perfectly lined up.
Good luck.
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