Nice Bridgeport! I’ve always wanted one of those.
I agree that the column is a weak link. In the original, it is thicker and welded to the base which is a thick cast iron. There also appear to be construction differences among the various Topgrafter clones. I posted about this earlier. The red colored one I have is of much higher quality overall.
Yeah, based on your reviews of the two clones, the one on Amazon is better. That’s the way it goes. Even Chinese clone shops try to cut a few more corners to get the absolute cheapest price (and product) vs. their competing clone shops. Wish I’d got the one from Amazon. But if the base is put together like mine, it’s still a faulty design waiting to break.
Sounds like the original was well engineered and well constructed.
I presume it slides into the square tube. I was thinking putting a bolt in it, sliding it into the tube 1/16" and tacking it with a mig to the inside of the tube. The tube would then sit square since the tack was inside. You might need a longer bolt.
Since I don’t know what kind of metal it is, I’m not even sure if it can be easily tacked.
Another option might be to let it stick out an 1/8" and tack it so the tube sits on the nut.
Hmm,
I’m not sure I’m understanding. A bolt mig welded inside the square column would be pretty big. I measured it just now and a 7/16-14 bolt would fit pretty tight inside.
But then there is trying to get everything square. As you know welding pulls everything every which way (when precision counts). You would want the column to fit really nice and square (perpendicular) to the base. I’d think that would be terribly hard to do with any kind of welding. Then of course you’d have to drill out the base to make room for the 7/16 bolt.
One might stand a better chance of mig welding the original square nut back in the tube (from the inside). But then again you have the weld pulling (akk). Maybe if one was very careful you could bend the tube back square (with a little heat) with the base and make it work.
My guess is the original square tube column is simple cheap 1018 steel, which would be weldable.
It may be too awkward. I don’t know. My thought was to use the bolt to position the nut inside the tube for welding, not to place it there permanently. I’ll have to take a closer look at mine. I’m just going from your pictures.
One could also tack the nut to a small piece of metal and take that to the tube outside. This would put the nut outside the tube. If length is critical (not sure) one could cut the tube to compensate.
Just thinking out loud, throwing out less expensive ideas… Hopefully mine won’t break and I won’t have to deal with it!
One quick and cheap fix may be to remove the spring assembly and install a long carriage bolt ending at the top of the column. Although you would lose the spring function the tool should be OK for home use.
That’s actually a pretty good idea, imo.
It wouldn’t have to be a carriage bolt, just any long bolt with a washer on the top end of the column. One would have to grind/file the tracking bolt on the side (the small bolt which follows the slot on the side, to allow clearance for the long vertical bolt installed on the top.) Would probably also have to drill out the bottom of the base for the long bolt to go through and put a nut on the bottom. But all this could be done by anyone with minimal tools (cordless drill, drill bit, hack saw, file).
As far as I can think about it, that seems like a good hack. I think the long bolt would hold the square column in place.
I’m thinking the long bolt going through the column wouldn’t want to be any bigger than a 5/16 bolt. Maybe even a 1/4"
I was thinking that the bolt on the side can be removed entirely with no adverse effect. It looks to me like it is there just for mounting the spring. I guess it would be easy enough to test.
I think you are right again. The bolt on the side does provide a stop, but of course that would also be accomplished by the proposed longitudinal bolt head on top. Good problem solving on your part.
I’ll probably will still mill a piece of square stock as I proposed earlier, but I think what you suggest will also work well. Again a good idea.
Given how cheap this tool is, it is still worth purchasing 2 just in case one breaks. I’ve used a lot of force on mine and I dont see it being particularly easy to break it in normal use.
Perhaps it depends on the “model”. My Aliexpress model failed after a not too thick graft. I would in no way expect a second unit to hold up better. I’ve found two pieces of junk aren’t really much better than one.
But… if the Amazon model is better, then that’s a go, imo.
Also, maybe I got an extra junky/weak model from Aliexpress.
Mine was from Ali as well. I wasn’t hard on mine I just used it as a grafting tool with scions not more than pencil size or close to it. Now I can use it as a hammer if I like.
Or a conversation piece. It’s such a contraption, who could guess what it’s used for, especially one that’s broken?
I took a closer look at mind and can see how tacking it back in place will be problematic.
One of the problems I had with mine was some damage to some of the softer woods by the anvil. I decided to try to pad it. I took a piece of 3M Scotch 2242 which is more rubber than tape. It does not stick well itself, but it has a little thickness to it. I laid it on top of the anvil and then put a piece of electrical tape over it to anchor it in place.
Next I closed it to cut the tape. I then use a little more electrical tape to secure the cut ends in place:
It is a little hard to see from the pic but there is a gap for the blades to go through and it closes and cuts fine. This would have been easier if I had removed the anvil. padded it, and then replaced it, but I didn’t want to mess with adjusting it just right.
Just thought I’d pass this on if anyone else is having a similar issue.
What softer woods are you using? I used them for figs which are quite soft.
This is THE tool and method recommended for grafting plumerias which are extremely soft.
I don’t have an issue with persimmon or Jujube, but for apples, the anvil can rip the bark slightly on the back side of the cut. When I looked that the pictures some folks have posted, I came to the conclusion that there are a number of Chinese companies making these knockoffs, each a bit differently. I notice that the anvils in some of the pics folks posted are finished like the rest of the tool. Mine are silver in color and made of a different kind of metal. They look like they were cast. They seem a bit rougher. This could also be why some are breaking and others are not. They all probably stole the same plans but came up with slightly different ways of manufacturing them.
The anvils I have on my red tool are nearly as good as on the Raggett tool(but Raggett is better). They are also made of cast iron and are very closely matched to the cutting blades.
I also bought another tool at that time from Alibaba that was a bit lighter in color. The anvil was entirely different and made of some light aluminum material. The fit wasn’t as good at all. The tool was significantly lighter if I recall.
That is another thing about Chinese knock-offs. There is nearly zero QC. I’ve noticed this in the remote sensing camera market as well. They have high-end features, very good picture quality, low cost but a short lifespan and one guy can get a really good one and the next a lemon. I’m guessing the cast on my anvils were just ratty and overlooked. I’ve only heard of a few folks complain about the same minor issue I was having with slightly damaged cambium.
So I finally got some time and made a new vertical shaft. Dan had a good hack to fix it if the nut on the bottom of the shaft pulls out. But if someone wants to retain the spring action, as it was original, here’s what I did (I doubt anyone on the forum is going to make one of these for themselves, but someone may choose to hire it done at a local shop.)
The slot isn’t pictured in the original one, but it’s there, it’s against the table (photography isn’t my strong suit).
I made the replacement out of a piece of 3/4" dia. 18/8 stainless round rod, because that’s what I had on hand. Really a piece of 5/8" square stock common 1018 steel would have been easier. Stainless is a lot harder to machine.
I made the replacement bar a little bigger because I didn’t like all the original slop between the casting which rides up and down on the bar. It took several attempts to get a good fit, as I kept machining the bar smaller and smaller till it fit tight. I also had to file a small chamfer on the corners to get a good fit. The original was about .510" dia.(I say about because the original wasn’t even square). The replacement I made at .525".
I made the slot tighter too. I cut it with a 3/16" end mill. The hole in the end for the spring is a simple 3/8" hole bored all the way down and stops just short of the other end.
For the roll pin which holds the spring in place, I just used a 3/32" in pin (and hole).
If you flip it around the other end looks like this:
I had to neck down the end of the replacement bar to fit in the base casting. The neck extends .100" past the shoulder. The dia. of the neck is .508" I had to file the corners just a bit and chamfer the ends to get it to fit in the base casting, and it’s a really tight fit at that. I had to tap on it with a hammer to get it to go in the base.
The tapped hole for the screw is an M6 X 1.00. I could have used an SAE tapered machine screw, but I just decided to reuse the metric screw which came with it originally.
(Just a quick word on tapping for anyone interested. Don’t use those cheap taps sold at the hardware store, unless you are going to tap something easy like aluminum. Otherwise they are prone to break. Once you break a tap off in a hole, you are up the creek without a paddle. Broken taps are nearly impossible to get out, unless you have some special tools. Stainless is even harder to tap. I used a brand new high quality sharp tap for this hole and was still putting quite a bit of torque to tap it. I was a little worried the tap was going to break.)
Here is the part back in the tool.
The part fits real tight and won’t break loose now, unless the bottom casting breaks.
Nice work.
You have a gift for machining, Mark.
Dax
